--- /dev/null
+/*
+ * cdjpeg.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains common support routines used by the IJG application
+ * programs (cjpeg, djpeg, jpegtran).
+ */
+
+#include "cdjpeg12.h" /* Common decls for cjpeg/djpeg applications */
+#include <ctype.h> /* to declare isupper(), tolower() */
+#ifdef NEED_SIGNAL_CATCHER
+#include <signal.h> /* to declare signal() */
+#endif
+#ifdef USE_SETMODE
+#include <fcntl.h> /* to declare setmode()'s parameter macros */
+/* If you have setmode() but not <io.h>, just delete this line: */
+#include <io.h> /* to declare setmode() */
+#endif
+
+
+/*
+ * Signal catcher to ensure that temporary files are removed before aborting.
+ * NB: for Amiga Manx C this is actually a global routine named _abort();
+ * we put "#define signal_catcher _abort" in jconfig.h. Talk about bogus...
+ */
+
+#ifdef NEED_SIGNAL_CATCHER
+
+static j_common_ptr sig_cinfo;
+
+void /* must be global for Manx C */
+signal_catcher (int signum)
+{
+ if (sig_cinfo != NULL) {
+ if (sig_cinfo->err != NULL) /* turn off trace output */
+ sig_cinfo->err->trace_level = 0;
+ jpeg_destroy(sig_cinfo); /* clean up memory allocation & temp files */
+ }
+ exit(EXIT_FAILURE);
+}
+
+
+GLOBAL(void)
+enable_signal_catcher (j_common_ptr cinfo)
+{
+ sig_cinfo = cinfo;
+#ifdef SIGINT /* not all systems have SIGINT */
+ signal(SIGINT, signal_catcher);
+#endif
+#ifdef SIGTERM /* not all systems have SIGTERM */
+ signal(SIGTERM, signal_catcher);
+#endif
+}
+
+#endif
+
+
+/*
+ * Optional progress monitor: display a percent-done figure on stderr.
+ */
+
+#ifdef PROGRESS_REPORT
+
+METHODDEF(void)
+progress_monitor (j_common_ptr cinfo)
+{
+ cd_progress_ptr prog = (cd_progress_ptr) cinfo->progress;
+ int total_passes = prog->pub.total_passes + prog->total_extra_passes;
+ int percent_done = (int) (prog->pub.pass_counter*100L/prog->pub.pass_limit);
+
+ if (percent_done != prog->percent_done) {
+ prog->percent_done = percent_done;
+ if (total_passes > 1) {
+ fprintf(stderr, "\rPass %d/%d: %3d%% ",
+ prog->pub.completed_passes + prog->completed_extra_passes + 1,
+ total_passes, percent_done);
+ } else {
+ fprintf(stderr, "\r %3d%% ", percent_done);
+ }
+ fflush(stderr);
+ }
+}
+
+
+GLOBAL(void)
+start_progress_monitor (j_common_ptr cinfo, cd_progress_ptr progress)
+{
+ /* Enable progress display, unless trace output is on */
+ if (cinfo->err->trace_level == 0) {
+ progress->pub.progress_monitor = progress_monitor;
+ progress->completed_extra_passes = 0;
+ progress->total_extra_passes = 0;
+ progress->percent_done = -1;
+ cinfo->progress = &progress->pub;
+ }
+}
+
+
+GLOBAL(void)
+end_progress_monitor (j_common_ptr cinfo)
+{
+ /* Clear away progress display */
+ if (cinfo->err->trace_level == 0) {
+ fprintf(stderr, "\r \r");
+ fflush(stderr);
+ }
+}
+
+#endif
+
+
+/*
+ * Case-insensitive matching of possibly-abbreviated keyword switches.
+ * keyword is the constant keyword (must be lower case already),
+ * minchars is length of minimum legal abbreviation.
+ */
+
+GLOBAL(boolean)
+keymatch (char * arg, const char * keyword, int minchars)
+{
+ register int ca, ck;
+ register int nmatched = 0;
+
+ while ((ca = *arg++) != '\0') {
+ if ((ck = *keyword++) == '\0')
+ return FALSE; /* arg longer than keyword, no good */
+ if (isupper(ca)) /* force arg to lcase (assume ck is already) */
+ ca = tolower(ca);
+ if (ca != ck)
+ return FALSE; /* no good */
+ nmatched++; /* count matched characters */
+ }
+ /* reached end of argument; fail if it's too short for unique abbrev */
+ if (nmatched < minchars)
+ return FALSE;
+ return TRUE; /* A-OK */
+}
+
+
+/*
+ * Routines to establish binary I/O mode for stdin and stdout.
+ * Non-Unix systems often require some hacking to get out of text mode.
+ */
+
+GLOBAL(FILE *)
+read_stdin (void)
+{
+ FILE * input_file = stdin;
+
+#ifdef USE_SETMODE /* need to hack file mode? */
+ setmode(fileno(stdin), O_BINARY);
+#endif
+#ifdef USE_FDOPEN /* need to re-open in binary mode? */
+ if ((input_file = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
+ fprintf(stderr, "Cannot reopen stdin\n");
+ exit(EXIT_FAILURE);
+ }
+#endif
+ return input_file;
+}
+
+
+GLOBAL(FILE *)
+write_stdout (void)
+{
+ FILE * output_file = stdout;
+
+#ifdef USE_SETMODE /* need to hack file mode? */
+ setmode(fileno(stdout), O_BINARY);
+#endif
+#ifdef USE_FDOPEN /* need to re-open in binary mode? */
+ if ((output_file = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
+ fprintf(stderr, "Cannot reopen stdout\n");
+ exit(EXIT_FAILURE);
+ }
+#endif
+ return output_file;
+}
--- /dev/null
+/*
+ * jcapimin.c
+ *
+ * Copyright (C) 1994-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the compression half
+ * of the JPEG library. These are the "minimum" API routines that may be
+ * needed in either the normal full-compression case or the transcoding-only
+ * case.
+ *
+ * Most of the routines intended to be called directly by an application
+ * are in this file or in jcapistd.c. But also see jcparam.c for
+ * parameter-setup helper routines, jcomapi.c for routines shared by
+ * compression and decompression, and jctrans.c for the transcoding case.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * Initialization of a JPEG compression object.
+ * The error manager must already be set up (in case memory manager fails).
+ */
+
+GLOBAL(void)
+jpeg_CreateCompress (j_compress_ptr cinfo, int version, size_t structsize)
+{
+ int i;
+
+ /* Guard against version mismatches between library and caller. */
+ cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
+ if (version != JPEG_LIB_VERSION)
+ ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
+ if (structsize != SIZEOF(struct jpeg_compress_struct))
+ ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
+ (int) SIZEOF(struct jpeg_compress_struct), (int) structsize);
+
+ /* For debugging purposes, we zero the whole master structure.
+ * But the application has already set the err pointer, and may have set
+ * client_data, so we have to save and restore those fields.
+ * Note: if application hasn't set client_data, tools like Purify may
+ * complain here.
+ */
+ {
+ struct jpeg_error_mgr * err = cinfo->err;
+ void * client_data = cinfo->client_data; /* ignore Purify complaint here */
+ MEMZERO(cinfo, SIZEOF(struct jpeg_compress_struct));
+ cinfo->err = err;
+ cinfo->client_data = client_data;
+ }
+ cinfo->is_decompressor = FALSE;
+
+ /* Initialize a memory manager instance for this object */
+ jinit_memory_mgr((j_common_ptr) cinfo);
+
+ /* Zero out pointers to permanent structures. */
+ cinfo->progress = NULL;
+ cinfo->dest = NULL;
+
+ cinfo->comp_info = NULL;
+
+ for (i = 0; i < NUM_QUANT_TBLS; i++)
+ cinfo->quant_tbl_ptrs[i] = NULL;
+
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ cinfo->dc_huff_tbl_ptrs[i] = NULL;
+ cinfo->ac_huff_tbl_ptrs[i] = NULL;
+ }
+
+ cinfo->script_space = NULL;
+
+ cinfo->input_gamma = 1.0; /* in case application forgets */
+
+ /* OK, I'm ready */
+ cinfo->global_state = CSTATE_START;
+}
+
+
+/*
+ * Destruction of a JPEG compression object
+ */
+
+GLOBAL(void)
+jpeg_destroy_compress (j_compress_ptr cinfo)
+{
+ jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
+}
+
+
+/*
+ * Abort processing of a JPEG compression operation,
+ * but don't destroy the object itself.
+ */
+
+GLOBAL(void)
+jpeg_abort_compress (j_compress_ptr cinfo)
+{
+ jpeg_abort((j_common_ptr) cinfo); /* use common routine */
+}
+
+
+/*
+ * Forcibly suppress or un-suppress all quantization and Huffman tables.
+ * Marks all currently defined tables as already written (if suppress)
+ * or not written (if !suppress). This will control whether they get emitted
+ * by a subsequent jpeg_start_compress call.
+ *
+ * This routine is exported for use by applications that want to produce
+ * abbreviated JPEG datastreams. It logically belongs in jcparam.c, but
+ * since it is called by jpeg_start_compress, we put it here --- otherwise
+ * jcparam.o would be linked whether the application used it or not.
+ */
+
+GLOBAL(void)
+jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress)
+{
+ int i;
+ JQUANT_TBL * qtbl;
+ JHUFF_TBL * htbl;
+
+ for (i = 0; i < NUM_QUANT_TBLS; i++) {
+ if ((qtbl = cinfo->quant_tbl_ptrs[i]) != NULL)
+ qtbl->sent_table = suppress;
+ }
+
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ if ((htbl = cinfo->dc_huff_tbl_ptrs[i]) != NULL)
+ htbl->sent_table = suppress;
+ if ((htbl = cinfo->ac_huff_tbl_ptrs[i]) != NULL)
+ htbl->sent_table = suppress;
+ }
+}
+
+
+/*
+ * Finish JPEG compression.
+ *
+ * If a multipass operating mode was selected, this may do a great deal of
+ * work including most of the actual output.
+ */
+
+GLOBAL(void)
+jpeg_finish_compress (j_compress_ptr cinfo)
+{
+ JDIMENSION iMCU_row;
+
+ if (cinfo->global_state == CSTATE_SCANNING ||
+ cinfo->global_state == CSTATE_RAW_OK) {
+ /* Terminate first pass */
+ if (cinfo->next_scanline < cinfo->image_height)
+ ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
+ (*cinfo->master->finish_pass) (cinfo);
+ } else if (cinfo->global_state != CSTATE_WRCOEFS)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ /* Perform any remaining passes */
+ while (! cinfo->master->is_last_pass) {
+ (*cinfo->master->prepare_for_pass) (cinfo);
+ for (iMCU_row = 0; iMCU_row < cinfo->total_iMCU_rows; iMCU_row++) {
+ if (cinfo->progress != NULL) {
+ cinfo->progress->pass_counter = (long) iMCU_row;
+ cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows;
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ }
+ /* We bypass the main controller and invoke coef controller directly;
+ * all work is being done from the coefficient buffer.
+ */
+ if (! (*cinfo->coef->compress_data) (cinfo, (JSAMPIMAGE) NULL))
+ ERREXIT(cinfo, JERR_CANT_SUSPEND);
+ }
+ (*cinfo->master->finish_pass) (cinfo);
+ }
+ /* Write EOI, do final cleanup */
+ (*cinfo->marker->write_file_trailer) (cinfo);
+ (*cinfo->dest->term_destination) (cinfo);
+ /* We can use jpeg_abort to release memory and reset global_state */
+ jpeg_abort((j_common_ptr) cinfo);
+}
+
+
+/*
+ * Write a special marker.
+ * This is only recommended for writing COM or APPn markers.
+ * Must be called after jpeg_start_compress() and before
+ * first call to jpeg_write_scanlines() or jpeg_write_raw_data().
+ */
+
+GLOBAL(void)
+jpeg_write_marker (j_compress_ptr cinfo, int marker,
+ const JOCTET *dataptr, unsigned int datalen)
+{
+ JMETHOD(void, write_marker_byte, (j_compress_ptr info, int val));
+
+ if (cinfo->next_scanline != 0 ||
+ (cinfo->global_state != CSTATE_SCANNING &&
+ cinfo->global_state != CSTATE_RAW_OK &&
+ cinfo->global_state != CSTATE_WRCOEFS))
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
+ write_marker_byte = cinfo->marker->write_marker_byte; /* copy for speed */
+ while (datalen--) {
+ (*write_marker_byte) (cinfo, *dataptr);
+ dataptr++;
+ }
+}
+
+/* Same, but piecemeal. */
+
+GLOBAL(void)
+jpeg_write_m_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
+{
+ if (cinfo->next_scanline != 0 ||
+ (cinfo->global_state != CSTATE_SCANNING &&
+ cinfo->global_state != CSTATE_RAW_OK &&
+ cinfo->global_state != CSTATE_WRCOEFS))
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ (*cinfo->marker->write_marker_header) (cinfo, marker, datalen);
+}
+
+GLOBAL(void)
+jpeg_write_m_byte (j_compress_ptr cinfo, int val)
+{
+ (*cinfo->marker->write_marker_byte) (cinfo, val);
+}
+
+
+/*
+ * Alternate compression function: just write an abbreviated table file.
+ * Before calling this, all parameters and a data destination must be set up.
+ *
+ * To produce a pair of files containing abbreviated tables and abbreviated
+ * image data, one would proceed as follows:
+ *
+ * initialize JPEG object
+ * set JPEG parameters
+ * set destination to table file
+ * jpeg_write_tables(cinfo);
+ * set destination to image file
+ * jpeg_start_compress(cinfo, FALSE);
+ * write data...
+ * jpeg_finish_compress(cinfo);
+ *
+ * jpeg_write_tables has the side effect of marking all tables written
+ * (same as jpeg_suppress_tables(..., TRUE)). Thus a subsequent start_compress
+ * will not re-emit the tables unless it is passed write_all_tables=TRUE.
+ */
+
+GLOBAL(void)
+jpeg_write_tables (j_compress_ptr cinfo)
+{
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ /* (Re)initialize error mgr and destination modules */
+ (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
+ (*cinfo->dest->init_destination) (cinfo);
+ /* Initialize the marker writer ... bit of a crock to do it here. */
+ jinit_marker_writer(cinfo);
+ /* Write them tables! */
+ (*cinfo->marker->write_tables_only) (cinfo);
+ /* And clean up. */
+ (*cinfo->dest->term_destination) (cinfo);
+ /*
+ * In library releases up through v6a, we called jpeg_abort() here to free
+ * any working memory allocated by the destination manager and marker
+ * writer. Some applications had a problem with that: they allocated space
+ * of their own from the library memory manager, and didn't want it to go
+ * away during write_tables. So now we do nothing. This will cause a
+ * memory leak if an app calls write_tables repeatedly without doing a full
+ * compression cycle or otherwise resetting the JPEG object. However, that
+ * seems less bad than unexpectedly freeing memory in the normal case.
+ * An app that prefers the old behavior can call jpeg_abort for itself after
+ * each call to jpeg_write_tables().
+ */
+}
--- /dev/null
+/*
+ * jcapistd.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the compression half
+ * of the JPEG library. These are the "standard" API routines that are
+ * used in the normal full-compression case. They are not used by a
+ * transcoding-only application. Note that if an application links in
+ * jpeg_start_compress, it will end up linking in the entire compressor.
+ * We thus must separate this file from jcapimin.c to avoid linking the
+ * whole compression library into a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * Compression initialization.
+ * Before calling this, all parameters and a data destination must be set up.
+ *
+ * We require a write_all_tables parameter as a failsafe check when writing
+ * multiple datastreams from the same compression object. Since prior runs
+ * will have left all the tables marked sent_table=TRUE, a subsequent run
+ * would emit an abbreviated stream (no tables) by default. This may be what
+ * is wanted, but for safety's sake it should not be the default behavior:
+ * programmers should have to make a deliberate choice to emit abbreviated
+ * images. Therefore the documentation and examples should encourage people
+ * to pass write_all_tables=TRUE; then it will take active thought to do the
+ * wrong thing.
+ */
+
+GLOBAL(void)
+jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
+{
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ if (write_all_tables)
+ jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */
+
+ /* (Re)initialize error mgr and destination modules */
+ (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
+ (*cinfo->dest->init_destination) (cinfo);
+ /* Perform master selection of active modules */
+ jinit_compress_master(cinfo);
+ /* Set up for the first pass */
+ (*cinfo->master->prepare_for_pass) (cinfo);
+ /* Ready for application to drive first pass through jpeg_write_scanlines
+ * or jpeg_write_raw_data.
+ */
+ cinfo->next_scanline = 0;
+ cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
+}
+
+
+/*
+ * Write some scanlines of data to the JPEG compressor.
+ *
+ * The return value will be the number of lines actually written.
+ * This should be less than the supplied num_lines only in case that
+ * the data destination module has requested suspension of the compressor,
+ * or if more than image_height scanlines are passed in.
+ *
+ * Note: we warn about excess calls to jpeg_write_scanlines() since
+ * this likely signals an application programmer error. However,
+ * excess scanlines passed in the last valid call are *silently* ignored,
+ * so that the application need not adjust num_lines for end-of-image
+ * when using a multiple-scanline buffer.
+ */
+
+GLOBAL(JDIMENSION)
+jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines,
+ JDIMENSION num_lines)
+{
+ JDIMENSION row_ctr, rows_left;
+
+ if (cinfo->global_state != CSTATE_SCANNING)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ if (cinfo->next_scanline >= cinfo->image_height)
+ WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
+
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->pass_counter = (long) cinfo->next_scanline;
+ cinfo->progress->pass_limit = (long) cinfo->image_height;
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ }
+
+ /* Give master control module another chance if this is first call to
+ * jpeg_write_scanlines. This lets output of the frame/scan headers be
+ * delayed so that application can write COM, etc, markers between
+ * jpeg_start_compress and jpeg_write_scanlines.
+ */
+ if (cinfo->master->call_pass_startup)
+ (*cinfo->master->pass_startup) (cinfo);
+
+ /* Ignore any extra scanlines at bottom of image. */
+ rows_left = cinfo->image_height - cinfo->next_scanline;
+ if (num_lines > rows_left)
+ num_lines = rows_left;
+
+ row_ctr = 0;
+ (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
+ cinfo->next_scanline += row_ctr;
+ return row_ctr;
+}
+
+
+/*
+ * Alternate entry point to write raw data.
+ * Processes exactly one iMCU row per call, unless suspended.
+ */
+
+GLOBAL(JDIMENSION)
+jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data,
+ JDIMENSION num_lines)
+{
+ JDIMENSION lines_per_iMCU_row;
+
+ if (cinfo->global_state != CSTATE_RAW_OK)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ if (cinfo->next_scanline >= cinfo->image_height) {
+ WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
+ return 0;
+ }
+
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->pass_counter = (long) cinfo->next_scanline;
+ cinfo->progress->pass_limit = (long) cinfo->image_height;
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ }
+
+ /* Give master control module another chance if this is first call to
+ * jpeg_write_raw_data. This lets output of the frame/scan headers be
+ * delayed so that application can write COM, etc, markers between
+ * jpeg_start_compress and jpeg_write_raw_data.
+ */
+ if (cinfo->master->call_pass_startup)
+ (*cinfo->master->pass_startup) (cinfo);
+
+ /* Verify that at least one iMCU row has been passed. */
+ lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
+ if (num_lines < lines_per_iMCU_row)
+ ERREXIT(cinfo, JERR_BUFFER_SIZE);
+
+ /* Directly compress the row. */
+ if (! (*cinfo->coef->compress_data) (cinfo, data)) {
+ /* If compressor did not consume the whole row, suspend processing. */
+ return 0;
+ }
+
+ /* OK, we processed one iMCU row. */
+ cinfo->next_scanline += lines_per_iMCU_row;
+ return lines_per_iMCU_row;
+}
--- /dev/null
+/*
+ * jccoefct.c
+ *
+ * Copyright (C) 1994-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the coefficient buffer controller for compression.
+ * This controller is the top level of the JPEG compressor proper.
+ * The coefficient buffer lies between forward-DCT and entropy encoding steps.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* We use a full-image coefficient buffer when doing Huffman optimization,
+ * and also for writing multiple-scan JPEG files. In all cases, the DCT
+ * step is run during the first pass, and subsequent passes need only read
+ * the buffered coefficients.
+ */
+#ifdef ENTROPY_OPT_SUPPORTED
+#define FULL_COEF_BUFFER_SUPPORTED
+#else
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+#define FULL_COEF_BUFFER_SUPPORTED
+#endif
+#endif
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_c_coef_controller pub; /* public fields */
+
+ JDIMENSION iMCU_row_num; /* iMCU row # within image */
+ JDIMENSION mcu_ctr; /* counts MCUs processed in current row */
+ int MCU_vert_offset; /* counts MCU rows within iMCU row */
+ int MCU_rows_per_iMCU_row; /* number of such rows needed */
+
+ /* For single-pass compression, it's sufficient to buffer just one MCU
+ * (although this may prove a bit slow in practice). We allocate a
+ * workspace of C_MAX_BLOCKS_IN_MCU coefficient blocks, and reuse it for each
+ * MCU constructed and sent. (On 80x86, the workspace is FAR even though
+ * it's not really very big; this is to keep the module interfaces unchanged
+ * when a large coefficient buffer is necessary.)
+ * In multi-pass modes, this array points to the current MCU's blocks
+ * within the virtual arrays.
+ */
+ JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
+
+ /* In multi-pass modes, we need a virtual block array for each component. */
+ jvirt_barray_ptr whole_image[MAX_COMPONENTS];
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+
+/* Forward declarations */
+METHODDEF(boolean) compress_data
+ JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+METHODDEF(boolean) compress_first_pass
+ JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+METHODDEF(boolean) compress_output
+ JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+#endif
+
+
+LOCAL(void)
+start_iMCU_row (j_compress_ptr cinfo)
+/* Reset within-iMCU-row counters for a new row */
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+ /* In an interleaved scan, an MCU row is the same as an iMCU row.
+ * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+ * But at the bottom of the image, process only what's left.
+ */
+ if (cinfo->comps_in_scan > 1) {
+ coef->MCU_rows_per_iMCU_row = 1;
+ } else {
+ if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1))
+ coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+ else
+ coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+ }
+
+ coef->mcu_ctr = 0;
+ coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+ coef->iMCU_row_num = 0;
+ start_iMCU_row(cinfo);
+
+ switch (pass_mode) {
+ case JBUF_PASS_THRU:
+ if (coef->whole_image[0] != NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ coef->pub.compress_data = compress_data;
+ break;
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+ case JBUF_SAVE_AND_PASS:
+ if (coef->whole_image[0] == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ coef->pub.compress_data = compress_first_pass;
+ break;
+ case JBUF_CRANK_DEST:
+ if (coef->whole_image[0] == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ coef->pub.compress_data = compress_output;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ break;
+ }
+}
+
+
+/*
+ * Process some data in the single-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the image.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf contains a plane for each component in image,
+ * which we index according to the component's SOF position.
+ */
+
+METHODDEF(boolean)
+compress_data (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ int blkn, bi, ci, yindex, yoffset, blockcnt;
+ JDIMENSION ypos, xpos;
+ jpeg_component_info *compptr;
+
+ /* Loop to write as much as one whole iMCU row */
+ for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+ yoffset++) {
+ for (MCU_col_num = coef->mcu_ctr; MCU_col_num <= last_MCU_col;
+ MCU_col_num++) {
+ /* Determine where data comes from in input_buf and do the DCT thing.
+ * Each call on forward_DCT processes a horizontal row of DCT blocks
+ * as wide as an MCU; we rely on having allocated the MCU_buffer[] blocks
+ * sequentially. Dummy blocks at the right or bottom edge are filled in
+ * specially. The data in them does not matter for image reconstruction,
+ * so we fill them with values that will encode to the smallest amount of
+ * data, viz: all zeroes in the AC entries, DC entries equal to previous
+ * block's DC value. (Thanks to Thomas Kinsman for this idea.)
+ */
+ blkn = 0;
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
+ : compptr->last_col_width;
+ xpos = MCU_col_num * compptr->MCU_sample_width;
+ ypos = yoffset * DCTSIZE; /* ypos == (yoffset+yindex) * DCTSIZE */
+ for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
+ if (coef->iMCU_row_num < last_iMCU_row ||
+ yoffset+yindex < compptr->last_row_height) {
+ (*cinfo->fdct->forward_DCT) (cinfo, compptr,
+ input_buf[compptr->component_index],
+ coef->MCU_buffer[blkn],
+ ypos, xpos, (JDIMENSION) blockcnt);
+ if (blockcnt < compptr->MCU_width) {
+ /* Create some dummy blocks at the right edge of the image. */
+ jzero_far((void FAR *) coef->MCU_buffer[blkn + blockcnt],
+ (compptr->MCU_width - blockcnt) * SIZEOF(JBLOCK));
+ for (bi = blockcnt; bi < compptr->MCU_width; bi++) {
+ coef->MCU_buffer[blkn+bi][0][0] = coef->MCU_buffer[blkn+bi-1][0][0];
+ }
+ }
+ } else {
+ /* Create a row of dummy blocks at the bottom of the image. */
+ jzero_far((void FAR *) coef->MCU_buffer[blkn],
+ compptr->MCU_width * SIZEOF(JBLOCK));
+ for (bi = 0; bi < compptr->MCU_width; bi++) {
+ coef->MCU_buffer[blkn+bi][0][0] = coef->MCU_buffer[blkn-1][0][0];
+ }
+ }
+ blkn += compptr->MCU_width;
+ ypos += DCTSIZE;
+ }
+ }
+ /* Try to write the MCU. In event of a suspension failure, we will
+ * re-DCT the MCU on restart (a bit inefficient, could be fixed...)
+ */
+ if (! (*cinfo->entropy->encode_mcu) (cinfo, coef->MCU_buffer)) {
+ /* Suspension forced; update state counters and exit */
+ coef->MCU_vert_offset = yoffset;
+ coef->mcu_ctr = MCU_col_num;
+ return FALSE;
+ }
+ }
+ /* Completed an MCU row, but perhaps not an iMCU row */
+ coef->mcu_ctr = 0;
+ }
+ /* Completed the iMCU row, advance counters for next one */
+ coef->iMCU_row_num++;
+ start_iMCU_row(cinfo);
+ return TRUE;
+}
+
+
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+
+/*
+ * Process some data in the first pass of a multi-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the image.
+ * This amount of data is read from the source buffer, DCT'd and quantized,
+ * and saved into the virtual arrays. We also generate suitable dummy blocks
+ * as needed at the right and lower edges. (The dummy blocks are constructed
+ * in the virtual arrays, which have been padded appropriately.) This makes
+ * it possible for subsequent passes not to worry about real vs. dummy blocks.
+ *
+ * We must also emit the data to the entropy encoder. This is conveniently
+ * done by calling compress_output() after we've loaded the current strip
+ * of the virtual arrays.
+ *
+ * NB: input_buf contains a plane for each component in image. All
+ * components are DCT'd and loaded into the virtual arrays in this pass.
+ * However, it may be that only a subset of the components are emitted to
+ * the entropy encoder during this first pass; be careful about looking
+ * at the scan-dependent variables (MCU dimensions, etc).
+ */
+
+METHODDEF(boolean)
+compress_first_pass (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ JDIMENSION blocks_across, MCUs_across, MCUindex;
+ int bi, ci, h_samp_factor, block_row, block_rows, ndummy;
+ JCOEF lastDC;
+ jpeg_component_info *compptr;
+ JBLOCKARRAY buffer;
+ JBLOCKROW thisblockrow, lastblockrow;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Align the virtual buffer for this component. */
+ buffer = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[ci],
+ coef->iMCU_row_num * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ /* Count non-dummy DCT block rows in this iMCU row. */
+ if (coef->iMCU_row_num < last_iMCU_row)
+ block_rows = compptr->v_samp_factor;
+ else {
+ /* NB: can't use last_row_height here, since may not be set! */
+ block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
+ if (block_rows == 0) block_rows = compptr->v_samp_factor;
+ }
+ blocks_across = compptr->width_in_blocks;
+ h_samp_factor = compptr->h_samp_factor;
+ /* Count number of dummy blocks to be added at the right margin. */
+ ndummy = (int) (blocks_across % h_samp_factor);
+ if (ndummy > 0)
+ ndummy = h_samp_factor - ndummy;
+ /* Perform DCT for all non-dummy blocks in this iMCU row. Each call
+ * on forward_DCT processes a complete horizontal row of DCT blocks.
+ */
+ for (block_row = 0; block_row < block_rows; block_row++) {
+ thisblockrow = buffer[block_row];
+ (*cinfo->fdct->forward_DCT) (cinfo, compptr,
+ input_buf[ci], thisblockrow,
+ (JDIMENSION) (block_row * DCTSIZE),
+ (JDIMENSION) 0, blocks_across);
+ if (ndummy > 0) {
+ /* Create dummy blocks at the right edge of the image. */
+ thisblockrow += blocks_across; /* => first dummy block */
+ jzero_far((void FAR *) thisblockrow, ndummy * SIZEOF(JBLOCK));
+ lastDC = thisblockrow[-1][0];
+ for (bi = 0; bi < ndummy; bi++) {
+ thisblockrow[bi][0] = lastDC;
+ }
+ }
+ }
+ /* If at end of image, create dummy block rows as needed.
+ * The tricky part here is that within each MCU, we want the DC values
+ * of the dummy blocks to match the last real block's DC value.
+ * This squeezes a few more bytes out of the resulting file...
+ */
+ if (coef->iMCU_row_num == last_iMCU_row) {
+ blocks_across += ndummy; /* include lower right corner */
+ MCUs_across = blocks_across / h_samp_factor;
+ for (block_row = block_rows; block_row < compptr->v_samp_factor;
+ block_row++) {
+ thisblockrow = buffer[block_row];
+ lastblockrow = buffer[block_row-1];
+ jzero_far((void FAR *) thisblockrow,
+ (size_t) (blocks_across * SIZEOF(JBLOCK)));
+ for (MCUindex = 0; MCUindex < MCUs_across; MCUindex++) {
+ lastDC = lastblockrow[h_samp_factor-1][0];
+ for (bi = 0; bi < h_samp_factor; bi++) {
+ thisblockrow[bi][0] = lastDC;
+ }
+ thisblockrow += h_samp_factor; /* advance to next MCU in row */
+ lastblockrow += h_samp_factor;
+ }
+ }
+ }
+ }
+ /* NB: compress_output will increment iMCU_row_num if successful.
+ * A suspension return will result in redoing all the work above next time.
+ */
+
+ /* Emit data to the entropy encoder, sharing code with subsequent passes */
+ return compress_output(cinfo, input_buf);
+}
+
+
+/*
+ * Process some data in subsequent passes of a multi-pass case.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the entropy coder.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf is ignored; it is likely to be a NULL pointer.
+ */
+
+METHODDEF(boolean)
+compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ int blkn, ci, xindex, yindex, yoffset;
+ JDIMENSION start_col;
+ JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+ JBLOCKROW buffer_ptr;
+ jpeg_component_info *compptr;
+
+ /* Align the virtual buffers for the components used in this scan.
+ * NB: during first pass, this is safe only because the buffers will
+ * already be aligned properly, so jmemmgr.c won't need to do any I/O.
+ */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ buffer[ci] = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+ coef->iMCU_row_num * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+
+ /* Loop to process one whole iMCU row */
+ for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+ yoffset++) {
+ for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
+ MCU_col_num++) {
+ /* Construct list of pointers to DCT blocks belonging to this MCU */
+ blkn = 0; /* index of current DCT block within MCU */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ start_col = MCU_col_num * compptr->MCU_width;
+ for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
+ buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
+ for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
+ coef->MCU_buffer[blkn++] = buffer_ptr++;
+ }
+ }
+ }
+ /* Try to write the MCU. */
+ if (! (*cinfo->entropy->encode_mcu) (cinfo, coef->MCU_buffer)) {
+ /* Suspension forced; update state counters and exit */
+ coef->MCU_vert_offset = yoffset;
+ coef->mcu_ctr = MCU_col_num;
+ return FALSE;
+ }
+ }
+ /* Completed an MCU row, but perhaps not an iMCU row */
+ coef->mcu_ctr = 0;
+ }
+ /* Completed the iMCU row, advance counters for next one */
+ coef->iMCU_row_num++;
+ start_iMCU_row(cinfo);
+ return TRUE;
+}
+
+#endif /* FULL_COEF_BUFFER_SUPPORTED */
+
+
+/*
+ * Initialize coefficient buffer controller.
+ */
+
+GLOBAL(void)
+jinit_c_coef_controller (j_compress_ptr cinfo, boolean need_full_buffer)
+{
+ my_coef_ptr coef;
+
+ coef = (my_coef_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_coef_controller));
+ cinfo->coef = (struct jpeg_c_coef_controller *) coef;
+ coef->pub.start_pass = start_pass_coef;
+
+ /* Create the coefficient buffer. */
+ if (need_full_buffer) {
+#ifdef FULL_COEF_BUFFER_SUPPORTED
+ /* Allocate a full-image virtual array for each component, */
+ /* padded to a multiple of samp_factor DCT blocks in each direction. */
+ int ci;
+ jpeg_component_info *compptr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+ (JDIMENSION) jround_up((long) compptr->width_in_blocks,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) compptr->v_samp_factor);
+ }
+#else
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+#endif
+ } else {
+ /* We only need a single-MCU buffer. */
+ JBLOCKROW buffer;
+ int i;
+
+ buffer = (JBLOCKROW)
+ (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
+ for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) {
+ coef->MCU_buffer[i] = buffer + i;
+ }
+ coef->whole_image[0] = NULL; /* flag for no virtual arrays */
+ }
+}
--- /dev/null
+/*
+ * jccolor.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains input colorspace conversion routines.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_color_converter pub; /* public fields */
+
+ /* Private state for RGB->YCC conversion */
+ INT32 * rgb_ycc_tab; /* => table for RGB to YCbCr conversion */
+} my_color_converter;
+
+typedef my_color_converter * my_cconvert_ptr;
+
+
+/**************** RGB -> YCbCr conversion: most common case **************/
+
+/*
+ * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
+ * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
+ * The conversion equations to be implemented are therefore
+ * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
+ * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
+ * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE
+ * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
+ * Note: older versions of the IJG code used a zero offset of MAXJSAMPLE/2,
+ * rather than CENTERJSAMPLE, for Cb and Cr. This gave equal positive and
+ * negative swings for Cb/Cr, but meant that grayscale values (Cb=Cr=0)
+ * were not represented exactly. Now we sacrifice exact representation of
+ * maximum red and maximum blue in order to get exact grayscales.
+ *
+ * To avoid floating-point arithmetic, we represent the fractional constants
+ * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
+ * the products by 2^16, with appropriate rounding, to get the correct answer.
+ *
+ * For even more speed, we avoid doing any multiplications in the inner loop
+ * by precalculating the constants times R,G,B for all possible values.
+ * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
+ * for 12-bit samples it is still acceptable. It's not very reasonable for
+ * 16-bit samples, but if you want lossless storage you shouldn't be changing
+ * colorspace anyway.
+ * The CENTERJSAMPLE offsets and the rounding fudge-factor of 0.5 are included
+ * in the tables to save adding them separately in the inner loop.
+ */
+
+#define SCALEBITS 16 /* speediest right-shift on some machines */
+#define CBCR_OFFSET ((INT32) CENTERJSAMPLE << SCALEBITS)
+#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
+#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
+
+/* We allocate one big table and divide it up into eight parts, instead of
+ * doing eight alloc_small requests. This lets us use a single table base
+ * address, which can be held in a register in the inner loops on many
+ * machines (more than can hold all eight addresses, anyway).
+ */
+
+#define R_Y_OFF 0 /* offset to R => Y section */
+#define G_Y_OFF (1*(MAXJSAMPLE+1)) /* offset to G => Y section */
+#define B_Y_OFF (2*(MAXJSAMPLE+1)) /* etc. */
+#define R_CB_OFF (3*(MAXJSAMPLE+1))
+#define G_CB_OFF (4*(MAXJSAMPLE+1))
+#define B_CB_OFF (5*(MAXJSAMPLE+1))
+#define R_CR_OFF B_CB_OFF /* B=>Cb, R=>Cr are the same */
+#define G_CR_OFF (6*(MAXJSAMPLE+1))
+#define B_CR_OFF (7*(MAXJSAMPLE+1))
+#define TABLE_SIZE (8*(MAXJSAMPLE+1))
+
+
+/*
+ * Initialize for RGB->YCC colorspace conversion.
+ */
+
+METHODDEF(void)
+rgb_ycc_start (j_compress_ptr cinfo)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ INT32 * rgb_ycc_tab;
+ INT32 i;
+
+ /* Allocate and fill in the conversion tables. */
+ cconvert->rgb_ycc_tab = rgb_ycc_tab = (INT32 *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (TABLE_SIZE * SIZEOF(INT32)));
+
+ for (i = 0; i <= MAXJSAMPLE; i++) {
+ rgb_ycc_tab[i+R_Y_OFF] = FIX(0.29900) * i;
+ rgb_ycc_tab[i+G_Y_OFF] = FIX(0.58700) * i;
+ rgb_ycc_tab[i+B_Y_OFF] = FIX(0.11400) * i + ONE_HALF;
+ rgb_ycc_tab[i+R_CB_OFF] = (-FIX(0.16874)) * i;
+ rgb_ycc_tab[i+G_CB_OFF] = (-FIX(0.33126)) * i;
+ /* We use a rounding fudge-factor of 0.5-epsilon for Cb and Cr.
+ * This ensures that the maximum output will round to MAXJSAMPLE
+ * not MAXJSAMPLE+1, and thus that we don't have to range-limit.
+ */
+ rgb_ycc_tab[i+B_CB_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1;
+/* B=>Cb and R=>Cr tables are the same
+ rgb_ycc_tab[i+R_CR_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1;
+*/
+ rgb_ycc_tab[i+G_CR_OFF] = (-FIX(0.41869)) * i;
+ rgb_ycc_tab[i+B_CR_OFF] = (-FIX(0.08131)) * i;
+ }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ *
+ * Note that we change from the application's interleaved-pixel format
+ * to our internal noninterleaved, one-plane-per-component format.
+ * The input buffer is therefore three times as wide as the output buffer.
+ *
+ * A starting row offset is provided only for the output buffer. The caller
+ * can easily adjust the passed input_buf value to accommodate any row
+ * offset required on that side.
+ */
+
+METHODDEF(void)
+rgb_ycc_convert (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+ JDIMENSION output_row, int num_rows)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ register int r, g, b;
+ register INT32 * ctab = cconvert->rgb_ycc_tab;
+ register JSAMPROW inptr;
+ register JSAMPROW outptr0, outptr1, outptr2;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->image_width;
+
+ while (--num_rows >= 0) {
+ inptr = *input_buf++;
+ outptr0 = output_buf[0][output_row];
+ outptr1 = output_buf[1][output_row];
+ outptr2 = output_buf[2][output_row];
+ output_row++;
+ for (col = 0; col < num_cols; col++) {
+ r = GETJSAMPLE(inptr[RGB_RED]);
+ g = GETJSAMPLE(inptr[RGB_GREEN]);
+ b = GETJSAMPLE(inptr[RGB_BLUE]);
+ inptr += RGB_PIXELSIZE;
+ /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
+ * must be too; we do not need an explicit range-limiting operation.
+ * Hence the value being shifted is never negative, and we don't
+ * need the general RIGHT_SHIFT macro.
+ */
+ /* Y */
+ outptr0[col] = (JSAMPLE)
+ ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
+ >> SCALEBITS);
+ /* Cb */
+ outptr1[col] = (JSAMPLE)
+ ((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
+ >> SCALEBITS);
+ /* Cr */
+ outptr2[col] = (JSAMPLE)
+ ((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
+ >> SCALEBITS);
+ }
+ }
+}
+
+
+/**************** Cases other than RGB -> YCbCr **************/
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles RGB->grayscale conversion, which is the same
+ * as the RGB->Y portion of RGB->YCbCr.
+ * We assume rgb_ycc_start has been called (we only use the Y tables).
+ */
+
+METHODDEF(void)
+rgb_gray_convert (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+ JDIMENSION output_row, int num_rows)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ register int r, g, b;
+ register INT32 * ctab = cconvert->rgb_ycc_tab;
+ register JSAMPROW inptr;
+ register JSAMPROW outptr;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->image_width;
+
+ while (--num_rows >= 0) {
+ inptr = *input_buf++;
+ outptr = output_buf[0][output_row];
+ output_row++;
+ for (col = 0; col < num_cols; col++) {
+ r = GETJSAMPLE(inptr[RGB_RED]);
+ g = GETJSAMPLE(inptr[RGB_GREEN]);
+ b = GETJSAMPLE(inptr[RGB_BLUE]);
+ inptr += RGB_PIXELSIZE;
+ /* Y */
+ outptr[col] = (JSAMPLE)
+ ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
+ >> SCALEBITS);
+ }
+ }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles Adobe-style CMYK->YCCK conversion,
+ * where we convert R=1-C, G=1-M, and B=1-Y to YCbCr using the same
+ * conversion as above, while passing K (black) unchanged.
+ * We assume rgb_ycc_start has been called.
+ */
+
+METHODDEF(void)
+cmyk_ycck_convert (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+ JDIMENSION output_row, int num_rows)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ register int r, g, b;
+ register INT32 * ctab = cconvert->rgb_ycc_tab;
+ register JSAMPROW inptr;
+ register JSAMPROW outptr0, outptr1, outptr2, outptr3;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->image_width;
+
+ while (--num_rows >= 0) {
+ inptr = *input_buf++;
+ outptr0 = output_buf[0][output_row];
+ outptr1 = output_buf[1][output_row];
+ outptr2 = output_buf[2][output_row];
+ outptr3 = output_buf[3][output_row];
+ output_row++;
+ for (col = 0; col < num_cols; col++) {
+ r = MAXJSAMPLE - GETJSAMPLE(inptr[0]);
+ g = MAXJSAMPLE - GETJSAMPLE(inptr[1]);
+ b = MAXJSAMPLE - GETJSAMPLE(inptr[2]);
+ /* K passes through as-is */
+ outptr3[col] = inptr[3]; /* don't need GETJSAMPLE here */
+ inptr += 4;
+ /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
+ * must be too; we do not need an explicit range-limiting operation.
+ * Hence the value being shifted is never negative, and we don't
+ * need the general RIGHT_SHIFT macro.
+ */
+ /* Y */
+ outptr0[col] = (JSAMPLE)
+ ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
+ >> SCALEBITS);
+ /* Cb */
+ outptr1[col] = (JSAMPLE)
+ ((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
+ >> SCALEBITS);
+ /* Cr */
+ outptr2[col] = (JSAMPLE)
+ ((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
+ >> SCALEBITS);
+ }
+ }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles grayscale output with no conversion.
+ * The source can be either plain grayscale or YCbCr (since Y == gray).
+ */
+
+METHODDEF(void)
+grayscale_convert (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+ JDIMENSION output_row, int num_rows)
+{
+ register JSAMPROW inptr;
+ register JSAMPROW outptr;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->image_width;
+ int instride = cinfo->input_components;
+
+ while (--num_rows >= 0) {
+ inptr = *input_buf++;
+ outptr = output_buf[0][output_row];
+ output_row++;
+ for (col = 0; col < num_cols; col++) {
+ outptr[col] = inptr[0]; /* don't need GETJSAMPLE() here */
+ inptr += instride;
+ }
+ }
+}
+
+
+/*
+ * Convert some rows of samples to the JPEG colorspace.
+ * This version handles multi-component colorspaces without conversion.
+ * We assume input_components == num_components.
+ */
+
+METHODDEF(void)
+null_convert (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
+ JDIMENSION output_row, int num_rows)
+{
+ register JSAMPROW inptr;
+ register JSAMPROW outptr;
+ register JDIMENSION col;
+ register int ci;
+ int nc = cinfo->num_components;
+ JDIMENSION num_cols = cinfo->image_width;
+
+ while (--num_rows >= 0) {
+ /* It seems fastest to make a separate pass for each component. */
+ for (ci = 0; ci < nc; ci++) {
+ inptr = *input_buf;
+ outptr = output_buf[ci][output_row];
+ for (col = 0; col < num_cols; col++) {
+ outptr[col] = inptr[ci]; /* don't need GETJSAMPLE() here */
+ inptr += nc;
+ }
+ }
+ input_buf++;
+ output_row++;
+ }
+}
+
+
+/*
+ * Empty method for start_pass.
+ */
+
+METHODDEF(void)
+null_method (j_compress_ptr cinfo)
+{
+ /* no work needed */
+}
+
+
+/*
+ * Module initialization routine for input colorspace conversion.
+ */
+
+GLOBAL(void)
+jinit_color_converter (j_compress_ptr cinfo)
+{
+ my_cconvert_ptr cconvert;
+
+ cconvert = (my_cconvert_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_color_converter));
+ cinfo->cconvert = (struct jpeg_color_converter *) cconvert;
+ /* set start_pass to null method until we find out differently */
+ cconvert->pub.start_pass = null_method;
+
+ /* Make sure input_components agrees with in_color_space */
+ switch (cinfo->in_color_space) {
+ case JCS_GRAYSCALE:
+ if (cinfo->input_components != 1)
+ ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
+ break;
+
+ case JCS_RGB:
+#if RGB_PIXELSIZE != 3
+ if (cinfo->input_components != RGB_PIXELSIZE)
+ ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
+ break;
+#endif /* else share code with YCbCr */
+
+ case JCS_YCbCr:
+ if (cinfo->input_components != 3)
+ ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
+ break;
+
+ case JCS_CMYK:
+ case JCS_YCCK:
+ if (cinfo->input_components != 4)
+ ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
+ break;
+
+ default: /* JCS_UNKNOWN can be anything */
+ if (cinfo->input_components < 1)
+ ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
+ break;
+ }
+
+ /* Check num_components, set conversion method based on requested space */
+ switch (cinfo->jpeg_color_space) {
+ case JCS_GRAYSCALE:
+ if (cinfo->num_components != 1)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ if (cinfo->in_color_space == JCS_GRAYSCALE)
+ cconvert->pub.color_convert = grayscale_convert;
+ else if (cinfo->in_color_space == JCS_RGB) {
+ cconvert->pub.start_pass = rgb_ycc_start;
+ cconvert->pub.color_convert = rgb_gray_convert;
+ } else if (cinfo->in_color_space == JCS_YCbCr)
+ cconvert->pub.color_convert = grayscale_convert;
+ else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ case JCS_RGB:
+ if (cinfo->num_components != 3)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ if (cinfo->in_color_space == JCS_RGB && RGB_PIXELSIZE == 3)
+ cconvert->pub.color_convert = null_convert;
+ else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ case JCS_YCbCr:
+ if (cinfo->num_components != 3)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ if (cinfo->in_color_space == JCS_RGB) {
+ cconvert->pub.start_pass = rgb_ycc_start;
+ cconvert->pub.color_convert = rgb_ycc_convert;
+ } else if (cinfo->in_color_space == JCS_YCbCr)
+ cconvert->pub.color_convert = null_convert;
+ else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ case JCS_CMYK:
+ if (cinfo->num_components != 4)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ if (cinfo->in_color_space == JCS_CMYK)
+ cconvert->pub.color_convert = null_convert;
+ else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ case JCS_YCCK:
+ if (cinfo->num_components != 4)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ if (cinfo->in_color_space == JCS_CMYK) {
+ cconvert->pub.start_pass = rgb_ycc_start;
+ cconvert->pub.color_convert = cmyk_ycck_convert;
+ } else if (cinfo->in_color_space == JCS_YCCK)
+ cconvert->pub.color_convert = null_convert;
+ else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ default: /* allow null conversion of JCS_UNKNOWN */
+ if (cinfo->jpeg_color_space != cinfo->in_color_space ||
+ cinfo->num_components != cinfo->input_components)
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ cconvert->pub.color_convert = null_convert;
+ break;
+ }
+}
--- /dev/null
+/*
+ * jcdctmgr.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the forward-DCT management logic.
+ * This code selects a particular DCT implementation to be used,
+ * and it performs related housekeeping chores including coefficient
+ * quantization.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+
+/* Private subobject for this module */
+
+typedef struct {
+ struct jpeg_forward_dct pub; /* public fields */
+
+ /* Pointer to the DCT routine actually in use */
+ forward_DCT_method_ptr do_dct;
+
+ /* The actual post-DCT divisors --- not identical to the quant table
+ * entries, because of scaling (especially for an unnormalized DCT).
+ * Each table is given in normal array order.
+ */
+ DCTELEM * divisors[NUM_QUANT_TBLS];
+
+#ifdef DCT_FLOAT_SUPPORTED
+ /* Same as above for the floating-point case. */
+ float_DCT_method_ptr do_float_dct;
+ FAST_FLOAT * float_divisors[NUM_QUANT_TBLS];
+#endif
+} my_fdct_controller;
+
+typedef my_fdct_controller * my_fdct_ptr;
+
+
+/*
+ * Initialize for a processing pass.
+ * Verify that all referenced Q-tables are present, and set up
+ * the divisor table for each one.
+ * In the current implementation, DCT of all components is done during
+ * the first pass, even if only some components will be output in the
+ * first scan. Hence all components should be examined here.
+ */
+
+METHODDEF(void)
+start_pass_fdctmgr (j_compress_ptr cinfo)
+{
+ my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+ int ci, qtblno, i;
+ jpeg_component_info *compptr;
+ JQUANT_TBL * qtbl;
+ DCTELEM * dtbl;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ qtblno = compptr->quant_tbl_no;
+ /* Make sure specified quantization table is present */
+ if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS ||
+ cinfo->quant_tbl_ptrs[qtblno] == NULL)
+ ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno);
+ qtbl = cinfo->quant_tbl_ptrs[qtblno];
+ /* Compute divisors for this quant table */
+ /* We may do this more than once for same table, but it's not a big deal */
+ switch (cinfo->dct_method) {
+#ifdef DCT_ISLOW_SUPPORTED
+ case JDCT_ISLOW:
+ /* For LL&M IDCT method, divisors are equal to raw quantization
+ * coefficients multiplied by 8 (to counteract scaling).
+ */
+ if (fdct->divisors[qtblno] == NULL) {
+ fdct->divisors[qtblno] = (DCTELEM *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ DCTSIZE2 * SIZEOF(DCTELEM));
+ }
+ dtbl = fdct->divisors[qtblno];
+ for (i = 0; i < DCTSIZE2; i++) {
+ dtbl[i] = ((DCTELEM) qtbl->quantval[i]) << 3;
+ }
+ break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+ case JDCT_IFAST:
+ {
+ /* For AA&N IDCT method, divisors are equal to quantization
+ * coefficients scaled by scalefactor[row]*scalefactor[col], where
+ * scalefactor[0] = 1
+ * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
+ * We apply a further scale factor of 8.
+ */
+#define CONST_BITS 14
+ static const INT16 aanscales[DCTSIZE2] = {
+ /* precomputed values scaled up by 14 bits */
+ 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
+ 22725, 31521, 29692, 26722, 22725, 17855, 12299, 6270,
+ 21407, 29692, 27969, 25172, 21407, 16819, 11585, 5906,
+ 19266, 26722, 25172, 22654, 19266, 15137, 10426, 5315,
+ 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
+ 12873, 17855, 16819, 15137, 12873, 10114, 6967, 3552,
+ 8867, 12299, 11585, 10426, 8867, 6967, 4799, 2446,
+ 4520, 6270, 5906, 5315, 4520, 3552, 2446, 1247
+ };
+ SHIFT_TEMPS
+
+ if (fdct->divisors[qtblno] == NULL) {
+ fdct->divisors[qtblno] = (DCTELEM *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ DCTSIZE2 * SIZEOF(DCTELEM));
+ }
+ dtbl = fdct->divisors[qtblno];
+ for (i = 0; i < DCTSIZE2; i++) {
+ dtbl[i] = (DCTELEM)
+ DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
+ (INT32) aanscales[i]),
+ CONST_BITS-3);
+ }
+ }
+ break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+ case JDCT_FLOAT:
+ {
+ /* For float AA&N IDCT method, divisors are equal to quantization
+ * coefficients scaled by scalefactor[row]*scalefactor[col], where
+ * scalefactor[0] = 1
+ * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
+ * We apply a further scale factor of 8.
+ * What's actually stored is 1/divisor so that the inner loop can
+ * use a multiplication rather than a division.
+ */
+ FAST_FLOAT * fdtbl;
+ int row, col;
+ static const double aanscalefactor[DCTSIZE] = {
+ 1.0, 1.387039845, 1.306562965, 1.175875602,
+ 1.0, 0.785694958, 0.541196100, 0.275899379
+ };
+
+ if (fdct->float_divisors[qtblno] == NULL) {
+ fdct->float_divisors[qtblno] = (FAST_FLOAT *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ DCTSIZE2 * SIZEOF(FAST_FLOAT));
+ }
+ fdtbl = fdct->float_divisors[qtblno];
+ i = 0;
+ for (row = 0; row < DCTSIZE; row++) {
+ for (col = 0; col < DCTSIZE; col++) {
+ fdtbl[i] = (FAST_FLOAT)
+ (1.0 / (((double) qtbl->quantval[i] *
+ aanscalefactor[row] * aanscalefactor[col] * 8.0)));
+ i++;
+ }
+ }
+ }
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+ }
+}
+
+
+/*
+ * Perform forward DCT on one or more blocks of a component.
+ *
+ * The input samples are taken from the sample_data[] array starting at
+ * position start_row/start_col, and moving to the right for any additional
+ * blocks. The quantized coefficients are returned in coef_blocks[].
+ */
+
+METHODDEF(void)
+forward_DCT (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
+ JDIMENSION start_row, JDIMENSION start_col,
+ JDIMENSION num_blocks)
+/* This version is used for integer DCT implementations. */
+{
+ /* This routine is heavily used, so it's worth coding it tightly. */
+ my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+ forward_DCT_method_ptr do_dct = fdct->do_dct;
+ DCTELEM * divisors = fdct->divisors[compptr->quant_tbl_no];
+ DCTELEM workspace[DCTSIZE2]; /* work area for FDCT subroutine */
+ JDIMENSION bi;
+
+ sample_data += start_row; /* fold in the vertical offset once */
+
+ for (bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE) {
+ /* Load data into workspace, applying unsigned->signed conversion */
+ { register DCTELEM *workspaceptr;
+ register JSAMPROW elemptr;
+ register int elemr;
+
+ workspaceptr = workspace;
+ for (elemr = 0; elemr < DCTSIZE; elemr++) {
+ elemptr = sample_data[elemr] + start_col;
+#if DCTSIZE == 8 /* unroll the inner loop */
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+#else
+ { register int elemc;
+ for (elemc = DCTSIZE; elemc > 0; elemc--) {
+ *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE;
+ }
+ }
+#endif
+ }
+ }
+
+ /* Perform the DCT */
+ (*do_dct) (workspace);
+
+ /* Quantize/descale the coefficients, and store into coef_blocks[] */
+ { register DCTELEM temp, qval;
+ register int i;
+ register JCOEFPTR output_ptr = coef_blocks[bi];
+
+ for (i = 0; i < DCTSIZE2; i++) {
+ qval = divisors[i];
+ temp = workspace[i];
+ /* Divide the coefficient value by qval, ensuring proper rounding.
+ * Since C does not specify the direction of rounding for negative
+ * quotients, we have to force the dividend positive for portability.
+ *
+ * In most files, at least half of the output values will be zero
+ * (at default quantization settings, more like three-quarters...)
+ * so we should ensure that this case is fast. On many machines,
+ * a comparison is enough cheaper than a divide to make a special test
+ * a win. Since both inputs will be nonnegative, we need only test
+ * for a < b to discover whether a/b is 0.
+ * If your machine's division is fast enough, define FAST_DIVIDE.
+ */
+#ifdef FAST_DIVIDE
+#define DIVIDE_BY(a,b) a /= b
+#else
+#define DIVIDE_BY(a,b) if (a >= b) a /= b; else a = 0
+#endif
+ if (temp < 0) {
+ temp = -temp;
+ temp += qval>>1; /* for rounding */
+ DIVIDE_BY(temp, qval);
+ temp = -temp;
+ } else {
+ temp += qval>>1; /* for rounding */
+ DIVIDE_BY(temp, qval);
+ }
+ output_ptr[i] = (JCOEF) temp;
+ }
+ }
+ }
+}
+
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+METHODDEF(void)
+forward_DCT_float (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY sample_data, JBLOCKROW coef_blocks,
+ JDIMENSION start_row, JDIMENSION start_col,
+ JDIMENSION num_blocks)
+/* This version is used for floating-point DCT implementations. */
+{
+ /* This routine is heavily used, so it's worth coding it tightly. */
+ my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct;
+ float_DCT_method_ptr do_dct = fdct->do_float_dct;
+ FAST_FLOAT * divisors = fdct->float_divisors[compptr->quant_tbl_no];
+ FAST_FLOAT workspace[DCTSIZE2]; /* work area for FDCT subroutine */
+ JDIMENSION bi;
+
+ sample_data += start_row; /* fold in the vertical offset once */
+
+ for (bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE) {
+ /* Load data into workspace, applying unsigned->signed conversion */
+ { register FAST_FLOAT *workspaceptr;
+ register JSAMPROW elemptr;
+ register int elemr;
+
+ workspaceptr = workspace;
+ for (elemr = 0; elemr < DCTSIZE; elemr++) {
+ elemptr = sample_data[elemr] + start_col;
+#if DCTSIZE == 8 /* unroll the inner loop */
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+#else
+ { register int elemc;
+ for (elemc = DCTSIZE; elemc > 0; elemc--) {
+ *workspaceptr++ = (FAST_FLOAT)
+ (GETJSAMPLE(*elemptr++) - CENTERJSAMPLE);
+ }
+ }
+#endif
+ }
+ }
+
+ /* Perform the DCT */
+ (*do_dct) (workspace);
+
+ /* Quantize/descale the coefficients, and store into coef_blocks[] */
+ { register FAST_FLOAT temp;
+ register int i;
+ register JCOEFPTR output_ptr = coef_blocks[bi];
+
+ for (i = 0; i < DCTSIZE2; i++) {
+ /* Apply the quantization and scaling factor */
+ temp = workspace[i] * divisors[i];
+ /* Round to nearest integer.
+ * Since C does not specify the direction of rounding for negative
+ * quotients, we have to force the dividend positive for portability.
+ * The maximum coefficient size is +-16K (for 12-bit data), so this
+ * code should work for either 16-bit or 32-bit ints.
+ */
+ output_ptr[i] = (JCOEF) ((int) (temp + (FAST_FLOAT) 16384.5) - 16384);
+ }
+ }
+ }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */
+
+
+/*
+ * Initialize FDCT manager.
+ */
+
+GLOBAL(void)
+jinit_forward_dct (j_compress_ptr cinfo)
+{
+ my_fdct_ptr fdct;
+ int i;
+
+ fdct = (my_fdct_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_fdct_controller));
+ cinfo->fdct = (struct jpeg_forward_dct *) fdct;
+ fdct->pub.start_pass = start_pass_fdctmgr;
+
+ switch (cinfo->dct_method) {
+#ifdef DCT_ISLOW_SUPPORTED
+ case JDCT_ISLOW:
+ fdct->pub.forward_DCT = forward_DCT;
+ fdct->do_dct = jpeg_fdct_islow;
+ break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+ case JDCT_IFAST:
+ fdct->pub.forward_DCT = forward_DCT;
+ fdct->do_dct = jpeg_fdct_ifast;
+ break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+ case JDCT_FLOAT:
+ fdct->pub.forward_DCT = forward_DCT_float;
+ fdct->do_float_dct = jpeg_fdct_float;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+
+ /* Mark divisor tables unallocated */
+ for (i = 0; i < NUM_QUANT_TBLS; i++) {
+ fdct->divisors[i] = NULL;
+#ifdef DCT_FLOAT_SUPPORTED
+ fdct->float_divisors[i] = NULL;
+#endif
+ }
+}
--- /dev/null
+/*
+ * jchuff.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy encoding routines.
+ *
+ * Much of the complexity here has to do with supporting output suspension.
+ * If the data destination module demands suspension, we want to be able to
+ * back up to the start of the current MCU. To do this, we copy state
+ * variables into local working storage, and update them back to the
+ * permanent JPEG objects only upon successful completion of an MCU.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jchuff12.h" /* Declarations shared with jcphuff.c */
+
+
+/* Expanded entropy encoder object for Huffman encoding.
+ *
+ * The savable_state subrecord contains fields that change within an MCU,
+ * but must not be updated permanently until we complete the MCU.
+ */
+
+typedef struct {
+ INT32 put_buffer; /* current bit-accumulation buffer */
+ int put_bits; /* # of bits now in it */
+ int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+} savable_state;
+
+/* This macro is to work around compilers with missing or broken
+ * structure assignment. You'll need to fix this code if you have
+ * such a compiler and you change MAX_COMPS_IN_SCAN.
+ */
+
+#ifndef NO_STRUCT_ASSIGN
+#define ASSIGN_STATE(dest,src) ((dest) = (src))
+#else
+#if MAX_COMPS_IN_SCAN == 4
+#define ASSIGN_STATE(dest,src) \
+ ((dest).put_buffer = (src).put_buffer, \
+ (dest).put_bits = (src).put_bits, \
+ (dest).last_dc_val[0] = (src).last_dc_val[0], \
+ (dest).last_dc_val[1] = (src).last_dc_val[1], \
+ (dest).last_dc_val[2] = (src).last_dc_val[2], \
+ (dest).last_dc_val[3] = (src).last_dc_val[3])
+#endif
+#endif
+
+
+typedef struct {
+ struct jpeg_entropy_encoder pub; /* public fields */
+
+ savable_state saved; /* Bit buffer & DC state at start of MCU */
+
+ /* These fields are NOT loaded into local working state. */
+ unsigned int restarts_to_go; /* MCUs left in this restart interval */
+ int next_restart_num; /* next restart number to write (0-7) */
+
+ /* Pointers to derived tables (these workspaces have image lifespan) */
+ c_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
+ c_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
+
+#ifdef ENTROPY_OPT_SUPPORTED /* Statistics tables for optimization */
+ long * dc_count_ptrs[NUM_HUFF_TBLS];
+ long * ac_count_ptrs[NUM_HUFF_TBLS];
+#endif
+} huff_entropy_encoder;
+
+typedef huff_entropy_encoder * huff_entropy_ptr;
+
+/* Working state while writing an MCU.
+ * This struct contains all the fields that are needed by subroutines.
+ */
+
+typedef struct {
+ JOCTET * next_output_byte; /* => next byte to write in buffer */
+ size_t free_in_buffer; /* # of byte spaces remaining in buffer */
+ savable_state cur; /* Current bit buffer & DC state */
+ j_compress_ptr cinfo; /* dump_buffer needs access to this */
+} working_state;
+
+
+/* Forward declarations */
+METHODDEF(boolean) encode_mcu_huff JPP((j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(void) finish_pass_huff JPP((j_compress_ptr cinfo));
+#ifdef ENTROPY_OPT_SUPPORTED
+METHODDEF(boolean) encode_mcu_gather JPP((j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(void) finish_pass_gather JPP((j_compress_ptr cinfo));
+#endif
+
+
+/*
+ * Initialize for a Huffman-compressed scan.
+ * If gather_statistics is TRUE, we do not output anything during the scan,
+ * just count the Huffman symbols used and generate Huffman code tables.
+ */
+
+METHODDEF(void)
+start_pass_huff (j_compress_ptr cinfo, boolean gather_statistics)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ int ci, dctbl, actbl;
+ jpeg_component_info * compptr;
+
+ if (gather_statistics) {
+#ifdef ENTROPY_OPT_SUPPORTED
+ entropy->pub.encode_mcu = encode_mcu_gather;
+ entropy->pub.finish_pass = finish_pass_gather;
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ entropy->pub.encode_mcu = encode_mcu_huff;
+ entropy->pub.finish_pass = finish_pass_huff;
+ }
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ dctbl = compptr->dc_tbl_no;
+ actbl = compptr->ac_tbl_no;
+ if (gather_statistics) {
+#ifdef ENTROPY_OPT_SUPPORTED
+ /* Check for invalid table indexes */
+ /* (make_c_derived_tbl does this in the other path) */
+ if (dctbl < 0 || dctbl >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, dctbl);
+ if (actbl < 0 || actbl >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, actbl);
+ /* Allocate and zero the statistics tables */
+ /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
+ if (entropy->dc_count_ptrs[dctbl] == NULL)
+ entropy->dc_count_ptrs[dctbl] = (long *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ 257 * SIZEOF(long));
+ MEMZERO(entropy->dc_count_ptrs[dctbl], 257 * SIZEOF(long));
+ if (entropy->ac_count_ptrs[actbl] == NULL)
+ entropy->ac_count_ptrs[actbl] = (long *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ 257 * SIZEOF(long));
+ MEMZERO(entropy->ac_count_ptrs[actbl], 257 * SIZEOF(long));
+#endif
+ } else {
+ /* Compute derived values for Huffman tables */
+ /* We may do this more than once for a table, but it's not expensive */
+ jpeg_make_c_derived_tbl(cinfo, TRUE, dctbl,
+ & entropy->dc_derived_tbls[dctbl]);
+ jpeg_make_c_derived_tbl(cinfo, FALSE, actbl,
+ & entropy->ac_derived_tbls[actbl]);
+ }
+ /* Initialize DC predictions to 0 */
+ entropy->saved.last_dc_val[ci] = 0;
+ }
+
+ /* Initialize bit buffer to empty */
+ entropy->saved.put_buffer = 0;
+ entropy->saved.put_bits = 0;
+
+ /* Initialize restart stuff */
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num = 0;
+}
+
+
+/*
+ * Compute the derived values for a Huffman table.
+ * This routine also performs some validation checks on the table.
+ *
+ * Note this is also used by jcphuff.c.
+ */
+
+GLOBAL(void)
+jpeg_make_c_derived_tbl (j_compress_ptr cinfo, boolean isDC, int tblno,
+ c_derived_tbl ** pdtbl)
+{
+ JHUFF_TBL *htbl;
+ c_derived_tbl *dtbl;
+ int p, i, l, lastp, si, maxsymbol;
+ char huffsize[257];
+ unsigned int huffcode[257];
+ unsigned int code;
+
+ /* Note that huffsize[] and huffcode[] are filled in code-length order,
+ * paralleling the order of the symbols themselves in htbl->huffval[].
+ */
+
+ /* Find the input Huffman table */
+ if (tblno < 0 || tblno >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
+ htbl =
+ isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno];
+ if (htbl == NULL)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
+
+ /* Allocate a workspace if we haven't already done so. */
+ if (*pdtbl == NULL)
+ *pdtbl = (c_derived_tbl *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(c_derived_tbl));
+ dtbl = *pdtbl;
+
+ /* Figure C.1: make table of Huffman code length for each symbol */
+
+ p = 0;
+ for (l = 1; l <= 16; l++) {
+ i = (int) htbl->bits[l];
+ if (i < 0 || p + i > 256) /* protect against table overrun */
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ while (i--)
+ huffsize[p++] = (char) l;
+ }
+ huffsize[p] = 0;
+ lastp = p;
+
+ /* Figure C.2: generate the codes themselves */
+ /* We also validate that the counts represent a legal Huffman code tree. */
+
+ code = 0;
+ si = huffsize[0];
+ p = 0;
+ while (huffsize[p]) {
+ while (((int) huffsize[p]) == si) {
+ huffcode[p++] = code;
+ code++;
+ }
+ /* code is now 1 more than the last code used for codelength si; but
+ * it must still fit in si bits, since no code is allowed to be all ones.
+ */
+ if (((INT32) code) >= (((INT32) 1) << si))
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ code <<= 1;
+ si++;
+ }
+
+ /* Figure C.3: generate encoding tables */
+ /* These are code and size indexed by symbol value */
+
+ /* Set all codeless symbols to have code length 0;
+ * this lets us detect duplicate VAL entries here, and later
+ * allows emit_bits to detect any attempt to emit such symbols.
+ */
+ MEMZERO(dtbl->ehufsi, SIZEOF(dtbl->ehufsi));
+
+ /* This is also a convenient place to check for out-of-range
+ * and duplicated VAL entries. We allow 0..255 for AC symbols
+ * but only 0..15 for DC. (We could constrain them further
+ * based on data depth and mode, but this seems enough.)
+ */
+ maxsymbol = isDC ? 15 : 255;
+
+ for (p = 0; p < lastp; p++) {
+ i = htbl->huffval[p];
+ if (i < 0 || i > maxsymbol || dtbl->ehufsi[i])
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ dtbl->ehufco[i] = huffcode[p];
+ dtbl->ehufsi[i] = huffsize[p];
+ }
+}
+
+
+/* Outputting bytes to the file */
+
+/* Emit a byte, taking 'action' if must suspend. */
+#define emit_byte(state,val,action) \
+ { *(state)->next_output_byte++ = (JOCTET) (val); \
+ if (--(state)->free_in_buffer == 0) \
+ if (! dump_buffer(state)) \
+ { action; } }
+
+
+LOCAL(boolean)
+dump_buffer (working_state * state)
+/* Empty the output buffer; return TRUE if successful, FALSE if must suspend */
+{
+ struct jpeg_destination_mgr * dest = state->cinfo->dest;
+
+ if (! (*dest->empty_output_buffer) (state->cinfo))
+ return FALSE;
+ /* After a successful buffer dump, must reset buffer pointers */
+ state->next_output_byte = dest->next_output_byte;
+ state->free_in_buffer = dest->free_in_buffer;
+ return TRUE;
+}
+
+
+/* Outputting bits to the file */
+
+/* Only the right 24 bits of put_buffer are used; the valid bits are
+ * left-justified in this part. At most 16 bits can be passed to emit_bits
+ * in one call, and we never retain more than 7 bits in put_buffer
+ * between calls, so 24 bits are sufficient.
+ */
+
+INLINE
+LOCAL(boolean)
+emit_bits (working_state * state, unsigned int code, int size)
+/* Emit some bits; return TRUE if successful, FALSE if must suspend */
+{
+ /* This routine is heavily used, so it's worth coding tightly. */
+ register INT32 put_buffer = (INT32) code;
+ register int put_bits = state->cur.put_bits;
+
+ /* if size is 0, caller used an invalid Huffman table entry */
+ if (size == 0)
+ ERREXIT(state->cinfo, JERR_HUFF_MISSING_CODE);
+
+ put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */
+
+ put_bits += size; /* new number of bits in buffer */
+
+ put_buffer <<= 24 - put_bits; /* align incoming bits */
+
+ put_buffer |= state->cur.put_buffer; /* and merge with old buffer contents */
+
+ while (put_bits >= 8) {
+ int c = (int) ((put_buffer >> 16) & 0xFF);
+
+ emit_byte(state, c, return FALSE);
+ if (c == 0xFF) { /* need to stuff a zero byte? */
+ emit_byte(state, 0, return FALSE);
+ }
+ put_buffer <<= 8;
+ put_bits -= 8;
+ }
+
+ state->cur.put_buffer = put_buffer; /* update state variables */
+ state->cur.put_bits = put_bits;
+
+ return TRUE;
+}
+
+
+LOCAL(boolean)
+flush_bits (working_state * state)
+{
+ if (! emit_bits(state, 0x7F, 7)) /* fill any partial byte with ones */
+ return FALSE;
+ state->cur.put_buffer = 0; /* and reset bit-buffer to empty */
+ state->cur.put_bits = 0;
+ return TRUE;
+}
+
+
+/* Encode a single block's worth of coefficients */
+
+LOCAL(boolean)
+encode_one_block (working_state * state, JCOEFPTR block, int last_dc_val,
+ c_derived_tbl *dctbl, c_derived_tbl *actbl)
+{
+ register int temp, temp2;
+ register int nbits;
+ register int k, r, i;
+
+ /* Encode the DC coefficient difference per section F.1.2.1 */
+
+ temp = temp2 = block[0] - last_dc_val;
+
+ if (temp < 0) {
+ temp = -temp; /* temp is abs value of input */
+ /* For a negative input, want temp2 = bitwise complement of abs(input) */
+ /* This code assumes we are on a two's complement machine */
+ temp2--;
+ }
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = 0;
+ while (temp) {
+ nbits++;
+ temp >>= 1;
+ }
+ /* Check for out-of-range coefficient values.
+ * Since we're encoding a difference, the range limit is twice as much.
+ */
+ if (nbits > MAX_COEF_BITS+1)
+ ERREXIT(state->cinfo, JERR_BAD_DCT_COEF);
+
+ /* Emit the Huffman-coded symbol for the number of bits */
+ if (! emit_bits(state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits]))
+ return FALSE;
+
+ /* Emit that number of bits of the value, if positive, */
+ /* or the complement of its magnitude, if negative. */
+ if (nbits) /* emit_bits rejects calls with size 0 */
+ if (! emit_bits(state, (unsigned int) temp2, nbits))
+ return FALSE;
+
+ /* Encode the AC coefficients per section F.1.2.2 */
+
+ r = 0; /* r = run length of zeros */
+
+ for (k = 1; k < DCTSIZE2; k++) {
+ if ((temp = block[jpeg_natural_order[k]]) == 0) {
+ r++;
+ } else {
+ /* if run length > 15, must emit special run-length-16 codes (0xF0) */
+ while (r > 15) {
+ if (! emit_bits(state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0]))
+ return FALSE;
+ r -= 16;
+ }
+
+ temp2 = temp;
+ if (temp < 0) {
+ temp = -temp; /* temp is abs value of input */
+ /* This code assumes we are on a two's complement machine */
+ temp2--;
+ }
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = 1; /* there must be at least one 1 bit */
+ while ((temp >>= 1))
+ nbits++;
+ /* Check for out-of-range coefficient values */
+ if (nbits > MAX_COEF_BITS)
+ ERREXIT(state->cinfo, JERR_BAD_DCT_COEF);
+
+ /* Emit Huffman symbol for run length / number of bits */
+ i = (r << 4) + nbits;
+ if (! emit_bits(state, actbl->ehufco[i], actbl->ehufsi[i]))
+ return FALSE;
+
+ /* Emit that number of bits of the value, if positive, */
+ /* or the complement of its magnitude, if negative. */
+ if (! emit_bits(state, (unsigned int) temp2, nbits))
+ return FALSE;
+
+ r = 0;
+ }
+ }
+
+ /* If the last coef(s) were zero, emit an end-of-block code */
+ if (r > 0)
+ if (! emit_bits(state, actbl->ehufco[0], actbl->ehufsi[0]))
+ return FALSE;
+
+ return TRUE;
+}
+
+
+/*
+ * Emit a restart marker & resynchronize predictions.
+ */
+
+LOCAL(boolean)
+emit_restart (working_state * state, int restart_num)
+{
+ int ci;
+
+ if (! flush_bits(state))
+ return FALSE;
+
+ emit_byte(state, 0xFF, return FALSE);
+ emit_byte(state, JPEG_RST0 + restart_num, return FALSE);
+
+ /* Re-initialize DC predictions to 0 */
+ for (ci = 0; ci < state->cinfo->comps_in_scan; ci++)
+ state->cur.last_dc_val[ci] = 0;
+
+ /* The restart counter is not updated until we successfully write the MCU. */
+
+ return TRUE;
+}
+
+
+/*
+ * Encode and output one MCU's worth of Huffman-compressed coefficients.
+ */
+
+METHODDEF(boolean)
+encode_mcu_huff (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ working_state state;
+ int blkn, ci;
+ jpeg_component_info * compptr;
+
+ /* Load up working state */
+ state.next_output_byte = cinfo->dest->next_output_byte;
+ state.free_in_buffer = cinfo->dest->free_in_buffer;
+ ASSIGN_STATE(state.cur, entropy->saved);
+ state.cinfo = cinfo;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0)
+ if (! emit_restart(&state, entropy->next_restart_num))
+ return FALSE;
+ }
+
+ /* Encode the MCU data blocks */
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ ci = cinfo->MCU_membership[blkn];
+ compptr = cinfo->cur_comp_info[ci];
+ if (! encode_one_block(&state,
+ MCU_data[blkn][0], state.cur.last_dc_val[ci],
+ entropy->dc_derived_tbls[compptr->dc_tbl_no],
+ entropy->ac_derived_tbls[compptr->ac_tbl_no]))
+ return FALSE;
+ /* Update last_dc_val */
+ state.cur.last_dc_val[ci] = MCU_data[blkn][0][0];
+ }
+
+ /* Completed MCU, so update state */
+ cinfo->dest->next_output_byte = state.next_output_byte;
+ cinfo->dest->free_in_buffer = state.free_in_buffer;
+ ASSIGN_STATE(entropy->saved, state.cur);
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * Finish up at the end of a Huffman-compressed scan.
+ */
+
+METHODDEF(void)
+finish_pass_huff (j_compress_ptr cinfo)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ working_state state;
+
+ /* Load up working state ... flush_bits needs it */
+ state.next_output_byte = cinfo->dest->next_output_byte;
+ state.free_in_buffer = cinfo->dest->free_in_buffer;
+ ASSIGN_STATE(state.cur, entropy->saved);
+ state.cinfo = cinfo;
+
+ /* Flush out the last data */
+ if (! flush_bits(&state))
+ ERREXIT(cinfo, JERR_CANT_SUSPEND);
+
+ /* Update state */
+ cinfo->dest->next_output_byte = state.next_output_byte;
+ cinfo->dest->free_in_buffer = state.free_in_buffer;
+ ASSIGN_STATE(entropy->saved, state.cur);
+}
+
+
+/*
+ * Huffman coding optimization.
+ *
+ * We first scan the supplied data and count the number of uses of each symbol
+ * that is to be Huffman-coded. (This process MUST agree with the code above.)
+ * Then we build a Huffman coding tree for the observed counts.
+ * Symbols which are not needed at all for the particular image are not
+ * assigned any code, which saves space in the DHT marker as well as in
+ * the compressed data.
+ */
+
+#ifdef ENTROPY_OPT_SUPPORTED
+
+
+/* Process a single block's worth of coefficients */
+
+LOCAL(void)
+htest_one_block (j_compress_ptr cinfo, JCOEFPTR block, int last_dc_val,
+ long dc_counts[], long ac_counts[])
+{
+ register int temp;
+ register int nbits;
+ register int k, r;
+
+ /* Encode the DC coefficient difference per section F.1.2.1 */
+
+ temp = block[0] - last_dc_val;
+ if (temp < 0)
+ temp = -temp;
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = 0;
+ while (temp) {
+ nbits++;
+ temp >>= 1;
+ }
+ /* Check for out-of-range coefficient values.
+ * Since we're encoding a difference, the range limit is twice as much.
+ */
+ if (nbits > MAX_COEF_BITS+1)
+ ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+
+ /* Count the Huffman symbol for the number of bits */
+ dc_counts[nbits]++;
+
+ /* Encode the AC coefficients per section F.1.2.2 */
+
+ r = 0; /* r = run length of zeros */
+
+ for (k = 1; k < DCTSIZE2; k++) {
+ if ((temp = block[jpeg_natural_order[k]]) == 0) {
+ r++;
+ } else {
+ /* if run length > 15, must emit special run-length-16 codes (0xF0) */
+ while (r > 15) {
+ ac_counts[0xF0]++;
+ r -= 16;
+ }
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ if (temp < 0)
+ temp = -temp;
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = 1; /* there must be at least one 1 bit */
+ while ((temp >>= 1))
+ nbits++;
+ /* Check for out-of-range coefficient values */
+ if (nbits > MAX_COEF_BITS)
+ ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+
+ /* Count Huffman symbol for run length / number of bits */
+ ac_counts[(r << 4) + nbits]++;
+
+ r = 0;
+ }
+ }
+
+ /* If the last coef(s) were zero, emit an end-of-block code */
+ if (r > 0)
+ ac_counts[0]++;
+}
+
+
+/*
+ * Trial-encode one MCU's worth of Huffman-compressed coefficients.
+ * No data is actually output, so no suspension return is possible.
+ */
+
+METHODDEF(boolean)
+encode_mcu_gather (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ int blkn, ci;
+ jpeg_component_info * compptr;
+
+ /* Take care of restart intervals if needed */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ /* Re-initialize DC predictions to 0 */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++)
+ entropy->saved.last_dc_val[ci] = 0;
+ /* Update restart state */
+ entropy->restarts_to_go = cinfo->restart_interval;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ ci = cinfo->MCU_membership[blkn];
+ compptr = cinfo->cur_comp_info[ci];
+ htest_one_block(cinfo, MCU_data[blkn][0], entropy->saved.last_dc_val[ci],
+ entropy->dc_count_ptrs[compptr->dc_tbl_no],
+ entropy->ac_count_ptrs[compptr->ac_tbl_no]);
+ entropy->saved.last_dc_val[ci] = MCU_data[blkn][0][0];
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * Generate the best Huffman code table for the given counts, fill htbl.
+ * Note this is also used by jcphuff.c.
+ *
+ * The JPEG standard requires that no symbol be assigned a codeword of all
+ * one bits (so that padding bits added at the end of a compressed segment
+ * can't look like a valid code). Because of the canonical ordering of
+ * codewords, this just means that there must be an unused slot in the
+ * longest codeword length category. Section K.2 of the JPEG spec suggests
+ * reserving such a slot by pretending that symbol 256 is a valid symbol
+ * with count 1. In theory that's not optimal; giving it count zero but
+ * including it in the symbol set anyway should give a better Huffman code.
+ * But the theoretically better code actually seems to come out worse in
+ * practice, because it produces more all-ones bytes (which incur stuffed
+ * zero bytes in the final file). In any case the difference is tiny.
+ *
+ * The JPEG standard requires Huffman codes to be no more than 16 bits long.
+ * If some symbols have a very small but nonzero probability, the Huffman tree
+ * must be adjusted to meet the code length restriction. We currently use
+ * the adjustment method suggested in JPEG section K.2. This method is *not*
+ * optimal; it may not choose the best possible limited-length code. But
+ * typically only very-low-frequency symbols will be given less-than-optimal
+ * lengths, so the code is almost optimal. Experimental comparisons against
+ * an optimal limited-length-code algorithm indicate that the difference is
+ * microscopic --- usually less than a hundredth of a percent of total size.
+ * So the extra complexity of an optimal algorithm doesn't seem worthwhile.
+ */
+
+GLOBAL(void)
+jpeg_gen_optimal_table (j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[])
+{
+#define MAX_CLEN 32 /* assumed maximum initial code length */
+ UINT8 bits[MAX_CLEN+1]; /* bits[k] = # of symbols with code length k */
+ int codesize[257]; /* codesize[k] = code length of symbol k */
+ int others[257]; /* next symbol in current branch of tree */
+ int c1, c2;
+ int p, i, j;
+ long v;
+
+ /* This algorithm is explained in section K.2 of the JPEG standard */
+
+ MEMZERO(bits, SIZEOF(bits));
+ MEMZERO(codesize, SIZEOF(codesize));
+ for (i = 0; i < 257; i++)
+ others[i] = -1; /* init links to empty */
+
+ freq[256] = 1; /* make sure 256 has a nonzero count */
+ /* Including the pseudo-symbol 256 in the Huffman procedure guarantees
+ * that no real symbol is given code-value of all ones, because 256
+ * will be placed last in the largest codeword category.
+ */
+
+ /* Huffman's basic algorithm to assign optimal code lengths to symbols */
+
+ for (;;) {
+ /* Find the smallest nonzero frequency, set c1 = its symbol */
+ /* In case of ties, take the larger symbol number */
+ c1 = -1;
+ v = 1000000000L;
+ for (i = 0; i <= 256; i++) {
+ if (freq[i] && freq[i] <= v) {
+ v = freq[i];
+ c1 = i;
+ }
+ }
+
+ /* Find the next smallest nonzero frequency, set c2 = its symbol */
+ /* In case of ties, take the larger symbol number */
+ c2 = -1;
+ v = 1000000000L;
+ for (i = 0; i <= 256; i++) {
+ if (freq[i] && freq[i] <= v && i != c1) {
+ v = freq[i];
+ c2 = i;
+ }
+ }
+
+ /* Done if we've merged everything into one frequency */
+ if (c2 < 0)
+ break;
+
+ /* Else merge the two counts/trees */
+ freq[c1] += freq[c2];
+ freq[c2] = 0;
+
+ /* Increment the codesize of everything in c1's tree branch */
+ codesize[c1]++;
+ while (others[c1] >= 0) {
+ c1 = others[c1];
+ codesize[c1]++;
+ }
+
+ others[c1] = c2; /* chain c2 onto c1's tree branch */
+
+ /* Increment the codesize of everything in c2's tree branch */
+ codesize[c2]++;
+ while (others[c2] >= 0) {
+ c2 = others[c2];
+ codesize[c2]++;
+ }
+ }
+
+ /* Now count the number of symbols of each code length */
+ for (i = 0; i <= 256; i++) {
+ if (codesize[i]) {
+ /* The JPEG standard seems to think that this can't happen, */
+ /* but I'm paranoid... */
+ if (codesize[i] > MAX_CLEN)
+ ERREXIT(cinfo, JERR_HUFF_CLEN_OVERFLOW);
+
+ bits[codesize[i]]++;
+ }
+ }
+
+ /* JPEG doesn't allow symbols with code lengths over 16 bits, so if the pure
+ * Huffman procedure assigned any such lengths, we must adjust the coding.
+ * Here is what the JPEG spec says about how this next bit works:
+ * Since symbols are paired for the longest Huffman code, the symbols are
+ * removed from this length category two at a time. The prefix for the pair
+ * (which is one bit shorter) is allocated to one of the pair; then,
+ * skipping the BITS entry for that prefix length, a code word from the next
+ * shortest nonzero BITS entry is converted into a prefix for two code words
+ * one bit longer.
+ */
+
+ for (i = MAX_CLEN; i > 16; i--) {
+ while (bits[i] > 0) {
+ j = i - 2; /* find length of new prefix to be used */
+ while (bits[j] == 0)
+ j--;
+
+ bits[i] -= 2; /* remove two symbols */
+ bits[i-1]++; /* one goes in this length */
+ bits[j+1] += 2; /* two new symbols in this length */
+ bits[j]--; /* symbol of this length is now a prefix */
+ }
+ }
+
+ /* Remove the count for the pseudo-symbol 256 from the largest codelength */
+ while (bits[i] == 0) /* find largest codelength still in use */
+ i--;
+ bits[i]--;
+
+ /* Return final symbol counts (only for lengths 0..16) */
+ MEMCOPY(htbl->bits, bits, SIZEOF(htbl->bits));
+
+ /* Return a list of the symbols sorted by code length */
+ /* It's not real clear to me why we don't need to consider the codelength
+ * changes made above, but the JPEG spec seems to think this works.
+ */
+ p = 0;
+ for (i = 1; i <= MAX_CLEN; i++) {
+ for (j = 0; j <= 255; j++) {
+ if (codesize[j] == i) {
+ htbl->huffval[p] = (UINT8) j;
+ p++;
+ }
+ }
+ }
+
+ /* Set sent_table FALSE so updated table will be written to JPEG file. */
+ htbl->sent_table = FALSE;
+}
+
+
+/*
+ * Finish up a statistics-gathering pass and create the new Huffman tables.
+ */
+
+METHODDEF(void)
+finish_pass_gather (j_compress_ptr cinfo)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ int ci, dctbl, actbl;
+ jpeg_component_info * compptr;
+ JHUFF_TBL **htblptr;
+ boolean did_dc[NUM_HUFF_TBLS];
+ boolean did_ac[NUM_HUFF_TBLS];
+
+ /* It's important not to apply jpeg_gen_optimal_table more than once
+ * per table, because it clobbers the input frequency counts!
+ */
+ MEMZERO(did_dc, SIZEOF(did_dc));
+ MEMZERO(did_ac, SIZEOF(did_ac));
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ dctbl = compptr->dc_tbl_no;
+ actbl = compptr->ac_tbl_no;
+ if (! did_dc[dctbl]) {
+ htblptr = & cinfo->dc_huff_tbl_ptrs[dctbl];
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+ jpeg_gen_optimal_table(cinfo, *htblptr, entropy->dc_count_ptrs[dctbl]);
+ did_dc[dctbl] = TRUE;
+ }
+ if (! did_ac[actbl]) {
+ htblptr = & cinfo->ac_huff_tbl_ptrs[actbl];
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+ jpeg_gen_optimal_table(cinfo, *htblptr, entropy->ac_count_ptrs[actbl]);
+ did_ac[actbl] = TRUE;
+ }
+ }
+}
+
+
+#endif /* ENTROPY_OPT_SUPPORTED */
+
+
+/*
+ * Module initialization routine for Huffman entropy encoding.
+ */
+
+GLOBAL(void)
+jinit_huff_encoder (j_compress_ptr cinfo)
+{
+ huff_entropy_ptr entropy;
+ int i;
+
+ entropy = (huff_entropy_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(huff_entropy_encoder));
+ cinfo->entropy = (struct jpeg_entropy_encoder *) entropy;
+ entropy->pub.start_pass = start_pass_huff;
+
+ /* Mark tables unallocated */
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
+#ifdef ENTROPY_OPT_SUPPORTED
+ entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL;
+#endif
+ }
+}
--- /dev/null
+/*
+ * jcinit.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains initialization logic for the JPEG compressor.
+ * This routine is in charge of selecting the modules to be executed and
+ * making an initialization call to each one.
+ *
+ * Logically, this code belongs in jcmaster.c. It's split out because
+ * linking this routine implies linking the entire compression library.
+ * For a transcoding-only application, we want to be able to use jcmaster.c
+ * without linking in the whole library.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * Master selection of compression modules.
+ * This is done once at the start of processing an image. We determine
+ * which modules will be used and give them appropriate initialization calls.
+ */
+
+GLOBAL(void)
+jinit_compress_master (j_compress_ptr cinfo)
+{
+ /* Initialize master control (includes parameter checking/processing) */
+ jinit_c_master_control(cinfo, FALSE /* full compression */);
+
+ /* Preprocessing */
+ if (! cinfo->raw_data_in) {
+ jinit_color_converter(cinfo);
+ jinit_downsampler(cinfo);
+ jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
+ }
+ /* Forward DCT */
+ jinit_forward_dct(cinfo);
+ /* Entropy encoding: either Huffman or arithmetic coding. */
+ if (cinfo->arith_code) {
+ ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+ } else {
+ if (cinfo->progressive_mode) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+ jinit_phuff_encoder(cinfo);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else
+ jinit_huff_encoder(cinfo);
+ }
+
+ /* Need a full-image coefficient buffer in any multi-pass mode. */
+ jinit_c_coef_controller(cinfo,
+ (boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
+ jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
+
+ jinit_marker_writer(cinfo);
+
+ /* We can now tell the memory manager to allocate virtual arrays. */
+ (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
+
+ /* Write the datastream header (SOI) immediately.
+ * Frame and scan headers are postponed till later.
+ * This lets application insert special markers after the SOI.
+ */
+ (*cinfo->marker->write_file_header) (cinfo);
+}
--- /dev/null
+/*
+ * jcmainct.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the main buffer controller for compression.
+ * The main buffer lies between the pre-processor and the JPEG
+ * compressor proper; it holds downsampled data in the JPEG colorspace.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Note: currently, there is no operating mode in which a full-image buffer
+ * is needed at this step. If there were, that mode could not be used with
+ * "raw data" input, since this module is bypassed in that case. However,
+ * we've left the code here for possible use in special applications.
+ */
+#undef FULL_MAIN_BUFFER_SUPPORTED
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_c_main_controller pub; /* public fields */
+
+ JDIMENSION cur_iMCU_row; /* number of current iMCU row */
+ JDIMENSION rowgroup_ctr; /* counts row groups received in iMCU row */
+ boolean suspended; /* remember if we suspended output */
+ J_BUF_MODE pass_mode; /* current operating mode */
+
+ /* If using just a strip buffer, this points to the entire set of buffers
+ * (we allocate one for each component). In the full-image case, this
+ * points to the currently accessible strips of the virtual arrays.
+ */
+ JSAMPARRAY buffer[MAX_COMPONENTS];
+
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+ /* If using full-image storage, this array holds pointers to virtual-array
+ * control blocks for each component. Unused if not full-image storage.
+ */
+ jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
+#endif
+} my_main_controller;
+
+typedef my_main_controller * my_main_ptr;
+
+
+/* Forward declarations */
+METHODDEF(void) process_data_simple_main
+ JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
+ JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+METHODDEF(void) process_data_buffer_main
+ JPP((j_compress_ptr cinfo, JSAMPARRAY input_buf,
+ JDIMENSION *in_row_ctr, JDIMENSION in_rows_avail));
+#endif
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_main (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+
+ /* Do nothing in raw-data mode. */
+ if (cinfo->raw_data_in)
+ return;
+
+ main->cur_iMCU_row = 0; /* initialize counters */
+ main->rowgroup_ctr = 0;
+ main->suspended = FALSE;
+ main->pass_mode = pass_mode; /* save mode for use by process_data */
+
+ switch (pass_mode) {
+ case JBUF_PASS_THRU:
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+ if (main->whole_image[0] != NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+#endif
+ main->pub.process_data = process_data_simple_main;
+ break;
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+ case JBUF_SAVE_SOURCE:
+ case JBUF_CRANK_DEST:
+ case JBUF_SAVE_AND_PASS:
+ if (main->whole_image[0] == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ main->pub.process_data = process_data_buffer_main;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ break;
+ }
+}
+
+
+/*
+ * Process some data.
+ * This routine handles the simple pass-through mode,
+ * where we have only a strip buffer.
+ */
+
+METHODDEF(void)
+process_data_simple_main (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
+ JDIMENSION in_rows_avail)
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+
+ while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
+ /* Read input data if we haven't filled the main buffer yet */
+ if (main->rowgroup_ctr < DCTSIZE)
+ (*cinfo->prep->pre_process_data) (cinfo,
+ input_buf, in_row_ctr, in_rows_avail,
+ main->buffer, &main->rowgroup_ctr,
+ (JDIMENSION) DCTSIZE);
+
+ /* If we don't have a full iMCU row buffered, return to application for
+ * more data. Note that preprocessor will always pad to fill the iMCU row
+ * at the bottom of the image.
+ */
+ if (main->rowgroup_ctr != DCTSIZE)
+ return;
+
+ /* Send the completed row to the compressor */
+ if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
+ /* If compressor did not consume the whole row, then we must need to
+ * suspend processing and return to the application. In this situation
+ * we pretend we didn't yet consume the last input row; otherwise, if
+ * it happened to be the last row of the image, the application would
+ * think we were done.
+ */
+ if (! main->suspended) {
+ (*in_row_ctr)--;
+ main->suspended = TRUE;
+ }
+ return;
+ }
+ /* We did finish the row. Undo our little suspension hack if a previous
+ * call suspended; then mark the main buffer empty.
+ */
+ if (main->suspended) {
+ (*in_row_ctr)++;
+ main->suspended = FALSE;
+ }
+ main->rowgroup_ctr = 0;
+ main->cur_iMCU_row++;
+ }
+}
+
+
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+
+/*
+ * Process some data.
+ * This routine handles all of the modes that use a full-size buffer.
+ */
+
+METHODDEF(void)
+process_data_buffer_main (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
+ JDIMENSION in_rows_avail)
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+ int ci;
+ jpeg_component_info *compptr;
+ boolean writing = (main->pass_mode != JBUF_CRANK_DEST);
+
+ while (main->cur_iMCU_row < cinfo->total_iMCU_rows) {
+ /* Realign the virtual buffers if at the start of an iMCU row. */
+ if (main->rowgroup_ctr == 0) {
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ main->buffer[ci] = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, main->whole_image[ci],
+ main->cur_iMCU_row * (compptr->v_samp_factor * DCTSIZE),
+ (JDIMENSION) (compptr->v_samp_factor * DCTSIZE), writing);
+ }
+ /* In a read pass, pretend we just read some source data. */
+ if (! writing) {
+ *in_row_ctr += cinfo->max_v_samp_factor * DCTSIZE;
+ main->rowgroup_ctr = DCTSIZE;
+ }
+ }
+
+ /* If a write pass, read input data until the current iMCU row is full. */
+ /* Note: preprocessor will pad if necessary to fill the last iMCU row. */
+ if (writing) {
+ (*cinfo->prep->pre_process_data) (cinfo,
+ input_buf, in_row_ctr, in_rows_avail,
+ main->buffer, &main->rowgroup_ctr,
+ (JDIMENSION) DCTSIZE);
+ /* Return to application if we need more data to fill the iMCU row. */
+ if (main->rowgroup_ctr < DCTSIZE)
+ return;
+ }
+
+ /* Emit data, unless this is a sink-only pass. */
+ if (main->pass_mode != JBUF_SAVE_SOURCE) {
+ if (! (*cinfo->coef->compress_data) (cinfo, main->buffer)) {
+ /* If compressor did not consume the whole row, then we must need to
+ * suspend processing and return to the application. In this situation
+ * we pretend we didn't yet consume the last input row; otherwise, if
+ * it happened to be the last row of the image, the application would
+ * think we were done.
+ */
+ if (! main->suspended) {
+ (*in_row_ctr)--;
+ main->suspended = TRUE;
+ }
+ return;
+ }
+ /* We did finish the row. Undo our little suspension hack if a previous
+ * call suspended; then mark the main buffer empty.
+ */
+ if (main->suspended) {
+ (*in_row_ctr)++;
+ main->suspended = FALSE;
+ }
+ }
+
+ /* If get here, we are done with this iMCU row. Mark buffer empty. */
+ main->rowgroup_ctr = 0;
+ main->cur_iMCU_row++;
+ }
+}
+
+#endif /* FULL_MAIN_BUFFER_SUPPORTED */
+
+
+/*
+ * Initialize main buffer controller.
+ */
+
+GLOBAL(void)
+jinit_c_main_controller (j_compress_ptr cinfo, boolean need_full_buffer)
+{
+ my_main_ptr main;
+ int ci;
+ jpeg_component_info *compptr;
+
+ main = (my_main_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_main_controller));
+ cinfo->main = (struct jpeg_c_main_controller *) main;
+ main->pub.start_pass = start_pass_main;
+
+ /* We don't need to create a buffer in raw-data mode. */
+ if (cinfo->raw_data_in)
+ return;
+
+ /* Create the buffer. It holds downsampled data, so each component
+ * may be of a different size.
+ */
+ if (need_full_buffer) {
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+ /* Allocate a full-image virtual array for each component */
+ /* Note we pad the bottom to a multiple of the iMCU height */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ main->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+ compptr->width_in_blocks * DCTSIZE,
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor) * DCTSIZE,
+ (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
+ }
+#else
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+#endif
+ } else {
+#ifdef FULL_MAIN_BUFFER_SUPPORTED
+ main->whole_image[0] = NULL; /* flag for no virtual arrays */
+#endif
+ /* Allocate a strip buffer for each component */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ main->buffer[ci] = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ compptr->width_in_blocks * DCTSIZE,
+ (JDIMENSION) (compptr->v_samp_factor * DCTSIZE));
+ }
+ }
+}
--- /dev/null
+/*
+ * jcmarker.c
+ *
+ * Copyright (C) 1991-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to write JPEG datastream markers.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+typedef enum { /* JPEG marker codes */
+ M_SOF0 = 0xc0,
+ M_SOF1 = 0xc1,
+ M_SOF2 = 0xc2,
+ M_SOF3 = 0xc3,
+
+ M_SOF5 = 0xc5,
+ M_SOF6 = 0xc6,
+ M_SOF7 = 0xc7,
+
+ M_JPG = 0xc8,
+ M_SOF9 = 0xc9,
+ M_SOF10 = 0xca,
+ M_SOF11 = 0xcb,
+
+ M_SOF13 = 0xcd,
+ M_SOF14 = 0xce,
+ M_SOF15 = 0xcf,
+
+ M_DHT = 0xc4,
+
+ M_DAC = 0xcc,
+
+ M_RST0 = 0xd0,
+ M_RST1 = 0xd1,
+ M_RST2 = 0xd2,
+ M_RST3 = 0xd3,
+ M_RST4 = 0xd4,
+ M_RST5 = 0xd5,
+ M_RST6 = 0xd6,
+ M_RST7 = 0xd7,
+
+ M_SOI = 0xd8,
+ M_EOI = 0xd9,
+ M_SOS = 0xda,
+ M_DQT = 0xdb,
+ M_DNL = 0xdc,
+ M_DRI = 0xdd,
+ M_DHP = 0xde,
+ M_EXP = 0xdf,
+
+ M_APP0 = 0xe0,
+ M_APP1 = 0xe1,
+ M_APP2 = 0xe2,
+ M_APP3 = 0xe3,
+ M_APP4 = 0xe4,
+ M_APP5 = 0xe5,
+ M_APP6 = 0xe6,
+ M_APP7 = 0xe7,
+ M_APP8 = 0xe8,
+ M_APP9 = 0xe9,
+ M_APP10 = 0xea,
+ M_APP11 = 0xeb,
+ M_APP12 = 0xec,
+ M_APP13 = 0xed,
+ M_APP14 = 0xee,
+ M_APP15 = 0xef,
+
+ M_JPG0 = 0xf0,
+ M_JPG13 = 0xfd,
+ M_COM = 0xfe,
+
+ M_TEM = 0x01,
+
+ M_ERROR = 0x100
+} JPEG_MARKER;
+
+
+/* Private state */
+
+typedef struct {
+ struct jpeg_marker_writer pub; /* public fields */
+
+ unsigned int last_restart_interval; /* last DRI value emitted; 0 after SOI */
+} my_marker_writer;
+
+typedef my_marker_writer * my_marker_ptr;
+
+
+/*
+ * Basic output routines.
+ *
+ * Note that we do not support suspension while writing a marker.
+ * Therefore, an application using suspension must ensure that there is
+ * enough buffer space for the initial markers (typ. 600-700 bytes) before
+ * calling jpeg_start_compress, and enough space to write the trailing EOI
+ * (a few bytes) before calling jpeg_finish_compress. Multipass compression
+ * modes are not supported at all with suspension, so those two are the only
+ * points where markers will be written.
+ */
+
+LOCAL(void)
+emit_byte (j_compress_ptr cinfo, int val)
+/* Emit a byte */
+{
+ struct jpeg_destination_mgr * dest = cinfo->dest;
+
+ *(dest->next_output_byte)++ = (JOCTET) val;
+ if (--dest->free_in_buffer == 0) {
+ if (! (*dest->empty_output_buffer) (cinfo))
+ ERREXIT(cinfo, JERR_CANT_SUSPEND);
+ }
+}
+
+
+LOCAL(void)
+emit_marker (j_compress_ptr cinfo, JPEG_MARKER mark)
+/* Emit a marker code */
+{
+ emit_byte(cinfo, 0xFF);
+ emit_byte(cinfo, (int) mark);
+}
+
+
+LOCAL(void)
+emit_2bytes (j_compress_ptr cinfo, int value)
+/* Emit a 2-byte integer; these are always MSB first in JPEG files */
+{
+ emit_byte(cinfo, (value >> 8) & 0xFF);
+ emit_byte(cinfo, value & 0xFF);
+}
+
+
+/*
+ * Routines to write specific marker types.
+ */
+
+LOCAL(int)
+emit_dqt (j_compress_ptr cinfo, int index)
+/* Emit a DQT marker */
+/* Returns the precision used (0 = 8bits, 1 = 16bits) for baseline checking */
+{
+ JQUANT_TBL * qtbl = cinfo->quant_tbl_ptrs[index];
+ int prec;
+ int i;
+
+ if (qtbl == NULL)
+ ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, index);
+
+ prec = 0;
+ for (i = 0; i < DCTSIZE2; i++) {
+ if (qtbl->quantval[i] > 255)
+ prec = 1;
+ }
+
+ if (! qtbl->sent_table) {
+ emit_marker(cinfo, M_DQT);
+
+ emit_2bytes(cinfo, prec ? DCTSIZE2*2 + 1 + 2 : DCTSIZE2 + 1 + 2);
+
+ emit_byte(cinfo, index + (prec<<4));
+
+ for (i = 0; i < DCTSIZE2; i++) {
+ /* The table entries must be emitted in zigzag order. */
+ unsigned int qval = qtbl->quantval[jpeg_natural_order[i]];
+ if (prec)
+ emit_byte(cinfo, (int) (qval >> 8));
+ emit_byte(cinfo, (int) (qval & 0xFF));
+ }
+
+ qtbl->sent_table = TRUE;
+ }
+
+ return prec;
+}
+
+
+LOCAL(void)
+emit_dht (j_compress_ptr cinfo, int index, boolean is_ac)
+/* Emit a DHT marker */
+{
+ JHUFF_TBL * htbl;
+ int length, i;
+
+ if (is_ac) {
+ htbl = cinfo->ac_huff_tbl_ptrs[index];
+ index += 0x10; /* output index has AC bit set */
+ } else {
+ htbl = cinfo->dc_huff_tbl_ptrs[index];
+ }
+
+ if (htbl == NULL)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, index);
+
+ if (! htbl->sent_table) {
+ emit_marker(cinfo, M_DHT);
+
+ length = 0;
+ for (i = 1; i <= 16; i++)
+ length += htbl->bits[i];
+
+ emit_2bytes(cinfo, length + 2 + 1 + 16);
+ emit_byte(cinfo, index);
+
+ for (i = 1; i <= 16; i++)
+ emit_byte(cinfo, htbl->bits[i]);
+
+ for (i = 0; i < length; i++)
+ emit_byte(cinfo, htbl->huffval[i]);
+
+ htbl->sent_table = TRUE;
+ }
+}
+
+
+LOCAL(void)
+emit_dac (j_compress_ptr cinfo)
+/* Emit a DAC marker */
+/* Since the useful info is so small, we want to emit all the tables in */
+/* one DAC marker. Therefore this routine does its own scan of the table. */
+{
+#ifdef C_ARITH_CODING_SUPPORTED
+ char dc_in_use[NUM_ARITH_TBLS];
+ char ac_in_use[NUM_ARITH_TBLS];
+ int length, i;
+ jpeg_component_info *compptr;
+
+ for (i = 0; i < NUM_ARITH_TBLS; i++)
+ dc_in_use[i] = ac_in_use[i] = 0;
+
+ for (i = 0; i < cinfo->comps_in_scan; i++) {
+ compptr = cinfo->cur_comp_info[i];
+ dc_in_use[compptr->dc_tbl_no] = 1;
+ ac_in_use[compptr->ac_tbl_no] = 1;
+ }
+
+ length = 0;
+ for (i = 0; i < NUM_ARITH_TBLS; i++)
+ length += dc_in_use[i] + ac_in_use[i];
+
+ emit_marker(cinfo, M_DAC);
+
+ emit_2bytes(cinfo, length*2 + 2);
+
+ for (i = 0; i < NUM_ARITH_TBLS; i++) {
+ if (dc_in_use[i]) {
+ emit_byte(cinfo, i);
+ emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
+ }
+ if (ac_in_use[i]) {
+ emit_byte(cinfo, i + 0x10);
+ emit_byte(cinfo, cinfo->arith_ac_K[i]);
+ }
+ }
+#endif /* C_ARITH_CODING_SUPPORTED */
+}
+
+
+LOCAL(void)
+emit_dri (j_compress_ptr cinfo)
+/* Emit a DRI marker */
+{
+ emit_marker(cinfo, M_DRI);
+
+ emit_2bytes(cinfo, 4); /* fixed length */
+
+ emit_2bytes(cinfo, (int) cinfo->restart_interval);
+}
+
+
+LOCAL(void)
+emit_sof (j_compress_ptr cinfo, JPEG_MARKER code)
+/* Emit a SOF marker */
+{
+ int ci;
+ jpeg_component_info *compptr;
+
+ emit_marker(cinfo, code);
+
+ emit_2bytes(cinfo, 3 * cinfo->num_components + 2 + 5 + 1); /* length */
+
+ /* Make sure image isn't bigger than SOF field can handle */
+ if ((long) cinfo->image_height > 65535L ||
+ (long) cinfo->image_width > 65535L)
+ ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) 65535);
+
+ emit_byte(cinfo, cinfo->data_precision);
+ emit_2bytes(cinfo, (int) cinfo->image_height);
+ emit_2bytes(cinfo, (int) cinfo->image_width);
+
+ emit_byte(cinfo, cinfo->num_components);
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ emit_byte(cinfo, compptr->component_id);
+ emit_byte(cinfo, (compptr->h_samp_factor << 4) + compptr->v_samp_factor);
+ emit_byte(cinfo, compptr->quant_tbl_no);
+ }
+}
+
+
+LOCAL(void)
+emit_sos (j_compress_ptr cinfo)
+/* Emit a SOS marker */
+{
+ int i, td, ta;
+ jpeg_component_info *compptr;
+
+ emit_marker(cinfo, M_SOS);
+
+ emit_2bytes(cinfo, 2 * cinfo->comps_in_scan + 2 + 1 + 3); /* length */
+
+ emit_byte(cinfo, cinfo->comps_in_scan);
+
+ for (i = 0; i < cinfo->comps_in_scan; i++) {
+ compptr = cinfo->cur_comp_info[i];
+ emit_byte(cinfo, compptr->component_id);
+ td = compptr->dc_tbl_no;
+ ta = compptr->ac_tbl_no;
+ if (cinfo->progressive_mode) {
+ /* Progressive mode: only DC or only AC tables are used in one scan;
+ * furthermore, Huffman coding of DC refinement uses no table at all.
+ * We emit 0 for unused field(s); this is recommended by the P&M text
+ * but does not seem to be specified in the standard.
+ */
+ if (cinfo->Ss == 0) {
+ ta = 0; /* DC scan */
+ if (cinfo->Ah != 0 && !cinfo->arith_code)
+ td = 0; /* no DC table either */
+ } else {
+ td = 0; /* AC scan */
+ }
+ }
+ emit_byte(cinfo, (td << 4) + ta);
+ }
+
+ emit_byte(cinfo, cinfo->Ss);
+ emit_byte(cinfo, cinfo->Se);
+ emit_byte(cinfo, (cinfo->Ah << 4) + cinfo->Al);
+}
+
+
+LOCAL(void)
+emit_jfif_app0 (j_compress_ptr cinfo)
+/* Emit a JFIF-compliant APP0 marker */
+{
+ /*
+ * Length of APP0 block (2 bytes)
+ * Block ID (4 bytes - ASCII "JFIF")
+ * Zero byte (1 byte to terminate the ID string)
+ * Version Major, Minor (2 bytes - major first)
+ * Units (1 byte - 0x00 = none, 0x01 = inch, 0x02 = cm)
+ * Xdpu (2 bytes - dots per unit horizontal)
+ * Ydpu (2 bytes - dots per unit vertical)
+ * Thumbnail X size (1 byte)
+ * Thumbnail Y size (1 byte)
+ */
+
+ emit_marker(cinfo, M_APP0);
+
+ emit_2bytes(cinfo, 2 + 4 + 1 + 2 + 1 + 2 + 2 + 1 + 1); /* length */
+
+ emit_byte(cinfo, 0x4A); /* Identifier: ASCII "JFIF" */
+ emit_byte(cinfo, 0x46);
+ emit_byte(cinfo, 0x49);
+ emit_byte(cinfo, 0x46);
+ emit_byte(cinfo, 0);
+ emit_byte(cinfo, cinfo->JFIF_major_version); /* Version fields */
+ emit_byte(cinfo, cinfo->JFIF_minor_version);
+ emit_byte(cinfo, cinfo->density_unit); /* Pixel size information */
+ emit_2bytes(cinfo, (int) cinfo->X_density);
+ emit_2bytes(cinfo, (int) cinfo->Y_density);
+ emit_byte(cinfo, 0); /* No thumbnail image */
+ emit_byte(cinfo, 0);
+}
+
+
+LOCAL(void)
+emit_adobe_app14 (j_compress_ptr cinfo)
+/* Emit an Adobe APP14 marker */
+{
+ /*
+ * Length of APP14 block (2 bytes)
+ * Block ID (5 bytes - ASCII "Adobe")
+ * Version Number (2 bytes - currently 100)
+ * Flags0 (2 bytes - currently 0)
+ * Flags1 (2 bytes - currently 0)
+ * Color transform (1 byte)
+ *
+ * Although Adobe TN 5116 mentions Version = 101, all the Adobe files
+ * now in circulation seem to use Version = 100, so that's what we write.
+ *
+ * We write the color transform byte as 1 if the JPEG color space is
+ * YCbCr, 2 if it's YCCK, 0 otherwise. Adobe's definition has to do with
+ * whether the encoder performed a transformation, which is pretty useless.
+ */
+
+ emit_marker(cinfo, M_APP14);
+
+ emit_2bytes(cinfo, 2 + 5 + 2 + 2 + 2 + 1); /* length */
+
+ emit_byte(cinfo, 0x41); /* Identifier: ASCII "Adobe" */
+ emit_byte(cinfo, 0x64);
+ emit_byte(cinfo, 0x6F);
+ emit_byte(cinfo, 0x62);
+ emit_byte(cinfo, 0x65);
+ emit_2bytes(cinfo, 100); /* Version */
+ emit_2bytes(cinfo, 0); /* Flags0 */
+ emit_2bytes(cinfo, 0); /* Flags1 */
+ switch (cinfo->jpeg_color_space) {
+ case JCS_YCbCr:
+ emit_byte(cinfo, 1); /* Color transform = 1 */
+ break;
+ case JCS_YCCK:
+ emit_byte(cinfo, 2); /* Color transform = 2 */
+ break;
+ default:
+ emit_byte(cinfo, 0); /* Color transform = 0 */
+ break;
+ }
+}
+
+
+/*
+ * These routines allow writing an arbitrary marker with parameters.
+ * The only intended use is to emit COM or APPn markers after calling
+ * write_file_header and before calling write_frame_header.
+ * Other uses are not guaranteed to produce desirable results.
+ * Counting the parameter bytes properly is the caller's responsibility.
+ */
+
+METHODDEF(void)
+write_marker_header (j_compress_ptr cinfo, int marker, unsigned int datalen)
+/* Emit an arbitrary marker header */
+{
+ if (datalen > (unsigned int) 65533) /* safety check */
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ emit_marker(cinfo, (JPEG_MARKER) marker);
+
+ emit_2bytes(cinfo, (int) (datalen + 2)); /* total length */
+}
+
+METHODDEF(void)
+write_marker_byte (j_compress_ptr cinfo, int val)
+/* Emit one byte of marker parameters following write_marker_header */
+{
+ emit_byte(cinfo, val);
+}
+
+
+/*
+ * Write datastream header.
+ * This consists of an SOI and optional APPn markers.
+ * We recommend use of the JFIF marker, but not the Adobe marker,
+ * when using YCbCr or grayscale data. The JFIF marker should NOT
+ * be used for any other JPEG colorspace. The Adobe marker is helpful
+ * to distinguish RGB, CMYK, and YCCK colorspaces.
+ * Note that an application can write additional header markers after
+ * jpeg_start_compress returns.
+ */
+
+METHODDEF(void)
+write_file_header (j_compress_ptr cinfo)
+{
+ my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
+
+ emit_marker(cinfo, M_SOI); /* first the SOI */
+
+ /* SOI is defined to reset restart interval to 0 */
+ marker->last_restart_interval = 0;
+
+ if (cinfo->write_JFIF_header) /* next an optional JFIF APP0 */
+ emit_jfif_app0(cinfo);
+ if (cinfo->write_Adobe_marker) /* next an optional Adobe APP14 */
+ emit_adobe_app14(cinfo);
+}
+
+
+/*
+ * Write frame header.
+ * This consists of DQT and SOFn markers.
+ * Note that we do not emit the SOF until we have emitted the DQT(s).
+ * This avoids compatibility problems with incorrect implementations that
+ * try to error-check the quant table numbers as soon as they see the SOF.
+ */
+
+METHODDEF(void)
+write_frame_header (j_compress_ptr cinfo)
+{
+ int ci, prec;
+ boolean is_baseline;
+ jpeg_component_info *compptr;
+
+ /* Emit DQT for each quantization table.
+ * Note that emit_dqt() suppresses any duplicate tables.
+ */
+ prec = 0;
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ prec += emit_dqt(cinfo, compptr->quant_tbl_no);
+ }
+ /* now prec is nonzero iff there are any 16-bit quant tables. */
+
+ /* Check for a non-baseline specification.
+ * Note we assume that Huffman table numbers won't be changed later.
+ */
+ if (cinfo->arith_code || cinfo->progressive_mode ||
+ cinfo->data_precision != 8) {
+ is_baseline = FALSE;
+ } else {
+ is_baseline = TRUE;
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ if (compptr->dc_tbl_no > 1 || compptr->ac_tbl_no > 1)
+ is_baseline = FALSE;
+ }
+ if (prec && is_baseline) {
+ is_baseline = FALSE;
+ /* If it's baseline except for quantizer size, warn the user */
+ TRACEMS(cinfo, 0, JTRC_16BIT_TABLES);
+ }
+ }
+
+ /* Emit the proper SOF marker */
+ if (cinfo->arith_code) {
+ emit_sof(cinfo, M_SOF9); /* SOF code for arithmetic coding */
+ } else {
+ if (cinfo->progressive_mode)
+ emit_sof(cinfo, M_SOF2); /* SOF code for progressive Huffman */
+ else if (is_baseline)
+ emit_sof(cinfo, M_SOF0); /* SOF code for baseline implementation */
+ else
+ emit_sof(cinfo, M_SOF1); /* SOF code for non-baseline Huffman file */
+ }
+}
+
+
+/*
+ * Write scan header.
+ * This consists of DHT or DAC markers, optional DRI, and SOS.
+ * Compressed data will be written following the SOS.
+ */
+
+METHODDEF(void)
+write_scan_header (j_compress_ptr cinfo)
+{
+ my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
+ int i;
+ jpeg_component_info *compptr;
+
+ if (cinfo->arith_code) {
+ /* Emit arith conditioning info. We may have some duplication
+ * if the file has multiple scans, but it's so small it's hardly
+ * worth worrying about.
+ */
+ emit_dac(cinfo);
+ } else {
+ /* Emit Huffman tables.
+ * Note that emit_dht() suppresses any duplicate tables.
+ */
+ for (i = 0; i < cinfo->comps_in_scan; i++) {
+ compptr = cinfo->cur_comp_info[i];
+ if (cinfo->progressive_mode) {
+ /* Progressive mode: only DC or only AC tables are used in one scan */
+ if (cinfo->Ss == 0) {
+ if (cinfo->Ah == 0) /* DC needs no table for refinement scan */
+ emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
+ } else {
+ emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
+ }
+ } else {
+ /* Sequential mode: need both DC and AC tables */
+ emit_dht(cinfo, compptr->dc_tbl_no, FALSE);
+ emit_dht(cinfo, compptr->ac_tbl_no, TRUE);
+ }
+ }
+ }
+
+ /* Emit DRI if required --- note that DRI value could change for each scan.
+ * We avoid wasting space with unnecessary DRIs, however.
+ */
+ if (cinfo->restart_interval != marker->last_restart_interval) {
+ emit_dri(cinfo);
+ marker->last_restart_interval = cinfo->restart_interval;
+ }
+
+ emit_sos(cinfo);
+}
+
+
+/*
+ * Write datastream trailer.
+ */
+
+METHODDEF(void)
+write_file_trailer (j_compress_ptr cinfo)
+{
+ emit_marker(cinfo, M_EOI);
+}
+
+
+/*
+ * Write an abbreviated table-specification datastream.
+ * This consists of SOI, DQT and DHT tables, and EOI.
+ * Any table that is defined and not marked sent_table = TRUE will be
+ * emitted. Note that all tables will be marked sent_table = TRUE at exit.
+ */
+
+METHODDEF(void)
+write_tables_only (j_compress_ptr cinfo)
+{
+ int i;
+
+ emit_marker(cinfo, M_SOI);
+
+ for (i = 0; i < NUM_QUANT_TBLS; i++) {
+ if (cinfo->quant_tbl_ptrs[i] != NULL)
+ (void) emit_dqt(cinfo, i);
+ }
+
+ if (! cinfo->arith_code) {
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ if (cinfo->dc_huff_tbl_ptrs[i] != NULL)
+ emit_dht(cinfo, i, FALSE);
+ if (cinfo->ac_huff_tbl_ptrs[i] != NULL)
+ emit_dht(cinfo, i, TRUE);
+ }
+ }
+
+ emit_marker(cinfo, M_EOI);
+}
+
+
+/*
+ * Initialize the marker writer module.
+ */
+
+GLOBAL(void)
+jinit_marker_writer (j_compress_ptr cinfo)
+{
+ my_marker_ptr marker;
+
+ /* Create the subobject */
+ marker = (my_marker_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_marker_writer));
+ cinfo->marker = (struct jpeg_marker_writer *) marker;
+ /* Initialize method pointers */
+ marker->pub.write_file_header = write_file_header;
+ marker->pub.write_frame_header = write_frame_header;
+ marker->pub.write_scan_header = write_scan_header;
+ marker->pub.write_file_trailer = write_file_trailer;
+ marker->pub.write_tables_only = write_tables_only;
+ marker->pub.write_marker_header = write_marker_header;
+ marker->pub.write_marker_byte = write_marker_byte;
+ /* Initialize private state */
+ marker->last_restart_interval = 0;
+}
--- /dev/null
+/*
+ * jcmaster.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains master control logic for the JPEG compressor.
+ * These routines are concerned with parameter validation, initial setup,
+ * and inter-pass control (determining the number of passes and the work
+ * to be done in each pass).
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Private state */
+
+typedef enum {
+ main_pass, /* input data, also do first output step */
+ huff_opt_pass, /* Huffman code optimization pass */
+ output_pass /* data output pass */
+} c_pass_type;
+
+typedef struct {
+ struct jpeg_comp_master pub; /* public fields */
+
+ c_pass_type pass_type; /* the type of the current pass */
+
+ int pass_number; /* # of passes completed */
+ int total_passes; /* total # of passes needed */
+
+ int scan_number; /* current index in scan_info[] */
+} my_comp_master;
+
+typedef my_comp_master * my_master_ptr;
+
+
+/*
+ * Support routines that do various essential calculations.
+ */
+
+LOCAL(void)
+initial_setup (j_compress_ptr cinfo)
+/* Do computations that are needed before master selection phase */
+{
+ int ci;
+ jpeg_component_info *compptr;
+ long samplesperrow;
+ JDIMENSION jd_samplesperrow;
+
+ /* Sanity check on image dimensions */
+ if (cinfo->image_height <= 0 || cinfo->image_width <= 0
+ || cinfo->num_components <= 0 || cinfo->input_components <= 0)
+ ERREXIT(cinfo, JERR_EMPTY_IMAGE);
+
+ /* Make sure image isn't bigger than I can handle */
+ if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
+ (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
+ ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
+
+ /* Width of an input scanline must be representable as JDIMENSION. */
+ samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
+ jd_samplesperrow = (JDIMENSION) samplesperrow;
+ if ((long) jd_samplesperrow != samplesperrow)
+ ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
+
+ /* For now, precision must match compiled-in value... */
+ if (cinfo->data_precision != BITS_IN_JSAMPLE)
+ ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
+
+ /* Check that number of components won't exceed internal array sizes */
+ if (cinfo->num_components > MAX_COMPONENTS)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+ MAX_COMPONENTS);
+
+ /* Compute maximum sampling factors; check factor validity */
+ cinfo->max_h_samp_factor = 1;
+ cinfo->max_v_samp_factor = 1;
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
+ compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
+ ERREXIT(cinfo, JERR_BAD_SAMPLING);
+ cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
+ compptr->h_samp_factor);
+ cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
+ compptr->v_samp_factor);
+ }
+
+ /* Compute dimensions of components */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Fill in the correct component_index value; don't rely on application */
+ compptr->component_index = ci;
+ /* For compression, we never do DCT scaling. */
+ compptr->DCT_scaled_size = DCTSIZE;
+ /* Size in DCT blocks */
+ compptr->width_in_blocks = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
+ (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ compptr->height_in_blocks = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
+ (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ /* Size in samples */
+ compptr->downsampled_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
+ (long) cinfo->max_h_samp_factor);
+ compptr->downsampled_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
+ (long) cinfo->max_v_samp_factor);
+ /* Mark component needed (this flag isn't actually used for compression) */
+ compptr->component_needed = TRUE;
+ }
+
+ /* Compute number of fully interleaved MCU rows (number of times that
+ * main controller will call coefficient controller).
+ */
+ cinfo->total_iMCU_rows = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height,
+ (long) (cinfo->max_v_samp_factor*DCTSIZE));
+}
+
+
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+
+LOCAL(void)
+validate_script (j_compress_ptr cinfo)
+/* Verify that the scan script in cinfo->scan_info[] is valid; also
+ * determine whether it uses progressive JPEG, and set cinfo->progressive_mode.
+ */
+{
+ const jpeg_scan_info * scanptr;
+ int scanno, ncomps, ci, coefi, thisi;
+ int Ss, Se, Ah, Al;
+ boolean component_sent[MAX_COMPONENTS];
+#ifdef C_PROGRESSIVE_SUPPORTED
+ int * last_bitpos_ptr;
+ int last_bitpos[MAX_COMPONENTS][DCTSIZE2];
+ /* -1 until that coefficient has been seen; then last Al for it */
+#endif
+
+ if (cinfo->num_scans <= 0)
+ ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);
+
+ /* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;
+ * for progressive JPEG, no scan can have this.
+ */
+ scanptr = cinfo->scan_info;
+ if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+ cinfo->progressive_mode = TRUE;
+ last_bitpos_ptr = & last_bitpos[0][0];
+ for (ci = 0; ci < cinfo->num_components; ci++)
+ for (coefi = 0; coefi < DCTSIZE2; coefi++)
+ *last_bitpos_ptr++ = -1;
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ cinfo->progressive_mode = FALSE;
+ for (ci = 0; ci < cinfo->num_components; ci++)
+ component_sent[ci] = FALSE;
+ }
+
+ for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) {
+ /* Validate component indexes */
+ ncomps = scanptr->comps_in_scan;
+ if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN);
+ for (ci = 0; ci < ncomps; ci++) {
+ thisi = scanptr->component_index[ci];
+ if (thisi < 0 || thisi >= cinfo->num_components)
+ ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
+ /* Components must appear in SOF order within each scan */
+ if (ci > 0 && thisi <= scanptr->component_index[ci-1])
+ ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
+ }
+ /* Validate progression parameters */
+ Ss = scanptr->Ss;
+ Se = scanptr->Se;
+ Ah = scanptr->Ah;
+ Al = scanptr->Al;
+ if (cinfo->progressive_mode) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+ /* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that
+ * seems wrong: the upper bound ought to depend on data precision.
+ * Perhaps they really meant 0..N+1 for N-bit precision.
+ * Here we allow 0..10 for 8-bit data; Al larger than 10 results in
+ * out-of-range reconstructed DC values during the first DC scan,
+ * which might cause problems for some decoders.
+ */
+#if BITS_IN_JSAMPLE == 8
+#define MAX_AH_AL 10
+#else
+#define MAX_AH_AL 13
+#endif
+ if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||
+ Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL)
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ if (Ss == 0) {
+ if (Se != 0) /* DC and AC together not OK */
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ } else {
+ if (ncomps != 1) /* AC scans must be for only one component */
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ }
+ for (ci = 0; ci < ncomps; ci++) {
+ last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0];
+ if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ for (coefi = Ss; coefi <= Se; coefi++) {
+ if (last_bitpos_ptr[coefi] < 0) {
+ /* first scan of this coefficient */
+ if (Ah != 0)
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ } else {
+ /* not first scan */
+ if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1)
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ }
+ last_bitpos_ptr[coefi] = Al;
+ }
+ }
+#endif
+ } else {
+ /* For sequential JPEG, all progression parameters must be these: */
+ if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0)
+ ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);
+ /* Make sure components are not sent twice */
+ for (ci = 0; ci < ncomps; ci++) {
+ thisi = scanptr->component_index[ci];
+ if (component_sent[thisi])
+ ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);
+ component_sent[thisi] = TRUE;
+ }
+ }
+ }
+
+ /* Now verify that everything got sent. */
+ if (cinfo->progressive_mode) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+ /* For progressive mode, we only check that at least some DC data
+ * got sent for each component; the spec does not require that all bits
+ * of all coefficients be transmitted. Would it be wiser to enforce
+ * transmission of all coefficient bits??
+ */
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ if (last_bitpos[ci][0] < 0)
+ ERREXIT(cinfo, JERR_MISSING_DATA);
+ }
+#endif
+ } else {
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ if (! component_sent[ci])
+ ERREXIT(cinfo, JERR_MISSING_DATA);
+ }
+ }
+}
+
+#endif /* C_MULTISCAN_FILES_SUPPORTED */
+
+
+LOCAL(void)
+select_scan_parameters (j_compress_ptr cinfo)
+/* Set up the scan parameters for the current scan */
+{
+ int ci;
+
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+ if (cinfo->scan_info != NULL) {
+ /* Prepare for current scan --- the script is already validated */
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+ const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;
+
+ cinfo->comps_in_scan = scanptr->comps_in_scan;
+ for (ci = 0; ci < scanptr->comps_in_scan; ci++) {
+ cinfo->cur_comp_info[ci] =
+ &cinfo->comp_info[scanptr->component_index[ci]];
+ }
+ cinfo->Ss = scanptr->Ss;
+ cinfo->Se = scanptr->Se;
+ cinfo->Ah = scanptr->Ah;
+ cinfo->Al = scanptr->Al;
+ }
+ else
+#endif
+ {
+ /* Prepare for single sequential-JPEG scan containing all components */
+ if (cinfo->num_components > MAX_COMPS_IN_SCAN)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+ MAX_COMPS_IN_SCAN);
+ cinfo->comps_in_scan = cinfo->num_components;
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];
+ }
+ cinfo->Ss = 0;
+ cinfo->Se = DCTSIZE2-1;
+ cinfo->Ah = 0;
+ cinfo->Al = 0;
+ }
+}
+
+
+LOCAL(void)
+per_scan_setup (j_compress_ptr cinfo)
+/* Do computations that are needed before processing a JPEG scan */
+/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */
+{
+ int ci, mcublks, tmp;
+ jpeg_component_info *compptr;
+
+ if (cinfo->comps_in_scan == 1) {
+
+ /* Noninterleaved (single-component) scan */
+ compptr = cinfo->cur_comp_info[0];
+
+ /* Overall image size in MCUs */
+ cinfo->MCUs_per_row = compptr->width_in_blocks;
+ cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
+
+ /* For noninterleaved scan, always one block per MCU */
+ compptr->MCU_width = 1;
+ compptr->MCU_height = 1;
+ compptr->MCU_blocks = 1;
+ compptr->MCU_sample_width = DCTSIZE;
+ compptr->last_col_width = 1;
+ /* For noninterleaved scans, it is convenient to define last_row_height
+ * as the number of block rows present in the last iMCU row.
+ */
+ tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
+ if (tmp == 0) tmp = compptr->v_samp_factor;
+ compptr->last_row_height = tmp;
+
+ /* Prepare array describing MCU composition */
+ cinfo->blocks_in_MCU = 1;
+ cinfo->MCU_membership[0] = 0;
+
+ } else {
+
+ /* Interleaved (multi-component) scan */
+ if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
+ MAX_COMPS_IN_SCAN);
+
+ /* Overall image size in MCUs */
+ cinfo->MCUs_per_row = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width,
+ (long) (cinfo->max_h_samp_factor*DCTSIZE));
+ cinfo->MCU_rows_in_scan = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height,
+ (long) (cinfo->max_v_samp_factor*DCTSIZE));
+
+ cinfo->blocks_in_MCU = 0;
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Sampling factors give # of blocks of component in each MCU */
+ compptr->MCU_width = compptr->h_samp_factor;
+ compptr->MCU_height = compptr->v_samp_factor;
+ compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
+ compptr->MCU_sample_width = compptr->MCU_width * DCTSIZE;
+ /* Figure number of non-dummy blocks in last MCU column & row */
+ tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
+ if (tmp == 0) tmp = compptr->MCU_width;
+ compptr->last_col_width = tmp;
+ tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
+ if (tmp == 0) tmp = compptr->MCU_height;
+ compptr->last_row_height = tmp;
+ /* Prepare array describing MCU composition */
+ mcublks = compptr->MCU_blocks;
+ if (cinfo->blocks_in_MCU + mcublks > C_MAX_BLOCKS_IN_MCU)
+ ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
+ while (mcublks-- > 0) {
+ cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
+ }
+ }
+
+ }
+
+ /* Convert restart specified in rows to actual MCU count. */
+ /* Note that count must fit in 16 bits, so we provide limiting. */
+ if (cinfo->restart_in_rows > 0) {
+ long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;
+ cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L);
+ }
+}
+
+
+/*
+ * Per-pass setup.
+ * This is called at the beginning of each pass. We determine which modules
+ * will be active during this pass and give them appropriate start_pass calls.
+ * We also set is_last_pass to indicate whether any more passes will be
+ * required.
+ */
+
+METHODDEF(void)
+prepare_for_pass (j_compress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+
+ switch (master->pass_type) {
+ case main_pass:
+ /* Initial pass: will collect input data, and do either Huffman
+ * optimization or data output for the first scan.
+ */
+ select_scan_parameters(cinfo);
+ per_scan_setup(cinfo);
+ if (! cinfo->raw_data_in) {
+ (*cinfo->cconvert->start_pass) (cinfo);
+ (*cinfo->downsample->start_pass) (cinfo);
+ (*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);
+ }
+ (*cinfo->fdct->start_pass) (cinfo);
+ (*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);
+ (*cinfo->coef->start_pass) (cinfo,
+ (master->total_passes > 1 ?
+ JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
+ (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
+ if (cinfo->optimize_coding) {
+ /* No immediate data output; postpone writing frame/scan headers */
+ master->pub.call_pass_startup = FALSE;
+ } else {
+ /* Will write frame/scan headers at first jpeg_write_scanlines call */
+ master->pub.call_pass_startup = TRUE;
+ }
+ break;
+#ifdef ENTROPY_OPT_SUPPORTED
+ case huff_opt_pass:
+ /* Do Huffman optimization for a scan after the first one. */
+ select_scan_parameters(cinfo);
+ per_scan_setup(cinfo);
+ if (cinfo->Ss != 0 || cinfo->Ah == 0 || cinfo->arith_code) {
+ (*cinfo->entropy->start_pass) (cinfo, TRUE);
+ (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
+ master->pub.call_pass_startup = FALSE;
+ break;
+ }
+ /* Special case: Huffman DC refinement scans need no Huffman table
+ * and therefore we can skip the optimization pass for them.
+ */
+ master->pass_type = output_pass;
+ master->pass_number++;
+ /*FALLTHROUGH*/
+#endif
+ case output_pass:
+ /* Do a data-output pass. */
+ /* We need not repeat per-scan setup if prior optimization pass did it. */
+ if (! cinfo->optimize_coding) {
+ select_scan_parameters(cinfo);
+ per_scan_setup(cinfo);
+ }
+ (*cinfo->entropy->start_pass) (cinfo, FALSE);
+ (*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);
+ /* We emit frame/scan headers now */
+ if (master->scan_number == 0)
+ (*cinfo->marker->write_frame_header) (cinfo);
+ (*cinfo->marker->write_scan_header) (cinfo);
+ master->pub.call_pass_startup = FALSE;
+ break;
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ }
+
+ master->pub.is_last_pass = (master->pass_number == master->total_passes-1);
+
+ /* Set up progress monitor's pass info if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->completed_passes = master->pass_number;
+ cinfo->progress->total_passes = master->total_passes;
+ }
+}
+
+
+/*
+ * Special start-of-pass hook.
+ * This is called by jpeg_write_scanlines if call_pass_startup is TRUE.
+ * In single-pass processing, we need this hook because we don't want to
+ * write frame/scan headers during jpeg_start_compress; we want to let the
+ * application write COM markers etc. between jpeg_start_compress and the
+ * jpeg_write_scanlines loop.
+ * In multi-pass processing, this routine is not used.
+ */
+
+METHODDEF(void)
+pass_startup (j_compress_ptr cinfo)
+{
+ cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */
+
+ (*cinfo->marker->write_frame_header) (cinfo);
+ (*cinfo->marker->write_scan_header) (cinfo);
+}
+
+
+/*
+ * Finish up at end of pass.
+ */
+
+METHODDEF(void)
+finish_pass_master (j_compress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+
+ /* The entropy coder always needs an end-of-pass call,
+ * either to analyze statistics or to flush its output buffer.
+ */
+ (*cinfo->entropy->finish_pass) (cinfo);
+
+ /* Update state for next pass */
+ switch (master->pass_type) {
+ case main_pass:
+ /* next pass is either output of scan 0 (after optimization)
+ * or output of scan 1 (if no optimization).
+ */
+ master->pass_type = output_pass;
+ if (! cinfo->optimize_coding)
+ master->scan_number++;
+ break;
+ case huff_opt_pass:
+ /* next pass is always output of current scan */
+ master->pass_type = output_pass;
+ break;
+ case output_pass:
+ /* next pass is either optimization or output of next scan */
+ if (cinfo->optimize_coding)
+ master->pass_type = huff_opt_pass;
+ master->scan_number++;
+ break;
+ }
+
+ master->pass_number++;
+}
+
+
+/*
+ * Initialize master compression control.
+ */
+
+GLOBAL(void)
+jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only)
+{
+ my_master_ptr master;
+
+ master = (my_master_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_comp_master));
+ cinfo->master = (struct jpeg_comp_master *) master;
+ master->pub.prepare_for_pass = prepare_for_pass;
+ master->pub.pass_startup = pass_startup;
+ master->pub.finish_pass = finish_pass_master;
+ master->pub.is_last_pass = FALSE;
+
+ /* Validate parameters, determine derived values */
+ initial_setup(cinfo);
+
+ if (cinfo->scan_info != NULL) {
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+ validate_script(cinfo);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ cinfo->progressive_mode = FALSE;
+ cinfo->num_scans = 1;
+ }
+
+ if (cinfo->progressive_mode) /* TEMPORARY HACK ??? */
+ cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
+
+ /* Initialize my private state */
+ if (transcode_only) {
+ /* no main pass in transcoding */
+ if (cinfo->optimize_coding)
+ master->pass_type = huff_opt_pass;
+ else
+ master->pass_type = output_pass;
+ } else {
+ /* for normal compression, first pass is always this type: */
+ master->pass_type = main_pass;
+ }
+ master->scan_number = 0;
+ master->pass_number = 0;
+ if (cinfo->optimize_coding)
+ master->total_passes = cinfo->num_scans * 2;
+ else
+ master->total_passes = cinfo->num_scans;
+}
--- /dev/null
+/*
+ * jcomapi.c
+ *
+ * Copyright (C) 1994-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface routines that are used for both
+ * compression and decompression.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * Abort processing of a JPEG compression or decompression operation,
+ * but don't destroy the object itself.
+ *
+ * For this, we merely clean up all the nonpermanent memory pools.
+ * Note that temp files (virtual arrays) are not allowed to belong to
+ * the permanent pool, so we will be able to close all temp files here.
+ * Closing a data source or destination, if necessary, is the application's
+ * responsibility.
+ */
+
+GLOBAL(void)
+jpeg_abort (j_common_ptr cinfo)
+{
+ int pool;
+
+ /* Do nothing if called on a not-initialized or destroyed JPEG object. */
+ if (cinfo->mem == NULL)
+ return;
+
+ /* Releasing pools in reverse order might help avoid fragmentation
+ * with some (brain-damaged) malloc libraries.
+ */
+ for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
+ (*cinfo->mem->free_pool) (cinfo, pool);
+ }
+
+ /* Reset overall state for possible reuse of object */
+ if (cinfo->is_decompressor) {
+ cinfo->global_state = DSTATE_START;
+ /* Try to keep application from accessing now-deleted marker list.
+ * A bit kludgy to do it here, but this is the most central place.
+ */
+ ((j_decompress_ptr) cinfo)->marker_list = NULL;
+ } else {
+ cinfo->global_state = CSTATE_START;
+ }
+}
+
+
+/*
+ * Destruction of a JPEG object.
+ *
+ * Everything gets deallocated except the master jpeg_compress_struct itself
+ * and the error manager struct. Both of these are supplied by the application
+ * and must be freed, if necessary, by the application. (Often they are on
+ * the stack and so don't need to be freed anyway.)
+ * Closing a data source or destination, if necessary, is the application's
+ * responsibility.
+ */
+
+GLOBAL(void)
+jpeg_destroy (j_common_ptr cinfo)
+{
+ /* We need only tell the memory manager to release everything. */
+ /* NB: mem pointer is NULL if memory mgr failed to initialize. */
+ if (cinfo->mem != NULL)
+ (*cinfo->mem->self_destruct) (cinfo);
+ cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */
+ cinfo->global_state = 0; /* mark it destroyed */
+}
+
+
+/*
+ * Convenience routines for allocating quantization and Huffman tables.
+ * (Would jutils.c be a more reasonable place to put these?)
+ */
+
+GLOBAL(JQUANT_TBL *)
+jpeg_alloc_quant_table (j_common_ptr cinfo)
+{
+ JQUANT_TBL *tbl;
+
+ tbl = (JQUANT_TBL *)
+ (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
+ tbl->sent_table = FALSE; /* make sure this is false in any new table */
+ return tbl;
+}
+
+
+GLOBAL(JHUFF_TBL *)
+jpeg_alloc_huff_table (j_common_ptr cinfo)
+{
+ JHUFF_TBL *tbl;
+
+ tbl = (JHUFF_TBL *)
+ (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
+ tbl->sent_table = FALSE; /* make sure this is false in any new table */
+ return tbl;
+}
--- /dev/null
+/*
+ * jcparam.c
+ *
+ * Copyright (C) 1991-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains optional default-setting code for the JPEG compressor.
+ * Applications do not have to use this file, but those that don't use it
+ * must know a lot more about the innards of the JPEG code.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * Quantization table setup routines
+ */
+
+GLOBAL(void)
+jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,
+ const unsigned int *basic_table,
+ int scale_factor, boolean force_baseline)
+/* Define a quantization table equal to the basic_table times
+ * a scale factor (given as a percentage).
+ * If force_baseline is TRUE, the computed quantization table entries
+ * are limited to 1..255 for JPEG baseline compatibility.
+ */
+{
+ JQUANT_TBL ** qtblptr;
+ int i;
+ long temp;
+
+ /* Safety check to ensure start_compress not called yet. */
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ if (which_tbl < 0 || which_tbl >= NUM_QUANT_TBLS)
+ ERREXIT1(cinfo, JERR_DQT_INDEX, which_tbl);
+
+ qtblptr = & cinfo->quant_tbl_ptrs[which_tbl];
+
+ if (*qtblptr == NULL)
+ *qtblptr = jpeg_alloc_quant_table((j_common_ptr) cinfo);
+
+ for (i = 0; i < DCTSIZE2; i++) {
+ temp = ((long) basic_table[i] * scale_factor + 50L) / 100L;
+ /* limit the values to the valid range */
+ if (temp <= 0L) temp = 1L;
+ if (temp > 32767L) temp = 32767L; /* max quantizer needed for 12 bits */
+ if (force_baseline && temp > 255L)
+ temp = 255L; /* limit to baseline range if requested */
+ (*qtblptr)->quantval[i] = (UINT16) temp;
+ }
+
+ /* Initialize sent_table FALSE so table will be written to JPEG file. */
+ (*qtblptr)->sent_table = FALSE;
+}
+
+
+GLOBAL(void)
+jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor,
+ boolean force_baseline)
+/* Set or change the 'quality' (quantization) setting, using default tables
+ * and a straight percentage-scaling quality scale. In most cases it's better
+ * to use jpeg_set_quality (below); this entry point is provided for
+ * applications that insist on a linear percentage scaling.
+ */
+{
+ /* These are the sample quantization tables given in JPEG spec section K.1.
+ * The spec says that the values given produce "good" quality, and
+ * when divided by 2, "very good" quality.
+ */
+ static const unsigned int std_luminance_quant_tbl[DCTSIZE2] = {
+ 16, 11, 10, 16, 24, 40, 51, 61,
+ 12, 12, 14, 19, 26, 58, 60, 55,
+ 14, 13, 16, 24, 40, 57, 69, 56,
+ 14, 17, 22, 29, 51, 87, 80, 62,
+ 18, 22, 37, 56, 68, 109, 103, 77,
+ 24, 35, 55, 64, 81, 104, 113, 92,
+ 49, 64, 78, 87, 103, 121, 120, 101,
+ 72, 92, 95, 98, 112, 100, 103, 99
+ };
+ static const unsigned int std_chrominance_quant_tbl[DCTSIZE2] = {
+ 17, 18, 24, 47, 99, 99, 99, 99,
+ 18, 21, 26, 66, 99, 99, 99, 99,
+ 24, 26, 56, 99, 99, 99, 99, 99,
+ 47, 66, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99,
+ 99, 99, 99, 99, 99, 99, 99, 99
+ };
+
+ /* Set up two quantization tables using the specified scaling */
+ jpeg_add_quant_table(cinfo, 0, std_luminance_quant_tbl,
+ scale_factor, force_baseline);
+ jpeg_add_quant_table(cinfo, 1, std_chrominance_quant_tbl,
+ scale_factor, force_baseline);
+}
+
+
+GLOBAL(int)
+jpeg_quality_scaling (int quality)
+/* Convert a user-specified quality rating to a percentage scaling factor
+ * for an underlying quantization table, using our recommended scaling curve.
+ * The input 'quality' factor should be 0 (terrible) to 100 (very good).
+ */
+{
+ /* Safety limit on quality factor. Convert 0 to 1 to avoid zero divide. */
+ if (quality <= 0) quality = 1;
+ if (quality > 100) quality = 100;
+
+ /* The basic table is used as-is (scaling 100) for a quality of 50.
+ * Qualities 50..100 are converted to scaling percentage 200 - 2*Q;
+ * note that at Q=100 the scaling is 0, which will cause jpeg_add_quant_table
+ * to make all the table entries 1 (hence, minimum quantization loss).
+ * Qualities 1..50 are converted to scaling percentage 5000/Q.
+ */
+ if (quality < 50)
+ quality = 5000 / quality;
+ else
+ quality = 200 - quality*2;
+
+ return quality;
+}
+
+
+GLOBAL(void)
+jpeg_set_quality (j_compress_ptr cinfo, int quality, boolean force_baseline)
+/* Set or change the 'quality' (quantization) setting, using default tables.
+ * This is the standard quality-adjusting entry point for typical user
+ * interfaces; only those who want detailed control over quantization tables
+ * would use the preceding three routines directly.
+ */
+{
+ /* Convert user 0-100 rating to percentage scaling */
+ quality = jpeg_quality_scaling(quality);
+
+ /* Set up standard quality tables */
+ jpeg_set_linear_quality(cinfo, quality, force_baseline);
+}
+
+
+/*
+ * Huffman table setup routines
+ */
+
+LOCAL(void)
+add_huff_table (j_compress_ptr cinfo,
+ JHUFF_TBL **htblptr, const UINT8 *bits, const UINT8 *val)
+/* Define a Huffman table */
+{
+ int nsymbols, len;
+
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+
+ /* Copy the number-of-symbols-of-each-code-length counts */
+ MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
+
+ /* Validate the counts. We do this here mainly so we can copy the right
+ * number of symbols from the val[] array, without risking marching off
+ * the end of memory. jchuff.c will do a more thorough test later.
+ */
+ nsymbols = 0;
+ for (len = 1; len <= 16; len++)
+ nsymbols += bits[len];
+ if (nsymbols < 1 || nsymbols > 256)
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+
+ MEMCOPY((*htblptr)->huffval, val, nsymbols * SIZEOF(UINT8));
+
+ /* Initialize sent_table FALSE so table will be written to JPEG file. */
+ (*htblptr)->sent_table = FALSE;
+}
+
+
+LOCAL(void)
+std_huff_tables (j_compress_ptr cinfo)
+/* Set up the standard Huffman tables (cf. JPEG standard section K.3) */
+/* IMPORTANT: these are only valid for 8-bit data precision! */
+{
+ static const UINT8 bits_dc_luminance[17] =
+ { /* 0-base */ 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0 };
+ static const UINT8 val_dc_luminance[] =
+ { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
+
+ static const UINT8 bits_dc_chrominance[17] =
+ { /* 0-base */ 0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0 };
+ static const UINT8 val_dc_chrominance[] =
+ { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
+
+ static const UINT8 bits_ac_luminance[17] =
+ { /* 0-base */ 0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d };
+ static const UINT8 val_ac_luminance[] =
+ { 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
+ 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
+ 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
+ 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
+ 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
+ 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
+ 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+ 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
+ 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+ 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
+ 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
+ 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
+ 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
+ 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+ 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
+ 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
+ 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
+ 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
+ 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
+ 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
+ 0xf9, 0xfa };
+
+ static const UINT8 bits_ac_chrominance[17] =
+ { /* 0-base */ 0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77 };
+ static const UINT8 val_ac_chrominance[] =
+ { 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
+ 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
+ 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
+ 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
+ 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
+ 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
+ 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
+ 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
+ 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
+ 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
+ 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+ 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
+ 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
+ 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
+ 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
+ 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
+ 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
+ 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
+ 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
+ 0xf9, 0xfa };
+
+ add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[0],
+ bits_dc_luminance, val_dc_luminance);
+ add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[0],
+ bits_ac_luminance, val_ac_luminance);
+ add_huff_table(cinfo, &cinfo->dc_huff_tbl_ptrs[1],
+ bits_dc_chrominance, val_dc_chrominance);
+ add_huff_table(cinfo, &cinfo->ac_huff_tbl_ptrs[1],
+ bits_ac_chrominance, val_ac_chrominance);
+}
+
+
+/*
+ * Default parameter setup for compression.
+ *
+ * Applications that don't choose to use this routine must do their
+ * own setup of all these parameters. Alternately, you can call this
+ * to establish defaults and then alter parameters selectively. This
+ * is the recommended approach since, if we add any new parameters,
+ * your code will still work (they'll be set to reasonable defaults).
+ */
+
+GLOBAL(void)
+jpeg_set_defaults (j_compress_ptr cinfo)
+{
+ int i;
+
+ /* Safety check to ensure start_compress not called yet. */
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ /* Allocate comp_info array large enough for maximum component count.
+ * Array is made permanent in case application wants to compress
+ * multiple images at same param settings.
+ */
+ if (cinfo->comp_info == NULL)
+ cinfo->comp_info = (jpeg_component_info *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ MAX_COMPONENTS * SIZEOF(jpeg_component_info));
+
+ /* Initialize everything not dependent on the color space */
+
+ cinfo->data_precision = BITS_IN_JSAMPLE;
+ /* Set up two quantization tables using default quality of 75 */
+ jpeg_set_quality(cinfo, 75, TRUE);
+ /* Set up two Huffman tables */
+ std_huff_tables(cinfo);
+
+ /* Initialize default arithmetic coding conditioning */
+ for (i = 0; i < NUM_ARITH_TBLS; i++) {
+ cinfo->arith_dc_L[i] = 0;
+ cinfo->arith_dc_U[i] = 1;
+ cinfo->arith_ac_K[i] = 5;
+ }
+
+ /* Default is no multiple-scan output */
+ cinfo->scan_info = NULL;
+ cinfo->num_scans = 0;
+
+ /* Expect normal source image, not raw downsampled data */
+ cinfo->raw_data_in = FALSE;
+
+ /* Use Huffman coding, not arithmetic coding, by default */
+ cinfo->arith_code = FALSE;
+
+ /* By default, don't do extra passes to optimize entropy coding */
+ cinfo->optimize_coding = FALSE;
+ /* The standard Huffman tables are only valid for 8-bit data precision.
+ * If the precision is higher, force optimization on so that usable
+ * tables will be computed. This test can be removed if default tables
+ * are supplied that are valid for the desired precision.
+ */
+ if (cinfo->data_precision > 8)
+ cinfo->optimize_coding = TRUE;
+
+ /* By default, use the simpler non-cosited sampling alignment */
+ cinfo->CCIR601_sampling = FALSE;
+
+ /* No input smoothing */
+ cinfo->smoothing_factor = 0;
+
+ /* DCT algorithm preference */
+ cinfo->dct_method = JDCT_DEFAULT;
+
+ /* No restart markers */
+ cinfo->restart_interval = 0;
+ cinfo->restart_in_rows = 0;
+
+ /* Fill in default JFIF marker parameters. Note that whether the marker
+ * will actually be written is determined by jpeg_set_colorspace.
+ *
+ * By default, the library emits JFIF version code 1.01.
+ * An application that wants to emit JFIF 1.02 extension markers should set
+ * JFIF_minor_version to 2. We could probably get away with just defaulting
+ * to 1.02, but there may still be some decoders in use that will complain
+ * about that; saying 1.01 should minimize compatibility problems.
+ */
+ cinfo->JFIF_major_version = 1; /* Default JFIF version = 1.01 */
+ cinfo->JFIF_minor_version = 1;
+ cinfo->density_unit = 0; /* Pixel size is unknown by default */
+ cinfo->X_density = 1; /* Pixel aspect ratio is square by default */
+ cinfo->Y_density = 1;
+
+ /* Choose JPEG colorspace based on input space, set defaults accordingly */
+
+ jpeg_default_colorspace(cinfo);
+}
+
+
+/*
+ * Select an appropriate JPEG colorspace for in_color_space.
+ */
+
+GLOBAL(void)
+jpeg_default_colorspace (j_compress_ptr cinfo)
+{
+ switch (cinfo->in_color_space) {
+ case JCS_GRAYSCALE:
+ jpeg_set_colorspace(cinfo, JCS_GRAYSCALE);
+ break;
+ case JCS_RGB:
+ jpeg_set_colorspace(cinfo, JCS_YCbCr);
+ break;
+ case JCS_YCbCr:
+ jpeg_set_colorspace(cinfo, JCS_YCbCr);
+ break;
+ case JCS_CMYK:
+ jpeg_set_colorspace(cinfo, JCS_CMYK); /* By default, no translation */
+ break;
+ case JCS_YCCK:
+ jpeg_set_colorspace(cinfo, JCS_YCCK);
+ break;
+ case JCS_UNKNOWN:
+ jpeg_set_colorspace(cinfo, JCS_UNKNOWN);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
+ }
+}
+
+
+/*
+ * Set the JPEG colorspace, and choose colorspace-dependent default values.
+ */
+
+GLOBAL(void)
+jpeg_set_colorspace (j_compress_ptr cinfo, J_COLOR_SPACE colorspace)
+{
+ jpeg_component_info * compptr;
+ int ci;
+
+#define SET_COMP(index,id,hsamp,vsamp,quant,dctbl,actbl) \
+ (compptr = &cinfo->comp_info[index], \
+ compptr->component_id = (id), \
+ compptr->h_samp_factor = (hsamp), \
+ compptr->v_samp_factor = (vsamp), \
+ compptr->quant_tbl_no = (quant), \
+ compptr->dc_tbl_no = (dctbl), \
+ compptr->ac_tbl_no = (actbl) )
+
+ /* Safety check to ensure start_compress not called yet. */
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ /* For all colorspaces, we use Q and Huff tables 0 for luminance components,
+ * tables 1 for chrominance components.
+ */
+
+ cinfo->jpeg_color_space = colorspace;
+
+ cinfo->write_JFIF_header = FALSE; /* No marker for non-JFIF colorspaces */
+ cinfo->write_Adobe_marker = FALSE; /* write no Adobe marker by default */
+
+ switch (colorspace) {
+ case JCS_GRAYSCALE:
+ cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
+ cinfo->num_components = 1;
+ /* JFIF specifies component ID 1 */
+ SET_COMP(0, 1, 1,1, 0, 0,0);
+ break;
+ case JCS_RGB:
+ cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag RGB */
+ cinfo->num_components = 3;
+ SET_COMP(0, 0x52 /* 'R' */, 1,1, 0, 0,0);
+ SET_COMP(1, 0x47 /* 'G' */, 1,1, 0, 0,0);
+ SET_COMP(2, 0x42 /* 'B' */, 1,1, 0, 0,0);
+ break;
+ case JCS_YCbCr:
+ cinfo->write_JFIF_header = TRUE; /* Write a JFIF marker */
+ cinfo->num_components = 3;
+ /* JFIF specifies component IDs 1,2,3 */
+ /* We default to 2x2 subsamples of chrominance */
+ SET_COMP(0, 1, 2,2, 0, 0,0);
+ SET_COMP(1, 2, 1,1, 1, 1,1);
+ SET_COMP(2, 3, 1,1, 1, 1,1);
+ break;
+ case JCS_CMYK:
+ cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag CMYK */
+ cinfo->num_components = 4;
+ SET_COMP(0, 0x43 /* 'C' */, 1,1, 0, 0,0);
+ SET_COMP(1, 0x4D /* 'M' */, 1,1, 0, 0,0);
+ SET_COMP(2, 0x59 /* 'Y' */, 1,1, 0, 0,0);
+ SET_COMP(3, 0x4B /* 'K' */, 1,1, 0, 0,0);
+ break;
+ case JCS_YCCK:
+ cinfo->write_Adobe_marker = TRUE; /* write Adobe marker to flag YCCK */
+ cinfo->num_components = 4;
+ SET_COMP(0, 1, 2,2, 0, 0,0);
+ SET_COMP(1, 2, 1,1, 1, 1,1);
+ SET_COMP(2, 3, 1,1, 1, 1,1);
+ SET_COMP(3, 4, 2,2, 0, 0,0);
+ break;
+ case JCS_UNKNOWN:
+ cinfo->num_components = cinfo->input_components;
+ if (cinfo->num_components < 1 || cinfo->num_components > MAX_COMPONENTS)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+ MAX_COMPONENTS);
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ SET_COMP(ci, ci, 1,1, 0, 0,0);
+ }
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ }
+}
+
+
+#ifdef C_PROGRESSIVE_SUPPORTED
+
+LOCAL(jpeg_scan_info *)
+fill_a_scan (jpeg_scan_info * scanptr, int ci,
+ int Ss, int Se, int Ah, int Al)
+/* Support routine: generate one scan for specified component */
+{
+ scanptr->comps_in_scan = 1;
+ scanptr->component_index[0] = ci;
+ scanptr->Ss = Ss;
+ scanptr->Se = Se;
+ scanptr->Ah = Ah;
+ scanptr->Al = Al;
+ scanptr++;
+ return scanptr;
+}
+
+LOCAL(jpeg_scan_info *)
+fill_scans (jpeg_scan_info * scanptr, int ncomps,
+ int Ss, int Se, int Ah, int Al)
+/* Support routine: generate one scan for each component */
+{
+ int ci;
+
+ for (ci = 0; ci < ncomps; ci++) {
+ scanptr->comps_in_scan = 1;
+ scanptr->component_index[0] = ci;
+ scanptr->Ss = Ss;
+ scanptr->Se = Se;
+ scanptr->Ah = Ah;
+ scanptr->Al = Al;
+ scanptr++;
+ }
+ return scanptr;
+}
+
+LOCAL(jpeg_scan_info *)
+fill_dc_scans (jpeg_scan_info * scanptr, int ncomps, int Ah, int Al)
+/* Support routine: generate interleaved DC scan if possible, else N scans */
+{
+ int ci;
+
+ if (ncomps <= MAX_COMPS_IN_SCAN) {
+ /* Single interleaved DC scan */
+ scanptr->comps_in_scan = ncomps;
+ for (ci = 0; ci < ncomps; ci++)
+ scanptr->component_index[ci] = ci;
+ scanptr->Ss = scanptr->Se = 0;
+ scanptr->Ah = Ah;
+ scanptr->Al = Al;
+ scanptr++;
+ } else {
+ /* Noninterleaved DC scan for each component */
+ scanptr = fill_scans(scanptr, ncomps, 0, 0, Ah, Al);
+ }
+ return scanptr;
+}
+
+
+/*
+ * Create a recommended progressive-JPEG script.
+ * cinfo->num_components and cinfo->jpeg_color_space must be correct.
+ */
+
+GLOBAL(void)
+jpeg_simple_progression (j_compress_ptr cinfo)
+{
+ int ncomps = cinfo->num_components;
+ int nscans;
+ jpeg_scan_info * scanptr;
+
+ /* Safety check to ensure start_compress not called yet. */
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ /* Figure space needed for script. Calculation must match code below! */
+ if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
+ /* Custom script for YCbCr color images. */
+ nscans = 10;
+ } else {
+ /* All-purpose script for other color spaces. */
+ if (ncomps > MAX_COMPS_IN_SCAN)
+ nscans = 6 * ncomps; /* 2 DC + 4 AC scans per component */
+ else
+ nscans = 2 + 4 * ncomps; /* 2 DC scans; 4 AC scans per component */
+ }
+
+ /* Allocate space for script.
+ * We need to put it in the permanent pool in case the application performs
+ * multiple compressions without changing the settings. To avoid a memory
+ * leak if jpeg_simple_progression is called repeatedly for the same JPEG
+ * object, we try to re-use previously allocated space, and we allocate
+ * enough space to handle YCbCr even if initially asked for grayscale.
+ */
+ if (cinfo->script_space == NULL || cinfo->script_space_size < nscans) {
+ cinfo->script_space_size = MAX(nscans, 10);
+ cinfo->script_space = (jpeg_scan_info *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ cinfo->script_space_size * SIZEOF(jpeg_scan_info));
+ }
+ scanptr = cinfo->script_space;
+ cinfo->scan_info = scanptr;
+ cinfo->num_scans = nscans;
+
+ if (ncomps == 3 && cinfo->jpeg_color_space == JCS_YCbCr) {
+ /* Custom script for YCbCr color images. */
+ /* Initial DC scan */
+ scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
+ /* Initial AC scan: get some luma data out in a hurry */
+ scanptr = fill_a_scan(scanptr, 0, 1, 5, 0, 2);
+ /* Chroma data is too small to be worth expending many scans on */
+ scanptr = fill_a_scan(scanptr, 2, 1, 63, 0, 1);
+ scanptr = fill_a_scan(scanptr, 1, 1, 63, 0, 1);
+ /* Complete spectral selection for luma AC */
+ scanptr = fill_a_scan(scanptr, 0, 6, 63, 0, 2);
+ /* Refine next bit of luma AC */
+ scanptr = fill_a_scan(scanptr, 0, 1, 63, 2, 1);
+ /* Finish DC successive approximation */
+ scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
+ /* Finish AC successive approximation */
+ scanptr = fill_a_scan(scanptr, 2, 1, 63, 1, 0);
+ scanptr = fill_a_scan(scanptr, 1, 1, 63, 1, 0);
+ /* Luma bottom bit comes last since it's usually largest scan */
+ scanptr = fill_a_scan(scanptr, 0, 1, 63, 1, 0);
+ } else {
+ /* All-purpose script for other color spaces. */
+ /* Successive approximation first pass */
+ scanptr = fill_dc_scans(scanptr, ncomps, 0, 1);
+ scanptr = fill_scans(scanptr, ncomps, 1, 5, 0, 2);
+ scanptr = fill_scans(scanptr, ncomps, 6, 63, 0, 2);
+ /* Successive approximation second pass */
+ scanptr = fill_scans(scanptr, ncomps, 1, 63, 2, 1);
+ /* Successive approximation final pass */
+ scanptr = fill_dc_scans(scanptr, ncomps, 1, 0);
+ scanptr = fill_scans(scanptr, ncomps, 1, 63, 1, 0);
+ }
+}
+
+#endif /* C_PROGRESSIVE_SUPPORTED */
--- /dev/null
+/*
+ * jcphuff.c
+ *
+ * Copyright (C) 1995-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy encoding routines for progressive JPEG.
+ *
+ * We do not support output suspension in this module, since the library
+ * currently does not allow multiple-scan files to be written with output
+ * suspension.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jchuff12.h" /* Declarations shared with jchuff.c */
+
+#ifdef C_PROGRESSIVE_SUPPORTED
+
+/* Expanded entropy encoder object for progressive Huffman encoding. */
+
+typedef struct {
+ struct jpeg_entropy_encoder pub; /* public fields */
+
+ /* Mode flag: TRUE for optimization, FALSE for actual data output */
+ boolean gather_statistics;
+
+ /* Bit-level coding status.
+ * next_output_byte/free_in_buffer are local copies of cinfo->dest fields.
+ */
+ JOCTET * next_output_byte; /* => next byte to write in buffer */
+ size_t free_in_buffer; /* # of byte spaces remaining in buffer */
+ INT32 put_buffer; /* current bit-accumulation buffer */
+ int put_bits; /* # of bits now in it */
+ j_compress_ptr cinfo; /* link to cinfo (needed for dump_buffer) */
+
+ /* Coding status for DC components */
+ int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+
+ /* Coding status for AC components */
+ int ac_tbl_no; /* the table number of the single component */
+ unsigned int EOBRUN; /* run length of EOBs */
+ unsigned int BE; /* # of buffered correction bits before MCU */
+ char * bit_buffer; /* buffer for correction bits (1 per char) */
+ /* packing correction bits tightly would save some space but cost time... */
+
+ unsigned int restarts_to_go; /* MCUs left in this restart interval */
+ int next_restart_num; /* next restart number to write (0-7) */
+
+ /* Pointers to derived tables (these workspaces have image lifespan).
+ * Since any one scan codes only DC or only AC, we only need one set
+ * of tables, not one for DC and one for AC.
+ */
+ c_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
+
+ /* Statistics tables for optimization; again, one set is enough */
+ long * count_ptrs[NUM_HUFF_TBLS];
+} phuff_entropy_encoder;
+
+typedef phuff_entropy_encoder * phuff_entropy_ptr;
+
+/* MAX_CORR_BITS is the number of bits the AC refinement correction-bit
+ * buffer can hold. Larger sizes may slightly improve compression, but
+ * 1000 is already well into the realm of overkill.
+ * The minimum safe size is 64 bits.
+ */
+
+#define MAX_CORR_BITS 1000 /* Max # of correction bits I can buffer */
+
+/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32.
+ * We assume that int right shift is unsigned if INT32 right shift is,
+ * which should be safe.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define ISHIFT_TEMPS int ishift_temp;
+#define IRIGHT_SHIFT(x,shft) \
+ ((ishift_temp = (x)) < 0 ? \
+ (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \
+ (ishift_temp >> (shft)))
+#else
+#define ISHIFT_TEMPS
+#define IRIGHT_SHIFT(x,shft) ((x) >> (shft))
+#endif
+
+/* Forward declarations */
+METHODDEF(boolean) encode_mcu_DC_first JPP((j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(boolean) encode_mcu_AC_first JPP((j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(boolean) encode_mcu_DC_refine JPP((j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(boolean) encode_mcu_AC_refine JPP((j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(void) finish_pass_phuff JPP((j_compress_ptr cinfo));
+METHODDEF(void) finish_pass_gather_phuff JPP((j_compress_ptr cinfo));
+
+
+/*
+ * Initialize for a Huffman-compressed scan using progressive JPEG.
+ */
+
+METHODDEF(void)
+start_pass_phuff (j_compress_ptr cinfo, boolean gather_statistics)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ boolean is_DC_band;
+ int ci, tbl;
+ jpeg_component_info * compptr;
+
+ entropy->cinfo = cinfo;
+ entropy->gather_statistics = gather_statistics;
+
+ is_DC_band = (cinfo->Ss == 0);
+
+ /* We assume jcmaster.c already validated the scan parameters. */
+
+ /* Select execution routines */
+ if (cinfo->Ah == 0) {
+ if (is_DC_band)
+ entropy->pub.encode_mcu = encode_mcu_DC_first;
+ else
+ entropy->pub.encode_mcu = encode_mcu_AC_first;
+ } else {
+ if (is_DC_band)
+ entropy->pub.encode_mcu = encode_mcu_DC_refine;
+ else {
+ entropy->pub.encode_mcu = encode_mcu_AC_refine;
+ /* AC refinement needs a correction bit buffer */
+ if (entropy->bit_buffer == NULL)
+ entropy->bit_buffer = (char *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ MAX_CORR_BITS * SIZEOF(char));
+ }
+ }
+ if (gather_statistics)
+ entropy->pub.finish_pass = finish_pass_gather_phuff;
+ else
+ entropy->pub.finish_pass = finish_pass_phuff;
+
+ /* Only DC coefficients may be interleaved, so cinfo->comps_in_scan = 1
+ * for AC coefficients.
+ */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Initialize DC predictions to 0 */
+ entropy->last_dc_val[ci] = 0;
+ /* Get table index */
+ if (is_DC_band) {
+ if (cinfo->Ah != 0) /* DC refinement needs no table */
+ continue;
+ tbl = compptr->dc_tbl_no;
+ } else {
+ entropy->ac_tbl_no = tbl = compptr->ac_tbl_no;
+ }
+ if (gather_statistics) {
+ /* Check for invalid table index */
+ /* (make_c_derived_tbl does this in the other path) */
+ if (tbl < 0 || tbl >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl);
+ /* Allocate and zero the statistics tables */
+ /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
+ if (entropy->count_ptrs[tbl] == NULL)
+ entropy->count_ptrs[tbl] = (long *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ 257 * SIZEOF(long));
+ MEMZERO(entropy->count_ptrs[tbl], 257 * SIZEOF(long));
+ } else {
+ /* Compute derived values for Huffman table */
+ /* We may do this more than once for a table, but it's not expensive */
+ jpeg_make_c_derived_tbl(cinfo, is_DC_band, tbl,
+ & entropy->derived_tbls[tbl]);
+ }
+ }
+
+ /* Initialize AC stuff */
+ entropy->EOBRUN = 0;
+ entropy->BE = 0;
+
+ /* Initialize bit buffer to empty */
+ entropy->put_buffer = 0;
+ entropy->put_bits = 0;
+
+ /* Initialize restart stuff */
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num = 0;
+}
+
+
+/* Outputting bytes to the file.
+ * NB: these must be called only when actually outputting,
+ * that is, entropy->gather_statistics == FALSE.
+ */
+
+/* Emit a byte */
+#define emit_byte(entropy,val) \
+ { *(entropy)->next_output_byte++ = (JOCTET) (val); \
+ if (--(entropy)->free_in_buffer == 0) \
+ dump_buffer(entropy); }
+
+
+LOCAL(void)
+dump_buffer (phuff_entropy_ptr entropy)
+/* Empty the output buffer; we do not support suspension in this module. */
+{
+ struct jpeg_destination_mgr * dest = entropy->cinfo->dest;
+
+ if (! (*dest->empty_output_buffer) (entropy->cinfo))
+ ERREXIT(entropy->cinfo, JERR_CANT_SUSPEND);
+ /* After a successful buffer dump, must reset buffer pointers */
+ entropy->next_output_byte = dest->next_output_byte;
+ entropy->free_in_buffer = dest->free_in_buffer;
+}
+
+
+/* Outputting bits to the file */
+
+/* Only the right 24 bits of put_buffer are used; the valid bits are
+ * left-justified in this part. At most 16 bits can be passed to emit_bits
+ * in one call, and we never retain more than 7 bits in put_buffer
+ * between calls, so 24 bits are sufficient.
+ */
+
+INLINE
+LOCAL(void)
+emit_bits (phuff_entropy_ptr entropy, unsigned int code, int size)
+/* Emit some bits, unless we are in gather mode */
+{
+ /* This routine is heavily used, so it's worth coding tightly. */
+ register INT32 put_buffer = (INT32) code;
+ register int put_bits = entropy->put_bits;
+
+ /* if size is 0, caller used an invalid Huffman table entry */
+ if (size == 0)
+ ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE);
+
+ if (entropy->gather_statistics)
+ return; /* do nothing if we're only getting stats */
+
+ put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */
+
+ put_bits += size; /* new number of bits in buffer */
+
+ put_buffer <<= 24 - put_bits; /* align incoming bits */
+
+ put_buffer |= entropy->put_buffer; /* and merge with old buffer contents */
+
+ while (put_bits >= 8) {
+ int c = (int) ((put_buffer >> 16) & 0xFF);
+
+ emit_byte(entropy, c);
+ if (c == 0xFF) { /* need to stuff a zero byte? */
+ emit_byte(entropy, 0);
+ }
+ put_buffer <<= 8;
+ put_bits -= 8;
+ }
+
+ entropy->put_buffer = put_buffer; /* update variables */
+ entropy->put_bits = put_bits;
+}
+
+
+LOCAL(void)
+flush_bits (phuff_entropy_ptr entropy)
+{
+ emit_bits(entropy, 0x7F, 7); /* fill any partial byte with ones */
+ entropy->put_buffer = 0; /* and reset bit-buffer to empty */
+ entropy->put_bits = 0;
+}
+
+
+/*
+ * Emit (or just count) a Huffman symbol.
+ */
+
+INLINE
+LOCAL(void)
+emit_symbol (phuff_entropy_ptr entropy, int tbl_no, int symbol)
+{
+ if (entropy->gather_statistics)
+ entropy->count_ptrs[tbl_no][symbol]++;
+ else {
+ c_derived_tbl * tbl = entropy->derived_tbls[tbl_no];
+ emit_bits(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]);
+ }
+}
+
+
+/*
+ * Emit bits from a correction bit buffer.
+ */
+
+LOCAL(void)
+emit_buffered_bits (phuff_entropy_ptr entropy, char * bufstart,
+ unsigned int nbits)
+{
+ if (entropy->gather_statistics)
+ return; /* no real work */
+
+ while (nbits > 0) {
+ emit_bits(entropy, (unsigned int) (*bufstart), 1);
+ bufstart++;
+ nbits--;
+ }
+}
+
+
+/*
+ * Emit any pending EOBRUN symbol.
+ */
+
+LOCAL(void)
+emit_eobrun (phuff_entropy_ptr entropy)
+{
+ register int temp, nbits;
+
+ if (entropy->EOBRUN > 0) { /* if there is any pending EOBRUN */
+ temp = entropy->EOBRUN;
+ nbits = 0;
+ while ((temp >>= 1))
+ nbits++;
+ /* safety check: shouldn't happen given limited correction-bit buffer */
+ if (nbits > 14)
+ ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE);
+
+ emit_symbol(entropy, entropy->ac_tbl_no, nbits << 4);
+ if (nbits)
+ emit_bits(entropy, entropy->EOBRUN, nbits);
+
+ entropy->EOBRUN = 0;
+
+ /* Emit any buffered correction bits */
+ emit_buffered_bits(entropy, entropy->bit_buffer, entropy->BE);
+ entropy->BE = 0;
+ }
+}
+
+
+/*
+ * Emit a restart marker & resynchronize predictions.
+ */
+
+LOCAL(void)
+emit_restart (phuff_entropy_ptr entropy, int restart_num)
+{
+ int ci;
+
+ emit_eobrun(entropy);
+
+ if (! entropy->gather_statistics) {
+ flush_bits(entropy);
+ emit_byte(entropy, 0xFF);
+ emit_byte(entropy, JPEG_RST0 + restart_num);
+ }
+
+ if (entropy->cinfo->Ss == 0) {
+ /* Re-initialize DC predictions to 0 */
+ for (ci = 0; ci < entropy->cinfo->comps_in_scan; ci++)
+ entropy->last_dc_val[ci] = 0;
+ } else {
+ /* Re-initialize all AC-related fields to 0 */
+ entropy->EOBRUN = 0;
+ entropy->BE = 0;
+ }
+}
+
+
+/*
+ * MCU encoding for DC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF(boolean)
+encode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ register int temp, temp2;
+ register int nbits;
+ int blkn, ci;
+ int Al = cinfo->Al;
+ JBLOCKROW block;
+ jpeg_component_info * compptr;
+ ISHIFT_TEMPS
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+ /* Encode the MCU data blocks */
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ block = MCU_data[blkn];
+ ci = cinfo->MCU_membership[blkn];
+ compptr = cinfo->cur_comp_info[ci];
+
+ /* Compute the DC value after the required point transform by Al.
+ * This is simply an arithmetic right shift.
+ */
+ temp2 = IRIGHT_SHIFT((int) ((*block)[0]), Al);
+
+ /* DC differences are figured on the point-transformed values. */
+ temp = temp2 - entropy->last_dc_val[ci];
+ entropy->last_dc_val[ci] = temp2;
+
+ /* Encode the DC coefficient difference per section G.1.2.1 */
+ temp2 = temp;
+ if (temp < 0) {
+ temp = -temp; /* temp is abs value of input */
+ /* For a negative input, want temp2 = bitwise complement of abs(input) */
+ /* This code assumes we are on a two's complement machine */
+ temp2--;
+ }
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = 0;
+ while (temp) {
+ nbits++;
+ temp >>= 1;
+ }
+ /* Check for out-of-range coefficient values.
+ * Since we're encoding a difference, the range limit is twice as much.
+ */
+ if (nbits > MAX_COEF_BITS+1)
+ ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+
+ /* Count/emit the Huffman-coded symbol for the number of bits */
+ emit_symbol(entropy, compptr->dc_tbl_no, nbits);
+
+ /* Emit that number of bits of the value, if positive, */
+ /* or the complement of its magnitude, if negative. */
+ if (nbits) /* emit_bits rejects calls with size 0 */
+ emit_bits(entropy, (unsigned int) temp2, nbits);
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * MCU encoding for AC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF(boolean)
+encode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ register int temp, temp2;
+ register int nbits;
+ register int r, k;
+ int Se = cinfo->Se;
+ int Al = cinfo->Al;
+ JBLOCKROW block;
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+ /* Encode the MCU data block */
+ block = MCU_data[0];
+
+ /* Encode the AC coefficients per section G.1.2.2, fig. G.3 */
+
+ r = 0; /* r = run length of zeros */
+
+ for (k = cinfo->Ss; k <= Se; k++) {
+ if ((temp = (*block)[jpeg_natural_order[k]]) == 0) {
+ r++;
+ continue;
+ }
+ /* We must apply the point transform by Al. For AC coefficients this
+ * is an integer division with rounding towards 0. To do this portably
+ * in C, we shift after obtaining the absolute value; so the code is
+ * interwoven with finding the abs value (temp) and output bits (temp2).
+ */
+ if (temp < 0) {
+ temp = -temp; /* temp is abs value of input */
+ temp >>= Al; /* apply the point transform */
+ /* For a negative coef, want temp2 = bitwise complement of abs(coef) */
+ temp2 = ~temp;
+ } else {
+ temp >>= Al; /* apply the point transform */
+ temp2 = temp;
+ }
+ /* Watch out for case that nonzero coef is zero after point transform */
+ if (temp == 0) {
+ r++;
+ continue;
+ }
+
+ /* Emit any pending EOBRUN */
+ if (entropy->EOBRUN > 0)
+ emit_eobrun(entropy);
+ /* if run length > 15, must emit special run-length-16 codes (0xF0) */
+ while (r > 15) {
+ emit_symbol(entropy, entropy->ac_tbl_no, 0xF0);
+ r -= 16;
+ }
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = 1; /* there must be at least one 1 bit */
+ while ((temp >>= 1))
+ nbits++;
+ /* Check for out-of-range coefficient values */
+ if (nbits > MAX_COEF_BITS)
+ ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+
+ /* Count/emit Huffman symbol for run length / number of bits */
+ emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + nbits);
+
+ /* Emit that number of bits of the value, if positive, */
+ /* or the complement of its magnitude, if negative. */
+ emit_bits(entropy, (unsigned int) temp2, nbits);
+
+ r = 0; /* reset zero run length */
+ }
+
+ if (r > 0) { /* If there are trailing zeroes, */
+ entropy->EOBRUN++; /* count an EOB */
+ if (entropy->EOBRUN == 0x7FFF)
+ emit_eobrun(entropy); /* force it out to avoid overflow */
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * MCU encoding for DC successive approximation refinement scan.
+ * Note: we assume such scans can be multi-component, although the spec
+ * is not very clear on the point.
+ */
+
+METHODDEF(boolean)
+encode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ register int temp;
+ int blkn;
+ int Al = cinfo->Al;
+ JBLOCKROW block;
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+ /* Encode the MCU data blocks */
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ block = MCU_data[blkn];
+
+ /* We simply emit the Al'th bit of the DC coefficient value. */
+ temp = (*block)[0];
+ emit_bits(entropy, (unsigned int) (temp >> Al), 1);
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * MCU encoding for AC successive approximation refinement scan.
+ */
+
+METHODDEF(boolean)
+encode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ register int temp;
+ register int r, k;
+ int EOB;
+ char *BR_buffer;
+ unsigned int BR;
+ int Se = cinfo->Se;
+ int Al = cinfo->Al;
+ JBLOCKROW block;
+ int absvalues[DCTSIZE2];
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+ /* Encode the MCU data block */
+ block = MCU_data[0];
+
+ /* It is convenient to make a pre-pass to determine the transformed
+ * coefficients' absolute values and the EOB position.
+ */
+ EOB = 0;
+ for (k = cinfo->Ss; k <= Se; k++) {
+ temp = (*block)[jpeg_natural_order[k]];
+ /* We must apply the point transform by Al. For AC coefficients this
+ * is an integer division with rounding towards 0. To do this portably
+ * in C, we shift after obtaining the absolute value.
+ */
+ if (temp < 0)
+ temp = -temp; /* temp is abs value of input */
+ temp >>= Al; /* apply the point transform */
+ absvalues[k] = temp; /* save abs value for main pass */
+ if (temp == 1)
+ EOB = k; /* EOB = index of last newly-nonzero coef */
+ }
+
+ /* Encode the AC coefficients per section G.1.2.3, fig. G.7 */
+
+ r = 0; /* r = run length of zeros */
+ BR = 0; /* BR = count of buffered bits added now */
+ BR_buffer = entropy->bit_buffer + entropy->BE; /* Append bits to buffer */
+
+ for (k = cinfo->Ss; k <= Se; k++) {
+ if ((temp = absvalues[k]) == 0) {
+ r++;
+ continue;
+ }
+
+ /* Emit any required ZRLs, but not if they can be folded into EOB */
+ while (r > 15 && k <= EOB) {
+ /* emit any pending EOBRUN and the BE correction bits */
+ emit_eobrun(entropy);
+ /* Emit ZRL */
+ emit_symbol(entropy, entropy->ac_tbl_no, 0xF0);
+ r -= 16;
+ /* Emit buffered correction bits that must be associated with ZRL */
+ emit_buffered_bits(entropy, BR_buffer, BR);
+ BR_buffer = entropy->bit_buffer; /* BE bits are gone now */
+ BR = 0;
+ }
+
+ /* If the coef was previously nonzero, it only needs a correction bit.
+ * NOTE: a straight translation of the spec's figure G.7 would suggest
+ * that we also need to test r > 15. But if r > 15, we can only get here
+ * if k > EOB, which implies that this coefficient is not 1.
+ */
+ if (temp > 1) {
+ /* The correction bit is the next bit of the absolute value. */
+ BR_buffer[BR++] = (char) (temp & 1);
+ continue;
+ }
+
+ /* Emit any pending EOBRUN and the BE correction bits */
+ emit_eobrun(entropy);
+
+ /* Count/emit Huffman symbol for run length / number of bits */
+ emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + 1);
+
+ /* Emit output bit for newly-nonzero coef */
+ temp = ((*block)[jpeg_natural_order[k]] < 0) ? 0 : 1;
+ emit_bits(entropy, (unsigned int) temp, 1);
+
+ /* Emit buffered correction bits that must be associated with this code */
+ emit_buffered_bits(entropy, BR_buffer, BR);
+ BR_buffer = entropy->bit_buffer; /* BE bits are gone now */
+ BR = 0;
+ r = 0; /* reset zero run length */
+ }
+
+ if (r > 0 || BR > 0) { /* If there are trailing zeroes, */
+ entropy->EOBRUN++; /* count an EOB */
+ entropy->BE += BR; /* concat my correction bits to older ones */
+ /* We force out the EOB if we risk either:
+ * 1. overflow of the EOB counter;
+ * 2. overflow of the correction bit buffer during the next MCU.
+ */
+ if (entropy->EOBRUN == 0x7FFF || entropy->BE > (MAX_CORR_BITS-DCTSIZE2+1))
+ emit_eobrun(entropy);
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * Finish up at the end of a Huffman-compressed progressive scan.
+ */
+
+METHODDEF(void)
+finish_pass_phuff (j_compress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Flush out any buffered data */
+ emit_eobrun(entropy);
+ flush_bits(entropy);
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+}
+
+
+/*
+ * Finish up a statistics-gathering pass and create the new Huffman tables.
+ */
+
+METHODDEF(void)
+finish_pass_gather_phuff (j_compress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ boolean is_DC_band;
+ int ci, tbl;
+ jpeg_component_info * compptr;
+ JHUFF_TBL **htblptr;
+ boolean did[NUM_HUFF_TBLS];
+
+ /* Flush out buffered data (all we care about is counting the EOB symbol) */
+ emit_eobrun(entropy);
+
+ is_DC_band = (cinfo->Ss == 0);
+
+ /* It's important not to apply jpeg_gen_optimal_table more than once
+ * per table, because it clobbers the input frequency counts!
+ */
+ MEMZERO(did, SIZEOF(did));
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ if (is_DC_band) {
+ if (cinfo->Ah != 0) /* DC refinement needs no table */
+ continue;
+ tbl = compptr->dc_tbl_no;
+ } else {
+ tbl = compptr->ac_tbl_no;
+ }
+ if (! did[tbl]) {
+ if (is_DC_band)
+ htblptr = & cinfo->dc_huff_tbl_ptrs[tbl];
+ else
+ htblptr = & cinfo->ac_huff_tbl_ptrs[tbl];
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+ jpeg_gen_optimal_table(cinfo, *htblptr, entropy->count_ptrs[tbl]);
+ did[tbl] = TRUE;
+ }
+ }
+}
+
+
+/*
+ * Module initialization routine for progressive Huffman entropy encoding.
+ */
+
+GLOBAL(void)
+jinit_phuff_encoder (j_compress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy;
+ int i;
+
+ entropy = (phuff_entropy_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(phuff_entropy_encoder));
+ cinfo->entropy = (struct jpeg_entropy_encoder *) entropy;
+ entropy->pub.start_pass = start_pass_phuff;
+
+ /* Mark tables unallocated */
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ entropy->derived_tbls[i] = NULL;
+ entropy->count_ptrs[i] = NULL;
+ }
+ entropy->bit_buffer = NULL; /* needed only in AC refinement scan */
+}
+
+#endif /* C_PROGRESSIVE_SUPPORTED */
--- /dev/null
+/*
+ * jcprepct.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the compression preprocessing controller.
+ * This controller manages the color conversion, downsampling,
+ * and edge expansion steps.
+ *
+ * Most of the complexity here is associated with buffering input rows
+ * as required by the downsampler. See the comments at the head of
+ * jcsample.c for the downsampler's needs.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* At present, jcsample.c can request context rows only for smoothing.
+ * In the future, we might also need context rows for CCIR601 sampling
+ * or other more-complex downsampling procedures. The code to support
+ * context rows should be compiled only if needed.
+ */
+#ifdef INPUT_SMOOTHING_SUPPORTED
+#define CONTEXT_ROWS_SUPPORTED
+#endif
+
+
+/*
+ * For the simple (no-context-row) case, we just need to buffer one
+ * row group's worth of pixels for the downsampling step. At the bottom of
+ * the image, we pad to a full row group by replicating the last pixel row.
+ * The downsampler's last output row is then replicated if needed to pad
+ * out to a full iMCU row.
+ *
+ * When providing context rows, we must buffer three row groups' worth of
+ * pixels. Three row groups are physically allocated, but the row pointer
+ * arrays are made five row groups high, with the extra pointers above and
+ * below "wrapping around" to point to the last and first real row groups.
+ * This allows the downsampler to access the proper context rows.
+ * At the top and bottom of the image, we create dummy context rows by
+ * copying the first or last real pixel row. This copying could be avoided
+ * by pointer hacking as is done in jdmainct.c, but it doesn't seem worth the
+ * trouble on the compression side.
+ */
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_c_prep_controller pub; /* public fields */
+
+ /* Downsampling input buffer. This buffer holds color-converted data
+ * until we have enough to do a downsample step.
+ */
+ JSAMPARRAY color_buf[MAX_COMPONENTS];
+
+ JDIMENSION rows_to_go; /* counts rows remaining in source image */
+ int next_buf_row; /* index of next row to store in color_buf */
+
+#ifdef CONTEXT_ROWS_SUPPORTED /* only needed for context case */
+ int this_row_group; /* starting row index of group to process */
+ int next_buf_stop; /* downsample when we reach this index */
+#endif
+} my_prep_controller;
+
+typedef my_prep_controller * my_prep_ptr;
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_prep (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+
+ if (pass_mode != JBUF_PASS_THRU)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+
+ /* Initialize total-height counter for detecting bottom of image */
+ prep->rows_to_go = cinfo->image_height;
+ /* Mark the conversion buffer empty */
+ prep->next_buf_row = 0;
+#ifdef CONTEXT_ROWS_SUPPORTED
+ /* Preset additional state variables for context mode.
+ * These aren't used in non-context mode, so we needn't test which mode.
+ */
+ prep->this_row_group = 0;
+ /* Set next_buf_stop to stop after two row groups have been read in. */
+ prep->next_buf_stop = 2 * cinfo->max_v_samp_factor;
+#endif
+}
+
+
+/*
+ * Expand an image vertically from height input_rows to height output_rows,
+ * by duplicating the bottom row.
+ */
+
+LOCAL(void)
+expand_bottom_edge (JSAMPARRAY image_data, JDIMENSION num_cols,
+ int input_rows, int output_rows)
+{
+ register int row;
+
+ for (row = input_rows; row < output_rows; row++) {
+ jcopy_sample_rows(image_data, input_rows-1, image_data, row,
+ 1, num_cols);
+ }
+}
+
+
+/*
+ * Process some data in the simple no-context case.
+ *
+ * Preprocessor output data is counted in "row groups". A row group
+ * is defined to be v_samp_factor sample rows of each component.
+ * Downsampling will produce this much data from each max_v_samp_factor
+ * input rows.
+ */
+
+METHODDEF(void)
+pre_process_data (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
+ JDIMENSION in_rows_avail,
+ JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr,
+ JDIMENSION out_row_groups_avail)
+{
+ my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+ int numrows, ci;
+ JDIMENSION inrows;
+ jpeg_component_info * compptr;
+
+ while (*in_row_ctr < in_rows_avail &&
+ *out_row_group_ctr < out_row_groups_avail) {
+ /* Do color conversion to fill the conversion buffer. */
+ inrows = in_rows_avail - *in_row_ctr;
+ numrows = cinfo->max_v_samp_factor - prep->next_buf_row;
+ numrows = (int) MIN((JDIMENSION) numrows, inrows);
+ (*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr,
+ prep->color_buf,
+ (JDIMENSION) prep->next_buf_row,
+ numrows);
+ *in_row_ctr += numrows;
+ prep->next_buf_row += numrows;
+ prep->rows_to_go -= numrows;
+ /* If at bottom of image, pad to fill the conversion buffer. */
+ if (prep->rows_to_go == 0 &&
+ prep->next_buf_row < cinfo->max_v_samp_factor) {
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ expand_bottom_edge(prep->color_buf[ci], cinfo->image_width,
+ prep->next_buf_row, cinfo->max_v_samp_factor);
+ }
+ prep->next_buf_row = cinfo->max_v_samp_factor;
+ }
+ /* If we've filled the conversion buffer, empty it. */
+ if (prep->next_buf_row == cinfo->max_v_samp_factor) {
+ (*cinfo->downsample->downsample) (cinfo,
+ prep->color_buf, (JDIMENSION) 0,
+ output_buf, *out_row_group_ctr);
+ prep->next_buf_row = 0;
+ (*out_row_group_ctr)++;
+ }
+ /* If at bottom of image, pad the output to a full iMCU height.
+ * Note we assume the caller is providing a one-iMCU-height output buffer!
+ */
+ if (prep->rows_to_go == 0 &&
+ *out_row_group_ctr < out_row_groups_avail) {
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ expand_bottom_edge(output_buf[ci],
+ compptr->width_in_blocks * DCTSIZE,
+ (int) (*out_row_group_ctr * compptr->v_samp_factor),
+ (int) (out_row_groups_avail * compptr->v_samp_factor));
+ }
+ *out_row_group_ctr = out_row_groups_avail;
+ break; /* can exit outer loop without test */
+ }
+ }
+}
+
+
+#ifdef CONTEXT_ROWS_SUPPORTED
+
+/*
+ * Process some data in the context case.
+ */
+
+METHODDEF(void)
+pre_process_context (j_compress_ptr cinfo,
+ JSAMPARRAY input_buf, JDIMENSION *in_row_ctr,
+ JDIMENSION in_rows_avail,
+ JSAMPIMAGE output_buf, JDIMENSION *out_row_group_ctr,
+ JDIMENSION out_row_groups_avail)
+{
+ my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+ int numrows, ci;
+ int buf_height = cinfo->max_v_samp_factor * 3;
+ JDIMENSION inrows;
+
+ while (*out_row_group_ctr < out_row_groups_avail) {
+ if (*in_row_ctr < in_rows_avail) {
+ /* Do color conversion to fill the conversion buffer. */
+ inrows = in_rows_avail - *in_row_ctr;
+ numrows = prep->next_buf_stop - prep->next_buf_row;
+ numrows = (int) MIN((JDIMENSION) numrows, inrows);
+ (*cinfo->cconvert->color_convert) (cinfo, input_buf + *in_row_ctr,
+ prep->color_buf,
+ (JDIMENSION) prep->next_buf_row,
+ numrows);
+ /* Pad at top of image, if first time through */
+ if (prep->rows_to_go == cinfo->image_height) {
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ int row;
+ for (row = 1; row <= cinfo->max_v_samp_factor; row++) {
+ jcopy_sample_rows(prep->color_buf[ci], 0,
+ prep->color_buf[ci], -row,
+ 1, cinfo->image_width);
+ }
+ }
+ }
+ *in_row_ctr += numrows;
+ prep->next_buf_row += numrows;
+ prep->rows_to_go -= numrows;
+ } else {
+ /* Return for more data, unless we are at the bottom of the image. */
+ if (prep->rows_to_go != 0)
+ break;
+ /* When at bottom of image, pad to fill the conversion buffer. */
+ if (prep->next_buf_row < prep->next_buf_stop) {
+ for (ci = 0; ci < cinfo->num_components; ci++) {
+ expand_bottom_edge(prep->color_buf[ci], cinfo->image_width,
+ prep->next_buf_row, prep->next_buf_stop);
+ }
+ prep->next_buf_row = prep->next_buf_stop;
+ }
+ }
+ /* If we've gotten enough data, downsample a row group. */
+ if (prep->next_buf_row == prep->next_buf_stop) {
+ (*cinfo->downsample->downsample) (cinfo,
+ prep->color_buf,
+ (JDIMENSION) prep->this_row_group,
+ output_buf, *out_row_group_ctr);
+ (*out_row_group_ctr)++;
+ /* Advance pointers with wraparound as necessary. */
+ prep->this_row_group += cinfo->max_v_samp_factor;
+ if (prep->this_row_group >= buf_height)
+ prep->this_row_group = 0;
+ if (prep->next_buf_row >= buf_height)
+ prep->next_buf_row = 0;
+ prep->next_buf_stop = prep->next_buf_row + cinfo->max_v_samp_factor;
+ }
+ }
+}
+
+
+/*
+ * Create the wrapped-around downsampling input buffer needed for context mode.
+ */
+
+LOCAL(void)
+create_context_buffer (j_compress_ptr cinfo)
+{
+ my_prep_ptr prep = (my_prep_ptr) cinfo->prep;
+ int rgroup_height = cinfo->max_v_samp_factor;
+ int ci, i;
+ jpeg_component_info * compptr;
+ JSAMPARRAY true_buffer, fake_buffer;
+
+ /* Grab enough space for fake row pointers for all the components;
+ * we need five row groups' worth of pointers for each component.
+ */
+ fake_buffer = (JSAMPARRAY)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (cinfo->num_components * 5 * rgroup_height) *
+ SIZEOF(JSAMPROW));
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Allocate the actual buffer space (3 row groups) for this component.
+ * We make the buffer wide enough to allow the downsampler to edge-expand
+ * horizontally within the buffer, if it so chooses.
+ */
+ true_buffer = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) (((long) compptr->width_in_blocks * DCTSIZE *
+ cinfo->max_h_samp_factor) / compptr->h_samp_factor),
+ (JDIMENSION) (3 * rgroup_height));
+ /* Copy true buffer row pointers into the middle of the fake row array */
+ MEMCOPY(fake_buffer + rgroup_height, true_buffer,
+ 3 * rgroup_height * SIZEOF(JSAMPROW));
+ /* Fill in the above and below wraparound pointers */
+ for (i = 0; i < rgroup_height; i++) {
+ fake_buffer[i] = true_buffer[2 * rgroup_height + i];
+ fake_buffer[4 * rgroup_height + i] = true_buffer[i];
+ }
+ prep->color_buf[ci] = fake_buffer + rgroup_height;
+ fake_buffer += 5 * rgroup_height; /* point to space for next component */
+ }
+}
+
+#endif /* CONTEXT_ROWS_SUPPORTED */
+
+
+/*
+ * Initialize preprocessing controller.
+ */
+
+GLOBAL(void)
+jinit_c_prep_controller (j_compress_ptr cinfo, boolean need_full_buffer)
+{
+ my_prep_ptr prep;
+ int ci;
+ jpeg_component_info * compptr;
+
+ if (need_full_buffer) /* safety check */
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+
+ prep = (my_prep_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_prep_controller));
+ cinfo->prep = (struct jpeg_c_prep_controller *) prep;
+ prep->pub.start_pass = start_pass_prep;
+
+ /* Allocate the color conversion buffer.
+ * We make the buffer wide enough to allow the downsampler to edge-expand
+ * horizontally within the buffer, if it so chooses.
+ */
+ if (cinfo->downsample->need_context_rows) {
+ /* Set up to provide context rows */
+#ifdef CONTEXT_ROWS_SUPPORTED
+ prep->pub.pre_process_data = pre_process_context;
+ create_context_buffer(cinfo);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ /* No context, just make it tall enough for one row group */
+ prep->pub.pre_process_data = pre_process_data;
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ prep->color_buf[ci] = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) (((long) compptr->width_in_blocks * DCTSIZE *
+ cinfo->max_h_samp_factor) / compptr->h_samp_factor),
+ (JDIMENSION) cinfo->max_v_samp_factor);
+ }
+ }
+}
--- /dev/null
+/*
+ * jcsample.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains downsampling routines.
+ *
+ * Downsampling input data is counted in "row groups". A row group
+ * is defined to be max_v_samp_factor pixel rows of each component,
+ * from which the downsampler produces v_samp_factor sample rows.
+ * A single row group is processed in each call to the downsampler module.
+ *
+ * The downsampler is responsible for edge-expansion of its output data
+ * to fill an integral number of DCT blocks horizontally. The source buffer
+ * may be modified if it is helpful for this purpose (the source buffer is
+ * allocated wide enough to correspond to the desired output width).
+ * The caller (the prep controller) is responsible for vertical padding.
+ *
+ * The downsampler may request "context rows" by setting need_context_rows
+ * during startup. In this case, the input arrays will contain at least
+ * one row group's worth of pixels above and below the passed-in data;
+ * the caller will create dummy rows at image top and bottom by replicating
+ * the first or last real pixel row.
+ *
+ * An excellent reference for image resampling is
+ * Digital Image Warping, George Wolberg, 1990.
+ * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
+ *
+ * The downsampling algorithm used here is a simple average of the source
+ * pixels covered by the output pixel. The hi-falutin sampling literature
+ * refers to this as a "box filter". In general the characteristics of a box
+ * filter are not very good, but for the specific cases we normally use (1:1
+ * and 2:1 ratios) the box is equivalent to a "triangle filter" which is not
+ * nearly so bad. If you intend to use other sampling ratios, you'd be well
+ * advised to improve this code.
+ *
+ * A simple input-smoothing capability is provided. This is mainly intended
+ * for cleaning up color-dithered GIF input files (if you find it inadequate,
+ * we suggest using an external filtering program such as pnmconvol). When
+ * enabled, each input pixel P is replaced by a weighted sum of itself and its
+ * eight neighbors. P's weight is 1-8*SF and each neighbor's weight is SF,
+ * where SF = (smoothing_factor / 1024).
+ * Currently, smoothing is only supported for 2h2v sampling factors.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Pointer to routine to downsample a single component */
+typedef JMETHOD(void, downsample1_ptr,
+ (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data));
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_downsampler pub; /* public fields */
+
+ /* Downsampling method pointers, one per component */
+ downsample1_ptr methods[MAX_COMPONENTS];
+} my_downsampler;
+
+typedef my_downsampler * my_downsample_ptr;
+
+
+/*
+ * Initialize for a downsampling pass.
+ */
+
+METHODDEF(void)
+start_pass_downsample (j_compress_ptr cinfo)
+{
+ /* no work for now */
+}
+
+
+/*
+ * Expand a component horizontally from width input_cols to width output_cols,
+ * by duplicating the rightmost samples.
+ */
+
+LOCAL(void)
+expand_right_edge (JSAMPARRAY image_data, int num_rows,
+ JDIMENSION input_cols, JDIMENSION output_cols)
+{
+ register JSAMPROW ptr;
+ register JSAMPLE pixval;
+ register int count;
+ int row;
+ int numcols = (int) (output_cols - input_cols);
+
+ if (numcols > 0) {
+ for (row = 0; row < num_rows; row++) {
+ ptr = image_data[row] + input_cols;
+ pixval = ptr[-1]; /* don't need GETJSAMPLE() here */
+ for (count = numcols; count > 0; count--)
+ *ptr++ = pixval;
+ }
+ }
+}
+
+
+/*
+ * Do downsampling for a whole row group (all components).
+ *
+ * In this version we simply downsample each component independently.
+ */
+
+METHODDEF(void)
+sep_downsample (j_compress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION in_row_index,
+ JSAMPIMAGE output_buf, JDIMENSION out_row_group_index)
+{
+ my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample;
+ int ci;
+ jpeg_component_info * compptr;
+ JSAMPARRAY in_ptr, out_ptr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ in_ptr = input_buf[ci] + in_row_index;
+ out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor);
+ (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr);
+ }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * One row group is processed per call.
+ * This version handles arbitrary integral sampling ratios, without smoothing.
+ * Note that this version is not actually used for customary sampling ratios.
+ */
+
+METHODDEF(void)
+int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data)
+{
+ int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v;
+ JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */
+ JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+ JSAMPROW inptr, outptr;
+ INT32 outvalue;
+
+ h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor;
+ v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor;
+ numpix = h_expand * v_expand;
+ numpix2 = numpix/2;
+
+ /* Expand input data enough to let all the output samples be generated
+ * by the standard loop. Special-casing padded output would be more
+ * efficient.
+ */
+ expand_right_edge(input_data, cinfo->max_v_samp_factor,
+ cinfo->image_width, output_cols * h_expand);
+
+ inrow = 0;
+ for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ for (outcol = 0, outcol_h = 0; outcol < output_cols;
+ outcol++, outcol_h += h_expand) {
+ outvalue = 0;
+ for (v = 0; v < v_expand; v++) {
+ inptr = input_data[inrow+v] + outcol_h;
+ for (h = 0; h < h_expand; h++) {
+ outvalue += (INT32) GETJSAMPLE(*inptr++);
+ }
+ }
+ *outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix);
+ }
+ inrow += v_expand;
+ }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the special case of a full-size component,
+ * without smoothing.
+ */
+
+METHODDEF(void)
+fullsize_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data)
+{
+ /* Copy the data */
+ jcopy_sample_rows(input_data, 0, output_data, 0,
+ cinfo->max_v_samp_factor, cinfo->image_width);
+ /* Edge-expand */
+ expand_right_edge(output_data, cinfo->max_v_samp_factor,
+ cinfo->image_width, compptr->width_in_blocks * DCTSIZE);
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the common case of 2:1 horizontal and 1:1 vertical,
+ * without smoothing.
+ *
+ * A note about the "bias" calculations: when rounding fractional values to
+ * integer, we do not want to always round 0.5 up to the next integer.
+ * If we did that, we'd introduce a noticeable bias towards larger values.
+ * Instead, this code is arranged so that 0.5 will be rounded up or down at
+ * alternate pixel locations (a simple ordered dither pattern).
+ */
+
+METHODDEF(void)
+h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data)
+{
+ int outrow;
+ JDIMENSION outcol;
+ JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+ register JSAMPROW inptr, outptr;
+ register int bias;
+
+ /* Expand input data enough to let all the output samples be generated
+ * by the standard loop. Special-casing padded output would be more
+ * efficient.
+ */
+ expand_right_edge(input_data, cinfo->max_v_samp_factor,
+ cinfo->image_width, output_cols * 2);
+
+ for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ inptr = input_data[outrow];
+ bias = 0; /* bias = 0,1,0,1,... for successive samples */
+ for (outcol = 0; outcol < output_cols; outcol++) {
+ *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1])
+ + bias) >> 1);
+ bias ^= 1; /* 0=>1, 1=>0 */
+ inptr += 2;
+ }
+ }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
+ * without smoothing.
+ */
+
+METHODDEF(void)
+h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data)
+{
+ int inrow, outrow;
+ JDIMENSION outcol;
+ JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+ register JSAMPROW inptr0, inptr1, outptr;
+ register int bias;
+
+ /* Expand input data enough to let all the output samples be generated
+ * by the standard loop. Special-casing padded output would be more
+ * efficient.
+ */
+ expand_right_edge(input_data, cinfo->max_v_samp_factor,
+ cinfo->image_width, output_cols * 2);
+
+ inrow = 0;
+ for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ inptr0 = input_data[inrow];
+ inptr1 = input_data[inrow+1];
+ bias = 1; /* bias = 1,2,1,2,... for successive samples */
+ for (outcol = 0; outcol < output_cols; outcol++) {
+ *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
+ GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1])
+ + bias) >> 2);
+ bias ^= 3; /* 1=>2, 2=>1 */
+ inptr0 += 2; inptr1 += 2;
+ }
+ inrow += 2;
+ }
+}
+
+
+#ifdef INPUT_SMOOTHING_SUPPORTED
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
+ * with smoothing. One row of context is required.
+ */
+
+METHODDEF(void)
+h2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data)
+{
+ int inrow, outrow;
+ JDIMENSION colctr;
+ JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+ register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
+ INT32 membersum, neighsum, memberscale, neighscale;
+
+ /* Expand input data enough to let all the output samples be generated
+ * by the standard loop. Special-casing padded output would be more
+ * efficient.
+ */
+ expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
+ cinfo->image_width, output_cols * 2);
+
+ /* We don't bother to form the individual "smoothed" input pixel values;
+ * we can directly compute the output which is the average of the four
+ * smoothed values. Each of the four member pixels contributes a fraction
+ * (1-8*SF) to its own smoothed image and a fraction SF to each of the three
+ * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final
+ * output. The four corner-adjacent neighbor pixels contribute a fraction
+ * SF to just one smoothed pixel, or SF/4 to the final output; while the
+ * eight edge-adjacent neighbors contribute SF to each of two smoothed
+ * pixels, or SF/2 overall. In order to use integer arithmetic, these
+ * factors are scaled by 2^16 = 65536.
+ * Also recall that SF = smoothing_factor / 1024.
+ */
+
+ memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */
+ neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */
+
+ inrow = 0;
+ for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ inptr0 = input_data[inrow];
+ inptr1 = input_data[inrow+1];
+ above_ptr = input_data[inrow-1];
+ below_ptr = input_data[inrow+2];
+
+ /* Special case for first column: pretend column -1 is same as column 0 */
+ membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
+ GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
+ neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
+ GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
+ GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[2]) +
+ GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[2]);
+ neighsum += neighsum;
+ neighsum += GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[2]) +
+ GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[2]);
+ membersum = membersum * memberscale + neighsum * neighscale;
+ *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
+ inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2;
+
+ for (colctr = output_cols - 2; colctr > 0; colctr--) {
+ /* sum of pixels directly mapped to this output element */
+ membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
+ GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
+ /* sum of edge-neighbor pixels */
+ neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
+ GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
+ GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[2]) +
+ GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[2]);
+ /* The edge-neighbors count twice as much as corner-neighbors */
+ neighsum += neighsum;
+ /* Add in the corner-neighbors */
+ neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[2]) +
+ GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[2]);
+ /* form final output scaled up by 2^16 */
+ membersum = membersum * memberscale + neighsum * neighscale;
+ /* round, descale and output it */
+ *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
+ inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2;
+ }
+
+ /* Special case for last column */
+ membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
+ GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
+ neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
+ GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
+ GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[1]) +
+ GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[1]);
+ neighsum += neighsum;
+ neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[1]) +
+ GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[1]);
+ membersum = membersum * memberscale + neighsum * neighscale;
+ *outptr = (JSAMPLE) ((membersum + 32768) >> 16);
+
+ inrow += 2;
+ }
+}
+
+
+/*
+ * Downsample pixel values of a single component.
+ * This version handles the special case of a full-size component,
+ * with smoothing. One row of context is required.
+ */
+
+METHODDEF(void)
+fullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr,
+ JSAMPARRAY input_data, JSAMPARRAY output_data)
+{
+ int outrow;
+ JDIMENSION colctr;
+ JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
+ register JSAMPROW inptr, above_ptr, below_ptr, outptr;
+ INT32 membersum, neighsum, memberscale, neighscale;
+ int colsum, lastcolsum, nextcolsum;
+
+ /* Expand input data enough to let all the output samples be generated
+ * by the standard loop. Special-casing padded output would be more
+ * efficient.
+ */
+ expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
+ cinfo->image_width, output_cols);
+
+ /* Each of the eight neighbor pixels contributes a fraction SF to the
+ * smoothed pixel, while the main pixel contributes (1-8*SF). In order
+ * to use integer arithmetic, these factors are multiplied by 2^16 = 65536.
+ * Also recall that SF = smoothing_factor / 1024.
+ */
+
+ memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */
+ neighscale = cinfo->smoothing_factor * 64; /* scaled SF */
+
+ for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
+ outptr = output_data[outrow];
+ inptr = input_data[outrow];
+ above_ptr = input_data[outrow-1];
+ below_ptr = input_data[outrow+1];
+
+ /* Special case for first column */
+ colsum = GETJSAMPLE(*above_ptr++) + GETJSAMPLE(*below_ptr++) +
+ GETJSAMPLE(*inptr);
+ membersum = GETJSAMPLE(*inptr++);
+ nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) +
+ GETJSAMPLE(*inptr);
+ neighsum = colsum + (colsum - membersum) + nextcolsum;
+ membersum = membersum * memberscale + neighsum * neighscale;
+ *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
+ lastcolsum = colsum; colsum = nextcolsum;
+
+ for (colctr = output_cols - 2; colctr > 0; colctr--) {
+ membersum = GETJSAMPLE(*inptr++);
+ above_ptr++; below_ptr++;
+ nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) +
+ GETJSAMPLE(*inptr);
+ neighsum = lastcolsum + (colsum - membersum) + nextcolsum;
+ membersum = membersum * memberscale + neighsum * neighscale;
+ *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
+ lastcolsum = colsum; colsum = nextcolsum;
+ }
+
+ /* Special case for last column */
+ membersum = GETJSAMPLE(*inptr);
+ neighsum = lastcolsum + (colsum - membersum) + colsum;
+ membersum = membersum * memberscale + neighsum * neighscale;
+ *outptr = (JSAMPLE) ((membersum + 32768) >> 16);
+
+ }
+}
+
+#endif /* INPUT_SMOOTHING_SUPPORTED */
+
+
+/*
+ * Module initialization routine for downsampling.
+ * Note that we must select a routine for each component.
+ */
+
+GLOBAL(void)
+jinit_downsampler (j_compress_ptr cinfo)
+{
+ my_downsample_ptr downsample;
+ int ci;
+ jpeg_component_info * compptr;
+ boolean smoothok = TRUE;
+
+ downsample = (my_downsample_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_downsampler));
+ cinfo->downsample = (struct jpeg_downsampler *) downsample;
+ downsample->pub.start_pass = start_pass_downsample;
+ downsample->pub.downsample = sep_downsample;
+ downsample->pub.need_context_rows = FALSE;
+
+ if (cinfo->CCIR601_sampling)
+ ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
+
+ /* Verify we can handle the sampling factors, and set up method pointers */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ if (compptr->h_samp_factor == cinfo->max_h_samp_factor &&
+ compptr->v_samp_factor == cinfo->max_v_samp_factor) {
+#ifdef INPUT_SMOOTHING_SUPPORTED
+ if (cinfo->smoothing_factor) {
+ downsample->methods[ci] = fullsize_smooth_downsample;
+ downsample->pub.need_context_rows = TRUE;
+ } else
+#endif
+ downsample->methods[ci] = fullsize_downsample;
+ } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
+ compptr->v_samp_factor == cinfo->max_v_samp_factor) {
+ smoothok = FALSE;
+ downsample->methods[ci] = h2v1_downsample;
+ } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
+ compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) {
+#ifdef INPUT_SMOOTHING_SUPPORTED
+ if (cinfo->smoothing_factor) {
+ downsample->methods[ci] = h2v2_smooth_downsample;
+ downsample->pub.need_context_rows = TRUE;
+ } else
+#endif
+ downsample->methods[ci] = h2v2_downsample;
+ } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 &&
+ (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) {
+ smoothok = FALSE;
+ downsample->methods[ci] = int_downsample;
+ } else
+ ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
+ }
+
+#ifdef INPUT_SMOOTHING_SUPPORTED
+ if (cinfo->smoothing_factor && !smoothok)
+ TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL);
+#endif
+}
--- /dev/null
+/*
+ * jctrans.c
+ *
+ * Copyright (C) 1995-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains library routines for transcoding compression,
+ * that is, writing raw DCT coefficient arrays to an output JPEG file.
+ * The routines in jcapimin.c will also be needed by a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Forward declarations */
+LOCAL(void) transencode_master_selection
+ JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
+LOCAL(void) transencode_coef_controller
+ JPP((j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays));
+
+
+/*
+ * Compression initialization for writing raw-coefficient data.
+ * Before calling this, all parameters and a data destination must be set up.
+ * Call jpeg_finish_compress() to actually write the data.
+ *
+ * The number of passed virtual arrays must match cinfo->num_components.
+ * Note that the virtual arrays need not be filled or even realized at
+ * the time write_coefficients is called; indeed, if the virtual arrays
+ * were requested from this compression object's memory manager, they
+ * typically will be realized during this routine and filled afterwards.
+ */
+
+GLOBAL(void)
+jpeg_write_coefficients (j_compress_ptr cinfo, jvirt_barray_ptr * coef_arrays)
+{
+ if (cinfo->global_state != CSTATE_START)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ /* Mark all tables to be written */
+ jpeg_suppress_tables(cinfo, FALSE);
+ /* (Re)initialize error mgr and destination modules */
+ (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
+ (*cinfo->dest->init_destination) (cinfo);
+ /* Perform master selection of active modules */
+ transencode_master_selection(cinfo, coef_arrays);
+ /* Wait for jpeg_finish_compress() call */
+ cinfo->next_scanline = 0; /* so jpeg_write_marker works */
+ cinfo->global_state = CSTATE_WRCOEFS;
+}
+
+
+/*
+ * Initialize the compression object with default parameters,
+ * then copy from the source object all parameters needed for lossless
+ * transcoding. Parameters that can be varied without loss (such as
+ * scan script and Huffman optimization) are left in their default states.
+ */
+
+GLOBAL(void)
+jpeg_copy_critical_parameters (j_decompress_ptr srcinfo,
+ j_compress_ptr dstinfo)
+{
+ JQUANT_TBL ** qtblptr;
+ jpeg_component_info *incomp, *outcomp;
+ JQUANT_TBL *c_quant, *slot_quant;
+ int tblno, ci, coefi;
+
+ /* Safety check to ensure start_compress not called yet. */
+ if (dstinfo->global_state != CSTATE_START)
+ ERREXIT1(dstinfo, JERR_BAD_STATE, dstinfo->global_state);
+ /* Copy fundamental image dimensions */
+ dstinfo->image_width = srcinfo->image_width;
+ dstinfo->image_height = srcinfo->image_height;
+ dstinfo->input_components = srcinfo->num_components;
+ dstinfo->in_color_space = srcinfo->jpeg_color_space;
+ /* Initialize all parameters to default values */
+ jpeg_set_defaults(dstinfo);
+ /* jpeg_set_defaults may choose wrong colorspace, eg YCbCr if input is RGB.
+ * Fix it to get the right header markers for the image colorspace.
+ */
+ jpeg_set_colorspace(dstinfo, srcinfo->jpeg_color_space);
+ dstinfo->data_precision = srcinfo->data_precision;
+ dstinfo->CCIR601_sampling = srcinfo->CCIR601_sampling;
+ /* Copy the source's quantization tables. */
+ for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
+ if (srcinfo->quant_tbl_ptrs[tblno] != NULL) {
+ qtblptr = & dstinfo->quant_tbl_ptrs[tblno];
+ if (*qtblptr == NULL)
+ *qtblptr = jpeg_alloc_quant_table((j_common_ptr) dstinfo);
+ MEMCOPY((*qtblptr)->quantval,
+ srcinfo->quant_tbl_ptrs[tblno]->quantval,
+ SIZEOF((*qtblptr)->quantval));
+ (*qtblptr)->sent_table = FALSE;
+ }
+ }
+ /* Copy the source's per-component info.
+ * Note we assume jpeg_set_defaults has allocated the dest comp_info array.
+ */
+ dstinfo->num_components = srcinfo->num_components;
+ if (dstinfo->num_components < 1 || dstinfo->num_components > MAX_COMPONENTS)
+ ERREXIT2(dstinfo, JERR_COMPONENT_COUNT, dstinfo->num_components,
+ MAX_COMPONENTS);
+ for (ci = 0, incomp = srcinfo->comp_info, outcomp = dstinfo->comp_info;
+ ci < dstinfo->num_components; ci++, incomp++, outcomp++) {
+ outcomp->component_id = incomp->component_id;
+ outcomp->h_samp_factor = incomp->h_samp_factor;
+ outcomp->v_samp_factor = incomp->v_samp_factor;
+ outcomp->quant_tbl_no = incomp->quant_tbl_no;
+ /* Make sure saved quantization table for component matches the qtable
+ * slot. If not, the input file re-used this qtable slot.
+ * IJG encoder currently cannot duplicate this.
+ */
+ tblno = outcomp->quant_tbl_no;
+ if (tblno < 0 || tblno >= NUM_QUANT_TBLS ||
+ srcinfo->quant_tbl_ptrs[tblno] == NULL)
+ ERREXIT1(dstinfo, JERR_NO_QUANT_TABLE, tblno);
+ slot_quant = srcinfo->quant_tbl_ptrs[tblno];
+ c_quant = incomp->quant_table;
+ if (c_quant != NULL) {
+ for (coefi = 0; coefi < DCTSIZE2; coefi++) {
+ if (c_quant->quantval[coefi] != slot_quant->quantval[coefi])
+ ERREXIT1(dstinfo, JERR_MISMATCHED_QUANT_TABLE, tblno);
+ }
+ }
+ /* Note: we do not copy the source's Huffman table assignments;
+ * instead we rely on jpeg_set_colorspace to have made a suitable choice.
+ */
+ }
+ /* Also copy JFIF version and resolution information, if available.
+ * Strictly speaking this isn't "critical" info, but it's nearly
+ * always appropriate to copy it if available. In particular,
+ * if the application chooses to copy JFIF 1.02 extension markers from
+ * the source file, we need to copy the version to make sure we don't
+ * emit a file that has 1.02 extensions but a claimed version of 1.01.
+ * We will *not*, however, copy version info from mislabeled "2.01" files.
+ */
+ if (srcinfo->saw_JFIF_marker) {
+ if (srcinfo->JFIF_major_version == 1) {
+ dstinfo->JFIF_major_version = srcinfo->JFIF_major_version;
+ dstinfo->JFIF_minor_version = srcinfo->JFIF_minor_version;
+ }
+ dstinfo->density_unit = srcinfo->density_unit;
+ dstinfo->X_density = srcinfo->X_density;
+ dstinfo->Y_density = srcinfo->Y_density;
+ }
+}
+
+
+/*
+ * Master selection of compression modules for transcoding.
+ * This substitutes for jcinit.c's initialization of the full compressor.
+ */
+
+LOCAL(void)
+transencode_master_selection (j_compress_ptr cinfo,
+ jvirt_barray_ptr * coef_arrays)
+{
+ /* Although we don't actually use input_components for transcoding,
+ * jcmaster.c's initial_setup will complain if input_components is 0.
+ */
+ cinfo->input_components = 1;
+ /* Initialize master control (includes parameter checking/processing) */
+ jinit_c_master_control(cinfo, TRUE /* transcode only */);
+
+ /* Entropy encoding: either Huffman or arithmetic coding. */
+ if (cinfo->arith_code) {
+ ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+ } else {
+ if (cinfo->progressive_mode) {
+#ifdef C_PROGRESSIVE_SUPPORTED
+ jinit_phuff_encoder(cinfo);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else
+ jinit_huff_encoder(cinfo);
+ }
+
+ /* We need a special coefficient buffer controller. */
+ transencode_coef_controller(cinfo, coef_arrays);
+
+ jinit_marker_writer(cinfo);
+
+ /* We can now tell the memory manager to allocate virtual arrays. */
+ (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
+
+ /* Write the datastream header (SOI, JFIF) immediately.
+ * Frame and scan headers are postponed till later.
+ * This lets application insert special markers after the SOI.
+ */
+ (*cinfo->marker->write_file_header) (cinfo);
+}
+
+
+/*
+ * The rest of this file is a special implementation of the coefficient
+ * buffer controller. This is similar to jccoefct.c, but it handles only
+ * output from presupplied virtual arrays. Furthermore, we generate any
+ * dummy padding blocks on-the-fly rather than expecting them to be present
+ * in the arrays.
+ */
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_c_coef_controller pub; /* public fields */
+
+ JDIMENSION iMCU_row_num; /* iMCU row # within image */
+ JDIMENSION mcu_ctr; /* counts MCUs processed in current row */
+ int MCU_vert_offset; /* counts MCU rows within iMCU row */
+ int MCU_rows_per_iMCU_row; /* number of such rows needed */
+
+ /* Virtual block array for each component. */
+ jvirt_barray_ptr * whole_image;
+
+ /* Workspace for constructing dummy blocks at right/bottom edges. */
+ JBLOCKROW dummy_buffer[C_MAX_BLOCKS_IN_MCU];
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+
+LOCAL(void)
+start_iMCU_row (j_compress_ptr cinfo)
+/* Reset within-iMCU-row counters for a new row */
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+ /* In an interleaved scan, an MCU row is the same as an iMCU row.
+ * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+ * But at the bottom of the image, process only what's left.
+ */
+ if (cinfo->comps_in_scan > 1) {
+ coef->MCU_rows_per_iMCU_row = 1;
+ } else {
+ if (coef->iMCU_row_num < (cinfo->total_iMCU_rows-1))
+ coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+ else
+ coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+ }
+
+ coef->mcu_ctr = 0;
+ coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_coef (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+ if (pass_mode != JBUF_CRANK_DEST)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+
+ coef->iMCU_row_num = 0;
+ start_iMCU_row(cinfo);
+}
+
+
+/*
+ * Process some data.
+ * We process the equivalent of one fully interleaved MCU row ("iMCU" row)
+ * per call, ie, v_samp_factor block rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the entropy coder.
+ * Returns TRUE if the iMCU row is completed, FALSE if suspended.
+ *
+ * NB: input_buf is ignored; it is likely to be a NULL pointer.
+ */
+
+METHODDEF(boolean)
+compress_output (j_compress_ptr cinfo, JSAMPIMAGE input_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ int blkn, ci, xindex, yindex, yoffset, blockcnt;
+ JDIMENSION start_col;
+ JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+ JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
+ JBLOCKROW buffer_ptr;
+ jpeg_component_info *compptr;
+
+ /* Align the virtual buffers for the components used in this scan. */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ buffer[ci] = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+ coef->iMCU_row_num * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+
+ /* Loop to process one whole iMCU row */
+ for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+ yoffset++) {
+ for (MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
+ MCU_col_num++) {
+ /* Construct list of pointers to DCT blocks belonging to this MCU */
+ blkn = 0; /* index of current DCT block within MCU */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ start_col = MCU_col_num * compptr->MCU_width;
+ blockcnt = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
+ : compptr->last_col_width;
+ for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
+ if (coef->iMCU_row_num < last_iMCU_row ||
+ yindex+yoffset < compptr->last_row_height) {
+ /* Fill in pointers to real blocks in this row */
+ buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
+ for (xindex = 0; xindex < blockcnt; xindex++)
+ MCU_buffer[blkn++] = buffer_ptr++;
+ } else {
+ /* At bottom of image, need a whole row of dummy blocks */
+ xindex = 0;
+ }
+ /* Fill in any dummy blocks needed in this row.
+ * Dummy blocks are filled in the same way as in jccoefct.c:
+ * all zeroes in the AC entries, DC entries equal to previous
+ * block's DC value. The init routine has already zeroed the
+ * AC entries, so we need only set the DC entries correctly.
+ */
+ for (; xindex < compptr->MCU_width; xindex++) {
+ MCU_buffer[blkn] = coef->dummy_buffer[blkn];
+ MCU_buffer[blkn][0][0] = MCU_buffer[blkn-1][0][0];
+ blkn++;
+ }
+ }
+ }
+ /* Try to write the MCU. */
+ if (! (*cinfo->entropy->encode_mcu) (cinfo, MCU_buffer)) {
+ /* Suspension forced; update state counters and exit */
+ coef->MCU_vert_offset = yoffset;
+ coef->mcu_ctr = MCU_col_num;
+ return FALSE;
+ }
+ }
+ /* Completed an MCU row, but perhaps not an iMCU row */
+ coef->mcu_ctr = 0;
+ }
+ /* Completed the iMCU row, advance counters for next one */
+ coef->iMCU_row_num++;
+ start_iMCU_row(cinfo);
+ return TRUE;
+}
+
+
+/*
+ * Initialize coefficient buffer controller.
+ *
+ * Each passed coefficient array must be the right size for that
+ * coefficient: width_in_blocks wide and height_in_blocks high,
+ * with unitheight at least v_samp_factor.
+ */
+
+LOCAL(void)
+transencode_coef_controller (j_compress_ptr cinfo,
+ jvirt_barray_ptr * coef_arrays)
+{
+ my_coef_ptr coef;
+ JBLOCKROW buffer;
+ int i;
+
+ coef = (my_coef_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_coef_controller));
+ cinfo->coef = (struct jpeg_c_coef_controller *) coef;
+ coef->pub.start_pass = start_pass_coef;
+ coef->pub.compress_data = compress_output;
+
+ /* Save pointer to virtual arrays */
+ coef->whole_image = coef_arrays;
+
+ /* Allocate and pre-zero space for dummy DCT blocks. */
+ buffer = (JBLOCKROW)
+ (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
+ jzero_far((void FAR *) buffer, C_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
+ for (i = 0; i < C_MAX_BLOCKS_IN_MCU; i++) {
+ coef->dummy_buffer[i] = buffer + i;
+ }
+}
--- /dev/null
+/*
+ * jdapimin.c
+ *
+ * Copyright (C) 1994-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the decompression half
+ * of the JPEG library. These are the "minimum" API routines that may be
+ * needed in either the normal full-decompression case or the
+ * transcoding-only case.
+ *
+ * Most of the routines intended to be called directly by an application
+ * are in this file or in jdapistd.c. But also see jcomapi.c for routines
+ * shared by compression and decompression, and jdtrans.c for the transcoding
+ * case.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * Initialization of a JPEG decompression object.
+ * The error manager must already be set up (in case memory manager fails).
+ */
+
+GLOBAL(void)
+jpeg_CreateDecompress (j_decompress_ptr cinfo, int version, size_t structsize)
+{
+ int i;
+
+ /* Guard against version mismatches between library and caller. */
+ cinfo->mem = NULL; /* so jpeg_destroy knows mem mgr not called */
+ if (version != JPEG_LIB_VERSION)
+ ERREXIT2(cinfo, JERR_BAD_LIB_VERSION, JPEG_LIB_VERSION, version);
+ if (structsize != SIZEOF(struct jpeg_decompress_struct))
+ ERREXIT2(cinfo, JERR_BAD_STRUCT_SIZE,
+ (int) SIZEOF(struct jpeg_decompress_struct), (int) structsize);
+
+ /* For debugging purposes, we zero the whole master structure.
+ * But the application has already set the err pointer, and may have set
+ * client_data, so we have to save and restore those fields.
+ * Note: if application hasn't set client_data, tools like Purify may
+ * complain here.
+ */
+ {
+ struct jpeg_error_mgr * err = cinfo->err;
+ void * client_data = cinfo->client_data; /* ignore Purify complaint here */
+ MEMZERO(cinfo, SIZEOF(struct jpeg_decompress_struct));
+ cinfo->err = err;
+ cinfo->client_data = client_data;
+ }
+ cinfo->is_decompressor = TRUE;
+
+ /* Initialize a memory manager instance for this object */
+ jinit_memory_mgr((j_common_ptr) cinfo);
+
+ /* Zero out pointers to permanent structures. */
+ cinfo->progress = NULL;
+ cinfo->src = NULL;
+
+ for (i = 0; i < NUM_QUANT_TBLS; i++)
+ cinfo->quant_tbl_ptrs[i] = NULL;
+
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ cinfo->dc_huff_tbl_ptrs[i] = NULL;
+ cinfo->ac_huff_tbl_ptrs[i] = NULL;
+ }
+
+ /* Initialize marker processor so application can override methods
+ * for COM, APPn markers before calling jpeg_read_header.
+ */
+ cinfo->marker_list = NULL;
+ jinit_marker_reader(cinfo);
+
+ /* And initialize the overall input controller. */
+ jinit_input_controller(cinfo);
+
+ /* OK, I'm ready */
+ cinfo->global_state = DSTATE_START;
+}
+
+
+/*
+ * Destruction of a JPEG decompression object
+ */
+
+GLOBAL(void)
+jpeg_destroy_decompress (j_decompress_ptr cinfo)
+{
+ jpeg_destroy((j_common_ptr) cinfo); /* use common routine */
+}
+
+
+/*
+ * Abort processing of a JPEG decompression operation,
+ * but don't destroy the object itself.
+ */
+
+GLOBAL(void)
+jpeg_abort_decompress (j_decompress_ptr cinfo)
+{
+ jpeg_abort((j_common_ptr) cinfo); /* use common routine */
+}
+
+
+/*
+ * Set default decompression parameters.
+ */
+
+LOCAL(void)
+default_decompress_parms (j_decompress_ptr cinfo)
+{
+ /* Guess the input colorspace, and set output colorspace accordingly. */
+ /* (Wish JPEG committee had provided a real way to specify this...) */
+ /* Note application may override our guesses. */
+ switch (cinfo->num_components) {
+ case 1:
+ cinfo->jpeg_color_space = JCS_GRAYSCALE;
+ cinfo->out_color_space = JCS_GRAYSCALE;
+ break;
+
+ case 3:
+ if (cinfo->saw_JFIF_marker) {
+ cinfo->jpeg_color_space = JCS_YCbCr; /* JFIF implies YCbCr */
+ } else if (cinfo->saw_Adobe_marker) {
+ switch (cinfo->Adobe_transform) {
+ case 0:
+ cinfo->jpeg_color_space = JCS_RGB;
+ break;
+ case 1:
+ cinfo->jpeg_color_space = JCS_YCbCr;
+ break;
+ default:
+ WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
+ cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
+ break;
+ }
+ } else {
+ /* Saw no special markers, try to guess from the component IDs */
+ int cid0 = cinfo->comp_info[0].component_id;
+ int cid1 = cinfo->comp_info[1].component_id;
+ int cid2 = cinfo->comp_info[2].component_id;
+
+ if (cid0 == 1 && cid1 == 2 && cid2 == 3)
+ cinfo->jpeg_color_space = JCS_YCbCr; /* assume JFIF w/out marker */
+ else if (cid0 == 82 && cid1 == 71 && cid2 == 66)
+ cinfo->jpeg_color_space = JCS_RGB; /* ASCII 'R', 'G', 'B' */
+ else {
+ TRACEMS3(cinfo, 1, JTRC_UNKNOWN_IDS, cid0, cid1, cid2);
+ cinfo->jpeg_color_space = JCS_YCbCr; /* assume it's YCbCr */
+ }
+ }
+ /* Always guess RGB is proper output colorspace. */
+ cinfo->out_color_space = JCS_RGB;
+ break;
+
+ case 4:
+ if (cinfo->saw_Adobe_marker) {
+ switch (cinfo->Adobe_transform) {
+ case 0:
+ cinfo->jpeg_color_space = JCS_CMYK;
+ break;
+ case 2:
+ cinfo->jpeg_color_space = JCS_YCCK;
+ break;
+ default:
+ WARNMS1(cinfo, JWRN_ADOBE_XFORM, cinfo->Adobe_transform);
+ cinfo->jpeg_color_space = JCS_YCCK; /* assume it's YCCK */
+ break;
+ }
+ } else {
+ /* No special markers, assume straight CMYK. */
+ cinfo->jpeg_color_space = JCS_CMYK;
+ }
+ cinfo->out_color_space = JCS_CMYK;
+ break;
+
+ default:
+ cinfo->jpeg_color_space = JCS_UNKNOWN;
+ cinfo->out_color_space = JCS_UNKNOWN;
+ break;
+ }
+
+ /* Set defaults for other decompression parameters. */
+ cinfo->scale_num = 1; /* 1:1 scaling */
+ cinfo->scale_denom = 1;
+ cinfo->output_gamma = 1.0;
+ cinfo->buffered_image = FALSE;
+ cinfo->raw_data_out = FALSE;
+ cinfo->dct_method = JDCT_DEFAULT;
+ cinfo->do_fancy_upsampling = TRUE;
+ cinfo->do_block_smoothing = TRUE;
+ cinfo->quantize_colors = FALSE;
+ /* We set these in case application only sets quantize_colors. */
+ cinfo->dither_mode = JDITHER_FS;
+#ifdef QUANT_2PASS_SUPPORTED
+ cinfo->two_pass_quantize = TRUE;
+#else
+ cinfo->two_pass_quantize = FALSE;
+#endif
+ cinfo->desired_number_of_colors = 256;
+ cinfo->colormap = NULL;
+ /* Initialize for no mode change in buffered-image mode. */
+ cinfo->enable_1pass_quant = FALSE;
+ cinfo->enable_external_quant = FALSE;
+ cinfo->enable_2pass_quant = FALSE;
+}
+
+
+/*
+ * Decompression startup: read start of JPEG datastream to see what's there.
+ * Need only initialize JPEG object and supply a data source before calling.
+ *
+ * This routine will read as far as the first SOS marker (ie, actual start of
+ * compressed data), and will save all tables and parameters in the JPEG
+ * object. It will also initialize the decompression parameters to default
+ * values, and finally return JPEG_HEADER_OK. On return, the application may
+ * adjust the decompression parameters and then call jpeg_start_decompress.
+ * (Or, if the application only wanted to determine the image parameters,
+ * the data need not be decompressed. In that case, call jpeg_abort or
+ * jpeg_destroy to release any temporary space.)
+ * If an abbreviated (tables only) datastream is presented, the routine will
+ * return JPEG_HEADER_TABLES_ONLY upon reaching EOI. The application may then
+ * re-use the JPEG object to read the abbreviated image datastream(s).
+ * It is unnecessary (but OK) to call jpeg_abort in this case.
+ * The JPEG_SUSPENDED return code only occurs if the data source module
+ * requests suspension of the decompressor. In this case the application
+ * should load more source data and then re-call jpeg_read_header to resume
+ * processing.
+ * If a non-suspending data source is used and require_image is TRUE, then the
+ * return code need not be inspected since only JPEG_HEADER_OK is possible.
+ *
+ * This routine is now just a front end to jpeg_consume_input, with some
+ * extra error checking.
+ */
+
+GLOBAL(int)
+jpeg_read_header (j_decompress_ptr cinfo, boolean require_image)
+{
+ int retcode;
+
+ if (cinfo->global_state != DSTATE_START &&
+ cinfo->global_state != DSTATE_INHEADER)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ retcode = jpeg_consume_input(cinfo);
+
+ switch (retcode) {
+ case JPEG_REACHED_SOS:
+ retcode = JPEG_HEADER_OK;
+ break;
+ case JPEG_REACHED_EOI:
+ if (require_image) /* Complain if application wanted an image */
+ ERREXIT(cinfo, JERR_NO_IMAGE);
+ /* Reset to start state; it would be safer to require the application to
+ * call jpeg_abort, but we can't change it now for compatibility reasons.
+ * A side effect is to free any temporary memory (there shouldn't be any).
+ */
+ jpeg_abort((j_common_ptr) cinfo); /* sets state = DSTATE_START */
+ retcode = JPEG_HEADER_TABLES_ONLY;
+ break;
+ case JPEG_SUSPENDED:
+ /* no work */
+ break;
+ }
+
+ return retcode;
+}
+
+
+/*
+ * Consume data in advance of what the decompressor requires.
+ * This can be called at any time once the decompressor object has
+ * been created and a data source has been set up.
+ *
+ * This routine is essentially a state machine that handles a couple
+ * of critical state-transition actions, namely initial setup and
+ * transition from header scanning to ready-for-start_decompress.
+ * All the actual input is done via the input controller's consume_input
+ * method.
+ */
+
+GLOBAL(int)
+jpeg_consume_input (j_decompress_ptr cinfo)
+{
+ int retcode = JPEG_SUSPENDED;
+
+ /* NB: every possible DSTATE value should be listed in this switch */
+ switch (cinfo->global_state) {
+ case DSTATE_START:
+ /* Start-of-datastream actions: reset appropriate modules */
+ (*cinfo->inputctl->reset_input_controller) (cinfo);
+ /* Initialize application's data source module */
+ (*cinfo->src->init_source) (cinfo);
+ cinfo->global_state = DSTATE_INHEADER;
+ /*FALLTHROUGH*/
+ case DSTATE_INHEADER:
+ retcode = (*cinfo->inputctl->consume_input) (cinfo);
+ if (retcode == JPEG_REACHED_SOS) { /* Found SOS, prepare to decompress */
+ /* Set up default parameters based on header data */
+ default_decompress_parms(cinfo);
+ /* Set global state: ready for start_decompress */
+ cinfo->global_state = DSTATE_READY;
+ }
+ break;
+ case DSTATE_READY:
+ /* Can't advance past first SOS until start_decompress is called */
+ retcode = JPEG_REACHED_SOS;
+ break;
+ case DSTATE_PRELOAD:
+ case DSTATE_PRESCAN:
+ case DSTATE_SCANNING:
+ case DSTATE_RAW_OK:
+ case DSTATE_BUFIMAGE:
+ case DSTATE_BUFPOST:
+ case DSTATE_STOPPING:
+ retcode = (*cinfo->inputctl->consume_input) (cinfo);
+ break;
+ default:
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ }
+ return retcode;
+}
+
+
+/*
+ * Have we finished reading the input file?
+ */
+
+GLOBAL(boolean)
+jpeg_input_complete (j_decompress_ptr cinfo)
+{
+ /* Check for valid jpeg object */
+ if (cinfo->global_state < DSTATE_START ||
+ cinfo->global_state > DSTATE_STOPPING)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ return cinfo->inputctl->eoi_reached;
+}
+
+
+/*
+ * Is there more than one scan?
+ */
+
+GLOBAL(boolean)
+jpeg_has_multiple_scans (j_decompress_ptr cinfo)
+{
+ /* Only valid after jpeg_read_header completes */
+ if (cinfo->global_state < DSTATE_READY ||
+ cinfo->global_state > DSTATE_STOPPING)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ return cinfo->inputctl->has_multiple_scans;
+}
+
+
+/*
+ * Finish JPEG decompression.
+ *
+ * This will normally just verify the file trailer and release temp storage.
+ *
+ * Returns FALSE if suspended. The return value need be inspected only if
+ * a suspending data source is used.
+ */
+
+GLOBAL(boolean)
+jpeg_finish_decompress (j_decompress_ptr cinfo)
+{
+ if ((cinfo->global_state == DSTATE_SCANNING ||
+ cinfo->global_state == DSTATE_RAW_OK) && ! cinfo->buffered_image) {
+ /* Terminate final pass of non-buffered mode */
+ if (cinfo->output_scanline < cinfo->output_height)
+ ERREXIT(cinfo, JERR_TOO_LITTLE_DATA);
+ (*cinfo->master->finish_output_pass) (cinfo);
+ cinfo->global_state = DSTATE_STOPPING;
+ } else if (cinfo->global_state == DSTATE_BUFIMAGE) {
+ /* Finishing after a buffered-image operation */
+ cinfo->global_state = DSTATE_STOPPING;
+ } else if (cinfo->global_state != DSTATE_STOPPING) {
+ /* STOPPING = repeat call after a suspension, anything else is error */
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ }
+ /* Read until EOI */
+ while (! cinfo->inputctl->eoi_reached) {
+ if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
+ return FALSE; /* Suspend, come back later */
+ }
+ /* Do final cleanup */
+ (*cinfo->src->term_source) (cinfo);
+ /* We can use jpeg_abort to release memory and reset global_state */
+ jpeg_abort((j_common_ptr) cinfo);
+ return TRUE;
+}
--- /dev/null
+/*
+ * jdapistd.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface code for the decompression half
+ * of the JPEG library. These are the "standard" API routines that are
+ * used in the normal full-decompression case. They are not used by a
+ * transcoding-only application. Note that if an application links in
+ * jpeg_start_decompress, it will end up linking in the entire decompressor.
+ * We thus must separate this file from jdapimin.c to avoid linking the
+ * whole decompression library into a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+/* Forward declarations */
+LOCAL(boolean) output_pass_setup JPP((j_decompress_ptr cinfo));
+
+
+/*
+ * Decompression initialization.
+ * jpeg_read_header must be completed before calling this.
+ *
+ * If a multipass operating mode was selected, this will do all but the
+ * last pass, and thus may take a great deal of time.
+ *
+ * Returns FALSE if suspended. The return value need be inspected only if
+ * a suspending data source is used.
+ */
+
+GLOBAL(boolean)
+jpeg_start_decompress (j_decompress_ptr cinfo)
+{
+ if (cinfo->global_state == DSTATE_READY) {
+ /* First call: initialize master control, select active modules */
+ jinit_master_decompress(cinfo);
+ if (cinfo->buffered_image) {
+ /* No more work here; expecting jpeg_start_output next */
+ cinfo->global_state = DSTATE_BUFIMAGE;
+ return TRUE;
+ }
+ cinfo->global_state = DSTATE_PRELOAD;
+ }
+ if (cinfo->global_state == DSTATE_PRELOAD) {
+ /* If file has multiple scans, absorb them all into the coef buffer */
+ if (cinfo->inputctl->has_multiple_scans) {
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+ for (;;) {
+ int retcode;
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL)
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ /* Absorb some more input */
+ retcode = (*cinfo->inputctl->consume_input) (cinfo);
+ if (retcode == JPEG_SUSPENDED)
+ return FALSE;
+ if (retcode == JPEG_REACHED_EOI)
+ break;
+ /* Advance progress counter if appropriate */
+ if (cinfo->progress != NULL &&
+ (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
+ if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
+ /* jdmaster underestimated number of scans; ratchet up one scan */
+ cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
+ }
+ }
+ }
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+ }
+ cinfo->output_scan_number = cinfo->input_scan_number;
+ } else if (cinfo->global_state != DSTATE_PRESCAN)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ /* Perform any dummy output passes, and set up for the final pass */
+ return output_pass_setup(cinfo);
+}
+
+
+/*
+ * Set up for an output pass, and perform any dummy pass(es) needed.
+ * Common subroutine for jpeg_start_decompress and jpeg_start_output.
+ * Entry: global_state = DSTATE_PRESCAN only if previously suspended.
+ * Exit: If done, returns TRUE and sets global_state for proper output mode.
+ * If suspended, returns FALSE and sets global_state = DSTATE_PRESCAN.
+ */
+
+LOCAL(boolean)
+output_pass_setup (j_decompress_ptr cinfo)
+{
+ if (cinfo->global_state != DSTATE_PRESCAN) {
+ /* First call: do pass setup */
+ (*cinfo->master->prepare_for_output_pass) (cinfo);
+ cinfo->output_scanline = 0;
+ cinfo->global_state = DSTATE_PRESCAN;
+ }
+ /* Loop over any required dummy passes */
+ while (cinfo->master->is_dummy_pass) {
+#ifdef QUANT_2PASS_SUPPORTED
+ /* Crank through the dummy pass */
+ while (cinfo->output_scanline < cinfo->output_height) {
+ JDIMENSION last_scanline;
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->pass_counter = (long) cinfo->output_scanline;
+ cinfo->progress->pass_limit = (long) cinfo->output_height;
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ }
+ /* Process some data */
+ last_scanline = cinfo->output_scanline;
+ (*cinfo->main->process_data) (cinfo, (JSAMPARRAY) NULL,
+ &cinfo->output_scanline, (JDIMENSION) 0);
+ if (cinfo->output_scanline == last_scanline)
+ return FALSE; /* No progress made, must suspend */
+ }
+ /* Finish up dummy pass, and set up for another one */
+ (*cinfo->master->finish_output_pass) (cinfo);
+ (*cinfo->master->prepare_for_output_pass) (cinfo);
+ cinfo->output_scanline = 0;
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif /* QUANT_2PASS_SUPPORTED */
+ }
+ /* Ready for application to drive output pass through
+ * jpeg_read_scanlines or jpeg_read_raw_data.
+ */
+ cinfo->global_state = cinfo->raw_data_out ? DSTATE_RAW_OK : DSTATE_SCANNING;
+ return TRUE;
+}
+
+
+/*
+ * Read some scanlines of data from the JPEG decompressor.
+ *
+ * The return value will be the number of lines actually read.
+ * This may be less than the number requested in several cases,
+ * including bottom of image, data source suspension, and operating
+ * modes that emit multiple scanlines at a time.
+ *
+ * Note: we warn about excess calls to jpeg_read_scanlines() since
+ * this likely signals an application programmer error. However,
+ * an oversize buffer (max_lines > scanlines remaining) is not an error.
+ */
+
+//GLOBAL(JDIMENSION)
+//jpeg_read_scanlines (j_decompress_ptr cinfo, JSAMPARRAY scanlines,
+// JDIMENSION max_lines)
+
+GLOBAL(JDIMENSION)
+jReadScanlines(j_decompress_ptr cinfo, JSAMPARRAY scanlines,
+ JDIMENSION max_lines)
+{
+ JDIMENSION row_ctr;
+
+ if (cinfo->global_state != DSTATE_SCANNING)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ if (cinfo->output_scanline >= cinfo->output_height) {
+ WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
+ return 0;
+ }
+
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->pass_counter = (long) cinfo->output_scanline;
+ cinfo->progress->pass_limit = (long) cinfo->output_height;
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ }
+
+ /* Process some data */
+ row_ctr = 0;
+ (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, max_lines);
+ cinfo->output_scanline += row_ctr;
+ return row_ctr;
+}
+
+
+/*
+ * Alternate entry point to read raw data.
+ * Processes exactly one iMCU row per call, unless suspended.
+ */
+
+GLOBAL(JDIMENSION)
+jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
+ JDIMENSION max_lines)
+{
+ JDIMENSION lines_per_iMCU_row;
+
+ if (cinfo->global_state != DSTATE_RAW_OK)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ if (cinfo->output_scanline >= cinfo->output_height) {
+ WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
+ return 0;
+ }
+
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->pass_counter = (long) cinfo->output_scanline;
+ cinfo->progress->pass_limit = (long) cinfo->output_height;
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ }
+
+ /* Verify that at least one iMCU row can be returned. */
+ lines_per_iMCU_row = cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size;
+ if (max_lines < lines_per_iMCU_row)
+ ERREXIT(cinfo, JERR_BUFFER_SIZE);
+
+ /* Decompress directly into user's buffer. */
+ if (! (*cinfo->coef->decompress_data) (cinfo, data))
+ return 0; /* suspension forced, can do nothing more */
+
+ /* OK, we processed one iMCU row. */
+ cinfo->output_scanline += lines_per_iMCU_row;
+ return lines_per_iMCU_row;
+}
+
+
+/* Additional entry points for buffered-image mode. */
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+
+/*
+ * Initialize for an output pass in buffered-image mode.
+ */
+
+GLOBAL(boolean)
+jpeg_start_output (j_decompress_ptr cinfo, int scan_number)
+{
+ if (cinfo->global_state != DSTATE_BUFIMAGE &&
+ cinfo->global_state != DSTATE_PRESCAN)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ /* Limit scan number to valid range */
+ if (scan_number <= 0)
+ scan_number = 1;
+ if (cinfo->inputctl->eoi_reached &&
+ scan_number > cinfo->input_scan_number)
+ scan_number = cinfo->input_scan_number;
+ cinfo->output_scan_number = scan_number;
+ /* Perform any dummy output passes, and set up for the real pass */
+ return output_pass_setup(cinfo);
+}
+
+
+/*
+ * Finish up after an output pass in buffered-image mode.
+ *
+ * Returns FALSE if suspended. The return value need be inspected only if
+ * a suspending data source is used.
+ */
+
+GLOBAL(boolean)
+jpeg_finish_output (j_decompress_ptr cinfo)
+{
+ if ((cinfo->global_state == DSTATE_SCANNING ||
+ cinfo->global_state == DSTATE_RAW_OK) && cinfo->buffered_image) {
+ /* Terminate this pass. */
+ /* We do not require the whole pass to have been completed. */
+ (*cinfo->master->finish_output_pass) (cinfo);
+ cinfo->global_state = DSTATE_BUFPOST;
+ } else if (cinfo->global_state != DSTATE_BUFPOST) {
+ /* BUFPOST = repeat call after a suspension, anything else is error */
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ }
+ /* Read markers looking for SOS or EOI */
+ while (cinfo->input_scan_number <= cinfo->output_scan_number &&
+ ! cinfo->inputctl->eoi_reached) {
+ if ((*cinfo->inputctl->consume_input) (cinfo) == JPEG_SUSPENDED)
+ return FALSE; /* Suspend, come back later */
+ }
+ cinfo->global_state = DSTATE_BUFIMAGE;
+ return TRUE;
+}
+
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
--- /dev/null
+/*
+ * jdatadst.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains compression data destination routines for the case of
+ * emitting JPEG data to a file (or any stdio stream). While these routines
+ * are sufficient for most applications, some will want to use a different
+ * destination manager.
+ * IMPORTANT: we assume that fwrite() will correctly transcribe an array of
+ * JOCTETs into 8-bit-wide elements on external storage. If char is wider
+ * than 8 bits on your machine, you may need to do some tweaking.
+ */
+
+/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jerror12.h"
+
+
+/* Expanded data destination object for stdio output */
+
+typedef struct {
+ struct jpeg_destination_mgr pub; /* public fields */
+
+ FILE * outfile; /* target stream */
+ JOCTET * buffer; /* start of buffer */
+} my_destination_mgr;
+
+typedef my_destination_mgr * my_dest_ptr;
+
+#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
+
+
+/*
+ * Initialize destination --- called by jpeg_start_compress
+ * before any data is actually written.
+ */
+
+METHODDEF(void)
+init_destination (j_compress_ptr cinfo)
+{
+ my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
+
+ /* Allocate the output buffer --- it will be released when done with image */
+ dest->buffer = (JOCTET *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ OUTPUT_BUF_SIZE * SIZEOF(JOCTET));
+
+ dest->pub.next_output_byte = dest->buffer;
+ dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
+}
+
+
+/*
+ * Empty the output buffer --- called whenever buffer fills up.
+ *
+ * In typical applications, this should write the entire output buffer
+ * (ignoring the current state of next_output_byte & free_in_buffer),
+ * reset the pointer & count to the start of the buffer, and return TRUE
+ * indicating that the buffer has been dumped.
+ *
+ * In applications that need to be able to suspend compression due to output
+ * overrun, a FALSE return indicates that the buffer cannot be emptied now.
+ * In this situation, the compressor will return to its caller (possibly with
+ * an indication that it has not accepted all the supplied scanlines). The
+ * application should resume compression after it has made more room in the
+ * output buffer. Note that there are substantial restrictions on the use of
+ * suspension --- see the documentation.
+ *
+ * When suspending, the compressor will back up to a convenient restart point
+ * (typically the start of the current MCU). next_output_byte & free_in_buffer
+ * indicate where the restart point will be if the current call returns FALSE.
+ * Data beyond this point will be regenerated after resumption, so do not
+ * write it out when emptying the buffer externally.
+ */
+
+METHODDEF(boolean)
+empty_output_buffer (j_compress_ptr cinfo)
+{
+ my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
+
+ if (JFWRITE(dest->outfile, dest->buffer, OUTPUT_BUF_SIZE) !=
+ (size_t) OUTPUT_BUF_SIZE)
+ ERREXIT(cinfo, JERR_FILE_WRITE);
+
+ dest->pub.next_output_byte = dest->buffer;
+ dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
+
+ return TRUE;
+}
+
+
+/*
+ * Terminate destination --- called by jpeg_finish_compress
+ * after all data has been written. Usually needs to flush buffer.
+ *
+ * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
+ * application must deal with any cleanup that should happen even
+ * for error exit.
+ */
+
+METHODDEF(void)
+term_destination (j_compress_ptr cinfo)
+{
+ my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
+ size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
+
+ /* Write any data remaining in the buffer */
+ if (datacount > 0) {
+ if (JFWRITE(dest->outfile, dest->buffer, datacount) != datacount)
+ ERREXIT(cinfo, JERR_FILE_WRITE);
+ }
+ fflush(dest->outfile);
+ /* Make sure we wrote the output file OK */
+ if (ferror(dest->outfile))
+ ERREXIT(cinfo, JERR_FILE_WRITE);
+}
+
+
+/*
+ * Prepare for output to a stdio stream.
+ * The caller must have already opened the stream, and is responsible
+ * for closing it after finishing compression.
+ */
+
+GLOBAL(void)
+jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile)
+{
+ my_dest_ptr dest;
+
+ /* The destination object is made permanent so that multiple JPEG images
+ * can be written to the same file without re-executing jpeg_stdio_dest.
+ * This makes it dangerous to use this manager and a different destination
+ * manager serially with the same JPEG object, because their private object
+ * sizes may be different. Caveat programmer.
+ */
+ if (cinfo->dest == NULL) { /* first time for this JPEG object? */
+ cinfo->dest = (struct jpeg_destination_mgr *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ SIZEOF(my_destination_mgr));
+ }
+
+ dest = (my_dest_ptr) cinfo->dest;
+ dest->pub.init_destination = init_destination;
+ dest->pub.empty_output_buffer = empty_output_buffer;
+ dest->pub.term_destination = term_destination;
+ dest->outfile = outfile;
+}
--- /dev/null
+/*
+ * jdatasrc.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains decompression data source routines for the case of
+ * reading JPEG data from a file (or any stdio stream). While these routines
+ * are sufficient for most applications, some will want to use a different
+ * source manager.
+ * IMPORTANT: we assume that fread() will correctly transcribe an array of
+ * JOCTETs from 8-bit-wide elements on external storage. If char is wider
+ * than 8 bits on your machine, you may need to do some tweaking.
+ */
+
+/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jerror12.h"
+
+
+/* Expanded data source object for stdio input */
+
+typedef struct {
+ struct jpeg_source_mgr pub; /* public fields */
+
+ FILE * infile; /* source stream */
+ JOCTET * buffer; /* start of buffer */
+ boolean start_of_file; /* have we gotten any data yet? */
+} my_source_mgr;
+
+typedef my_source_mgr * my_src_ptr;
+
+#define INPUT_BUF_SIZE 4096 /* choose an efficiently fread'able size */
+
+
+/*
+ * Initialize source --- called by jpeg_read_header
+ * before any data is actually read.
+ */
+
+METHODDEF(void)
+init_source (j_decompress_ptr cinfo)
+{
+ my_src_ptr src = (my_src_ptr) cinfo->src;
+
+ /* We reset the empty-input-file flag for each image,
+ * but we don't clear the input buffer.
+ * This is correct behavior for reading a series of images from one source.
+ */
+ src->start_of_file = TRUE;
+}
+
+
+/*
+ * Fill the input buffer --- called whenever buffer is emptied.
+ *
+ * In typical applications, this should read fresh data into the buffer
+ * (ignoring the current state of next_input_byte & bytes_in_buffer),
+ * reset the pointer & count to the start of the buffer, and return TRUE
+ * indicating that the buffer has been reloaded. It is not necessary to
+ * fill the buffer entirely, only to obtain at least one more byte.
+ *
+ * There is no such thing as an EOF return. If the end of the file has been
+ * reached, the routine has a choice of ERREXIT() or inserting fake data into
+ * the buffer. In most cases, generating a warning message and inserting a
+ * fake EOI marker is the best course of action --- this will allow the
+ * decompressor to output however much of the image is there. However,
+ * the resulting error message is misleading if the real problem is an empty
+ * input file, so we handle that case specially.
+ *
+ * In applications that need to be able to suspend compression due to input
+ * not being available yet, a FALSE return indicates that no more data can be
+ * obtained right now, but more may be forthcoming later. In this situation,
+ * the decompressor will return to its caller (with an indication of the
+ * number of scanlines it has read, if any). The application should resume
+ * decompression after it has loaded more data into the input buffer. Note
+ * that there are substantial restrictions on the use of suspension --- see
+ * the documentation.
+ *
+ * When suspending, the decompressor will back up to a convenient restart point
+ * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
+ * indicate where the restart point will be if the current call returns FALSE.
+ * Data beyond this point must be rescanned after resumption, so move it to
+ * the front of the buffer rather than discarding it.
+ */
+
+METHODDEF(boolean)
+fill_input_buffer (j_decompress_ptr cinfo)
+{
+ my_src_ptr src = (my_src_ptr) cinfo->src;
+ size_t nbytes;
+
+ nbytes = JFREAD(src->infile, src->buffer, INPUT_BUF_SIZE);
+
+ if (nbytes <= 0) {
+ if (src->start_of_file) /* Treat empty input file as fatal error */
+ ERREXIT(cinfo, JERR_INPUT_EMPTY);
+ WARNMS(cinfo, JWRN_JPEG_EOF);
+ /* Insert a fake EOI marker */
+ src->buffer[0] = (JOCTET) 0xFF;
+ src->buffer[1] = (JOCTET) JPEG_EOI;
+ nbytes = 2;
+ }
+
+ src->pub.next_input_byte = src->buffer;
+ src->pub.bytes_in_buffer = nbytes;
+ src->start_of_file = FALSE;
+
+ return TRUE;
+}
+
+
+/*
+ * Skip data --- used to skip over a potentially large amount of
+ * uninteresting data (such as an APPn marker).
+ *
+ * Writers of suspendable-input applications must note that skip_input_data
+ * is not granted the right to give a suspension return. If the skip extends
+ * beyond the data currently in the buffer, the buffer can be marked empty so
+ * that the next read will cause a fill_input_buffer call that can suspend.
+ * Arranging for additional bytes to be discarded before reloading the input
+ * buffer is the application writer's problem.
+ */
+
+METHODDEF(void)
+skip_input_data (j_decompress_ptr cinfo, long num_bytes)
+{
+ my_src_ptr src = (my_src_ptr) cinfo->src;
+
+ /* Just a dumb implementation for now. Could use fseek() except
+ * it doesn't work on pipes. Not clear that being smart is worth
+ * any trouble anyway --- large skips are infrequent.
+ */
+ if (num_bytes > 0) {
+ while (num_bytes > (long) src->pub.bytes_in_buffer) {
+ num_bytes -= (long) src->pub.bytes_in_buffer;
+ (void) fill_input_buffer(cinfo);
+ /* note we assume that fill_input_buffer will never return FALSE,
+ * so suspension need not be handled.
+ */
+ }
+ src->pub.next_input_byte += (size_t) num_bytes;
+ src->pub.bytes_in_buffer -= (size_t) num_bytes;
+ }
+}
+
+
+/*
+ * An additional method that can be provided by data source modules is the
+ * resync_to_restart method for error recovery in the presence of RST markers.
+ * For the moment, this source module just uses the default resync method
+ * provided by the JPEG library. That method assumes that no backtracking
+ * is possible.
+ */
+
+
+/*
+ * Terminate source --- called by jpeg_finish_decompress
+ * after all data has been read. Often a no-op.
+ *
+ * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
+ * application must deal with any cleanup that should happen even
+ * for error exit.
+ */
+
+METHODDEF(void)
+term_source (j_decompress_ptr cinfo)
+{
+ /* no work necessary here */
+}
+
+
+/*
+ * Prepare for input from a stdio stream.
+ * The caller must have already opened the stream, and is responsible
+ * for closing it after finishing decompression.
+ */
+
+GLOBAL(void)
+jpeg_stdio_src (j_decompress_ptr cinfo, FILE * infile)
+{
+ my_src_ptr src;
+
+ /* The source object and input buffer are made permanent so that a series
+ * of JPEG images can be read from the same file by calling jpeg_stdio_src
+ * only before the first one. (If we discarded the buffer at the end of
+ * one image, we'd likely lose the start of the next one.)
+ * This makes it unsafe to use this manager and a different source
+ * manager serially with the same JPEG object. Caveat programmer.
+ */
+ if (cinfo->src == NULL) { /* first time for this JPEG object? */
+ cinfo->src = (struct jpeg_source_mgr *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ SIZEOF(my_source_mgr));
+ src = (my_src_ptr) cinfo->src;
+ src->buffer = (JOCTET *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ INPUT_BUF_SIZE * SIZEOF(JOCTET));
+ }
+
+ src = (my_src_ptr) cinfo->src;
+ src->pub.init_source = init_source;
+ src->pub.fill_input_buffer = fill_input_buffer;
+ src->pub.skip_input_data = skip_input_data;
+ src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
+ src->pub.term_source = term_source;
+ src->infile = infile;
+ src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
+ src->pub.next_input_byte = NULL; /* until buffer loaded */
+}
--- /dev/null
+/*
+ * jdcoefct.c
+ *
+ * Copyright (C) 1994-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the coefficient buffer controller for decompression.
+ * This controller is the top level of the JPEG decompressor proper.
+ * The coefficient buffer lies between entropy decoding and inverse-DCT steps.
+ *
+ * In buffered-image mode, this controller is the interface between
+ * input-oriented processing and output-oriented processing.
+ * Also, the input side (only) is used when reading a file for transcoding.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+/* Block smoothing is only applicable for progressive JPEG, so: */
+#ifndef D_PROGRESSIVE_SUPPORTED
+#undef BLOCK_SMOOTHING_SUPPORTED
+#endif
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_d_coef_controller pub; /* public fields */
+
+ /* These variables keep track of the current location of the input side. */
+ /* cinfo->input_iMCU_row is also used for this. */
+ JDIMENSION MCU_ctr; /* counts MCUs processed in current row */
+ int MCU_vert_offset; /* counts MCU rows within iMCU row */
+ int MCU_rows_per_iMCU_row; /* number of such rows needed */
+
+ /* The output side's location is represented by cinfo->output_iMCU_row. */
+
+ /* In single-pass modes, it's sufficient to buffer just one MCU.
+ * We allocate a workspace of D_MAX_BLOCKS_IN_MCU coefficient blocks,
+ * and let the entropy decoder write into that workspace each time.
+ * (On 80x86, the workspace is FAR even though it's not really very big;
+ * this is to keep the module interfaces unchanged when a large coefficient
+ * buffer is necessary.)
+ * In multi-pass modes, this array points to the current MCU's blocks
+ * within the virtual arrays; it is used only by the input side.
+ */
+ JBLOCKROW MCU_buffer[D_MAX_BLOCKS_IN_MCU];
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+ /* In multi-pass modes, we need a virtual block array for each component. */
+ jvirt_barray_ptr whole_image[MAX_COMPONENTS];
+#endif
+
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+ /* When doing block smoothing, we latch coefficient Al values here */
+ int * coef_bits_latch;
+#define SAVED_COEFS 6 /* we save coef_bits[0..5] */
+#endif
+} my_coef_controller;
+
+typedef my_coef_controller * my_coef_ptr;
+
+/* Forward declarations */
+METHODDEF(int) decompress_onepass
+ JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+METHODDEF(int) decompress_data
+ JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
+#endif
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+LOCAL(boolean) smoothing_ok JPP((j_decompress_ptr cinfo));
+METHODDEF(int) decompress_smooth_data
+ JPP((j_decompress_ptr cinfo, JSAMPIMAGE output_buf));
+#endif
+
+
+LOCAL(void)
+start_iMCU_row (j_decompress_ptr cinfo)
+/* Reset within-iMCU-row counters for a new row (input side) */
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+ /* In an interleaved scan, an MCU row is the same as an iMCU row.
+ * In a noninterleaved scan, an iMCU row has v_samp_factor MCU rows.
+ * But at the bottom of the image, process only what's left.
+ */
+ if (cinfo->comps_in_scan > 1) {
+ coef->MCU_rows_per_iMCU_row = 1;
+ } else {
+ if (cinfo->input_iMCU_row < (cinfo->total_iMCU_rows-1))
+ coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+ else
+ coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+ }
+
+ coef->MCU_ctr = 0;
+ coef->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for an input processing pass.
+ */
+
+METHODDEF(void)
+start_input_pass (j_decompress_ptr cinfo)
+{
+ cinfo->input_iMCU_row = 0;
+ start_iMCU_row(cinfo);
+}
+
+
+/*
+ * Initialize for an output processing pass.
+ */
+
+METHODDEF(void)
+start_output_pass (j_decompress_ptr cinfo)
+{
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+
+ /* If multipass, check to see whether to use block smoothing on this pass */
+ if (coef->pub.coef_arrays != NULL) {
+ if (cinfo->do_block_smoothing && smoothing_ok(cinfo))
+ coef->pub.decompress_data = decompress_smooth_data;
+ else
+ coef->pub.decompress_data = decompress_data;
+ }
+#endif
+ cinfo->output_iMCU_row = 0;
+}
+
+
+/*
+ * Decompress and return some data in the single-pass case.
+ * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
+ * Input and output must run in lockstep since we have only a one-MCU buffer.
+ * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
+ *
+ * NB: output_buf contains a plane for each component in image,
+ * which we index according to the component's SOF position.
+ */
+
+METHODDEF(int)
+decompress_onepass (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ int blkn, ci, xindex, yindex, yoffset, useful_width;
+ JSAMPARRAY output_ptr;
+ JDIMENSION start_col, output_col;
+ jpeg_component_info *compptr;
+ inverse_DCT_method_ptr inverse_DCT;
+
+ /* Loop to process as much as one whole iMCU row */
+ for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+ yoffset++) {
+ for (MCU_col_num = coef->MCU_ctr; MCU_col_num <= last_MCU_col;
+ MCU_col_num++) {
+ /* Try to fetch an MCU. Entropy decoder expects buffer to be zeroed. */
+ jzero_far((void FAR *) coef->MCU_buffer[0],
+ (size_t) (cinfo->blocks_in_MCU * SIZEOF(JBLOCK)));
+ if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
+ /* Suspension forced; update state counters and exit */
+ coef->MCU_vert_offset = yoffset;
+ coef->MCU_ctr = MCU_col_num;
+ return JPEG_SUSPENDED;
+ }
+ /* Determine where data should go in output_buf and do the IDCT thing.
+ * We skip dummy blocks at the right and bottom edges (but blkn gets
+ * incremented past them!). Note the inner loop relies on having
+ * allocated the MCU_buffer[] blocks sequentially.
+ */
+ blkn = 0; /* index of current DCT block within MCU */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Don't bother to IDCT an uninteresting component. */
+ if (! compptr->component_needed) {
+ blkn += compptr->MCU_blocks;
+ continue;
+ }
+ inverse_DCT = cinfo->idct->inverse_DCT[compptr->component_index];
+ useful_width = (MCU_col_num < last_MCU_col) ? compptr->MCU_width
+ : compptr->last_col_width;
+ output_ptr = output_buf[compptr->component_index] +
+ yoffset * compptr->DCT_scaled_size;
+ start_col = MCU_col_num * compptr->MCU_sample_width;
+ for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
+ if (cinfo->input_iMCU_row < last_iMCU_row ||
+ yoffset+yindex < compptr->last_row_height) {
+ output_col = start_col;
+ for (xindex = 0; xindex < useful_width; xindex++) {
+ (*inverse_DCT) (cinfo, compptr,
+ (JCOEFPTR) coef->MCU_buffer[blkn+xindex],
+ output_ptr, output_col);
+ output_col += compptr->DCT_scaled_size;
+ }
+ }
+ blkn += compptr->MCU_width;
+ output_ptr += compptr->DCT_scaled_size;
+ }
+ }
+ }
+ /* Completed an MCU row, but perhaps not an iMCU row */
+ coef->MCU_ctr = 0;
+ }
+ /* Completed the iMCU row, advance counters for next one */
+ cinfo->output_iMCU_row++;
+ if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
+ start_iMCU_row(cinfo);
+ return JPEG_ROW_COMPLETED;
+ }
+ /* Completed the scan */
+ (*cinfo->inputctl->finish_input_pass) (cinfo);
+ return JPEG_SCAN_COMPLETED;
+}
+
+
+/*
+ * Dummy consume-input routine for single-pass operation.
+ */
+
+METHODDEF(int)
+dummy_consume_data (j_decompress_ptr cinfo)
+{
+ return JPEG_SUSPENDED; /* Always indicate nothing was done */
+}
+
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+
+/*
+ * Consume input data and store it in the full-image coefficient buffer.
+ * We read as much as one fully interleaved MCU row ("iMCU" row) per call,
+ * ie, v_samp_factor block rows for each component in the scan.
+ * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
+ */
+
+METHODDEF(int)
+consume_data (j_decompress_ptr cinfo)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ int blkn, ci, xindex, yindex, yoffset;
+ JDIMENSION start_col;
+ JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
+ JBLOCKROW buffer_ptr;
+ jpeg_component_info *compptr;
+
+ /* Align the virtual buffers for the components used in this scan. */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ buffer[ci] = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[compptr->component_index],
+ cinfo->input_iMCU_row * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ /* Note: entropy decoder expects buffer to be zeroed,
+ * but this is handled automatically by the memory manager
+ * because we requested a pre-zeroed array.
+ */
+ }
+
+ /* Loop to process one whole iMCU row */
+ for (yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
+ yoffset++) {
+ for (MCU_col_num = coef->MCU_ctr; MCU_col_num < cinfo->MCUs_per_row;
+ MCU_col_num++) {
+ /* Construct list of pointers to DCT blocks belonging to this MCU */
+ blkn = 0; /* index of current DCT block within MCU */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ start_col = MCU_col_num * compptr->MCU_width;
+ for (yindex = 0; yindex < compptr->MCU_height; yindex++) {
+ buffer_ptr = buffer[ci][yindex+yoffset] + start_col;
+ for (xindex = 0; xindex < compptr->MCU_width; xindex++) {
+ coef->MCU_buffer[blkn++] = buffer_ptr++;
+ }
+ }
+ }
+ /* Try to fetch the MCU. */
+ if (! (*cinfo->entropy->decode_mcu) (cinfo, coef->MCU_buffer)) {
+ /* Suspension forced; update state counters and exit */
+ coef->MCU_vert_offset = yoffset;
+ coef->MCU_ctr = MCU_col_num;
+ return JPEG_SUSPENDED;
+ }
+ }
+ /* Completed an MCU row, but perhaps not an iMCU row */
+ coef->MCU_ctr = 0;
+ }
+ /* Completed the iMCU row, advance counters for next one */
+ if (++(cinfo->input_iMCU_row) < cinfo->total_iMCU_rows) {
+ start_iMCU_row(cinfo);
+ return JPEG_ROW_COMPLETED;
+ }
+ /* Completed the scan */
+ (*cinfo->inputctl->finish_input_pass) (cinfo);
+ return JPEG_SCAN_COMPLETED;
+}
+
+
+/*
+ * Decompress and return some data in the multi-pass case.
+ * Always attempts to emit one fully interleaved MCU row ("iMCU" row).
+ * Return value is JPEG_ROW_COMPLETED, JPEG_SCAN_COMPLETED, or JPEG_SUSPENDED.
+ *
+ * NB: output_buf contains a plane for each component in image.
+ */
+
+METHODDEF(int)
+decompress_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ JDIMENSION block_num;
+ int ci, block_row, block_rows;
+ JBLOCKARRAY buffer;
+ JBLOCKROW buffer_ptr;
+ JSAMPARRAY output_ptr;
+ JDIMENSION output_col;
+ jpeg_component_info *compptr;
+ inverse_DCT_method_ptr inverse_DCT;
+
+ /* Force some input to be done if we are getting ahead of the input. */
+ while (cinfo->input_scan_number < cinfo->output_scan_number ||
+ (cinfo->input_scan_number == cinfo->output_scan_number &&
+ cinfo->input_iMCU_row <= cinfo->output_iMCU_row)) {
+ if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
+ return JPEG_SUSPENDED;
+ }
+
+ /* OK, output from the virtual arrays. */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Don't bother to IDCT an uninteresting component. */
+ if (! compptr->component_needed)
+ continue;
+ /* Align the virtual buffer for this component. */
+ buffer = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[ci],
+ cinfo->output_iMCU_row * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ /* Count non-dummy DCT block rows in this iMCU row. */
+ if (cinfo->output_iMCU_row < last_iMCU_row)
+ block_rows = compptr->v_samp_factor;
+ else {
+ /* NB: can't use last_row_height here; it is input-side-dependent! */
+ block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
+ if (block_rows == 0) block_rows = compptr->v_samp_factor;
+ }
+ inverse_DCT = cinfo->idct->inverse_DCT[ci];
+ output_ptr = output_buf[ci];
+ /* Loop over all DCT blocks to be processed. */
+ for (block_row = 0; block_row < block_rows; block_row++) {
+ buffer_ptr = buffer[block_row];
+ output_col = 0;
+ for (block_num = 0; block_num < compptr->width_in_blocks; block_num++) {
+ (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) buffer_ptr,
+ output_ptr, output_col);
+ buffer_ptr++;
+ output_col += compptr->DCT_scaled_size;
+ }
+ output_ptr += compptr->DCT_scaled_size;
+ }
+ }
+
+ if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
+ return JPEG_ROW_COMPLETED;
+ return JPEG_SCAN_COMPLETED;
+}
+
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+
+
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+
+/*
+ * This code applies interblock smoothing as described by section K.8
+ * of the JPEG standard: the first 5 AC coefficients are estimated from
+ * the DC values of a DCT block and its 8 neighboring blocks.
+ * We apply smoothing only for progressive JPEG decoding, and only if
+ * the coefficients it can estimate are not yet known to full precision.
+ */
+
+/* Natural-order array positions of the first 5 zigzag-order coefficients */
+#define Q01_POS 1
+#define Q10_POS 8
+#define Q20_POS 16
+#define Q11_POS 9
+#define Q02_POS 2
+
+/*
+ * Determine whether block smoothing is applicable and safe.
+ * We also latch the current states of the coef_bits[] entries for the
+ * AC coefficients; otherwise, if the input side of the decompressor
+ * advances into a new scan, we might think the coefficients are known
+ * more accurately than they really are.
+ */
+
+LOCAL(boolean)
+smoothing_ok (j_decompress_ptr cinfo)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ boolean smoothing_useful = FALSE;
+ int ci, coefi;
+ jpeg_component_info *compptr;
+ JQUANT_TBL * qtable;
+ int * coef_bits;
+ int * coef_bits_latch;
+
+ if (! cinfo->progressive_mode || cinfo->coef_bits == NULL)
+ return FALSE;
+
+ /* Allocate latch area if not already done */
+ if (coef->coef_bits_latch == NULL)
+ coef->coef_bits_latch = (int *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ cinfo->num_components *
+ (SAVED_COEFS * SIZEOF(int)));
+ coef_bits_latch = coef->coef_bits_latch;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* All components' quantization values must already be latched. */
+ if ((qtable = compptr->quant_table) == NULL)
+ return FALSE;
+ /* Verify DC & first 5 AC quantizers are nonzero to avoid zero-divide. */
+ if (qtable->quantval[0] == 0 ||
+ qtable->quantval[Q01_POS] == 0 ||
+ qtable->quantval[Q10_POS] == 0 ||
+ qtable->quantval[Q20_POS] == 0 ||
+ qtable->quantval[Q11_POS] == 0 ||
+ qtable->quantval[Q02_POS] == 0)
+ return FALSE;
+ /* DC values must be at least partly known for all components. */
+ coef_bits = cinfo->coef_bits[ci];
+ if (coef_bits[0] < 0)
+ return FALSE;
+ /* Block smoothing is helpful if some AC coefficients remain inaccurate. */
+ for (coefi = 1; coefi <= 5; coefi++) {
+ coef_bits_latch[coefi] = coef_bits[coefi];
+ if (coef_bits[coefi] != 0)
+ smoothing_useful = TRUE;
+ }
+ coef_bits_latch += SAVED_COEFS;
+ }
+
+ return smoothing_useful;
+}
+
+
+/*
+ * Variant of decompress_data for use when doing block smoothing.
+ */
+
+METHODDEF(int)
+decompress_smooth_data (j_decompress_ptr cinfo, JSAMPIMAGE output_buf)
+{
+ my_coef_ptr coef = (my_coef_ptr) cinfo->coef;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ JDIMENSION block_num, last_block_column;
+ int ci, block_row, block_rows, access_rows;
+ JBLOCKARRAY buffer;
+ JBLOCKROW buffer_ptr, prev_block_row, next_block_row;
+ JSAMPARRAY output_ptr;
+ JDIMENSION output_col;
+ jpeg_component_info *compptr;
+ inverse_DCT_method_ptr inverse_DCT;
+ boolean first_row, last_row;
+ JBLOCK workspace;
+ int *coef_bits;
+ JQUANT_TBL *quanttbl;
+ INT32 Q00,Q01,Q02,Q10,Q11,Q20, num;
+ int DC1,DC2,DC3,DC4,DC5,DC6,DC7,DC8,DC9;
+ int Al, pred;
+
+ /* Force some input to be done if we are getting ahead of the input. */
+ while (cinfo->input_scan_number <= cinfo->output_scan_number &&
+ ! cinfo->inputctl->eoi_reached) {
+ if (cinfo->input_scan_number == cinfo->output_scan_number) {
+ /* If input is working on current scan, we ordinarily want it to
+ * have completed the current row. But if input scan is DC,
+ * we want it to keep one row ahead so that next block row's DC
+ * values are up to date.
+ */
+ JDIMENSION delta = (cinfo->Ss == 0) ? 1 : 0;
+ if (cinfo->input_iMCU_row > cinfo->output_iMCU_row+delta)
+ break;
+ }
+ if ((*cinfo->inputctl->consume_input)(cinfo) == JPEG_SUSPENDED)
+ return JPEG_SUSPENDED;
+ }
+
+ /* OK, output from the virtual arrays. */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Don't bother to IDCT an uninteresting component. */
+ if (! compptr->component_needed)
+ continue;
+ /* Count non-dummy DCT block rows in this iMCU row. */
+ if (cinfo->output_iMCU_row < last_iMCU_row) {
+ block_rows = compptr->v_samp_factor;
+ access_rows = block_rows * 2; /* this and next iMCU row */
+ last_row = FALSE;
+ } else {
+ /* NB: can't use last_row_height here; it is input-side-dependent! */
+ block_rows = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
+ if (block_rows == 0) block_rows = compptr->v_samp_factor;
+ access_rows = block_rows; /* this iMCU row only */
+ last_row = TRUE;
+ }
+ /* Align the virtual buffer for this component. */
+ if (cinfo->output_iMCU_row > 0) {
+ access_rows += compptr->v_samp_factor; /* prior iMCU row too */
+ buffer = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[ci],
+ (cinfo->output_iMCU_row - 1) * compptr->v_samp_factor,
+ (JDIMENSION) access_rows, FALSE);
+ buffer += compptr->v_samp_factor; /* point to current iMCU row */
+ first_row = FALSE;
+ } else {
+ buffer = (*cinfo->mem->access_virt_barray)
+ ((j_common_ptr) cinfo, coef->whole_image[ci],
+ (JDIMENSION) 0, (JDIMENSION) access_rows, FALSE);
+ first_row = TRUE;
+ }
+ /* Fetch component-dependent info */
+ coef_bits = coef->coef_bits_latch + (ci * SAVED_COEFS);
+ quanttbl = compptr->quant_table;
+ Q00 = quanttbl->quantval[0];
+ Q01 = quanttbl->quantval[Q01_POS];
+ Q10 = quanttbl->quantval[Q10_POS];
+ Q20 = quanttbl->quantval[Q20_POS];
+ Q11 = quanttbl->quantval[Q11_POS];
+ Q02 = quanttbl->quantval[Q02_POS];
+ inverse_DCT = cinfo->idct->inverse_DCT[ci];
+ output_ptr = output_buf[ci];
+ /* Loop over all DCT blocks to be processed. */
+ for (block_row = 0; block_row < block_rows; block_row++) {
+ buffer_ptr = buffer[block_row];
+ if (first_row && block_row == 0)
+ prev_block_row = buffer_ptr;
+ else
+ prev_block_row = buffer[block_row-1];
+ if (last_row && block_row == block_rows-1)
+ next_block_row = buffer_ptr;
+ else
+ next_block_row = buffer[block_row+1];
+ /* We fetch the surrounding DC values using a sliding-register approach.
+ * Initialize all nine here so as to do the right thing on narrow pics.
+ */
+ DC1 = DC2 = DC3 = (int) prev_block_row[0][0];
+ DC4 = DC5 = DC6 = (int) buffer_ptr[0][0];
+ DC7 = DC8 = DC9 = (int) next_block_row[0][0];
+ output_col = 0;
+ last_block_column = compptr->width_in_blocks - 1;
+ for (block_num = 0; block_num <= last_block_column; block_num++) {
+ /* Fetch current DCT block into workspace so we can modify it. */
+ jcopy_block_row(buffer_ptr, (JBLOCKROW) workspace, (JDIMENSION) 1);
+ /* Update DC values */
+ if (block_num < last_block_column) {
+ DC3 = (int) prev_block_row[1][0];
+ DC6 = (int) buffer_ptr[1][0];
+ DC9 = (int) next_block_row[1][0];
+ }
+ /* Compute coefficient estimates per K.8.
+ * An estimate is applied only if coefficient is still zero,
+ * and is not known to be fully accurate.
+ */
+ /* AC01 */
+ if ((Al=coef_bits[1]) != 0 && workspace[1] == 0) {
+ num = 36 * Q00 * (DC4 - DC6);
+ if (num >= 0) {
+ pred = (int) (((Q01<<7) + num) / (Q01<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ } else {
+ pred = (int) (((Q01<<7) - num) / (Q01<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ pred = -pred;
+ }
+ workspace[1] = (JCOEF) pred;
+ }
+ /* AC10 */
+ if ((Al=coef_bits[2]) != 0 && workspace[8] == 0) {
+ num = 36 * Q00 * (DC2 - DC8);
+ if (num >= 0) {
+ pred = (int) (((Q10<<7) + num) / (Q10<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ } else {
+ pred = (int) (((Q10<<7) - num) / (Q10<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ pred = -pred;
+ }
+ workspace[8] = (JCOEF) pred;
+ }
+ /* AC20 */
+ if ((Al=coef_bits[3]) != 0 && workspace[16] == 0) {
+ num = 9 * Q00 * (DC2 + DC8 - 2*DC5);
+ if (num >= 0) {
+ pred = (int) (((Q20<<7) + num) / (Q20<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ } else {
+ pred = (int) (((Q20<<7) - num) / (Q20<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ pred = -pred;
+ }
+ workspace[16] = (JCOEF) pred;
+ }
+ /* AC11 */
+ if ((Al=coef_bits[4]) != 0 && workspace[9] == 0) {
+ num = 5 * Q00 * (DC1 - DC3 - DC7 + DC9);
+ if (num >= 0) {
+ pred = (int) (((Q11<<7) + num) / (Q11<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ } else {
+ pred = (int) (((Q11<<7) - num) / (Q11<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ pred = -pred;
+ }
+ workspace[9] = (JCOEF) pred;
+ }
+ /* AC02 */
+ if ((Al=coef_bits[5]) != 0 && workspace[2] == 0) {
+ num = 9 * Q00 * (DC4 + DC6 - 2*DC5);
+ if (num >= 0) {
+ pred = (int) (((Q02<<7) + num) / (Q02<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ } else {
+ pred = (int) (((Q02<<7) - num) / (Q02<<8));
+ if (Al > 0 && pred >= (1<<Al))
+ pred = (1<<Al)-1;
+ pred = -pred;
+ }
+ workspace[2] = (JCOEF) pred;
+ }
+ /* OK, do the IDCT */
+ (*inverse_DCT) (cinfo, compptr, (JCOEFPTR) workspace,
+ output_ptr, output_col);
+ /* Advance for next column */
+ DC1 = DC2; DC2 = DC3;
+ DC4 = DC5; DC5 = DC6;
+ DC7 = DC8; DC8 = DC9;
+ buffer_ptr++, prev_block_row++, next_block_row++;
+ output_col += compptr->DCT_scaled_size;
+ }
+ output_ptr += compptr->DCT_scaled_size;
+ }
+ }
+
+ if (++(cinfo->output_iMCU_row) < cinfo->total_iMCU_rows)
+ return JPEG_ROW_COMPLETED;
+ return JPEG_SCAN_COMPLETED;
+}
+
+#endif /* BLOCK_SMOOTHING_SUPPORTED */
+
+
+/*
+ * Initialize coefficient buffer controller.
+ */
+
+GLOBAL(void)
+jinit_d_coef_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
+{
+ my_coef_ptr coef;
+
+ coef = (my_coef_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_coef_controller));
+ cinfo->coef = (struct jpeg_d_coef_controller *) coef;
+ coef->pub.start_input_pass = start_input_pass;
+ coef->pub.start_output_pass = start_output_pass;
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+ coef->coef_bits_latch = NULL;
+#endif
+
+ /* Create the coefficient buffer. */
+ if (need_full_buffer) {
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+ /* Allocate a full-image virtual array for each component, */
+ /* padded to a multiple of samp_factor DCT blocks in each direction. */
+ /* Note we ask for a pre-zeroed array. */
+ int ci, access_rows;
+ jpeg_component_info *compptr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ access_rows = compptr->v_samp_factor;
+#ifdef BLOCK_SMOOTHING_SUPPORTED
+ /* If block smoothing could be used, need a bigger window */
+ if (cinfo->progressive_mode)
+ access_rows *= 3;
+#endif
+ coef->whole_image[ci] = (*cinfo->mem->request_virt_barray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, TRUE,
+ (JDIMENSION) jround_up((long) compptr->width_in_blocks,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) access_rows);
+ }
+ coef->pub.consume_data = consume_data;
+ coef->pub.decompress_data = decompress_data;
+ coef->pub.coef_arrays = coef->whole_image; /* link to virtual arrays */
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ /* We only need a single-MCU buffer. */
+ JBLOCKROW buffer;
+ int i;
+
+ buffer = (JBLOCKROW)
+ (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ D_MAX_BLOCKS_IN_MCU * SIZEOF(JBLOCK));
+ for (i = 0; i < D_MAX_BLOCKS_IN_MCU; i++) {
+ coef->MCU_buffer[i] = buffer + i;
+ }
+ coef->pub.consume_data = dummy_consume_data;
+ coef->pub.decompress_data = decompress_onepass;
+ coef->pub.coef_arrays = NULL; /* flag for no virtual arrays */
+ }
+}
--- /dev/null
+/*
+ * jdcolor.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains output colorspace conversion routines.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_color_deconverter pub; /* public fields */
+
+ /* Private state for YCC->RGB conversion */
+ int * Cr_r_tab; /* => table for Cr to R conversion */
+ int * Cb_b_tab; /* => table for Cb to B conversion */
+ INT32 * Cr_g_tab; /* => table for Cr to G conversion */
+ INT32 * Cb_g_tab; /* => table for Cb to G conversion */
+} my_color_deconverter;
+
+typedef my_color_deconverter * my_cconvert_ptr;
+
+
+/**************** YCbCr -> RGB conversion: most common case **************/
+
+/*
+ * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
+ * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
+ * The conversion equations to be implemented are therefore
+ * R = Y + 1.40200 * Cr
+ * G = Y - 0.34414 * Cb - 0.71414 * Cr
+ * B = Y + 1.77200 * Cb
+ * where Cb and Cr represent the incoming values less CENTERJSAMPLE.
+ * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
+ *
+ * To avoid floating-point arithmetic, we represent the fractional constants
+ * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
+ * the products by 2^16, with appropriate rounding, to get the correct answer.
+ * Notice that Y, being an integral input, does not contribute any fraction
+ * so it need not participate in the rounding.
+ *
+ * For even more speed, we avoid doing any multiplications in the inner loop
+ * by precalculating the constants times Cb and Cr for all possible values.
+ * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
+ * for 12-bit samples it is still acceptable. It's not very reasonable for
+ * 16-bit samples, but if you want lossless storage you shouldn't be changing
+ * colorspace anyway.
+ * The Cr=>R and Cb=>B values can be rounded to integers in advance; the
+ * values for the G calculation are left scaled up, since we must add them
+ * together before rounding.
+ */
+
+#define SCALEBITS 16 /* speediest right-shift on some machines */
+#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
+#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
+
+
+/*
+ * Initialize tables for YCC->RGB colorspace conversion.
+ */
+
+LOCAL(void)
+build_ycc_rgb_table (j_decompress_ptr cinfo)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ int i;
+ INT32 x;
+ SHIFT_TEMPS
+
+ cconvert->Cr_r_tab = (int *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(int));
+ cconvert->Cb_b_tab = (int *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(int));
+ cconvert->Cr_g_tab = (INT32 *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(INT32));
+ cconvert->Cb_g_tab = (INT32 *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(INT32));
+
+ for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
+ /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
+ /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
+ /* Cr=>R value is nearest int to 1.40200 * x */
+ cconvert->Cr_r_tab[i] = (int)
+ RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
+ /* Cb=>B value is nearest int to 1.77200 * x */
+ cconvert->Cb_b_tab[i] = (int)
+ RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
+ /* Cr=>G value is scaled-up -0.71414 * x */
+ cconvert->Cr_g_tab[i] = (- FIX(0.71414)) * x;
+ /* Cb=>G value is scaled-up -0.34414 * x */
+ /* We also add in ONE_HALF so that need not do it in inner loop */
+ cconvert->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF;
+ }
+}
+
+
+/*
+ * Convert some rows of samples to the output colorspace.
+ *
+ * Note that we change from noninterleaved, one-plane-per-component format
+ * to interleaved-pixel format. The output buffer is therefore three times
+ * as wide as the input buffer.
+ * A starting row offset is provided only for the input buffer. The caller
+ * can easily adjust the passed output_buf value to accommodate any row
+ * offset required on that side.
+ */
+
+METHODDEF(void)
+ycc_rgb_convert (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION input_row,
+ JSAMPARRAY output_buf, int num_rows)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ register int y, cb, cr;
+ register JSAMPROW outptr;
+ register JSAMPROW inptr0, inptr1, inptr2;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->output_width;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ register int * Crrtab = cconvert->Cr_r_tab;
+ register int * Cbbtab = cconvert->Cb_b_tab;
+ register INT32 * Crgtab = cconvert->Cr_g_tab;
+ register INT32 * Cbgtab = cconvert->Cb_g_tab;
+ SHIFT_TEMPS
+
+ while (--num_rows >= 0) {
+ inptr0 = input_buf[0][input_row];
+ inptr1 = input_buf[1][input_row];
+ inptr2 = input_buf[2][input_row];
+ input_row++;
+ outptr = *output_buf++;
+ for (col = 0; col < num_cols; col++) {
+ y = GETJSAMPLE(inptr0[col]);
+ cb = GETJSAMPLE(inptr1[col]);
+ cr = GETJSAMPLE(inptr2[col]);
+ /* Range-limiting is essential due to noise introduced by DCT losses. */
+ outptr[RGB_RED] = range_limit[y + Crrtab[cr]];
+ outptr[RGB_GREEN] = range_limit[y +
+ ((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
+ SCALEBITS))];
+ outptr[RGB_BLUE] = range_limit[y + Cbbtab[cb]];
+ outptr += RGB_PIXELSIZE;
+ }
+ }
+}
+
+
+/**************** Cases other than YCbCr -> RGB **************/
+
+
+/*
+ * Color conversion for no colorspace change: just copy the data,
+ * converting from separate-planes to interleaved representation.
+ */
+
+METHODDEF(void)
+null_convert (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION input_row,
+ JSAMPARRAY output_buf, int num_rows)
+{
+ register JSAMPROW inptr, outptr;
+ register JDIMENSION count;
+ register int num_components = cinfo->num_components;
+ JDIMENSION num_cols = cinfo->output_width;
+ int ci;
+
+ while (--num_rows >= 0) {
+ for (ci = 0; ci < num_components; ci++) {
+ inptr = input_buf[ci][input_row];
+ outptr = output_buf[0] + ci;
+ for (count = num_cols; count > 0; count--) {
+ *outptr = *inptr++; /* needn't bother with GETJSAMPLE() here */
+ outptr += num_components;
+ }
+ }
+ input_row++;
+ output_buf++;
+ }
+}
+
+
+/*
+ * Color conversion for grayscale: just copy the data.
+ * This also works for YCbCr -> grayscale conversion, in which
+ * we just copy the Y (luminance) component and ignore chrominance.
+ */
+
+METHODDEF(void)
+grayscale_convert (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION input_row,
+ JSAMPARRAY output_buf, int num_rows)
+{
+ jcopy_sample_rows(input_buf[0], (int) input_row, output_buf, 0,
+ num_rows, cinfo->output_width);
+}
+
+
+/*
+ * Convert grayscale to RGB: just duplicate the graylevel three times.
+ * This is provided to support applications that don't want to cope
+ * with grayscale as a separate case.
+ */
+
+METHODDEF(void)
+gray_rgb_convert (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION input_row,
+ JSAMPARRAY output_buf, int num_rows)
+{
+ register JSAMPROW inptr, outptr;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->output_width;
+
+ while (--num_rows >= 0) {
+ inptr = input_buf[0][input_row++];
+ outptr = *output_buf++;
+ for (col = 0; col < num_cols; col++) {
+ /* We can dispense with GETJSAMPLE() here */
+ outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
+ outptr += RGB_PIXELSIZE;
+ }
+ }
+}
+
+
+/*
+ * Adobe-style YCCK->CMYK conversion.
+ * We convert YCbCr to R=1-C, G=1-M, and B=1-Y using the same
+ * conversion as above, while passing K (black) unchanged.
+ * We assume build_ycc_rgb_table has been called.
+ */
+
+METHODDEF(void)
+ycck_cmyk_convert (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION input_row,
+ JSAMPARRAY output_buf, int num_rows)
+{
+ my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
+ register int y, cb, cr;
+ register JSAMPROW outptr;
+ register JSAMPROW inptr0, inptr1, inptr2, inptr3;
+ register JDIMENSION col;
+ JDIMENSION num_cols = cinfo->output_width;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ register int * Crrtab = cconvert->Cr_r_tab;
+ register int * Cbbtab = cconvert->Cb_b_tab;
+ register INT32 * Crgtab = cconvert->Cr_g_tab;
+ register INT32 * Cbgtab = cconvert->Cb_g_tab;
+ SHIFT_TEMPS
+
+ while (--num_rows >= 0) {
+ inptr0 = input_buf[0][input_row];
+ inptr1 = input_buf[1][input_row];
+ inptr2 = input_buf[2][input_row];
+ inptr3 = input_buf[3][input_row];
+ input_row++;
+ outptr = *output_buf++;
+ for (col = 0; col < num_cols; col++) {
+ y = GETJSAMPLE(inptr0[col]);
+ cb = GETJSAMPLE(inptr1[col]);
+ cr = GETJSAMPLE(inptr2[col]);
+ /* Range-limiting is essential due to noise introduced by DCT losses. */
+ outptr[0] = range_limit[MAXJSAMPLE - (y + Crrtab[cr])]; /* red */
+ outptr[1] = range_limit[MAXJSAMPLE - (y + /* green */
+ ((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
+ SCALEBITS)))];
+ outptr[2] = range_limit[MAXJSAMPLE - (y + Cbbtab[cb])]; /* blue */
+ /* K passes through unchanged */
+ outptr[3] = inptr3[col]; /* don't need GETJSAMPLE here */
+ outptr += 4;
+ }
+ }
+}
+
+
+/*
+ * Empty method for start_pass.
+ */
+
+METHODDEF(void)
+start_pass_dcolor (j_decompress_ptr cinfo)
+{
+ /* no work needed */
+}
+
+
+/*
+ * Module initialization routine for output colorspace conversion.
+ */
+
+GLOBAL(void)
+jinit_color_deconverter (j_decompress_ptr cinfo)
+{
+ my_cconvert_ptr cconvert;
+ int ci;
+
+ cconvert = (my_cconvert_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_color_deconverter));
+ cinfo->cconvert = (struct jpeg_color_deconverter *) cconvert;
+ cconvert->pub.start_pass = start_pass_dcolor;
+
+ /* Make sure num_components agrees with jpeg_color_space */
+ switch (cinfo->jpeg_color_space) {
+ case JCS_GRAYSCALE:
+ if (cinfo->num_components != 1)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ break;
+
+ case JCS_RGB:
+ case JCS_YCbCr:
+ if (cinfo->num_components != 3)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ break;
+
+ case JCS_CMYK:
+ case JCS_YCCK:
+ if (cinfo->num_components != 4)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ break;
+
+ default: /* JCS_UNKNOWN can be anything */
+ if (cinfo->num_components < 1)
+ ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
+ break;
+ }
+
+ /* Set out_color_components and conversion method based on requested space.
+ * Also clear the component_needed flags for any unused components,
+ * so that earlier pipeline stages can avoid useless computation.
+ */
+
+ switch (cinfo->out_color_space) {
+ case JCS_GRAYSCALE:
+ cinfo->out_color_components = 1;
+ if (cinfo->jpeg_color_space == JCS_GRAYSCALE ||
+ cinfo->jpeg_color_space == JCS_YCbCr) {
+ cconvert->pub.color_convert = grayscale_convert;
+ /* For color->grayscale conversion, only the Y (0) component is needed */
+ for (ci = 1; ci < cinfo->num_components; ci++)
+ cinfo->comp_info[ci].component_needed = FALSE;
+ } else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ case JCS_RGB:
+ cinfo->out_color_components = RGB_PIXELSIZE;
+ if (cinfo->jpeg_color_space == JCS_YCbCr) {
+ cconvert->pub.color_convert = ycc_rgb_convert;
+ build_ycc_rgb_table(cinfo);
+ } else if (cinfo->jpeg_color_space == JCS_GRAYSCALE) {
+ cconvert->pub.color_convert = gray_rgb_convert;
+ } else if (cinfo->jpeg_color_space == JCS_RGB && RGB_PIXELSIZE == 3) {
+ cconvert->pub.color_convert = null_convert;
+ } else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ case JCS_CMYK:
+ cinfo->out_color_components = 4;
+ if (cinfo->jpeg_color_space == JCS_YCCK) {
+ cconvert->pub.color_convert = ycck_cmyk_convert;
+ build_ycc_rgb_table(cinfo);
+ } else if (cinfo->jpeg_color_space == JCS_CMYK) {
+ cconvert->pub.color_convert = null_convert;
+ } else
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+
+ default:
+ /* Permit null conversion to same output space */
+ if (cinfo->out_color_space == cinfo->jpeg_color_space) {
+ cinfo->out_color_components = cinfo->num_components;
+ cconvert->pub.color_convert = null_convert;
+ } else /* unsupported non-null conversion */
+ ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
+ break;
+ }
+
+ if (cinfo->quantize_colors)
+ cinfo->output_components = 1; /* single colormapped output component */
+ else
+ cinfo->output_components = cinfo->out_color_components;
+}
--- /dev/null
+/*
+ * jddctmgr.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the inverse-DCT management logic.
+ * This code selects a particular IDCT implementation to be used,
+ * and it performs related housekeeping chores. No code in this file
+ * is executed per IDCT step, only during output pass setup.
+ *
+ * Note that the IDCT routines are responsible for performing coefficient
+ * dequantization as well as the IDCT proper. This module sets up the
+ * dequantization multiplier table needed by the IDCT routine.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+
+/*
+ * The decompressor input side (jdinput.c) saves away the appropriate
+ * quantization table for each component at the start of the first scan
+ * involving that component. (This is necessary in order to correctly
+ * decode files that reuse Q-table slots.)
+ * When we are ready to make an output pass, the saved Q-table is converted
+ * to a multiplier table that will actually be used by the IDCT routine.
+ * The multiplier table contents are IDCT-method-dependent. To support
+ * application changes in IDCT method between scans, we can remake the
+ * multiplier tables if necessary.
+ * In buffered-image mode, the first output pass may occur before any data
+ * has been seen for some components, and thus before their Q-tables have
+ * been saved away. To handle this case, multiplier tables are preset
+ * to zeroes; the result of the IDCT will be a neutral gray level.
+ */
+
+
+/* Private subobject for this module */
+
+typedef struct {
+ struct jpeg_inverse_dct pub; /* public fields */
+
+ /* This array contains the IDCT method code that each multiplier table
+ * is currently set up for, or -1 if it's not yet set up.
+ * The actual multiplier tables are pointed to by dct_table in the
+ * per-component comp_info structures.
+ */
+ int cur_method[MAX_COMPONENTS];
+} my_idct_controller;
+
+typedef my_idct_controller * my_idct_ptr;
+
+
+/* Allocated multiplier tables: big enough for any supported variant */
+
+typedef union {
+ ISLOW_MULT_TYPE islow_array[DCTSIZE2];
+#ifdef DCT_IFAST_SUPPORTED
+ IFAST_MULT_TYPE ifast_array[DCTSIZE2];
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+ FLOAT_MULT_TYPE float_array[DCTSIZE2];
+#endif
+} multiplier_table;
+
+
+/* The current scaled-IDCT routines require ISLOW-style multiplier tables,
+ * so be sure to compile that code if either ISLOW or SCALING is requested.
+ */
+#ifdef DCT_ISLOW_SUPPORTED
+#define PROVIDE_ISLOW_TABLES
+#else
+#ifdef IDCT_SCALING_SUPPORTED
+#define PROVIDE_ISLOW_TABLES
+#endif
+#endif
+
+
+/*
+ * Prepare for an output pass.
+ * Here we select the proper IDCT routine for each component and build
+ * a matching multiplier table.
+ */
+
+METHODDEF(void)
+start_pass (j_decompress_ptr cinfo)
+{
+ my_idct_ptr idct = (my_idct_ptr) cinfo->idct;
+ int ci, i;
+ jpeg_component_info *compptr;
+ int method = 0;
+ inverse_DCT_method_ptr method_ptr = NULL;
+ JQUANT_TBL * qtbl;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Select the proper IDCT routine for this component's scaling */
+ switch (compptr->DCT_scaled_size) {
+#ifdef IDCT_SCALING_SUPPORTED
+ case 1:
+ method_ptr = jpeg_idct_1x1;
+ method = JDCT_ISLOW; /* jidctred uses islow-style table */
+ break;
+ case 2:
+ method_ptr = jpeg_idct_2x2;
+ method = JDCT_ISLOW; /* jidctred uses islow-style table */
+ break;
+ case 4:
+ method_ptr = jpeg_idct_4x4;
+ method = JDCT_ISLOW; /* jidctred uses islow-style table */
+ break;
+#endif
+ case DCTSIZE:
+ switch (cinfo->dct_method) {
+#ifdef DCT_ISLOW_SUPPORTED
+ case JDCT_ISLOW:
+ method_ptr = jpeg_idct_islow;
+ method = JDCT_ISLOW;
+ break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+ case JDCT_IFAST:
+ method_ptr = jpeg_idct_ifast;
+ method = JDCT_IFAST;
+ break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+ case JDCT_FLOAT:
+ method_ptr = jpeg_idct_float;
+ method = JDCT_FLOAT;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+ break;
+ default:
+ ERREXIT1(cinfo, JERR_BAD_DCTSIZE, compptr->DCT_scaled_size);
+ break;
+ }
+ idct->pub.inverse_DCT[ci] = method_ptr;
+ /* Create multiplier table from quant table.
+ * However, we can skip this if the component is uninteresting
+ * or if we already built the table. Also, if no quant table
+ * has yet been saved for the component, we leave the
+ * multiplier table all-zero; we'll be reading zeroes from the
+ * coefficient controller's buffer anyway.
+ */
+ if (! compptr->component_needed || idct->cur_method[ci] == method)
+ continue;
+ qtbl = compptr->quant_table;
+ if (qtbl == NULL) /* happens if no data yet for component */
+ continue;
+ idct->cur_method[ci] = method;
+ switch (method) {
+#ifdef PROVIDE_ISLOW_TABLES
+ case JDCT_ISLOW:
+ {
+ /* For LL&M IDCT method, multipliers are equal to raw quantization
+ * coefficients, but are stored as ints to ensure access efficiency.
+ */
+ ISLOW_MULT_TYPE * ismtbl = (ISLOW_MULT_TYPE *) compptr->dct_table;
+ for (i = 0; i < DCTSIZE2; i++) {
+ ismtbl[i] = (ISLOW_MULT_TYPE) qtbl->quantval[i];
+ }
+ }
+ break;
+#endif
+#ifdef DCT_IFAST_SUPPORTED
+ case JDCT_IFAST:
+ {
+ /* For AA&N IDCT method, multipliers are equal to quantization
+ * coefficients scaled by scalefactor[row]*scalefactor[col], where
+ * scalefactor[0] = 1
+ * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
+ * For integer operation, the multiplier table is to be scaled by
+ * IFAST_SCALE_BITS.
+ */
+ IFAST_MULT_TYPE * ifmtbl = (IFAST_MULT_TYPE *) compptr->dct_table;
+#define CONST_BITS 14
+ static const INT16 aanscales[DCTSIZE2] = {
+ /* precomputed values scaled up by 14 bits */
+ 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
+ 22725, 31521, 29692, 26722, 22725, 17855, 12299, 6270,
+ 21407, 29692, 27969, 25172, 21407, 16819, 11585, 5906,
+ 19266, 26722, 25172, 22654, 19266, 15137, 10426, 5315,
+ 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520,
+ 12873, 17855, 16819, 15137, 12873, 10114, 6967, 3552,
+ 8867, 12299, 11585, 10426, 8867, 6967, 4799, 2446,
+ 4520, 6270, 5906, 5315, 4520, 3552, 2446, 1247
+ };
+ SHIFT_TEMPS
+
+ for (i = 0; i < DCTSIZE2; i++) {
+ ifmtbl[i] = (IFAST_MULT_TYPE)
+ DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i],
+ (INT32) aanscales[i]),
+ CONST_BITS-IFAST_SCALE_BITS);
+ }
+ }
+ break;
+#endif
+#ifdef DCT_FLOAT_SUPPORTED
+ case JDCT_FLOAT:
+ {
+ /* For float AA&N IDCT method, multipliers are equal to quantization
+ * coefficients scaled by scalefactor[row]*scalefactor[col], where
+ * scalefactor[0] = 1
+ * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7
+ */
+ FLOAT_MULT_TYPE * fmtbl = (FLOAT_MULT_TYPE *) compptr->dct_table;
+ int row, col;
+ static const double aanscalefactor[DCTSIZE] = {
+ 1.0, 1.387039845, 1.306562965, 1.175875602,
+ 1.0, 0.785694958, 0.541196100, 0.275899379
+ };
+
+ i = 0;
+ for (row = 0; row < DCTSIZE; row++) {
+ for (col = 0; col < DCTSIZE; col++) {
+ fmtbl[i] = (FLOAT_MULT_TYPE)
+ ((double) qtbl->quantval[i] *
+ aanscalefactor[row] * aanscalefactor[col]);
+ i++;
+ }
+ }
+ }
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+ }
+}
+
+
+/*
+ * Initialize IDCT manager.
+ */
+
+GLOBAL(void)
+jinit_inverse_dct (j_decompress_ptr cinfo)
+{
+ my_idct_ptr idct;
+ int ci;
+ jpeg_component_info *compptr;
+
+ idct = (my_idct_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_idct_controller));
+ cinfo->idct = (struct jpeg_inverse_dct *) idct;
+ idct->pub.start_pass = start_pass;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Allocate and pre-zero a multiplier table for each component */
+ compptr->dct_table =
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(multiplier_table));
+ MEMZERO(compptr->dct_table, SIZEOF(multiplier_table));
+ /* Mark multiplier table not yet set up for any method */
+ idct->cur_method[ci] = -1;
+ }
+}
--- /dev/null
+/*
+ * jdhuff.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy decoding routines.
+ *
+ * Much of the complexity here has to do with supporting input suspension.
+ * If the data source module demands suspension, we want to be able to back
+ * up to the start of the current MCU. To do this, we copy state variables
+ * into local working storage, and update them back to the permanent
+ * storage only upon successful completion of an MCU.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdhuff12.h" /* Declarations shared with jdphuff.c */
+
+
+/*
+ * Expanded entropy decoder object for Huffman decoding.
+ *
+ * The savable_state subrecord contains fields that change within an MCU,
+ * but must not be updated permanently until we complete the MCU.
+ */
+
+typedef struct {
+ int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+} savable_state;
+
+/* This macro is to work around compilers with missing or broken
+ * structure assignment. You'll need to fix this code if you have
+ * such a compiler and you change MAX_COMPS_IN_SCAN.
+ */
+
+#ifndef NO_STRUCT_ASSIGN
+#define ASSIGN_STATE(dest,src) ((dest) = (src))
+#else
+#if MAX_COMPS_IN_SCAN == 4
+#define ASSIGN_STATE(dest,src) \
+ ((dest).last_dc_val[0] = (src).last_dc_val[0], \
+ (dest).last_dc_val[1] = (src).last_dc_val[1], \
+ (dest).last_dc_val[2] = (src).last_dc_val[2], \
+ (dest).last_dc_val[3] = (src).last_dc_val[3])
+#endif
+#endif
+
+
+typedef struct {
+ struct jpeg_entropy_decoder pub; /* public fields */
+
+ /* These fields are loaded into local variables at start of each MCU.
+ * In case of suspension, we exit WITHOUT updating them.
+ */
+ bitread_perm_state bitstate; /* Bit buffer at start of MCU */
+ savable_state saved; /* Other state at start of MCU */
+
+ /* These fields are NOT loaded into local working state. */
+ unsigned int restarts_to_go; /* MCUs left in this restart interval */
+
+ /* Pointers to derived tables (these workspaces have image lifespan) */
+ d_derived_tbl * dc_derived_tbls[NUM_HUFF_TBLS];
+ d_derived_tbl * ac_derived_tbls[NUM_HUFF_TBLS];
+
+ /* Precalculated info set up by start_pass for use in decode_mcu: */
+
+ /* Pointers to derived tables to be used for each block within an MCU */
+ d_derived_tbl * dc_cur_tbls[D_MAX_BLOCKS_IN_MCU];
+ d_derived_tbl * ac_cur_tbls[D_MAX_BLOCKS_IN_MCU];
+ /* Whether we care about the DC and AC coefficient values for each block */
+ boolean dc_needed[D_MAX_BLOCKS_IN_MCU];
+ boolean ac_needed[D_MAX_BLOCKS_IN_MCU];
+} huff_entropy_decoder;
+
+typedef huff_entropy_decoder * huff_entropy_ptr;
+
+
+/*
+ * Initialize for a Huffman-compressed scan.
+ */
+
+METHODDEF(void)
+start_pass_huff_decoder (j_decompress_ptr cinfo)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ int ci, blkn, dctbl, actbl;
+ jpeg_component_info * compptr;
+
+ /* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG.
+ * This ought to be an error condition, but we make it a warning because
+ * there are some baseline files out there with all zeroes in these bytes.
+ */
+ if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2-1 ||
+ cinfo->Ah != 0 || cinfo->Al != 0)
+ WARNMS(cinfo, JWRN_NOT_SEQUENTIAL);
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ dctbl = compptr->dc_tbl_no;
+ actbl = compptr->ac_tbl_no;
+ /* Compute derived values for Huffman tables */
+ /* We may do this more than once for a table, but it's not expensive */
+ jpeg_make_d_derived_tbl(cinfo, TRUE, dctbl,
+ & entropy->dc_derived_tbls[dctbl]);
+ jpeg_make_d_derived_tbl(cinfo, FALSE, actbl,
+ & entropy->ac_derived_tbls[actbl]);
+ /* Initialize DC predictions to 0 */
+ entropy->saved.last_dc_val[ci] = 0;
+ }
+
+ /* Precalculate decoding info for each block in an MCU of this scan */
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ ci = cinfo->MCU_membership[blkn];
+ compptr = cinfo->cur_comp_info[ci];
+ /* Precalculate which table to use for each block */
+ entropy->dc_cur_tbls[blkn] = entropy->dc_derived_tbls[compptr->dc_tbl_no];
+ entropy->ac_cur_tbls[blkn] = entropy->ac_derived_tbls[compptr->ac_tbl_no];
+ /* Decide whether we really care about the coefficient values */
+ if (compptr->component_needed) {
+ entropy->dc_needed[blkn] = TRUE;
+ /* we don't need the ACs if producing a 1/8th-size image */
+ entropy->ac_needed[blkn] = (compptr->DCT_scaled_size > 1);
+ } else {
+ entropy->dc_needed[blkn] = entropy->ac_needed[blkn] = FALSE;
+ }
+ }
+
+ /* Initialize bitread state variables */
+ entropy->bitstate.bits_left = 0;
+ entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */
+ entropy->pub.insufficient_data = FALSE;
+
+ /* Initialize restart counter */
+ entropy->restarts_to_go = cinfo->restart_interval;
+}
+
+
+/*
+ * Compute the derived values for a Huffman table.
+ * This routine also performs some validation checks on the table.
+ *
+ * Note this is also used by jdphuff.c.
+ */
+
+GLOBAL(void)
+jpeg_make_d_derived_tbl (j_decompress_ptr cinfo, boolean isDC, int tblno,
+ d_derived_tbl ** pdtbl)
+{
+ JHUFF_TBL *htbl;
+ d_derived_tbl *dtbl;
+ int p, i, l, si, numsymbols;
+ int lookbits, ctr;
+ char huffsize[257];
+ unsigned int huffcode[257];
+ unsigned int code;
+
+ /* Note that huffsize[] and huffcode[] are filled in code-length order,
+ * paralleling the order of the symbols themselves in htbl->huffval[].
+ */
+
+ /* Find the input Huffman table */
+ if (tblno < 0 || tblno >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
+ htbl =
+ isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno];
+ if (htbl == NULL)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno);
+
+ /* Allocate a workspace if we haven't already done so. */
+ if (*pdtbl == NULL)
+ *pdtbl = (d_derived_tbl *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(d_derived_tbl));
+ dtbl = *pdtbl;
+ dtbl->pub = htbl; /* fill in back link */
+
+ /* Figure C.1: make table of Huffman code length for each symbol */
+
+ p = 0;
+ for (l = 1; l <= 16; l++) {
+ i = (int) htbl->bits[l];
+ if (i < 0 || p + i > 256) /* protect against table overrun */
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ while (i--)
+ huffsize[p++] = (char) l;
+ }
+ huffsize[p] = 0;
+ numsymbols = p;
+
+ /* Figure C.2: generate the codes themselves */
+ /* We also validate that the counts represent a legal Huffman code tree. */
+
+ code = 0;
+ si = huffsize[0];
+ p = 0;
+ while (huffsize[p]) {
+ while (((int) huffsize[p]) == si) {
+ huffcode[p++] = code;
+ code++;
+ }
+ /* code is now 1 more than the last code used for codelength si; but
+ * it must still fit in si bits, since no code is allowed to be all ones.
+ */
+ if (((INT32) code) >= (((INT32) 1) << si))
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ code <<= 1;
+ si++;
+ }
+
+ /* Figure F.15: generate decoding tables for bit-sequential decoding */
+
+ p = 0;
+ for (l = 1; l <= 16; l++) {
+ if (htbl->bits[l]) {
+ /* valoffset[l] = huffval[] index of 1st symbol of code length l,
+ * minus the minimum code of length l
+ */
+ dtbl->valoffset[l] = (INT32) p - (INT32) huffcode[p];
+ p += htbl->bits[l];
+ dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */
+ } else {
+ dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
+ }
+ }
+ dtbl->maxcode[17] = 0xFFFFFL; /* ensures jpeg_huff_decode terminates */
+
+ /* Compute lookahead tables to speed up decoding.
+ * First we set all the table entries to 0, indicating "too long";
+ * then we iterate through the Huffman codes that are short enough and
+ * fill in all the entries that correspond to bit sequences starting
+ * with that code.
+ */
+
+ MEMZERO(dtbl->look_nbits, SIZEOF(dtbl->look_nbits));
+
+ p = 0;
+ for (l = 1; l <= HUFF_LOOKAHEAD; l++) {
+ for (i = 1; i <= (int) htbl->bits[l]; i++, p++) {
+ /* l = current code's length, p = its index in huffcode[] & huffval[]. */
+ /* Generate left-justified code followed by all possible bit sequences */
+ lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l);
+ for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--) {
+ dtbl->look_nbits[lookbits] = l;
+ dtbl->look_sym[lookbits] = htbl->huffval[p];
+ lookbits++;
+ }
+ }
+ }
+
+ /* Validate symbols as being reasonable.
+ * For AC tables, we make no check, but accept all byte values 0..255.
+ * For DC tables, we require the symbols to be in range 0..15.
+ * (Tighter bounds could be applied depending on the data depth and mode,
+ * but this is sufficient to ensure safe decoding.)
+ */
+ if (isDC) {
+ for (i = 0; i < numsymbols; i++) {
+ int sym = htbl->huffval[i];
+ if (sym < 0 || sym > 15)
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+ }
+ }
+}
+
+
+/*
+ * Out-of-line code for bit fetching (shared with jdphuff.c).
+ * See jdhuff.h for info about usage.
+ * Note: current values of get_buffer and bits_left are passed as parameters,
+ * but are returned in the corresponding fields of the state struct.
+ *
+ * On most machines MIN_GET_BITS should be 25 to allow the full 32-bit width
+ * of get_buffer to be used. (On machines with wider words, an even larger
+ * buffer could be used.) However, on some machines 32-bit shifts are
+ * quite slow and take time proportional to the number of places shifted.
+ * (This is true with most PC compilers, for instance.) In this case it may
+ * be a win to set MIN_GET_BITS to the minimum value of 15. This reduces the
+ * average shift distance at the cost of more calls to jpeg_fill_bit_buffer.
+ */
+
+#ifdef SLOW_SHIFT_32
+#define MIN_GET_BITS 15 /* minimum allowable value */
+#else
+#define MIN_GET_BITS (BIT_BUF_SIZE-7)
+#endif
+
+
+GLOBAL(boolean)
+jpeg_fill_bit_buffer (bitread_working_state * state,
+ register bit_buf_type get_buffer, register int bits_left,
+ int nbits)
+/* Load up the bit buffer to a depth of at least nbits */
+{
+ /* Copy heavily used state fields into locals (hopefully registers) */
+ register const JOCTET * next_input_byte = state->next_input_byte;
+ register size_t bytes_in_buffer = state->bytes_in_buffer;
+ j_decompress_ptr cinfo = state->cinfo;
+
+ /* Attempt to load at least MIN_GET_BITS bits into get_buffer. */
+ /* (It is assumed that no request will be for more than that many bits.) */
+ /* We fail to do so only if we hit a marker or are forced to suspend. */
+
+ if (cinfo->unread_marker == 0) { /* cannot advance past a marker */
+ while (bits_left < MIN_GET_BITS) {
+ register int c;
+
+ /* Attempt to read a byte */
+ if (bytes_in_buffer == 0) {
+ if (! (*cinfo->src->fill_input_buffer) (cinfo))
+ return FALSE;
+ next_input_byte = cinfo->src->next_input_byte;
+ bytes_in_buffer = cinfo->src->bytes_in_buffer;
+ }
+ bytes_in_buffer--;
+ c = GETJOCTET(*next_input_byte++);
+
+ /* If it's 0xFF, check and discard stuffed zero byte */
+ if (c == 0xFF) {
+ /* Loop here to discard any padding FF's on terminating marker,
+ * so that we can save a valid unread_marker value. NOTE: we will
+ * accept multiple FF's followed by a 0 as meaning a single FF data
+ * byte. This data pattern is not valid according to the standard.
+ */
+ do {
+ if (bytes_in_buffer == 0) {
+ if (! (*cinfo->src->fill_input_buffer) (cinfo))
+ return FALSE;
+ next_input_byte = cinfo->src->next_input_byte;
+ bytes_in_buffer = cinfo->src->bytes_in_buffer;
+ }
+ bytes_in_buffer--;
+ c = GETJOCTET(*next_input_byte++);
+ } while (c == 0xFF);
+
+ if (c == 0) {
+ /* Found FF/00, which represents an FF data byte */
+ c = 0xFF;
+ } else {
+ /* Oops, it's actually a marker indicating end of compressed data.
+ * Save the marker code for later use.
+ * Fine point: it might appear that we should save the marker into
+ * bitread working state, not straight into permanent state. But
+ * once we have hit a marker, we cannot need to suspend within the
+ * current MCU, because we will read no more bytes from the data
+ * source. So it is OK to update permanent state right away.
+ */
+ cinfo->unread_marker = c;
+ /* See if we need to insert some fake zero bits. */
+ goto no_more_bytes;
+ }
+ }
+
+ /* OK, load c into get_buffer */
+ get_buffer = (get_buffer << 8) | c;
+ bits_left += 8;
+ } /* end while */
+ } else {
+ no_more_bytes:
+ /* We get here if we've read the marker that terminates the compressed
+ * data segment. There should be enough bits in the buffer register
+ * to satisfy the request; if so, no problem.
+ */
+ if (nbits > bits_left) {
+ /* Uh-oh. Report corrupted data to user and stuff zeroes into
+ * the data stream, so that we can produce some kind of image.
+ * We use a nonvolatile flag to ensure that only one warning message
+ * appears per data segment.
+ */
+ if (! cinfo->entropy->insufficient_data) {
+ WARNMS(cinfo, JWRN_HIT_MARKER);
+ cinfo->entropy->insufficient_data = TRUE;
+ }
+ /* Fill the buffer with zero bits */
+ get_buffer <<= MIN_GET_BITS - bits_left;
+ bits_left = MIN_GET_BITS;
+ }
+ }
+
+ /* Unload the local registers */
+ state->next_input_byte = next_input_byte;
+ state->bytes_in_buffer = bytes_in_buffer;
+ state->get_buffer = get_buffer;
+ state->bits_left = bits_left;
+
+ return TRUE;
+}
+
+
+/*
+ * Out-of-line code for Huffman code decoding.
+ * See jdhuff.h for info about usage.
+ */
+
+GLOBAL(int)
+jpeg_huff_decode (bitread_working_state * state,
+ register bit_buf_type get_buffer, register int bits_left,
+ d_derived_tbl * htbl, int min_bits)
+{
+ register int l = min_bits;
+ register INT32 code;
+
+ /* HUFF_DECODE has determined that the code is at least min_bits */
+ /* bits long, so fetch that many bits in one swoop. */
+
+ CHECK_BIT_BUFFER(*state, l, return -1);
+ code = GET_BITS(l);
+
+ /* Collect the rest of the Huffman code one bit at a time. */
+ /* This is per Figure F.16 in the JPEG spec. */
+
+ while (code > htbl->maxcode[l]) {
+ code <<= 1;
+ CHECK_BIT_BUFFER(*state, 1, return -1);
+ code |= GET_BITS(1);
+ l++;
+ }
+
+ /* Unload the local registers */
+ state->get_buffer = get_buffer;
+ state->bits_left = bits_left;
+
+ /* With garbage input we may reach the sentinel value l = 17. */
+
+ if (l > 16) {
+ WARNMS(state->cinfo, JWRN_HUFF_BAD_CODE);
+ return 0; /* fake a zero as the safest result */
+ }
+
+ return htbl->pub->huffval[ (int) (code + htbl->valoffset[l]) ];
+}
+
+
+/*
+ * Figure F.12: extend sign bit.
+ * On some machines, a shift and add will be faster than a table lookup.
+ */
+
+#ifdef AVOID_TABLES
+
+#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x))
+
+#else
+
+#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
+
+static const int extend_test[16] = /* entry n is 2**(n-1) */
+ { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
+ 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
+
+static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
+ { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
+ ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
+ ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
+ ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 };
+
+#endif /* AVOID_TABLES */
+
+
+/*
+ * Check for a restart marker & resynchronize decoder.
+ * Returns FALSE if must suspend.
+ */
+
+LOCAL(boolean)
+process_restart (j_decompress_ptr cinfo)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ int ci;
+
+ /* Throw away any unused bits remaining in bit buffer; */
+ /* include any full bytes in next_marker's count of discarded bytes */
+ cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
+ entropy->bitstate.bits_left = 0;
+
+ /* Advance past the RSTn marker */
+ if (! (*cinfo->marker->read_restart_marker) (cinfo))
+ return FALSE;
+
+ /* Re-initialize DC predictions to 0 */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++)
+ entropy->saved.last_dc_val[ci] = 0;
+
+ /* Reset restart counter */
+ entropy->restarts_to_go = cinfo->restart_interval;
+
+ /* Reset out-of-data flag, unless read_restart_marker left us smack up
+ * against a marker. In that case we will end up treating the next data
+ * segment as empty, and we can avoid producing bogus output pixels by
+ * leaving the flag set.
+ */
+ if (cinfo->unread_marker == 0)
+ entropy->pub.insufficient_data = FALSE;
+
+ return TRUE;
+}
+
+
+/*
+ * Decode and return one MCU's worth of Huffman-compressed coefficients.
+ * The coefficients are reordered from zigzag order into natural array order,
+ * but are not dequantized.
+ *
+ * The i'th block of the MCU is stored into the block pointed to by
+ * MCU_data[i]. WE ASSUME THIS AREA HAS BEEN ZEROED BY THE CALLER.
+ * (Wholesale zeroing is usually a little faster than retail...)
+ *
+ * Returns FALSE if data source requested suspension. In that case no
+ * changes have been made to permanent state. (Exception: some output
+ * coefficients may already have been assigned. This is harmless for
+ * this module, since we'll just re-assign them on the next call.)
+ */
+
+METHODDEF(boolean)
+decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ huff_entropy_ptr entropy = (huff_entropy_ptr) cinfo->entropy;
+ int blkn;
+ BITREAD_STATE_VARS;
+ savable_state state;
+
+ /* Process restart marker if needed; may have to suspend */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0)
+ if (! process_restart(cinfo))
+ return FALSE;
+ }
+
+ /* If we've run out of data, just leave the MCU set to zeroes.
+ * This way, we return uniform gray for the remainder of the segment.
+ */
+ if (! entropy->pub.insufficient_data) {
+
+ /* Load up working state */
+ BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
+ ASSIGN_STATE(state, entropy->saved);
+
+ /* Outer loop handles each block in the MCU */
+
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ JBLOCKROW block = MCU_data[blkn];
+ d_derived_tbl * dctbl = entropy->dc_cur_tbls[blkn];
+ d_derived_tbl * actbl = entropy->ac_cur_tbls[blkn];
+ register int s, k, r;
+
+ /* Decode a single block's worth of coefficients */
+
+ /* Section F.2.2.1: decode the DC coefficient difference */
+ HUFF_DECODE(s, br_state, dctbl, return FALSE, label1);
+ if (s) {
+ CHECK_BIT_BUFFER(br_state, s, return FALSE);
+ r = GET_BITS(s);
+ s = HUFF_EXTEND(r, s);
+ }
+
+ if (entropy->dc_needed[blkn]) {
+ /* Convert DC difference to actual value, update last_dc_val */
+ int ci = cinfo->MCU_membership[blkn];
+ s += state.last_dc_val[ci];
+ state.last_dc_val[ci] = s;
+ /* Output the DC coefficient (assumes jpeg_natural_order[0] = 0) */
+ (*block)[0] = (JCOEF) s;
+ }
+
+ if (entropy->ac_needed[blkn]) {
+
+ /* Section F.2.2.2: decode the AC coefficients */
+ /* Since zeroes are skipped, output area must be cleared beforehand */
+ for (k = 1; k < DCTSIZE2; k++) {
+ HUFF_DECODE(s, br_state, actbl, return FALSE, label2);
+
+ r = s >> 4;
+ s &= 15;
+
+ if (s) {
+ k += r;
+ CHECK_BIT_BUFFER(br_state, s, return FALSE);
+ r = GET_BITS(s);
+ s = HUFF_EXTEND(r, s);
+ /* Output coefficient in natural (dezigzagged) order.
+ * Note: the extra entries in jpeg_natural_order[] will save us
+ * if k >= DCTSIZE2, which could happen if the data is corrupted.
+ */
+ (*block)[jpeg_natural_order[k]] = (JCOEF) s;
+ } else {
+ if (r != 15)
+ break;
+ k += 15;
+ }
+ }
+
+ } else {
+
+ /* Section F.2.2.2: decode the AC coefficients */
+ /* In this path we just discard the values */
+ for (k = 1; k < DCTSIZE2; k++) {
+ HUFF_DECODE(s, br_state, actbl, return FALSE, label3);
+
+ r = s >> 4;
+ s &= 15;
+
+ if (s) {
+ k += r;
+ CHECK_BIT_BUFFER(br_state, s, return FALSE);
+ DROP_BITS(s);
+ } else {
+ if (r != 15)
+ break;
+ k += 15;
+ }
+ }
+
+ }
+ }
+
+ /* Completed MCU, so update state */
+ BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+ ASSIGN_STATE(entropy->saved, state);
+ }
+
+ /* Account for restart interval (no-op if not using restarts) */
+ entropy->restarts_to_go--;
+
+ return TRUE;
+}
+
+
+/*
+ * Module initialization routine for Huffman entropy decoding.
+ */
+
+GLOBAL(void)
+jinit_huff_decoder (j_decompress_ptr cinfo)
+{
+ huff_entropy_ptr entropy;
+ int i;
+
+ entropy = (huff_entropy_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(huff_entropy_decoder));
+ cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
+ entropy->pub.start_pass = start_pass_huff_decoder;
+ entropy->pub.decode_mcu = decode_mcu;
+
+ /* Mark tables unallocated */
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL;
+ }
+}
--- /dev/null
+/*
+ * jdinput.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains input control logic for the JPEG decompressor.
+ * These routines are concerned with controlling the decompressor's input
+ * processing (marker reading and coefficient decoding). The actual input
+ * reading is done in jdmarker.c, jdhuff.c, and jdphuff.c.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Private state */
+
+typedef struct {
+ struct jpeg_input_controller pub; /* public fields */
+
+ boolean inheaders; /* TRUE until first SOS is reached */
+} my_input_controller;
+
+typedef my_input_controller * my_inputctl_ptr;
+
+
+/* Forward declarations */
+METHODDEF(int) consume_markers JPP((j_decompress_ptr cinfo));
+
+
+/*
+ * Routines to calculate various quantities related to the size of the image.
+ */
+
+LOCAL(void)
+initial_setup (j_decompress_ptr cinfo)
+/* Called once, when first SOS marker is reached */
+{
+ int ci;
+ jpeg_component_info *compptr;
+
+ /* Make sure image isn't bigger than I can handle */
+ if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION ||
+ (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION)
+ ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
+
+ /* For now, precision must match compiled-in value... */
+ if (cinfo->data_precision != BITS_IN_JSAMPLE)
+ ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
+
+ /* Check that number of components won't exceed internal array sizes */
+ if (cinfo->num_components > MAX_COMPONENTS)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,
+ MAX_COMPONENTS);
+
+ /* Compute maximum sampling factors; check factor validity */
+ cinfo->max_h_samp_factor = 1;
+ cinfo->max_v_samp_factor = 1;
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR ||
+ compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR)
+ ERREXIT(cinfo, JERR_BAD_SAMPLING);
+ cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor,
+ compptr->h_samp_factor);
+ cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor,
+ compptr->v_samp_factor);
+ }
+
+ /* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE.
+ * In the full decompressor, this will be overridden by jdmaster.c;
+ * but in the transcoder, jdmaster.c is not used, so we must do it here.
+ */
+ cinfo->min_DCT_scaled_size = DCTSIZE;
+
+ /* Compute dimensions of components */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ compptr->DCT_scaled_size = DCTSIZE;
+ /* Size in DCT blocks */
+ compptr->width_in_blocks = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
+ (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ compptr->height_in_blocks = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
+ (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ /* downsampled_width and downsampled_height will also be overridden by
+ * jdmaster.c if we are doing full decompression. The transcoder library
+ * doesn't use these values, but the calling application might.
+ */
+ /* Size in samples */
+ compptr->downsampled_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
+ (long) cinfo->max_h_samp_factor);
+ compptr->downsampled_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor,
+ (long) cinfo->max_v_samp_factor);
+ /* Mark component needed, until color conversion says otherwise */
+ compptr->component_needed = TRUE;
+ /* Mark no quantization table yet saved for component */
+ compptr->quant_table = NULL;
+ }
+
+ /* Compute number of fully interleaved MCU rows. */
+ cinfo->total_iMCU_rows = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height,
+ (long) (cinfo->max_v_samp_factor*DCTSIZE));
+
+ /* Decide whether file contains multiple scans */
+ if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode)
+ cinfo->inputctl->has_multiple_scans = TRUE;
+ else
+ cinfo->inputctl->has_multiple_scans = FALSE;
+}
+
+
+LOCAL(void)
+per_scan_setup (j_decompress_ptr cinfo)
+/* Do computations that are needed before processing a JPEG scan */
+/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */
+{
+ int ci, mcublks, tmp;
+ jpeg_component_info *compptr;
+
+ if (cinfo->comps_in_scan == 1) {
+
+ /* Noninterleaved (single-component) scan */
+ compptr = cinfo->cur_comp_info[0];
+
+ /* Overall image size in MCUs */
+ cinfo->MCUs_per_row = compptr->width_in_blocks;
+ cinfo->MCU_rows_in_scan = compptr->height_in_blocks;
+
+ /* For noninterleaved scan, always one block per MCU */
+ compptr->MCU_width = 1;
+ compptr->MCU_height = 1;
+ compptr->MCU_blocks = 1;
+ compptr->MCU_sample_width = compptr->DCT_scaled_size;
+ compptr->last_col_width = 1;
+ /* For noninterleaved scans, it is convenient to define last_row_height
+ * as the number of block rows present in the last iMCU row.
+ */
+ tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor);
+ if (tmp == 0) tmp = compptr->v_samp_factor;
+ compptr->last_row_height = tmp;
+
+ /* Prepare array describing MCU composition */
+ cinfo->blocks_in_MCU = 1;
+ cinfo->MCU_membership[0] = 0;
+
+ } else {
+
+ /* Interleaved (multi-component) scan */
+ if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN)
+ ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan,
+ MAX_COMPS_IN_SCAN);
+
+ /* Overall image size in MCUs */
+ cinfo->MCUs_per_row = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width,
+ (long) (cinfo->max_h_samp_factor*DCTSIZE));
+ cinfo->MCU_rows_in_scan = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height,
+ (long) (cinfo->max_v_samp_factor*DCTSIZE));
+
+ cinfo->blocks_in_MCU = 0;
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Sampling factors give # of blocks of component in each MCU */
+ compptr->MCU_width = compptr->h_samp_factor;
+ compptr->MCU_height = compptr->v_samp_factor;
+ compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
+ compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size;
+ /* Figure number of non-dummy blocks in last MCU column & row */
+ tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
+ if (tmp == 0) tmp = compptr->MCU_width;
+ compptr->last_col_width = tmp;
+ tmp = (int) (compptr->height_in_blocks % compptr->MCU_height);
+ if (tmp == 0) tmp = compptr->MCU_height;
+ compptr->last_row_height = tmp;
+ /* Prepare array describing MCU composition */
+ mcublks = compptr->MCU_blocks;
+ if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU)
+ ERREXIT(cinfo, JERR_BAD_MCU_SIZE);
+ while (mcublks-- > 0) {
+ cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;
+ }
+ }
+
+ }
+}
+
+
+/*
+ * Save away a copy of the Q-table referenced by each component present
+ * in the current scan, unless already saved during a prior scan.
+ *
+ * In a multiple-scan JPEG file, the encoder could assign different components
+ * the same Q-table slot number, but change table definitions between scans
+ * so that each component uses a different Q-table. (The IJG encoder is not
+ * currently capable of doing this, but other encoders might.) Since we want
+ * to be able to dequantize all the components at the end of the file, this
+ * means that we have to save away the table actually used for each component.
+ * We do this by copying the table at the start of the first scan containing
+ * the component.
+ * The JPEG spec prohibits the encoder from changing the contents of a Q-table
+ * slot between scans of a component using that slot. If the encoder does so
+ * anyway, this decoder will simply use the Q-table values that were current
+ * at the start of the first scan for the component.
+ *
+ * The decompressor output side looks only at the saved quant tables,
+ * not at the current Q-table slots.
+ */
+
+LOCAL(void)
+latch_quant_tables (j_decompress_ptr cinfo)
+{
+ int ci, qtblno;
+ jpeg_component_info *compptr;
+ JQUANT_TBL * qtbl;
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* No work if we already saved Q-table for this component */
+ if (compptr->quant_table != NULL)
+ continue;
+ /* Make sure specified quantization table is present */
+ qtblno = compptr->quant_tbl_no;
+ if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS ||
+ cinfo->quant_tbl_ptrs[qtblno] == NULL)
+ ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno);
+ /* OK, save away the quantization table */
+ qtbl = (JQUANT_TBL *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(JQUANT_TBL));
+ MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL));
+ compptr->quant_table = qtbl;
+ }
+}
+
+
+/*
+ * Initialize the input modules to read a scan of compressed data.
+ * The first call to this is done by jdmaster.c after initializing
+ * the entire decompressor (during jpeg_start_decompress).
+ * Subsequent calls come from consume_markers, below.
+ */
+
+METHODDEF(void)
+start_input_pass (j_decompress_ptr cinfo)
+{
+ per_scan_setup(cinfo);
+ latch_quant_tables(cinfo);
+ (*cinfo->entropy->start_pass) (cinfo);
+ (*cinfo->coef->start_input_pass) (cinfo);
+ cinfo->inputctl->consume_input = cinfo->coef->consume_data;
+}
+
+
+/*
+ * Finish up after inputting a compressed-data scan.
+ * This is called by the coefficient controller after it's read all
+ * the expected data of the scan.
+ */
+
+METHODDEF(void)
+finish_input_pass (j_decompress_ptr cinfo)
+{
+ cinfo->inputctl->consume_input = consume_markers;
+}
+
+
+/*
+ * Read JPEG markers before, between, or after compressed-data scans.
+ * Change state as necessary when a new scan is reached.
+ * Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
+ *
+ * The consume_input method pointer points either here or to the
+ * coefficient controller's consume_data routine, depending on whether
+ * we are reading a compressed data segment or inter-segment markers.
+ */
+
+METHODDEF(int)
+consume_markers (j_decompress_ptr cinfo)
+{
+ my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
+ int val;
+
+ if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */
+ return JPEG_REACHED_EOI;
+
+ val = (*cinfo->marker->read_markers) (cinfo);
+
+ switch (val) {
+ case JPEG_REACHED_SOS: /* Found SOS */
+ if (inputctl->inheaders) { /* 1st SOS */
+ initial_setup(cinfo);
+ inputctl->inheaders = FALSE;
+ /* Note: start_input_pass must be called by jdmaster.c
+ * before any more input can be consumed. jdapimin.c is
+ * responsible for enforcing this sequencing.
+ */
+ } else { /* 2nd or later SOS marker */
+ if (! inputctl->pub.has_multiple_scans)
+ ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */
+ start_input_pass(cinfo);
+ }
+ break;
+ case JPEG_REACHED_EOI: /* Found EOI */
+ inputctl->pub.eoi_reached = TRUE;
+ if (inputctl->inheaders) { /* Tables-only datastream, apparently */
+ if (cinfo->marker->saw_SOF)
+ ERREXIT(cinfo, JERR_SOF_NO_SOS);
+ } else {
+ /* Prevent infinite loop in coef ctlr's decompress_data routine
+ * if user set output_scan_number larger than number of scans.
+ */
+ if (cinfo->output_scan_number > cinfo->input_scan_number)
+ cinfo->output_scan_number = cinfo->input_scan_number;
+ }
+ break;
+ case JPEG_SUSPENDED:
+ break;
+ }
+
+ return val;
+}
+
+
+/*
+ * Reset state to begin a fresh datastream.
+ */
+
+METHODDEF(void)
+reset_input_controller (j_decompress_ptr cinfo)
+{
+ my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl;
+
+ inputctl->pub.consume_input = consume_markers;
+ inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
+ inputctl->pub.eoi_reached = FALSE;
+ inputctl->inheaders = TRUE;
+ /* Reset other modules */
+ (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
+ (*cinfo->marker->reset_marker_reader) (cinfo);
+ /* Reset progression state -- would be cleaner if entropy decoder did this */
+ cinfo->coef_bits = NULL;
+}
+
+
+/*
+ * Initialize the input controller module.
+ * This is called only once, when the decompression object is created.
+ */
+
+GLOBAL(void)
+jinit_input_controller (j_decompress_ptr cinfo)
+{
+ my_inputctl_ptr inputctl;
+
+ /* Create subobject in permanent pool */
+ inputctl = (my_inputctl_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ SIZEOF(my_input_controller));
+ cinfo->inputctl = (struct jpeg_input_controller *) inputctl;
+ /* Initialize method pointers */
+ inputctl->pub.consume_input = consume_markers;
+ inputctl->pub.reset_input_controller = reset_input_controller;
+ inputctl->pub.start_input_pass = start_input_pass;
+ inputctl->pub.finish_input_pass = finish_input_pass;
+ /* Initialize state: can't use reset_input_controller since we don't
+ * want to try to reset other modules yet.
+ */
+ inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */
+ inputctl->pub.eoi_reached = FALSE;
+ inputctl->inheaders = TRUE;
+}
--- /dev/null
+/*
+ * jdmainct.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the main buffer controller for decompression.
+ * The main buffer lies between the JPEG decompressor proper and the
+ * post-processor; it holds downsampled data in the JPEG colorspace.
+ *
+ * Note that this code is bypassed in raw-data mode, since the application
+ * supplies the equivalent of the main buffer in that case.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * In the current system design, the main buffer need never be a full-image
+ * buffer; any full-height buffers will be found inside the coefficient or
+ * postprocessing controllers. Nonetheless, the main controller is not
+ * trivial. Its responsibility is to provide context rows for upsampling/
+ * rescaling, and doing this in an efficient fashion is a bit tricky.
+ *
+ * Postprocessor input data is counted in "row groups". A row group
+ * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
+ * sample rows of each component. (We require DCT_scaled_size values to be
+ * chosen such that these numbers are integers. In practice DCT_scaled_size
+ * values will likely be powers of two, so we actually have the stronger
+ * condition that DCT_scaled_size / min_DCT_scaled_size is an integer.)
+ * Upsampling will typically produce max_v_samp_factor pixel rows from each
+ * row group (times any additional scale factor that the upsampler is
+ * applying).
+ *
+ * The coefficient controller will deliver data to us one iMCU row at a time;
+ * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or
+ * exactly min_DCT_scaled_size row groups. (This amount of data corresponds
+ * to one row of MCUs when the image is fully interleaved.) Note that the
+ * number of sample rows varies across components, but the number of row
+ * groups does not. Some garbage sample rows may be included in the last iMCU
+ * row at the bottom of the image.
+ *
+ * Depending on the vertical scaling algorithm used, the upsampler may need
+ * access to the sample row(s) above and below its current input row group.
+ * The upsampler is required to set need_context_rows TRUE at global selection
+ * time if so. When need_context_rows is FALSE, this controller can simply
+ * obtain one iMCU row at a time from the coefficient controller and dole it
+ * out as row groups to the postprocessor.
+ *
+ * When need_context_rows is TRUE, this controller guarantees that the buffer
+ * passed to postprocessing contains at least one row group's worth of samples
+ * above and below the row group(s) being processed. Note that the context
+ * rows "above" the first passed row group appear at negative row offsets in
+ * the passed buffer. At the top and bottom of the image, the required
+ * context rows are manufactured by duplicating the first or last real sample
+ * row; this avoids having special cases in the upsampling inner loops.
+ *
+ * The amount of context is fixed at one row group just because that's a
+ * convenient number for this controller to work with. The existing
+ * upsamplers really only need one sample row of context. An upsampler
+ * supporting arbitrary output rescaling might wish for more than one row
+ * group of context when shrinking the image; tough, we don't handle that.
+ * (This is justified by the assumption that downsizing will be handled mostly
+ * by adjusting the DCT_scaled_size values, so that the actual scale factor at
+ * the upsample step needn't be much less than one.)
+ *
+ * To provide the desired context, we have to retain the last two row groups
+ * of one iMCU row while reading in the next iMCU row. (The last row group
+ * can't be processed until we have another row group for its below-context,
+ * and so we have to save the next-to-last group too for its above-context.)
+ * We could do this most simply by copying data around in our buffer, but
+ * that'd be very slow. We can avoid copying any data by creating a rather
+ * strange pointer structure. Here's how it works. We allocate a workspace
+ * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number
+ * of row groups per iMCU row). We create two sets of redundant pointers to
+ * the workspace. Labeling the physical row groups 0 to M+1, the synthesized
+ * pointer lists look like this:
+ * M+1 M-1
+ * master pointer --> 0 master pointer --> 0
+ * 1 1
+ * ... ...
+ * M-3 M-3
+ * M-2 M
+ * M-1 M+1
+ * M M-2
+ * M+1 M-1
+ * 0 0
+ * We read alternate iMCU rows using each master pointer; thus the last two
+ * row groups of the previous iMCU row remain un-overwritten in the workspace.
+ * The pointer lists are set up so that the required context rows appear to
+ * be adjacent to the proper places when we pass the pointer lists to the
+ * upsampler.
+ *
+ * The above pictures describe the normal state of the pointer lists.
+ * At top and bottom of the image, we diddle the pointer lists to duplicate
+ * the first or last sample row as necessary (this is cheaper than copying
+ * sample rows around).
+ *
+ * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that
+ * situation each iMCU row provides only one row group so the buffering logic
+ * must be different (eg, we must read two iMCU rows before we can emit the
+ * first row group). For now, we simply do not support providing context
+ * rows when min_DCT_scaled_size is 1. That combination seems unlikely to
+ * be worth providing --- if someone wants a 1/8th-size preview, they probably
+ * want it quick and dirty, so a context-free upsampler is sufficient.
+ */
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_d_main_controller pub; /* public fields */
+
+ /* Pointer to allocated workspace (M or M+2 row groups). */
+ JSAMPARRAY buffer[MAX_COMPONENTS];
+
+ boolean buffer_full; /* Have we gotten an iMCU row from decoder? */
+ JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */
+
+ /* Remaining fields are only used in the context case. */
+
+ /* These are the master pointers to the funny-order pointer lists. */
+ JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */
+
+ int whichptr; /* indicates which pointer set is now in use */
+ int context_state; /* process_data state machine status */
+ JDIMENSION rowgroups_avail; /* row groups available to postprocessor */
+ JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */
+} my_main_controller;
+
+typedef my_main_controller * my_main_ptr;
+
+/* context_state values: */
+#define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */
+#define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */
+#define CTX_POSTPONED_ROW 2 /* feeding postponed row group */
+
+
+/* Forward declarations */
+METHODDEF(void) process_data_simple_main
+ JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
+ JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
+METHODDEF(void) process_data_context_main
+ JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
+ JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
+#ifdef QUANT_2PASS_SUPPORTED
+METHODDEF(void) process_data_crank_post
+ JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf,
+ JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail));
+#endif
+
+
+LOCAL(void)
+alloc_funny_pointers (j_decompress_ptr cinfo)
+/* Allocate space for the funny pointer lists.
+ * This is done only once, not once per pass.
+ */
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+ int ci, rgroup;
+ int M = cinfo->min_DCT_scaled_size;
+ jpeg_component_info *compptr;
+ JSAMPARRAY xbuf;
+
+ /* Get top-level space for component array pointers.
+ * We alloc both arrays with one call to save a few cycles.
+ */
+ main->xbuffer[0] = (JSAMPIMAGE)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ cinfo->num_components * 2 * SIZEOF(JSAMPARRAY));
+ main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
+ cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ /* Get space for pointer lists --- M+4 row groups in each list.
+ * We alloc both pointer lists with one call to save a few cycles.
+ */
+ xbuf = (JSAMPARRAY)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ 2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW));
+ xbuf += rgroup; /* want one row group at negative offsets */
+ main->xbuffer[0][ci] = xbuf;
+ xbuf += rgroup * (M + 4);
+ main->xbuffer[1][ci] = xbuf;
+ }
+}
+
+
+LOCAL(void)
+make_funny_pointers (j_decompress_ptr cinfo)
+/* Create the funny pointer lists discussed in the comments above.
+ * The actual workspace is already allocated (in main->buffer),
+ * and the space for the pointer lists is allocated too.
+ * This routine just fills in the curiously ordered lists.
+ * This will be repeated at the beginning of each pass.
+ */
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+ int ci, i, rgroup;
+ int M = cinfo->min_DCT_scaled_size;
+ jpeg_component_info *compptr;
+ JSAMPARRAY buf, xbuf0, xbuf1;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
+ cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ xbuf0 = main->xbuffer[0][ci];
+ xbuf1 = main->xbuffer[1][ci];
+ /* First copy the workspace pointers as-is */
+ buf = main->buffer[ci];
+ for (i = 0; i < rgroup * (M + 2); i++) {
+ xbuf0[i] = xbuf1[i] = buf[i];
+ }
+ /* In the second list, put the last four row groups in swapped order */
+ for (i = 0; i < rgroup * 2; i++) {
+ xbuf1[rgroup*(M-2) + i] = buf[rgroup*M + i];
+ xbuf1[rgroup*M + i] = buf[rgroup*(M-2) + i];
+ }
+ /* The wraparound pointers at top and bottom will be filled later
+ * (see set_wraparound_pointers, below). Initially we want the "above"
+ * pointers to duplicate the first actual data line. This only needs
+ * to happen in xbuffer[0].
+ */
+ for (i = 0; i < rgroup; i++) {
+ xbuf0[i - rgroup] = xbuf0[0];
+ }
+ }
+}
+
+
+LOCAL(void)
+set_wraparound_pointers (j_decompress_ptr cinfo)
+/* Set up the "wraparound" pointers at top and bottom of the pointer lists.
+ * This changes the pointer list state from top-of-image to the normal state.
+ */
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+ int ci, i, rgroup;
+ int M = cinfo->min_DCT_scaled_size;
+ jpeg_component_info *compptr;
+ JSAMPARRAY xbuf0, xbuf1;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
+ cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ xbuf0 = main->xbuffer[0][ci];
+ xbuf1 = main->xbuffer[1][ci];
+ for (i = 0; i < rgroup; i++) {
+ xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i];
+ xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i];
+ xbuf0[rgroup*(M+2) + i] = xbuf0[i];
+ xbuf1[rgroup*(M+2) + i] = xbuf1[i];
+ }
+ }
+}
+
+
+LOCAL(void)
+set_bottom_pointers (j_decompress_ptr cinfo)
+/* Change the pointer lists to duplicate the last sample row at the bottom
+ * of the image. whichptr indicates which xbuffer holds the final iMCU row.
+ * Also sets rowgroups_avail to indicate number of nondummy row groups in row.
+ */
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+ int ci, i, rgroup, iMCUheight, rows_left;
+ jpeg_component_info *compptr;
+ JSAMPARRAY xbuf;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Count sample rows in one iMCU row and in one row group */
+ iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size;
+ rgroup = iMCUheight / cinfo->min_DCT_scaled_size;
+ /* Count nondummy sample rows remaining for this component */
+ rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight);
+ if (rows_left == 0) rows_left = iMCUheight;
+ /* Count nondummy row groups. Should get same answer for each component,
+ * so we need only do it once.
+ */
+ if (ci == 0) {
+ main->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1);
+ }
+ /* Duplicate the last real sample row rgroup*2 times; this pads out the
+ * last partial rowgroup and ensures at least one full rowgroup of context.
+ */
+ xbuf = main->xbuffer[main->whichptr][ci];
+ for (i = 0; i < rgroup * 2; i++) {
+ xbuf[rows_left + i] = xbuf[rows_left-1];
+ }
+ }
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+
+ switch (pass_mode) {
+ case JBUF_PASS_THRU:
+ if (cinfo->upsample->need_context_rows) {
+ main->pub.process_data = process_data_context_main;
+ make_funny_pointers(cinfo); /* Create the xbuffer[] lists */
+ main->whichptr = 0; /* Read first iMCU row into xbuffer[0] */
+ main->context_state = CTX_PREPARE_FOR_IMCU;
+ main->iMCU_row_ctr = 0;
+ } else {
+ /* Simple case with no context needed */
+ main->pub.process_data = process_data_simple_main;
+ }
+ main->buffer_full = FALSE; /* Mark buffer empty */
+ main->rowgroup_ctr = 0;
+ break;
+#ifdef QUANT_2PASS_SUPPORTED
+ case JBUF_CRANK_DEST:
+ /* For last pass of 2-pass quantization, just crank the postprocessor */
+ main->pub.process_data = process_data_crank_post;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ break;
+ }
+}
+
+
+/*
+ * Process some data.
+ * This handles the simple case where no context is required.
+ */
+
+METHODDEF(void)
+process_data_simple_main (j_decompress_ptr cinfo,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+ JDIMENSION rowgroups_avail;
+
+ /* Read input data if we haven't filled the main buffer yet */
+ if (! main->buffer_full) {
+ if (! (*cinfo->coef->decompress_data) (cinfo, main->buffer))
+ return; /* suspension forced, can do nothing more */
+ main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
+ }
+
+ /* There are always min_DCT_scaled_size row groups in an iMCU row. */
+ rowgroups_avail = (JDIMENSION) cinfo->min_DCT_scaled_size;
+ /* Note: at the bottom of the image, we may pass extra garbage row groups
+ * to the postprocessor. The postprocessor has to check for bottom
+ * of image anyway (at row resolution), so no point in us doing it too.
+ */
+
+ /* Feed the postprocessor */
+ (*cinfo->post->post_process_data) (cinfo, main->buffer,
+ &main->rowgroup_ctr, rowgroups_avail,
+ output_buf, out_row_ctr, out_rows_avail);
+
+ /* Has postprocessor consumed all the data yet? If so, mark buffer empty */
+ if (main->rowgroup_ctr >= rowgroups_avail) {
+ main->buffer_full = FALSE;
+ main->rowgroup_ctr = 0;
+ }
+}
+
+
+/*
+ * Process some data.
+ * This handles the case where context rows must be provided.
+ */
+
+METHODDEF(void)
+process_data_context_main (j_decompress_ptr cinfo,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ my_main_ptr main = (my_main_ptr) cinfo->main;
+
+ /* Read input data if we haven't filled the main buffer yet */
+ if (! main->buffer_full) {
+ if (! (*cinfo->coef->decompress_data) (cinfo,
+ main->xbuffer[main->whichptr]))
+ return; /* suspension forced, can do nothing more */
+ main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */
+ main->iMCU_row_ctr++; /* count rows received */
+ }
+
+ /* Postprocessor typically will not swallow all the input data it is handed
+ * in one call (due to filling the output buffer first). Must be prepared
+ * to exit and restart. This switch lets us keep track of how far we got.
+ * Note that each case falls through to the next on successful completion.
+ */
+ switch (main->context_state) {
+ case CTX_POSTPONED_ROW:
+ /* Call postprocessor using previously set pointers for postponed row */
+ (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr],
+ &main->rowgroup_ctr, main->rowgroups_avail,
+ output_buf, out_row_ctr, out_rows_avail);
+ if (main->rowgroup_ctr < main->rowgroups_avail)
+ return; /* Need to suspend */
+ main->context_state = CTX_PREPARE_FOR_IMCU;
+ if (*out_row_ctr >= out_rows_avail)
+ return; /* Postprocessor exactly filled output buf */
+ /*FALLTHROUGH*/
+ case CTX_PREPARE_FOR_IMCU:
+ /* Prepare to process first M-1 row groups of this iMCU row */
+ main->rowgroup_ctr = 0;
+ main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size - 1);
+ /* Check for bottom of image: if so, tweak pointers to "duplicate"
+ * the last sample row, and adjust rowgroups_avail to ignore padding rows.
+ */
+ if (main->iMCU_row_ctr == cinfo->total_iMCU_rows)
+ set_bottom_pointers(cinfo);
+ main->context_state = CTX_PROCESS_IMCU;
+ /*FALLTHROUGH*/
+ case CTX_PROCESS_IMCU:
+ /* Call postprocessor using previously set pointers */
+ (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr],
+ &main->rowgroup_ctr, main->rowgroups_avail,
+ output_buf, out_row_ctr, out_rows_avail);
+ if (main->rowgroup_ctr < main->rowgroups_avail)
+ return; /* Need to suspend */
+ /* After the first iMCU, change wraparound pointers to normal state */
+ if (main->iMCU_row_ctr == 1)
+ set_wraparound_pointers(cinfo);
+ /* Prepare to load new iMCU row using other xbuffer list */
+ main->whichptr ^= 1; /* 0=>1 or 1=>0 */
+ main->buffer_full = FALSE;
+ /* Still need to process last row group of this iMCU row, */
+ /* which is saved at index M+1 of the other xbuffer */
+ main->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_scaled_size + 1);
+ main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size + 2);
+ main->context_state = CTX_POSTPONED_ROW;
+ }
+}
+
+
+/*
+ * Process some data.
+ * Final pass of two-pass quantization: just call the postprocessor.
+ * Source data will be the postprocessor controller's internal buffer.
+ */
+
+#ifdef QUANT_2PASS_SUPPORTED
+
+METHODDEF(void)
+process_data_crank_post (j_decompress_ptr cinfo,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ (*cinfo->post->post_process_data) (cinfo, (JSAMPIMAGE) NULL,
+ (JDIMENSION *) NULL, (JDIMENSION) 0,
+ output_buf, out_row_ctr, out_rows_avail);
+}
+
+#endif /* QUANT_2PASS_SUPPORTED */
+
+
+/*
+ * Initialize main buffer controller.
+ */
+
+GLOBAL(void)
+jinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
+{
+ my_main_ptr main;
+ int ci, rgroup, ngroups;
+ jpeg_component_info *compptr;
+
+ main = (my_main_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_main_controller));
+ cinfo->main = (struct jpeg_d_main_controller *) main;
+ main->pub.start_pass = start_pass_main;
+
+ if (need_full_buffer) /* shouldn't happen */
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+
+ /* Allocate the workspace.
+ * ngroups is the number of row groups we need.
+ */
+ if (cinfo->upsample->need_context_rows) {
+ if (cinfo->min_DCT_scaled_size < 2) /* unsupported, see comments above */
+ ERREXIT(cinfo, JERR_NOTIMPL);
+ alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */
+ ngroups = cinfo->min_DCT_scaled_size + 2;
+ } else {
+ ngroups = cinfo->min_DCT_scaled_size;
+ }
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
+ cinfo->min_DCT_scaled_size; /* height of a row group of component */
+ main->buffer[ci] = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ compptr->width_in_blocks * compptr->DCT_scaled_size,
+ (JDIMENSION) (rgroup * ngroups));
+ }
+}
--- /dev/null
+/*
+ * jdmarker.c
+ *
+ * Copyright (C) 1991-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to decode JPEG datastream markers.
+ * Most of the complexity arises from our desire to support input
+ * suspension: if not all of the data for a marker is available,
+ * we must exit back to the application. On resumption, we reprocess
+ * the marker.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+typedef enum { /* JPEG marker codes */
+ M_SOF0 = 0xc0,
+ M_SOF1 = 0xc1,
+ M_SOF2 = 0xc2,
+ M_SOF3 = 0xc3,
+
+ M_SOF5 = 0xc5,
+ M_SOF6 = 0xc6,
+ M_SOF7 = 0xc7,
+
+ M_JPG = 0xc8,
+ M_SOF9 = 0xc9,
+ M_SOF10 = 0xca,
+ M_SOF11 = 0xcb,
+
+ M_SOF13 = 0xcd,
+ M_SOF14 = 0xce,
+ M_SOF15 = 0xcf,
+
+ M_DHT = 0xc4,
+
+ M_DAC = 0xcc,
+
+ M_RST0 = 0xd0,
+ M_RST1 = 0xd1,
+ M_RST2 = 0xd2,
+ M_RST3 = 0xd3,
+ M_RST4 = 0xd4,
+ M_RST5 = 0xd5,
+ M_RST6 = 0xd6,
+ M_RST7 = 0xd7,
+
+ M_SOI = 0xd8,
+ M_EOI = 0xd9,
+ M_SOS = 0xda,
+ M_DQT = 0xdb,
+ M_DNL = 0xdc,
+ M_DRI = 0xdd,
+ M_DHP = 0xde,
+ M_EXP = 0xdf,
+
+ M_APP0 = 0xe0,
+ M_APP1 = 0xe1,
+ M_APP2 = 0xe2,
+ M_APP3 = 0xe3,
+ M_APP4 = 0xe4,
+ M_APP5 = 0xe5,
+ M_APP6 = 0xe6,
+ M_APP7 = 0xe7,
+ M_APP8 = 0xe8,
+ M_APP9 = 0xe9,
+ M_APP10 = 0xea,
+ M_APP11 = 0xeb,
+ M_APP12 = 0xec,
+ M_APP13 = 0xed,
+ M_APP14 = 0xee,
+ M_APP15 = 0xef,
+
+ M_JPG0 = 0xf0,
+ M_JPG13 = 0xfd,
+ M_COM = 0xfe,
+
+ M_TEM = 0x01,
+
+ M_ERROR = 0x100
+} JPEG_MARKER;
+
+
+/* Private state */
+
+typedef struct {
+ struct jpeg_marker_reader pub; /* public fields */
+
+ /* Application-overridable marker processing methods */
+ jpeg_marker_parser_method process_COM;
+ jpeg_marker_parser_method process_APPn[16];
+
+ /* Limit on marker data length to save for each marker type */
+ unsigned int length_limit_COM;
+ unsigned int length_limit_APPn[16];
+
+ /* Status of COM/APPn marker saving */
+ jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */
+ unsigned int bytes_read; /* data bytes read so far in marker */
+ /* Note: cur_marker is not linked into marker_list until it's all read. */
+} my_marker_reader;
+
+typedef my_marker_reader * my_marker_ptr;
+
+
+/*
+ * Macros for fetching data from the data source module.
+ *
+ * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
+ * the current restart point; we update them only when we have reached a
+ * suitable place to restart if a suspension occurs.
+ */
+
+/* Declare and initialize local copies of input pointer/count */
+#define INPUT_VARS(cinfo) \
+ struct jpeg_source_mgr * datasrc = (cinfo)->src; \
+ const JOCTET * next_input_byte = datasrc->next_input_byte; \
+ size_t bytes_in_buffer = datasrc->bytes_in_buffer
+
+/* Unload the local copies --- do this only at a restart boundary */
+#define INPUT_SYNC(cinfo) \
+ ( datasrc->next_input_byte = next_input_byte, \
+ datasrc->bytes_in_buffer = bytes_in_buffer )
+
+/* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
+#define INPUT_RELOAD(cinfo) \
+ ( next_input_byte = datasrc->next_input_byte, \
+ bytes_in_buffer = datasrc->bytes_in_buffer )
+
+/* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
+ * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
+ * but we must reload the local copies after a successful fill.
+ */
+#define MAKE_BYTE_AVAIL(cinfo,action) \
+ if (bytes_in_buffer == 0) { \
+ if (! (*datasrc->fill_input_buffer) (cinfo)) \
+ { action; } \
+ INPUT_RELOAD(cinfo); \
+ }
+
+/* Read a byte into variable V.
+ * If must suspend, take the specified action (typically "return FALSE").
+ */
+#define INPUT_BYTE(cinfo,V,action) \
+ MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
+ bytes_in_buffer--; \
+ V = GETJOCTET(*next_input_byte++); )
+
+/* As above, but read two bytes interpreted as an unsigned 16-bit integer.
+ * V should be declared unsigned int or perhaps INT32.
+ */
+#define INPUT_2BYTES(cinfo,V,action) \
+ MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
+ bytes_in_buffer--; \
+ V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
+ MAKE_BYTE_AVAIL(cinfo,action); \
+ bytes_in_buffer--; \
+ V += GETJOCTET(*next_input_byte++); )
+
+
+/*
+ * Routines to process JPEG markers.
+ *
+ * Entry condition: JPEG marker itself has been read and its code saved
+ * in cinfo->unread_marker; input restart point is just after the marker.
+ *
+ * Exit: if return TRUE, have read and processed any parameters, and have
+ * updated the restart point to point after the parameters.
+ * If return FALSE, was forced to suspend before reaching end of
+ * marker parameters; restart point has not been moved. Same routine
+ * will be called again after application supplies more input data.
+ *
+ * This approach to suspension assumes that all of a marker's parameters
+ * can fit into a single input bufferload. This should hold for "normal"
+ * markers. Some COM/APPn markers might have large parameter segments
+ * that might not fit. If we are simply dropping such a marker, we use
+ * skip_input_data to get past it, and thereby put the problem on the
+ * source manager's shoulders. If we are saving the marker's contents
+ * into memory, we use a slightly different convention: when forced to
+ * suspend, the marker processor updates the restart point to the end of
+ * what it's consumed (ie, the end of the buffer) before returning FALSE.
+ * On resumption, cinfo->unread_marker still contains the marker code,
+ * but the data source will point to the next chunk of marker data.
+ * The marker processor must retain internal state to deal with this.
+ *
+ * Note that we don't bother to avoid duplicate trace messages if a
+ * suspension occurs within marker parameters. Other side effects
+ * require more care.
+ */
+
+
+LOCAL(boolean)
+get_soi (j_decompress_ptr cinfo)
+/* Process an SOI marker */
+{
+ int i;
+
+ TRACEMS(cinfo, 1, JTRC_SOI);
+
+ if (cinfo->marker->saw_SOI)
+ ERREXIT(cinfo, JERR_SOI_DUPLICATE);
+
+ /* Reset all parameters that are defined to be reset by SOI */
+
+ for (i = 0; i < NUM_ARITH_TBLS; i++) {
+ cinfo->arith_dc_L[i] = 0;
+ cinfo->arith_dc_U[i] = 1;
+ cinfo->arith_ac_K[i] = 5;
+ }
+ cinfo->restart_interval = 0;
+
+ /* Set initial assumptions for colorspace etc */
+
+ cinfo->jpeg_color_space = JCS_UNKNOWN;
+ cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
+
+ cinfo->saw_JFIF_marker = FALSE;
+ cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
+ cinfo->JFIF_minor_version = 1;
+ cinfo->density_unit = 0;
+ cinfo->X_density = 1;
+ cinfo->Y_density = 1;
+ cinfo->saw_Adobe_marker = FALSE;
+ cinfo->Adobe_transform = 0;
+
+ cinfo->marker->saw_SOI = TRUE;
+
+ return TRUE;
+}
+
+
+LOCAL(boolean)
+get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
+/* Process a SOFn marker */
+{
+ INT32 length;
+ int c, ci;
+ jpeg_component_info * compptr;
+ INPUT_VARS(cinfo);
+
+ cinfo->progressive_mode = is_prog;
+ cinfo->arith_code = is_arith;
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+
+ INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
+ INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
+ INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
+ INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
+
+ length -= 8;
+
+ TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
+ (int) cinfo->image_width, (int) cinfo->image_height,
+ cinfo->num_components);
+
+ if (cinfo->marker->saw_SOF)
+ ERREXIT(cinfo, JERR_SOF_DUPLICATE);
+
+ /* We don't support files in which the image height is initially specified */
+ /* as 0 and is later redefined by DNL. As long as we have to check that, */
+ /* might as well have a general sanity check. */
+ if (cinfo->image_height <= 0 || cinfo->image_width <= 0
+ || cinfo->num_components <= 0)
+ ERREXIT(cinfo, JERR_EMPTY_IMAGE);
+
+ if (length != (cinfo->num_components * 3))
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ if (cinfo->comp_info == NULL) /* do only once, even if suspend */
+ cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ cinfo->num_components * SIZEOF(jpeg_component_info));
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ compptr->component_index = ci;
+ INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
+ INPUT_BYTE(cinfo, c, return FALSE);
+ compptr->h_samp_factor = (c >> 4) & 15;
+ compptr->v_samp_factor = (c ) & 15;
+ INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
+
+ TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
+ compptr->component_id, compptr->h_samp_factor,
+ compptr->v_samp_factor, compptr->quant_tbl_no);
+ }
+
+ cinfo->marker->saw_SOF = TRUE;
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+LOCAL(boolean)
+get_sos (j_decompress_ptr cinfo)
+/* Process a SOS marker */
+{
+ INT32 length;
+ int i, ci, n, c, cc;
+ jpeg_component_info * compptr;
+ INPUT_VARS(cinfo);
+
+ if (! cinfo->marker->saw_SOF)
+ ERREXIT(cinfo, JERR_SOS_NO_SOF);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+
+ INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
+
+ TRACEMS1(cinfo, 1, JTRC_SOS, n);
+
+ if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ cinfo->comps_in_scan = n;
+
+ /* Collect the component-spec parameters */
+
+ for (i = 0; i < n; i++) {
+ INPUT_BYTE(cinfo, cc, return FALSE);
+ INPUT_BYTE(cinfo, c, return FALSE);
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ if (cc == compptr->component_id)
+ goto id_found;
+ }
+
+ ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
+
+ id_found:
+
+ cinfo->cur_comp_info[i] = compptr;
+ compptr->dc_tbl_no = (c >> 4) & 15;
+ compptr->ac_tbl_no = (c ) & 15;
+
+ TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
+ compptr->dc_tbl_no, compptr->ac_tbl_no);
+ }
+
+ /* Collect the additional scan parameters Ss, Se, Ah/Al. */
+ INPUT_BYTE(cinfo, c, return FALSE);
+ cinfo->Ss = c;
+ INPUT_BYTE(cinfo, c, return FALSE);
+ cinfo->Se = c;
+ INPUT_BYTE(cinfo, c, return FALSE);
+ cinfo->Ah = (c >> 4) & 15;
+ cinfo->Al = (c ) & 15;
+
+ TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
+ cinfo->Ah, cinfo->Al);
+
+ /* Prepare to scan data & restart markers */
+ cinfo->marker->next_restart_num = 0;
+
+ /* Count another SOS marker */
+ cinfo->input_scan_number++;
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+#ifdef D_ARITH_CODING_SUPPORTED
+
+LOCAL(boolean)
+get_dac (j_decompress_ptr cinfo)
+/* Process a DAC marker */
+{
+ INT32 length;
+ int index, val;
+ INPUT_VARS(cinfo);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+ length -= 2;
+
+ while (length > 0) {
+ INPUT_BYTE(cinfo, index, return FALSE);
+ INPUT_BYTE(cinfo, val, return FALSE);
+
+ length -= 2;
+
+ TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
+
+ if (index < 0 || index >= (2*NUM_ARITH_TBLS))
+ ERREXIT1(cinfo, JERR_DAC_INDEX, index);
+
+ if (index >= NUM_ARITH_TBLS) { /* define AC table */
+ cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
+ } else { /* define DC table */
+ cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
+ cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
+ if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
+ ERREXIT1(cinfo, JERR_DAC_VALUE, val);
+ }
+ }
+
+ if (length != 0)
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+#else /* ! D_ARITH_CODING_SUPPORTED */
+
+#define get_dac(cinfo) skip_variable(cinfo)
+
+#endif /* D_ARITH_CODING_SUPPORTED */
+
+
+LOCAL(boolean)
+get_dht (j_decompress_ptr cinfo)
+/* Process a DHT marker */
+{
+ INT32 length;
+ UINT8 bits[17];
+ UINT8 huffval[256];
+ int i, index, count;
+ JHUFF_TBL **htblptr;
+ INPUT_VARS(cinfo);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+ length -= 2;
+
+ while (length > 16) {
+ INPUT_BYTE(cinfo, index, return FALSE);
+
+ TRACEMS1(cinfo, 1, JTRC_DHT, index);
+
+ bits[0] = 0;
+ count = 0;
+ for (i = 1; i <= 16; i++) {
+ INPUT_BYTE(cinfo, bits[i], return FALSE);
+ count += bits[i];
+ }
+
+ length -= 1 + 16;
+
+ TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
+ bits[1], bits[2], bits[3], bits[4],
+ bits[5], bits[6], bits[7], bits[8]);
+ TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
+ bits[9], bits[10], bits[11], bits[12],
+ bits[13], bits[14], bits[15], bits[16]);
+
+ /* Here we just do minimal validation of the counts to avoid walking
+ * off the end of our table space. jdhuff.c will check more carefully.
+ */
+ if (count > 256 || ((INT32) count) > length)
+ ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
+
+ for (i = 0; i < count; i++)
+ INPUT_BYTE(cinfo, huffval[i], return FALSE);
+
+ length -= count;
+
+ if (index & 0x10) { /* AC table definition */
+ index -= 0x10;
+ htblptr = &cinfo->ac_huff_tbl_ptrs[index];
+ } else { /* DC table definition */
+ htblptr = &cinfo->dc_huff_tbl_ptrs[index];
+ }
+
+ if (index < 0 || index >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_DHT_INDEX, index);
+
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
+
+ MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
+ MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
+ }
+
+ if (length != 0)
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+LOCAL(boolean)
+get_dqt (j_decompress_ptr cinfo)
+/* Process a DQT marker */
+{
+ INT32 length;
+ int n, i, prec;
+ unsigned int tmp;
+ JQUANT_TBL *quant_ptr;
+ INPUT_VARS(cinfo);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+ length -= 2;
+
+ while (length > 0) {
+ INPUT_BYTE(cinfo, n, return FALSE);
+ prec = n >> 4;
+ n &= 0x0F;
+
+ TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
+
+ if (n >= NUM_QUANT_TBLS)
+ ERREXIT1(cinfo, JERR_DQT_INDEX, n);
+
+ if (cinfo->quant_tbl_ptrs[n] == NULL)
+ cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
+ quant_ptr = cinfo->quant_tbl_ptrs[n];
+
+ for (i = 0; i < DCTSIZE2; i++) {
+ if (prec)
+ INPUT_2BYTES(cinfo, tmp, return FALSE);
+ else
+ INPUT_BYTE(cinfo, tmp, return FALSE);
+ /* We convert the zigzag-order table to natural array order. */
+ quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
+ }
+
+ if (cinfo->err->trace_level >= 2) {
+ for (i = 0; i < DCTSIZE2; i += 8) {
+ TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
+ quant_ptr->quantval[i], quant_ptr->quantval[i+1],
+ quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
+ quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
+ quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
+ }
+ }
+
+ length -= DCTSIZE2+1;
+ if (prec) length -= DCTSIZE2;
+ }
+
+ if (length != 0)
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+LOCAL(boolean)
+get_dri (j_decompress_ptr cinfo)
+/* Process a DRI marker */
+{
+ INT32 length;
+ unsigned int tmp;
+ INPUT_VARS(cinfo);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+
+ if (length != 4)
+ ERREXIT(cinfo, JERR_BAD_LENGTH);
+
+ INPUT_2BYTES(cinfo, tmp, return FALSE);
+
+ TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
+
+ cinfo->restart_interval = tmp;
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+/*
+ * Routines for processing APPn and COM markers.
+ * These are either saved in memory or discarded, per application request.
+ * APP0 and APP14 are specially checked to see if they are
+ * JFIF and Adobe markers, respectively.
+ */
+
+#define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
+#define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
+#define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
+
+
+LOCAL(void)
+examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
+ unsigned int datalen, INT32 remaining)
+/* Examine first few bytes from an APP0.
+ * Take appropriate action if it is a JFIF marker.
+ * datalen is # of bytes at data[], remaining is length of rest of marker data.
+ */
+{
+ INT32 totallen = (INT32) datalen + remaining;
+
+ if (datalen >= APP0_DATA_LEN &&
+ GETJOCTET(data[0]) == 0x4A &&
+ GETJOCTET(data[1]) == 0x46 &&
+ GETJOCTET(data[2]) == 0x49 &&
+ GETJOCTET(data[3]) == 0x46 &&
+ GETJOCTET(data[4]) == 0) {
+ /* Found JFIF APP0 marker: save info */
+ cinfo->saw_JFIF_marker = TRUE;
+ cinfo->JFIF_major_version = GETJOCTET(data[5]);
+ cinfo->JFIF_minor_version = GETJOCTET(data[6]);
+ cinfo->density_unit = GETJOCTET(data[7]);
+ cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
+ cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
+ /* Check version.
+ * Major version must be 1, anything else signals an incompatible change.
+ * (We used to treat this as an error, but now it's a nonfatal warning,
+ * because some bozo at Hijaak couldn't read the spec.)
+ * Minor version should be 0..2, but process anyway if newer.
+ */
+ if (cinfo->JFIF_major_version != 1)
+ WARNMS2(cinfo, JWRN_JFIF_MAJOR,
+ cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
+ /* Generate trace messages */
+ TRACEMS5(cinfo, 1, JTRC_JFIF,
+ cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
+ cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
+ /* Validate thumbnail dimensions and issue appropriate messages */
+ if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
+ TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
+ GETJOCTET(data[12]), GETJOCTET(data[13]));
+ totallen -= APP0_DATA_LEN;
+ if (totallen !=
+ ((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
+ TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
+ } else if (datalen >= 6 &&
+ GETJOCTET(data[0]) == 0x4A &&
+ GETJOCTET(data[1]) == 0x46 &&
+ GETJOCTET(data[2]) == 0x58 &&
+ GETJOCTET(data[3]) == 0x58 &&
+ GETJOCTET(data[4]) == 0) {
+ /* Found JFIF "JFXX" extension APP0 marker */
+ /* The library doesn't actually do anything with these,
+ * but we try to produce a helpful trace message.
+ */
+ switch (GETJOCTET(data[5])) {
+ case 0x10:
+ TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
+ break;
+ case 0x11:
+ TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
+ break;
+ case 0x13:
+ TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
+ break;
+ default:
+ TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
+ GETJOCTET(data[5]), (int) totallen);
+ break;
+ }
+ } else {
+ /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
+ TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
+ }
+}
+
+
+LOCAL(void)
+examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
+ unsigned int datalen, INT32 remaining)
+/* Examine first few bytes from an APP14.
+ * Take appropriate action if it is an Adobe marker.
+ * datalen is # of bytes at data[], remaining is length of rest of marker data.
+ */
+{
+ unsigned int version, flags0, flags1, transform;
+
+ if (datalen >= APP14_DATA_LEN &&
+ GETJOCTET(data[0]) == 0x41 &&
+ GETJOCTET(data[1]) == 0x64 &&
+ GETJOCTET(data[2]) == 0x6F &&
+ GETJOCTET(data[3]) == 0x62 &&
+ GETJOCTET(data[4]) == 0x65) {
+ /* Found Adobe APP14 marker */
+ version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
+ flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
+ flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
+ transform = GETJOCTET(data[11]);
+ TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
+ cinfo->saw_Adobe_marker = TRUE;
+ cinfo->Adobe_transform = (UINT8) transform;
+ } else {
+ /* Start of APP14 does not match "Adobe", or too short */
+ TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
+ }
+}
+
+
+METHODDEF(boolean)
+get_interesting_appn (j_decompress_ptr cinfo)
+/* Process an APP0 or APP14 marker without saving it */
+{
+ INT32 length;
+ JOCTET b[APPN_DATA_LEN];
+ unsigned int i, numtoread;
+ INPUT_VARS(cinfo);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+ length -= 2;
+
+ /* get the interesting part of the marker data */
+ if (length >= APPN_DATA_LEN)
+ numtoread = APPN_DATA_LEN;
+ else if (length > 0)
+ numtoread = (unsigned int) length;
+ else
+ numtoread = 0;
+ for (i = 0; i < numtoread; i++)
+ INPUT_BYTE(cinfo, b[i], return FALSE);
+ length -= numtoread;
+
+ /* process it */
+ switch (cinfo->unread_marker) {
+ case M_APP0:
+ examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
+ break;
+ case M_APP14:
+ examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
+ break;
+ default:
+ /* can't get here unless jpeg_save_markers chooses wrong processor */
+ ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
+ break;
+ }
+
+ /* skip any remaining data -- could be lots */
+ INPUT_SYNC(cinfo);
+ if (length > 0)
+ (*cinfo->src->skip_input_data) (cinfo, (long) length);
+
+ return TRUE;
+}
+
+
+#ifdef SAVE_MARKERS_SUPPORTED
+
+METHODDEF(boolean)
+save_marker (j_decompress_ptr cinfo)
+/* Save an APPn or COM marker into the marker list */
+{
+ my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
+ jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
+ unsigned int bytes_read, data_length;
+ JOCTET FAR * data;
+ INT32 length = 0;
+ INPUT_VARS(cinfo);
+
+ if (cur_marker == NULL) {
+ /* begin reading a marker */
+ INPUT_2BYTES(cinfo, length, return FALSE);
+ length -= 2;
+ if (length >= 0) { /* watch out for bogus length word */
+ /* figure out how much we want to save */
+ unsigned int limit;
+ if (cinfo->unread_marker == (int) M_COM)
+ limit = marker->length_limit_COM;
+ else
+ limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
+ if ((unsigned int) length < limit)
+ limit = (unsigned int) length;
+ /* allocate and initialize the marker item */
+ cur_marker = (jpeg_saved_marker_ptr)
+ (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(struct jpeg_marker_struct) + limit);
+ cur_marker->next = NULL;
+ cur_marker->marker = (UINT8) cinfo->unread_marker;
+ cur_marker->original_length = (unsigned int) length;
+ cur_marker->data_length = limit;
+ /* data area is just beyond the jpeg_marker_struct */
+ data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
+ marker->cur_marker = cur_marker;
+ marker->bytes_read = 0;
+ bytes_read = 0;
+ data_length = limit;
+ } else {
+ /* deal with bogus length word */
+ bytes_read = data_length = 0;
+ data = NULL;
+ }
+ } else {
+ /* resume reading a marker */
+ bytes_read = marker->bytes_read;
+ data_length = cur_marker->data_length;
+ data = cur_marker->data + bytes_read;
+ }
+
+ while (bytes_read < data_length) {
+ INPUT_SYNC(cinfo); /* move the restart point to here */
+ marker->bytes_read = bytes_read;
+ /* If there's not at least one byte in buffer, suspend */
+ MAKE_BYTE_AVAIL(cinfo, return FALSE);
+ /* Copy bytes with reasonable rapidity */
+ while (bytes_read < data_length && bytes_in_buffer > 0) {
+ *data++ = *next_input_byte++;
+ bytes_in_buffer--;
+ bytes_read++;
+ }
+ }
+
+ /* Done reading what we want to read */
+ if (cur_marker != NULL) { /* will be NULL if bogus length word */
+ /* Add new marker to end of list */
+ if (cinfo->marker_list == NULL) {
+ cinfo->marker_list = cur_marker;
+ } else {
+ jpeg_saved_marker_ptr prev = cinfo->marker_list;
+ while (prev->next != NULL)
+ prev = prev->next;
+ prev->next = cur_marker;
+ }
+ /* Reset pointer & calc remaining data length */
+ data = cur_marker->data;
+ length = cur_marker->original_length - data_length;
+ }
+ /* Reset to initial state for next marker */
+ marker->cur_marker = NULL;
+
+ /* Process the marker if interesting; else just make a generic trace msg */
+ switch (cinfo->unread_marker) {
+ case M_APP0:
+ examine_app0(cinfo, data, data_length, length);
+ break;
+ case M_APP14:
+ examine_app14(cinfo, data, data_length, length);
+ break;
+ default:
+ TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
+ (int) (data_length + length));
+ break;
+ }
+
+ /* skip any remaining data -- could be lots */
+ INPUT_SYNC(cinfo); /* do before skip_input_data */
+ if (length > 0)
+ (*cinfo->src->skip_input_data) (cinfo, (long) length);
+
+ return TRUE;
+}
+
+#endif /* SAVE_MARKERS_SUPPORTED */
+
+
+METHODDEF(boolean)
+skip_variable (j_decompress_ptr cinfo)
+/* Skip over an unknown or uninteresting variable-length marker */
+{
+ INT32 length;
+ INPUT_VARS(cinfo);
+
+ INPUT_2BYTES(cinfo, length, return FALSE);
+ length -= 2;
+
+ TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
+
+ INPUT_SYNC(cinfo); /* do before skip_input_data */
+ if (length > 0)
+ (*cinfo->src->skip_input_data) (cinfo, (long) length);
+
+ return TRUE;
+}
+
+
+/*
+ * Find the next JPEG marker, save it in cinfo->unread_marker.
+ * Returns FALSE if had to suspend before reaching a marker;
+ * in that case cinfo->unread_marker is unchanged.
+ *
+ * Note that the result might not be a valid marker code,
+ * but it will never be 0 or FF.
+ */
+
+LOCAL(boolean)
+next_marker (j_decompress_ptr cinfo)
+{
+ int c;
+ INPUT_VARS(cinfo);
+
+ for (;;) {
+ INPUT_BYTE(cinfo, c, return FALSE);
+ /* Skip any non-FF bytes.
+ * This may look a bit inefficient, but it will not occur in a valid file.
+ * We sync after each discarded byte so that a suspending data source
+ * can discard the byte from its buffer.
+ */
+ while (c != 0xFF) {
+ cinfo->marker->discarded_bytes++;
+ INPUT_SYNC(cinfo);
+ INPUT_BYTE(cinfo, c, return FALSE);
+ }
+ /* This loop swallows any duplicate FF bytes. Extra FFs are legal as
+ * pad bytes, so don't count them in discarded_bytes. We assume there
+ * will not be so many consecutive FF bytes as to overflow a suspending
+ * data source's input buffer.
+ */
+ do {
+ INPUT_BYTE(cinfo, c, return FALSE);
+ } while (c == 0xFF);
+ if (c != 0)
+ break; /* found a valid marker, exit loop */
+ /* Reach here if we found a stuffed-zero data sequence (FF/00).
+ * Discard it and loop back to try again.
+ */
+ cinfo->marker->discarded_bytes += 2;
+ INPUT_SYNC(cinfo);
+ }
+
+ if (cinfo->marker->discarded_bytes != 0) {
+ WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
+ cinfo->marker->discarded_bytes = 0;
+ }
+
+ cinfo->unread_marker = c;
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+LOCAL(boolean)
+first_marker (j_decompress_ptr cinfo)
+/* Like next_marker, but used to obtain the initial SOI marker. */
+/* For this marker, we do not allow preceding garbage or fill; otherwise,
+ * we might well scan an entire input file before realizing it ain't JPEG.
+ * If an application wants to process non-JFIF files, it must seek to the
+ * SOI before calling the JPEG library.
+ */
+{
+ int c, c2;
+ INPUT_VARS(cinfo);
+
+ INPUT_BYTE(cinfo, c, return FALSE);
+ INPUT_BYTE(cinfo, c2, return FALSE);
+ if (c != 0xFF || c2 != (int) M_SOI)
+ ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
+
+ cinfo->unread_marker = c2;
+
+ INPUT_SYNC(cinfo);
+ return TRUE;
+}
+
+
+/*
+ * Read markers until SOS or EOI.
+ *
+ * Returns same codes as are defined for jpeg_consume_input:
+ * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
+ */
+
+METHODDEF(int)
+read_markers (j_decompress_ptr cinfo)
+{
+ /* Outer loop repeats once for each marker. */
+ for (;;) {
+ /* Collect the marker proper, unless we already did. */
+ /* NB: first_marker() enforces the requirement that SOI appear first. */
+ if (cinfo->unread_marker == 0) {
+ if (! cinfo->marker->saw_SOI) {
+ if (! first_marker(cinfo))
+ return JPEG_SUSPENDED;
+ } else {
+ if (! next_marker(cinfo))
+ return JPEG_SUSPENDED;
+ }
+ }
+ /* At this point cinfo->unread_marker contains the marker code and the
+ * input point is just past the marker proper, but before any parameters.
+ * A suspension will cause us to return with this state still true.
+ */
+ switch (cinfo->unread_marker) {
+ case M_SOI:
+ if (! get_soi(cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_SOF0: /* Baseline */
+ case M_SOF1: /* Extended sequential, Huffman */
+ if (! get_sof(cinfo, FALSE, FALSE))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_SOF2: /* Progressive, Huffman */
+ if (! get_sof(cinfo, TRUE, FALSE))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_SOF9: /* Extended sequential, arithmetic */
+ if (! get_sof(cinfo, FALSE, TRUE))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_SOF10: /* Progressive, arithmetic */
+ if (! get_sof(cinfo, TRUE, TRUE))
+ return JPEG_SUSPENDED;
+ break;
+
+ /* Currently unsupported SOFn types */
+ case M_SOF3: /* Lossless, Huffman */
+ case M_SOF5: /* Differential sequential, Huffman */
+ case M_SOF6: /* Differential progressive, Huffman */
+ case M_SOF7: /* Differential lossless, Huffman */
+ case M_JPG: /* Reserved for JPEG extensions */
+ case M_SOF11: /* Lossless, arithmetic */
+ case M_SOF13: /* Differential sequential, arithmetic */
+ case M_SOF14: /* Differential progressive, arithmetic */
+ case M_SOF15: /* Differential lossless, arithmetic */
+ ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
+ break;
+
+ case M_SOS:
+ if (! get_sos(cinfo))
+ return JPEG_SUSPENDED;
+ cinfo->unread_marker = 0; /* processed the marker */
+ return JPEG_REACHED_SOS;
+
+ case M_EOI:
+ TRACEMS(cinfo, 1, JTRC_EOI);
+ cinfo->unread_marker = 0; /* processed the marker */
+ return JPEG_REACHED_EOI;
+
+ case M_DAC:
+ if (! get_dac(cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_DHT:
+ if (! get_dht(cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_DQT:
+ if (! get_dqt(cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_DRI:
+ if (! get_dri(cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_APP0:
+ case M_APP1:
+ case M_APP2:
+ case M_APP3:
+ case M_APP4:
+ case M_APP5:
+ case M_APP6:
+ case M_APP7:
+ case M_APP8:
+ case M_APP9:
+ case M_APP10:
+ case M_APP11:
+ case M_APP12:
+ case M_APP13:
+ case M_APP14:
+ case M_APP15:
+ if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
+ cinfo->unread_marker - (int) M_APP0]) (cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_COM:
+ if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ case M_RST0: /* these are all parameterless */
+ case M_RST1:
+ case M_RST2:
+ case M_RST3:
+ case M_RST4:
+ case M_RST5:
+ case M_RST6:
+ case M_RST7:
+ case M_TEM:
+ TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
+ break;
+
+ case M_DNL: /* Ignore DNL ... perhaps the wrong thing */
+ if (! skip_variable(cinfo))
+ return JPEG_SUSPENDED;
+ break;
+
+ default: /* must be DHP, EXP, JPGn, or RESn */
+ /* For now, we treat the reserved markers as fatal errors since they are
+ * likely to be used to signal incompatible JPEG Part 3 extensions.
+ * Once the JPEG 3 version-number marker is well defined, this code
+ * ought to change!
+ */
+ ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
+ break;
+ }
+ /* Successfully processed marker, so reset state variable */
+ cinfo->unread_marker = 0;
+ } /* end loop */
+}
+
+
+/*
+ * Read a restart marker, which is expected to appear next in the datastream;
+ * if the marker is not there, take appropriate recovery action.
+ * Returns FALSE if suspension is required.
+ *
+ * This is called by the entropy decoder after it has read an appropriate
+ * number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder
+ * has already read a marker from the data source. Under normal conditions
+ * cinfo->unread_marker will be reset to 0 before returning; if not reset,
+ * it holds a marker which the decoder will be unable to read past.
+ */
+
+METHODDEF(boolean)
+read_restart_marker (j_decompress_ptr cinfo)
+{
+ /* Obtain a marker unless we already did. */
+ /* Note that next_marker will complain if it skips any data. */
+ if (cinfo->unread_marker == 0) {
+ if (! next_marker(cinfo))
+ return FALSE;
+ }
+
+ if (cinfo->unread_marker ==
+ ((int) M_RST0 + cinfo->marker->next_restart_num)) {
+ /* Normal case --- swallow the marker and let entropy decoder continue */
+ TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
+ cinfo->unread_marker = 0;
+ } else {
+ /* Uh-oh, the restart markers have been messed up. */
+ /* Let the data source manager determine how to resync. */
+ if (! (*cinfo->src->resync_to_restart) (cinfo,
+ cinfo->marker->next_restart_num))
+ return FALSE;
+ }
+
+ /* Update next-restart state */
+ cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
+
+ return TRUE;
+}
+
+
+/*
+ * This is the default resync_to_restart method for data source managers
+ * to use if they don't have any better approach. Some data source managers
+ * may be able to back up, or may have additional knowledge about the data
+ * which permits a more intelligent recovery strategy; such managers would
+ * presumably supply their own resync method.
+ *
+ * read_restart_marker calls resync_to_restart if it finds a marker other than
+ * the restart marker it was expecting. (This code is *not* used unless
+ * a nonzero restart interval has been declared.) cinfo->unread_marker is
+ * the marker code actually found (might be anything, except 0 or FF).
+ * The desired restart marker number (0..7) is passed as a parameter.
+ * This routine is supposed to apply whatever error recovery strategy seems
+ * appropriate in order to position the input stream to the next data segment.
+ * Note that cinfo->unread_marker is treated as a marker appearing before
+ * the current data-source input point; usually it should be reset to zero
+ * before returning.
+ * Returns FALSE if suspension is required.
+ *
+ * This implementation is substantially constrained by wanting to treat the
+ * input as a data stream; this means we can't back up. Therefore, we have
+ * only the following actions to work with:
+ * 1. Simply discard the marker and let the entropy decoder resume at next
+ * byte of file.
+ * 2. Read forward until we find another marker, discarding intervening
+ * data. (In theory we could look ahead within the current bufferload,
+ * without having to discard data if we don't find the desired marker.
+ * This idea is not implemented here, in part because it makes behavior
+ * dependent on buffer size and chance buffer-boundary positions.)
+ * 3. Leave the marker unread (by failing to zero cinfo->unread_marker).
+ * This will cause the entropy decoder to process an empty data segment,
+ * inserting dummy zeroes, and then we will reprocess the marker.
+ *
+ * #2 is appropriate if we think the desired marker lies ahead, while #3 is
+ * appropriate if the found marker is a future restart marker (indicating
+ * that we have missed the desired restart marker, probably because it got
+ * corrupted).
+ * We apply #2 or #3 if the found marker is a restart marker no more than
+ * two counts behind or ahead of the expected one. We also apply #2 if the
+ * found marker is not a legal JPEG marker code (it's certainly bogus data).
+ * If the found marker is a restart marker more than 2 counts away, we do #1
+ * (too much risk that the marker is erroneous; with luck we will be able to
+ * resync at some future point).
+ * For any valid non-restart JPEG marker, we apply #3. This keeps us from
+ * overrunning the end of a scan. An implementation limited to single-scan
+ * files might find it better to apply #2 for markers other than EOI, since
+ * any other marker would have to be bogus data in that case.
+ */
+
+GLOBAL(boolean)
+jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
+{
+ int marker = cinfo->unread_marker;
+ int action = 1;
+
+ /* Always put up a warning. */
+ WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
+
+ /* Outer loop handles repeated decision after scanning forward. */
+ for (;;) {
+ if (marker < (int) M_SOF0)
+ action = 2; /* invalid marker */
+ else if (marker < (int) M_RST0 || marker > (int) M_RST7)
+ action = 3; /* valid non-restart marker */
+ else {
+ if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
+ marker == ((int) M_RST0 + ((desired+2) & 7)))
+ action = 3; /* one of the next two expected restarts */
+ else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
+ marker == ((int) M_RST0 + ((desired-2) & 7)))
+ action = 2; /* a prior restart, so advance */
+ else
+ action = 1; /* desired restart or too far away */
+ }
+ TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
+ switch (action) {
+ case 1:
+ /* Discard marker and let entropy decoder resume processing. */
+ cinfo->unread_marker = 0;
+ return TRUE;
+ case 2:
+ /* Scan to the next marker, and repeat the decision loop. */
+ if (! next_marker(cinfo))
+ return FALSE;
+ marker = cinfo->unread_marker;
+ break;
+ case 3:
+ /* Return without advancing past this marker. */
+ /* Entropy decoder will be forced to process an empty segment. */
+ return TRUE;
+ }
+ } /* end loop */
+}
+
+
+/*
+ * Reset marker processing state to begin a fresh datastream.
+ */
+
+METHODDEF(void)
+reset_marker_reader (j_decompress_ptr cinfo)
+{
+ my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
+
+ cinfo->comp_info = NULL; /* until allocated by get_sof */
+ cinfo->input_scan_number = 0; /* no SOS seen yet */
+ cinfo->unread_marker = 0; /* no pending marker */
+ marker->pub.saw_SOI = FALSE; /* set internal state too */
+ marker->pub.saw_SOF = FALSE;
+ marker->pub.discarded_bytes = 0;
+ marker->cur_marker = NULL;
+}
+
+
+/*
+ * Initialize the marker reader module.
+ * This is called only once, when the decompression object is created.
+ */
+
+GLOBAL(void)
+jinit_marker_reader (j_decompress_ptr cinfo)
+{
+ my_marker_ptr marker;
+ int i;
+
+ /* Create subobject in permanent pool */
+ marker = (my_marker_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ SIZEOF(my_marker_reader));
+ cinfo->marker = (struct jpeg_marker_reader *) marker;
+ /* Initialize public method pointers */
+ marker->pub.reset_marker_reader = reset_marker_reader;
+ marker->pub.read_markers = read_markers;
+ marker->pub.read_restart_marker = read_restart_marker;
+ /* Initialize COM/APPn processing.
+ * By default, we examine and then discard APP0 and APP14,
+ * but simply discard COM and all other APPn.
+ */
+ marker->process_COM = skip_variable;
+ marker->length_limit_COM = 0;
+ for (i = 0; i < 16; i++) {
+ marker->process_APPn[i] = skip_variable;
+ marker->length_limit_APPn[i] = 0;
+ }
+ marker->process_APPn[0] = get_interesting_appn;
+ marker->process_APPn[14] = get_interesting_appn;
+ /* Reset marker processing state */
+ reset_marker_reader(cinfo);
+}
+
+
+/*
+ * Control saving of COM and APPn markers into marker_list.
+ */
+
+#ifdef SAVE_MARKERS_SUPPORTED
+
+GLOBAL(void)
+jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
+ unsigned int length_limit)
+{
+ my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
+ long maxlength;
+ jpeg_marker_parser_method processor;
+
+ /* Length limit mustn't be larger than what we can allocate
+ * (should only be a concern in a 16-bit environment).
+ */
+ maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
+ if (((long) length_limit) > maxlength)
+ length_limit = (unsigned int) maxlength;
+
+ /* Choose processor routine to use.
+ * APP0/APP14 have special requirements.
+ */
+ if (length_limit) {
+ processor = save_marker;
+ /* If saving APP0/APP14, save at least enough for our internal use. */
+ if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
+ length_limit = APP0_DATA_LEN;
+ else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
+ length_limit = APP14_DATA_LEN;
+ } else {
+ processor = skip_variable;
+ /* If discarding APP0/APP14, use our regular on-the-fly processor. */
+ if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
+ processor = get_interesting_appn;
+ }
+
+ if (marker_code == (int) M_COM) {
+ marker->process_COM = processor;
+ marker->length_limit_COM = length_limit;
+ } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
+ marker->process_APPn[marker_code - (int) M_APP0] = processor;
+ marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
+ } else
+ ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
+}
+
+#endif /* SAVE_MARKERS_SUPPORTED */
+
+
+/*
+ * Install a special processing method for COM or APPn markers.
+ */
+
+GLOBAL(void)
+jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
+ jpeg_marker_parser_method routine)
+{
+ my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
+
+ if (marker_code == (int) M_COM)
+ marker->process_COM = routine;
+ else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
+ marker->process_APPn[marker_code - (int) M_APP0] = routine;
+ else
+ ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
+}
--- /dev/null
+/*
+ * jdmaster.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains master control logic for the JPEG decompressor.
+ * These routines are concerned with selecting the modules to be executed
+ * and with determining the number of passes and the work to be done in each
+ * pass.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Private state */
+
+typedef struct {
+ struct jpeg_decomp_master pub; /* public fields */
+
+ int pass_number; /* # of passes completed */
+
+ boolean using_merged_upsample; /* TRUE if using merged upsample/cconvert */
+
+ /* Saved references to initialized quantizer modules,
+ * in case we need to switch modes.
+ */
+ struct jpeg_color_quantizer * quantizer_1pass;
+ struct jpeg_color_quantizer * quantizer_2pass;
+} my_decomp_master;
+
+typedef my_decomp_master * my_master_ptr;
+
+
+/*
+ * Determine whether merged upsample/color conversion should be used.
+ * CRUCIAL: this must match the actual capabilities of jdmerge.c!
+ */
+
+LOCAL(boolean)
+use_merged_upsample (j_decompress_ptr cinfo)
+{
+#ifdef UPSAMPLE_MERGING_SUPPORTED
+ /* Merging is the equivalent of plain box-filter upsampling */
+ if (cinfo->do_fancy_upsampling || cinfo->CCIR601_sampling)
+ return FALSE;
+ /* jdmerge.c only supports YCC=>RGB color conversion */
+ if (cinfo->jpeg_color_space != JCS_YCbCr || cinfo->num_components != 3 ||
+ cinfo->out_color_space != JCS_RGB ||
+ cinfo->out_color_components != RGB_PIXELSIZE)
+ return FALSE;
+ /* and it only handles 2h1v or 2h2v sampling ratios */
+ if (cinfo->comp_info[0].h_samp_factor != 2 ||
+ cinfo->comp_info[1].h_samp_factor != 1 ||
+ cinfo->comp_info[2].h_samp_factor != 1 ||
+ cinfo->comp_info[0].v_samp_factor > 2 ||
+ cinfo->comp_info[1].v_samp_factor != 1 ||
+ cinfo->comp_info[2].v_samp_factor != 1)
+ return FALSE;
+ /* furthermore, it doesn't work if we've scaled the IDCTs differently */
+ if (cinfo->comp_info[0].DCT_scaled_size != cinfo->min_DCT_scaled_size ||
+ cinfo->comp_info[1].DCT_scaled_size != cinfo->min_DCT_scaled_size ||
+ cinfo->comp_info[2].DCT_scaled_size != cinfo->min_DCT_scaled_size)
+ return FALSE;
+ /* ??? also need to test for upsample-time rescaling, when & if supported */
+ return TRUE; /* by golly, it'll work... */
+#else
+ return FALSE;
+#endif
+}
+
+
+/*
+ * Compute output image dimensions and related values.
+ * NOTE: this is exported for possible use by application.
+ * Hence it mustn't do anything that can't be done twice.
+ * Also note that it may be called before the master module is initialized!
+ */
+
+GLOBAL(void)
+jpeg_calc_output_dimensions (j_decompress_ptr cinfo)
+/* Do computations that are needed before master selection phase */
+{
+#ifdef IDCT_SCALING_SUPPORTED
+ int ci;
+ jpeg_component_info *compptr;
+#endif
+
+ /* Prevent application from calling me at wrong times */
+ if (cinfo->global_state != DSTATE_READY)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+#ifdef IDCT_SCALING_SUPPORTED
+
+ /* Compute actual output image dimensions and DCT scaling choices. */
+ if (cinfo->scale_num * 8 <= cinfo->scale_denom) {
+ /* Provide 1/8 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width, 8L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height, 8L);
+ cinfo->min_DCT_scaled_size = 1;
+ } else if (cinfo->scale_num * 4 <= cinfo->scale_denom) {
+ /* Provide 1/4 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width, 4L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height, 4L);
+ cinfo->min_DCT_scaled_size = 2;
+ } else if (cinfo->scale_num * 2 <= cinfo->scale_denom) {
+ /* Provide 1/2 scaling */
+ cinfo->output_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width, 2L);
+ cinfo->output_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height, 2L);
+ cinfo->min_DCT_scaled_size = 4;
+ } else {
+ /* Provide 1/1 scaling */
+ cinfo->output_width = cinfo->image_width;
+ cinfo->output_height = cinfo->image_height;
+ cinfo->min_DCT_scaled_size = DCTSIZE;
+ }
+ /* In selecting the actual DCT scaling for each component, we try to
+ * scale up the chroma components via IDCT scaling rather than upsampling.
+ * This saves time if the upsampler gets to use 1:1 scaling.
+ * Note this code assumes that the supported DCT scalings are powers of 2.
+ */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ int ssize = cinfo->min_DCT_scaled_size;
+ while (ssize < DCTSIZE &&
+ (compptr->h_samp_factor * ssize * 2 <=
+ cinfo->max_h_samp_factor * cinfo->min_DCT_scaled_size) &&
+ (compptr->v_samp_factor * ssize * 2 <=
+ cinfo->max_v_samp_factor * cinfo->min_DCT_scaled_size)) {
+ ssize = ssize * 2;
+ }
+ compptr->DCT_scaled_size = ssize;
+ }
+
+ /* Recompute downsampled dimensions of components;
+ * application needs to know these if using raw downsampled data.
+ */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Size in samples, after IDCT scaling */
+ compptr->downsampled_width = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_width *
+ (long) (compptr->h_samp_factor * compptr->DCT_scaled_size),
+ (long) (cinfo->max_h_samp_factor * DCTSIZE));
+ compptr->downsampled_height = (JDIMENSION)
+ jdiv_round_up((long) cinfo->image_height *
+ (long) (compptr->v_samp_factor * compptr->DCT_scaled_size),
+ (long) (cinfo->max_v_samp_factor * DCTSIZE));
+ }
+
+#else /* !IDCT_SCALING_SUPPORTED */
+
+ /* Hardwire it to "no scaling" */
+ cinfo->output_width = cinfo->image_width;
+ cinfo->output_height = cinfo->image_height;
+ /* jdinput.c has already initialized DCT_scaled_size to DCTSIZE,
+ * and has computed unscaled downsampled_width and downsampled_height.
+ */
+
+#endif /* IDCT_SCALING_SUPPORTED */
+
+ /* Report number of components in selected colorspace. */
+ /* Probably this should be in the color conversion module... */
+ switch (cinfo->out_color_space) {
+ case JCS_GRAYSCALE:
+ cinfo->out_color_components = 1;
+ break;
+ case JCS_RGB:
+#if RGB_PIXELSIZE != 3
+ cinfo->out_color_components = RGB_PIXELSIZE;
+ break;
+#endif /* else share code with YCbCr */
+ case JCS_YCbCr:
+ cinfo->out_color_components = 3;
+ break;
+ case JCS_CMYK:
+ case JCS_YCCK:
+ cinfo->out_color_components = 4;
+ break;
+ default: /* else must be same colorspace as in file */
+ cinfo->out_color_components = cinfo->num_components;
+ break;
+ }
+ cinfo->output_components = (cinfo->quantize_colors ? 1 :
+ cinfo->out_color_components);
+
+ /* See if upsampler will want to emit more than one row at a time */
+ if (use_merged_upsample(cinfo))
+ cinfo->rec_outbuf_height = cinfo->max_v_samp_factor;
+ else
+ cinfo->rec_outbuf_height = 1;
+}
+
+
+/*
+ * Several decompression processes need to range-limit values to the range
+ * 0..MAXJSAMPLE; the input value may fall somewhat outside this range
+ * due to noise introduced by quantization, roundoff error, etc. These
+ * processes are inner loops and need to be as fast as possible. On most
+ * machines, particularly CPUs with pipelines or instruction prefetch,
+ * a (subscript-check-less) C table lookup
+ * x = sample_range_limit[x];
+ * is faster than explicit tests
+ * if (x < 0) x = 0;
+ * else if (x > MAXJSAMPLE) x = MAXJSAMPLE;
+ * These processes all use a common table prepared by the routine below.
+ *
+ * For most steps we can mathematically guarantee that the initial value
+ * of x is within MAXJSAMPLE+1 of the legal range, so a table running from
+ * -(MAXJSAMPLE+1) to 2*MAXJSAMPLE+1 is sufficient. But for the initial
+ * limiting step (just after the IDCT), a wildly out-of-range value is
+ * possible if the input data is corrupt. To avoid any chance of indexing
+ * off the end of memory and getting a bad-pointer trap, we perform the
+ * post-IDCT limiting thus:
+ * x = range_limit[x & MASK];
+ * where MASK is 2 bits wider than legal sample data, ie 10 bits for 8-bit
+ * samples. Under normal circumstances this is more than enough range and
+ * a correct output will be generated; with bogus input data the mask will
+ * cause wraparound, and we will safely generate a bogus-but-in-range output.
+ * For the post-IDCT step, we want to convert the data from signed to unsigned
+ * representation by adding CENTERJSAMPLE at the same time that we limit it.
+ * So the post-IDCT limiting table ends up looking like this:
+ * CENTERJSAMPLE,CENTERJSAMPLE+1,...,MAXJSAMPLE,
+ * MAXJSAMPLE (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
+ * 0 (repeat 2*(MAXJSAMPLE+1)-CENTERJSAMPLE times),
+ * 0,1,...,CENTERJSAMPLE-1
+ * Negative inputs select values from the upper half of the table after
+ * masking.
+ *
+ * We can save some space by overlapping the start of the post-IDCT table
+ * with the simpler range limiting table. The post-IDCT table begins at
+ * sample_range_limit + CENTERJSAMPLE.
+ *
+ * Note that the table is allocated in near data space on PCs; it's small
+ * enough and used often enough to justify this.
+ */
+
+LOCAL(void)
+prepare_range_limit_table (j_decompress_ptr cinfo)
+/* Allocate and fill in the sample_range_limit table */
+{
+ JSAMPLE * table;
+ int i;
+
+ table = (JSAMPLE *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (5 * (MAXJSAMPLE+1) + CENTERJSAMPLE) * SIZEOF(JSAMPLE));
+ table += (MAXJSAMPLE+1); /* allow negative subscripts of simple table */
+ cinfo->sample_range_limit = table;
+ /* First segment of "simple" table: limit[x] = 0 for x < 0 */
+ MEMZERO(table - (MAXJSAMPLE+1), (MAXJSAMPLE+1) * SIZEOF(JSAMPLE));
+ /* Main part of "simple" table: limit[x] = x */
+ for (i = 0; i <= MAXJSAMPLE; i++)
+ table[i] = (JSAMPLE) i;
+ table += CENTERJSAMPLE; /* Point to where post-IDCT table starts */
+ /* End of simple table, rest of first half of post-IDCT table */
+ for (i = CENTERJSAMPLE; i < 2*(MAXJSAMPLE+1); i++)
+ table[i] = MAXJSAMPLE;
+ /* Second half of post-IDCT table */
+ MEMZERO(table + (2 * (MAXJSAMPLE+1)),
+ (2 * (MAXJSAMPLE+1) - CENTERJSAMPLE) * SIZEOF(JSAMPLE));
+ MEMCOPY(table + (4 * (MAXJSAMPLE+1) - CENTERJSAMPLE),
+ cinfo->sample_range_limit, CENTERJSAMPLE * SIZEOF(JSAMPLE));
+}
+
+
+/*
+ * Master selection of decompression modules.
+ * This is done once at jpeg_start_decompress time. We determine
+ * which modules will be used and give them appropriate initialization calls.
+ * We also initialize the decompressor input side to begin consuming data.
+ *
+ * Since jpeg_read_header has finished, we know what is in the SOF
+ * and (first) SOS markers. We also have all the application parameter
+ * settings.
+ */
+
+LOCAL(void)
+master_selection (j_decompress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+ boolean use_c_buffer;
+ long samplesperrow;
+ JDIMENSION jd_samplesperrow;
+
+ /* Initialize dimensions and other stuff */
+ jpeg_calc_output_dimensions(cinfo);
+ prepare_range_limit_table(cinfo);
+
+ /* Width of an output scanline must be representable as JDIMENSION. */
+ samplesperrow = (long) cinfo->output_width * (long) cinfo->out_color_components;
+ jd_samplesperrow = (JDIMENSION) samplesperrow;
+ if ((long) jd_samplesperrow != samplesperrow)
+ ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
+
+ /* Initialize my private state */
+ master->pass_number = 0;
+ master->using_merged_upsample = use_merged_upsample(cinfo);
+
+ /* Color quantizer selection */
+ master->quantizer_1pass = NULL;
+ master->quantizer_2pass = NULL;
+ /* No mode changes if not using buffered-image mode. */
+ if (! cinfo->quantize_colors || ! cinfo->buffered_image) {
+ cinfo->enable_1pass_quant = FALSE;
+ cinfo->enable_external_quant = FALSE;
+ cinfo->enable_2pass_quant = FALSE;
+ }
+ if (cinfo->quantize_colors) {
+ if (cinfo->raw_data_out)
+ ERREXIT(cinfo, JERR_NOTIMPL);
+ /* 2-pass quantizer only works in 3-component color space. */
+ if (cinfo->out_color_components != 3) {
+ cinfo->enable_1pass_quant = TRUE;
+ cinfo->enable_external_quant = FALSE;
+ cinfo->enable_2pass_quant = FALSE;
+ cinfo->colormap = NULL;
+ } else if (cinfo->colormap != NULL) {
+ cinfo->enable_external_quant = TRUE;
+ } else if (cinfo->two_pass_quantize) {
+ cinfo->enable_2pass_quant = TRUE;
+ } else {
+ cinfo->enable_1pass_quant = TRUE;
+ }
+
+ if (cinfo->enable_1pass_quant) {
+#ifdef QUANT_1PASS_SUPPORTED
+ jinit_1pass_quantizer(cinfo);
+ master->quantizer_1pass = cinfo->cquantize;
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ }
+
+ /* We use the 2-pass code to map to external colormaps. */
+ if (cinfo->enable_2pass_quant || cinfo->enable_external_quant) {
+#ifdef QUANT_2PASS_SUPPORTED
+ jinit_2pass_quantizer(cinfo);
+ master->quantizer_2pass = cinfo->cquantize;
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ }
+ /* If both quantizers are initialized, the 2-pass one is left active;
+ * this is necessary for starting with quantization to an external map.
+ */
+ }
+
+ /* Post-processing: in particular, color conversion first */
+ if (! cinfo->raw_data_out) {
+ if (master->using_merged_upsample) {
+#ifdef UPSAMPLE_MERGING_SUPPORTED
+ jinit_merged_upsampler(cinfo); /* does color conversion too */
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ jinit_color_deconverter(cinfo);
+ jinit_upsampler(cinfo);
+ }
+ jinit_d_post_controller(cinfo, cinfo->enable_2pass_quant);
+ }
+ /* Inverse DCT */
+ jinit_inverse_dct(cinfo);
+ /* Entropy decoding: either Huffman or arithmetic coding. */
+ if (cinfo->arith_code) {
+ ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+ } else {
+ if (cinfo->progressive_mode) {
+#ifdef D_PROGRESSIVE_SUPPORTED
+ jinit_phuff_decoder(cinfo);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else
+ jinit_huff_decoder(cinfo);
+ }
+
+ /* Initialize principal buffer controllers. */
+ use_c_buffer = cinfo->inputctl->has_multiple_scans || cinfo->buffered_image;
+ jinit_d_coef_controller(cinfo, use_c_buffer);
+
+ if (! cinfo->raw_data_out)
+ jinit_d_main_controller(cinfo, FALSE /* never need full buffer here */);
+
+ /* We can now tell the memory manager to allocate virtual arrays. */
+ (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
+
+ /* Initialize input side of decompressor to consume first scan. */
+ (*cinfo->inputctl->start_input_pass) (cinfo);
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+ /* If jpeg_start_decompress will read the whole file, initialize
+ * progress monitoring appropriately. The input step is counted
+ * as one pass.
+ */
+ if (cinfo->progress != NULL && ! cinfo->buffered_image &&
+ cinfo->inputctl->has_multiple_scans) {
+ int nscans;
+ /* Estimate number of scans to set pass_limit. */
+ if (cinfo->progressive_mode) {
+ /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
+ nscans = 2 + 3 * cinfo->num_components;
+ } else {
+ /* For a nonprogressive multiscan file, estimate 1 scan per component. */
+ nscans = cinfo->num_components;
+ }
+ cinfo->progress->pass_counter = 0L;
+ cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
+ cinfo->progress->completed_passes = 0;
+ cinfo->progress->total_passes = (cinfo->enable_2pass_quant ? 3 : 2);
+ /* Count the input pass as done */
+ master->pass_number++;
+ }
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+}
+
+
+/*
+ * Per-pass setup.
+ * This is called at the beginning of each output pass. We determine which
+ * modules will be active during this pass and give them appropriate
+ * start_pass calls. We also set is_dummy_pass to indicate whether this
+ * is a "real" output pass or a dummy pass for color quantization.
+ * (In the latter case, jdapistd.c will crank the pass to completion.)
+ */
+
+METHODDEF(void)
+prepare_for_output_pass (j_decompress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+
+ if (master->pub.is_dummy_pass) {
+#ifdef QUANT_2PASS_SUPPORTED
+ /* Final pass of 2-pass quantization */
+ master->pub.is_dummy_pass = FALSE;
+ (*cinfo->cquantize->start_pass) (cinfo, FALSE);
+ (*cinfo->post->start_pass) (cinfo, JBUF_CRANK_DEST);
+ (*cinfo->main->start_pass) (cinfo, JBUF_CRANK_DEST);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif /* QUANT_2PASS_SUPPORTED */
+ } else {
+ if (cinfo->quantize_colors && cinfo->colormap == NULL) {
+ /* Select new quantization method */
+ if (cinfo->two_pass_quantize && cinfo->enable_2pass_quant) {
+ cinfo->cquantize = master->quantizer_2pass;
+ master->pub.is_dummy_pass = TRUE;
+ } else if (cinfo->enable_1pass_quant) {
+ cinfo->cquantize = master->quantizer_1pass;
+ } else {
+ ERREXIT(cinfo, JERR_MODE_CHANGE);
+ }
+ }
+ (*cinfo->idct->start_pass) (cinfo);
+ (*cinfo->coef->start_output_pass) (cinfo);
+ if (! cinfo->raw_data_out) {
+ if (! master->using_merged_upsample)
+ (*cinfo->cconvert->start_pass) (cinfo);
+ (*cinfo->upsample->start_pass) (cinfo);
+ if (cinfo->quantize_colors)
+ (*cinfo->cquantize->start_pass) (cinfo, master->pub.is_dummy_pass);
+ (*cinfo->post->start_pass) (cinfo,
+ (master->pub.is_dummy_pass ? JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));
+ (*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);
+ }
+ }
+
+ /* Set up progress monitor's pass info if present */
+ if (cinfo->progress != NULL) {
+ cinfo->progress->completed_passes = master->pass_number;
+ cinfo->progress->total_passes = master->pass_number +
+ (master->pub.is_dummy_pass ? 2 : 1);
+ /* In buffered-image mode, we assume one more output pass if EOI not
+ * yet reached, but no more passes if EOI has been reached.
+ */
+ if (cinfo->buffered_image && ! cinfo->inputctl->eoi_reached) {
+ cinfo->progress->total_passes += (cinfo->enable_2pass_quant ? 2 : 1);
+ }
+ }
+}
+
+
+/*
+ * Finish up at end of an output pass.
+ */
+
+METHODDEF(void)
+finish_output_pass (j_decompress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+
+ if (cinfo->quantize_colors)
+ (*cinfo->cquantize->finish_pass) (cinfo);
+ master->pass_number++;
+}
+
+
+#ifdef D_MULTISCAN_FILES_SUPPORTED
+
+/*
+ * Switch to a new external colormap between output passes.
+ */
+
+GLOBAL(void)
+jpeg_new_colormap (j_decompress_ptr cinfo)
+{
+ my_master_ptr master = (my_master_ptr) cinfo->master;
+
+ /* Prevent application from calling me at wrong times */
+ if (cinfo->global_state != DSTATE_BUFIMAGE)
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+
+ if (cinfo->quantize_colors && cinfo->enable_external_quant &&
+ cinfo->colormap != NULL) {
+ /* Select 2-pass quantizer for external colormap use */
+ cinfo->cquantize = master->quantizer_2pass;
+ /* Notify quantizer of colormap change */
+ (*cinfo->cquantize->new_color_map) (cinfo);
+ master->pub.is_dummy_pass = FALSE; /* just in case */
+ } else
+ ERREXIT(cinfo, JERR_MODE_CHANGE);
+}
+
+#endif /* D_MULTISCAN_FILES_SUPPORTED */
+
+
+/*
+ * Initialize master decompression control and select active modules.
+ * This is performed at the start of jpeg_start_decompress.
+ */
+
+GLOBAL(void)
+jinit_master_decompress (j_decompress_ptr cinfo)
+{
+ my_master_ptr master;
+
+ master = (my_master_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_decomp_master));
+ cinfo->master = (struct jpeg_decomp_master *) master;
+ master->pub.prepare_for_output_pass = prepare_for_output_pass;
+ master->pub.finish_output_pass = finish_output_pass;
+
+ master->pub.is_dummy_pass = FALSE;
+
+ master_selection(cinfo);
+}
--- /dev/null
+/*
+ * jdmerge.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains code for merged upsampling/color conversion.
+ *
+ * This file combines functions from jdsample.c and jdcolor.c;
+ * read those files first to understand what's going on.
+ *
+ * When the chroma components are to be upsampled by simple replication
+ * (ie, box filtering), we can save some work in color conversion by
+ * calculating all the output pixels corresponding to a pair of chroma
+ * samples at one time. In the conversion equations
+ * R = Y + K1 * Cr
+ * G = Y + K2 * Cb + K3 * Cr
+ * B = Y + K4 * Cb
+ * only the Y term varies among the group of pixels corresponding to a pair
+ * of chroma samples, so the rest of the terms can be calculated just once.
+ * At typical sampling ratios, this eliminates half or three-quarters of the
+ * multiplications needed for color conversion.
+ *
+ * This file currently provides implementations for the following cases:
+ * YCbCr => RGB color conversion only.
+ * Sampling ratios of 2h1v or 2h2v.
+ * No scaling needed at upsample time.
+ * Corner-aligned (non-CCIR601) sampling alignment.
+ * Other special cases could be added, but in most applications these are
+ * the only common cases. (For uncommon cases we fall back on the more
+ * general code in jdsample.c and jdcolor.c.)
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+#ifdef UPSAMPLE_MERGING_SUPPORTED
+
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_upsampler pub; /* public fields */
+
+ /* Pointer to routine to do actual upsampling/conversion of one row group */
+ JMETHOD(void, upmethod, (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+ JSAMPARRAY output_buf));
+
+ /* Private state for YCC->RGB conversion */
+ int * Cr_r_tab; /* => table for Cr to R conversion */
+ int * Cb_b_tab; /* => table for Cb to B conversion */
+ INT32 * Cr_g_tab; /* => table for Cr to G conversion */
+ INT32 * Cb_g_tab; /* => table for Cb to G conversion */
+
+ /* For 2:1 vertical sampling, we produce two output rows at a time.
+ * We need a "spare" row buffer to hold the second output row if the
+ * application provides just a one-row buffer; we also use the spare
+ * to discard the dummy last row if the image height is odd.
+ */
+ JSAMPROW spare_row;
+ boolean spare_full; /* T if spare buffer is occupied */
+
+ JDIMENSION out_row_width; /* samples per output row */
+ JDIMENSION rows_to_go; /* counts rows remaining in image */
+} my_upsampler;
+
+typedef my_upsampler * my_upsample_ptr;
+
+#define SCALEBITS 16 /* speediest right-shift on some machines */
+#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
+#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
+
+
+/*
+ * Initialize tables for YCC->RGB colorspace conversion.
+ * This is taken directly from jdcolor.c; see that file for more info.
+ */
+
+LOCAL(void)
+build_ycc_rgb_table (j_decompress_ptr cinfo)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ int i;
+ INT32 x;
+ SHIFT_TEMPS
+
+ upsample->Cr_r_tab = (int *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(int));
+ upsample->Cb_b_tab = (int *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(int));
+ upsample->Cr_g_tab = (INT32 *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(INT32));
+ upsample->Cb_g_tab = (INT32 *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (MAXJSAMPLE+1) * SIZEOF(INT32));
+
+ for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
+ /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
+ /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
+ /* Cr=>R value is nearest int to 1.40200 * x */
+ upsample->Cr_r_tab[i] = (int)
+ RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
+ /* Cb=>B value is nearest int to 1.77200 * x */
+ upsample->Cb_b_tab[i] = (int)
+ RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
+ /* Cr=>G value is scaled-up -0.71414 * x */
+ upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x;
+ /* Cb=>G value is scaled-up -0.34414 * x */
+ /* We also add in ONE_HALF so that need not do it in inner loop */
+ upsample->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF;
+ }
+}
+
+
+/*
+ * Initialize for an upsampling pass.
+ */
+
+METHODDEF(void)
+start_pass_merged_upsample (j_decompress_ptr cinfo)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+
+ /* Mark the spare buffer empty */
+ upsample->spare_full = FALSE;
+ /* Initialize total-height counter for detecting bottom of image */
+ upsample->rows_to_go = cinfo->output_height;
+}
+
+
+/*
+ * Control routine to do upsampling (and color conversion).
+ *
+ * The control routine just handles the row buffering considerations.
+ */
+
+METHODDEF(void)
+merged_2v_upsample (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+/* 2:1 vertical sampling case: may need a spare row. */
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ JSAMPROW work_ptrs[2];
+ JDIMENSION num_rows; /* number of rows returned to caller */
+
+ if (upsample->spare_full) {
+ /* If we have a spare row saved from a previous cycle, just return it. */
+ jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
+ 1, upsample->out_row_width);
+ num_rows = 1;
+ upsample->spare_full = FALSE;
+ } else {
+ /* Figure number of rows to return to caller. */
+ num_rows = 2;
+ /* Not more than the distance to the end of the image. */
+ if (num_rows > upsample->rows_to_go)
+ num_rows = upsample->rows_to_go;
+ /* And not more than what the client can accept: */
+ out_rows_avail -= *out_row_ctr;
+ if (num_rows > out_rows_avail)
+ num_rows = out_rows_avail;
+ /* Create output pointer array for upsampler. */
+ work_ptrs[0] = output_buf[*out_row_ctr];
+ if (num_rows > 1) {
+ work_ptrs[1] = output_buf[*out_row_ctr + 1];
+ } else {
+ work_ptrs[1] = upsample->spare_row;
+ upsample->spare_full = TRUE;
+ }
+ /* Now do the upsampling. */
+ (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs);
+ }
+
+ /* Adjust counts */
+ *out_row_ctr += num_rows;
+ upsample->rows_to_go -= num_rows;
+ /* When the buffer is emptied, declare this input row group consumed */
+ if (! upsample->spare_full)
+ (*in_row_group_ctr)++;
+}
+
+
+METHODDEF(void)
+merged_1v_upsample (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+/* 1:1 vertical sampling case: much easier, never need a spare row. */
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+
+ /* Just do the upsampling. */
+ (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,
+ output_buf + *out_row_ctr);
+ /* Adjust counts */
+ (*out_row_ctr)++;
+ (*in_row_group_ctr)++;
+}
+
+
+/*
+ * These are the routines invoked by the control routines to do
+ * the actual upsampling/conversion. One row group is processed per call.
+ *
+ * Note: since we may be writing directly into application-supplied buffers,
+ * we have to be honest about the output width; we can't assume the buffer
+ * has been rounded up to an even width.
+ */
+
+
+/*
+ * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
+ */
+
+METHODDEF(void)
+h2v1_merged_upsample (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+ JSAMPARRAY output_buf)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ register int y, cred, cgreen, cblue;
+ int cb, cr;
+ register JSAMPROW outptr;
+ JSAMPROW inptr0, inptr1, inptr2;
+ JDIMENSION col;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ int * Crrtab = upsample->Cr_r_tab;
+ int * Cbbtab = upsample->Cb_b_tab;
+ INT32 * Crgtab = upsample->Cr_g_tab;
+ INT32 * Cbgtab = upsample->Cb_g_tab;
+ SHIFT_TEMPS
+
+ inptr0 = input_buf[0][in_row_group_ctr];
+ inptr1 = input_buf[1][in_row_group_ctr];
+ inptr2 = input_buf[2][in_row_group_ctr];
+ outptr = output_buf[0];
+ /* Loop for each pair of output pixels */
+ for (col = cinfo->output_width >> 1; col > 0; col--) {
+ /* Do the chroma part of the calculation */
+ cb = GETJSAMPLE(*inptr1++);
+ cr = GETJSAMPLE(*inptr2++);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+ /* Fetch 2 Y values and emit 2 pixels */
+ y = GETJSAMPLE(*inptr0++);
+ outptr[RGB_RED] = range_limit[y + cred];
+ outptr[RGB_GREEN] = range_limit[y + cgreen];
+ outptr[RGB_BLUE] = range_limit[y + cblue];
+ outptr += RGB_PIXELSIZE;
+ y = GETJSAMPLE(*inptr0++);
+ outptr[RGB_RED] = range_limit[y + cred];
+ outptr[RGB_GREEN] = range_limit[y + cgreen];
+ outptr[RGB_BLUE] = range_limit[y + cblue];
+ outptr += RGB_PIXELSIZE;
+ }
+ /* If image width is odd, do the last output column separately */
+ if (cinfo->output_width & 1) {
+ cb = GETJSAMPLE(*inptr1);
+ cr = GETJSAMPLE(*inptr2);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+ y = GETJSAMPLE(*inptr0);
+ outptr[RGB_RED] = range_limit[y + cred];
+ outptr[RGB_GREEN] = range_limit[y + cgreen];
+ outptr[RGB_BLUE] = range_limit[y + cblue];
+ }
+}
+
+
+/*
+ * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
+ */
+
+METHODDEF(void)
+h2v2_merged_upsample (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+ JSAMPARRAY output_buf)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ register int y, cred, cgreen, cblue;
+ int cb, cr;
+ register JSAMPROW outptr0, outptr1;
+ JSAMPROW inptr00, inptr01, inptr1, inptr2;
+ JDIMENSION col;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ int * Crrtab = upsample->Cr_r_tab;
+ int * Cbbtab = upsample->Cb_b_tab;
+ INT32 * Crgtab = upsample->Cr_g_tab;
+ INT32 * Cbgtab = upsample->Cb_g_tab;
+ SHIFT_TEMPS
+
+ inptr00 = input_buf[0][in_row_group_ctr*2];
+ inptr01 = input_buf[0][in_row_group_ctr*2 + 1];
+ inptr1 = input_buf[1][in_row_group_ctr];
+ inptr2 = input_buf[2][in_row_group_ctr];
+ outptr0 = output_buf[0];
+ outptr1 = output_buf[1];
+ /* Loop for each group of output pixels */
+ for (col = cinfo->output_width >> 1; col > 0; col--) {
+ /* Do the chroma part of the calculation */
+ cb = GETJSAMPLE(*inptr1++);
+ cr = GETJSAMPLE(*inptr2++);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+ /* Fetch 4 Y values and emit 4 pixels */
+ y = GETJSAMPLE(*inptr00++);
+ outptr0[RGB_RED] = range_limit[y + cred];
+ outptr0[RGB_GREEN] = range_limit[y + cgreen];
+ outptr0[RGB_BLUE] = range_limit[y + cblue];
+ outptr0 += RGB_PIXELSIZE;
+ y = GETJSAMPLE(*inptr00++);
+ outptr0[RGB_RED] = range_limit[y + cred];
+ outptr0[RGB_GREEN] = range_limit[y + cgreen];
+ outptr0[RGB_BLUE] = range_limit[y + cblue];
+ outptr0 += RGB_PIXELSIZE;
+ y = GETJSAMPLE(*inptr01++);
+ outptr1[RGB_RED] = range_limit[y + cred];
+ outptr1[RGB_GREEN] = range_limit[y + cgreen];
+ outptr1[RGB_BLUE] = range_limit[y + cblue];
+ outptr1 += RGB_PIXELSIZE;
+ y = GETJSAMPLE(*inptr01++);
+ outptr1[RGB_RED] = range_limit[y + cred];
+ outptr1[RGB_GREEN] = range_limit[y + cgreen];
+ outptr1[RGB_BLUE] = range_limit[y + cblue];
+ outptr1 += RGB_PIXELSIZE;
+ }
+ /* If image width is odd, do the last output column separately */
+ if (cinfo->output_width & 1) {
+ cb = GETJSAMPLE(*inptr1);
+ cr = GETJSAMPLE(*inptr2);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+ y = GETJSAMPLE(*inptr00);
+ outptr0[RGB_RED] = range_limit[y + cred];
+ outptr0[RGB_GREEN] = range_limit[y + cgreen];
+ outptr0[RGB_BLUE] = range_limit[y + cblue];
+ y = GETJSAMPLE(*inptr01);
+ outptr1[RGB_RED] = range_limit[y + cred];
+ outptr1[RGB_GREEN] = range_limit[y + cgreen];
+ outptr1[RGB_BLUE] = range_limit[y + cblue];
+ }
+}
+
+
+/*
+ * Module initialization routine for merged upsampling/color conversion.
+ *
+ * NB: this is called under the conditions determined by use_merged_upsample()
+ * in jdmaster.c. That routine MUST correspond to the actual capabilities
+ * of this module; no safety checks are made here.
+ */
+
+GLOBAL(void)
+jinit_merged_upsampler (j_decompress_ptr cinfo)
+{
+ my_upsample_ptr upsample;
+
+ upsample = (my_upsample_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_upsampler));
+ cinfo->upsample = (struct jpeg_upsampler *) upsample;
+ upsample->pub.start_pass = start_pass_merged_upsample;
+ upsample->pub.need_context_rows = FALSE;
+
+ upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;
+
+ if (cinfo->max_v_samp_factor == 2) {
+ upsample->pub.upsample = merged_2v_upsample;
+ upsample->upmethod = h2v2_merged_upsample;
+ /* Allocate a spare row buffer */
+ upsample->spare_row = (JSAMPROW)
+ (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (size_t) (upsample->out_row_width * SIZEOF(JSAMPLE)));
+ } else {
+ upsample->pub.upsample = merged_1v_upsample;
+ upsample->upmethod = h2v1_merged_upsample;
+ /* No spare row needed */
+ upsample->spare_row = NULL;
+ }
+
+ build_ycc_rgb_table(cinfo);
+}
+
+#endif /* UPSAMPLE_MERGING_SUPPORTED */
--- /dev/null
+/*
+ * jdphuff.c
+ *
+ * Copyright (C) 1995-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains Huffman entropy decoding routines for progressive JPEG.
+ *
+ * Much of the complexity here has to do with supporting input suspension.
+ * If the data source module demands suspension, we want to be able to back
+ * up to the start of the current MCU. To do this, we copy state variables
+ * into local working storage, and update them back to the permanent
+ * storage only upon successful completion of an MCU.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdhuff12.h" /* Declarations shared with jdhuff.c */
+
+
+#ifdef D_PROGRESSIVE_SUPPORTED
+
+/*
+ * Expanded entropy decoder object for progressive Huffman decoding.
+ *
+ * The savable_state subrecord contains fields that change within an MCU,
+ * but must not be updated permanently until we complete the MCU.
+ */
+
+typedef struct {
+ unsigned int EOBRUN; /* remaining EOBs in EOBRUN */
+ int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+} savable_state;
+
+/* This macro is to work around compilers with missing or broken
+ * structure assignment. You'll need to fix this code if you have
+ * such a compiler and you change MAX_COMPS_IN_SCAN.
+ */
+
+#ifndef NO_STRUCT_ASSIGN
+#define ASSIGN_STATE(dest,src) ((dest) = (src))
+#else
+#if MAX_COMPS_IN_SCAN == 4
+#define ASSIGN_STATE(dest,src) \
+ ((dest).EOBRUN = (src).EOBRUN, \
+ (dest).last_dc_val[0] = (src).last_dc_val[0], \
+ (dest).last_dc_val[1] = (src).last_dc_val[1], \
+ (dest).last_dc_val[2] = (src).last_dc_val[2], \
+ (dest).last_dc_val[3] = (src).last_dc_val[3])
+#endif
+#endif
+
+
+typedef struct {
+ struct jpeg_entropy_decoder pub; /* public fields */
+
+ /* These fields are loaded into local variables at start of each MCU.
+ * In case of suspension, we exit WITHOUT updating them.
+ */
+ bitread_perm_state bitstate; /* Bit buffer at start of MCU */
+ savable_state saved; /* Other state at start of MCU */
+
+ /* These fields are NOT loaded into local working state. */
+ unsigned int restarts_to_go; /* MCUs left in this restart interval */
+
+ /* Pointers to derived tables (these workspaces have image lifespan) */
+ d_derived_tbl * derived_tbls[NUM_HUFF_TBLS];
+
+ d_derived_tbl * ac_derived_tbl; /* active table during an AC scan */
+} phuff_entropy_decoder;
+
+typedef phuff_entropy_decoder * phuff_entropy_ptr;
+
+/* Forward declarations */
+METHODDEF(boolean) decode_mcu_DC_first JPP((j_decompress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(boolean) decode_mcu_AC_first JPP((j_decompress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(boolean) decode_mcu_DC_refine JPP((j_decompress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+METHODDEF(boolean) decode_mcu_AC_refine JPP((j_decompress_ptr cinfo,
+ JBLOCKROW *MCU_data));
+
+
+/*
+ * Initialize for a Huffman-compressed scan.
+ */
+
+METHODDEF(void)
+start_pass_phuff_decoder (j_decompress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ boolean is_DC_band, bad;
+ int ci, coefi, tbl;
+ int *coef_bit_ptr;
+ jpeg_component_info * compptr;
+
+ is_DC_band = (cinfo->Ss == 0);
+
+ /* Validate scan parameters */
+ bad = FALSE;
+ if (is_DC_band) {
+ if (cinfo->Se != 0)
+ bad = TRUE;
+ } else {
+ /* need not check Ss/Se < 0 since they came from unsigned bytes */
+ if (cinfo->Ss > cinfo->Se || cinfo->Se >= DCTSIZE2)
+ bad = TRUE;
+ /* AC scans may have only one component */
+ if (cinfo->comps_in_scan != 1)
+ bad = TRUE;
+ }
+ if (cinfo->Ah != 0) {
+ /* Successive approximation refinement scan: must have Al = Ah-1. */
+ if (cinfo->Al != cinfo->Ah-1)
+ bad = TRUE;
+ }
+ if (cinfo->Al > 13) /* need not check for < 0 */
+ bad = TRUE;
+ /* Arguably the maximum Al value should be less than 13 for 8-bit precision,
+ * but the spec doesn't say so, and we try to be liberal about what we
+ * accept. Note: large Al values could result in out-of-range DC
+ * coefficients during early scans, leading to bizarre displays due to
+ * overflows in the IDCT math. But we won't crash.
+ */
+ if (bad)
+ ERREXIT4(cinfo, JERR_BAD_PROGRESSION,
+ cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al);
+ /* Update progression status, and verify that scan order is legal.
+ * Note that inter-scan inconsistencies are treated as warnings
+ * not fatal errors ... not clear if this is right way to behave.
+ */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ int cindex = cinfo->cur_comp_info[ci]->component_index;
+ coef_bit_ptr = & cinfo->coef_bits[cindex][0];
+ if (!is_DC_band && coef_bit_ptr[0] < 0) /* AC without prior DC scan */
+ WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, 0);
+ for (coefi = cinfo->Ss; coefi <= cinfo->Se; coefi++) {
+ int expected = (coef_bit_ptr[coefi] < 0) ? 0 : coef_bit_ptr[coefi];
+ if (cinfo->Ah != expected)
+ WARNMS2(cinfo, JWRN_BOGUS_PROGRESSION, cindex, coefi);
+ coef_bit_ptr[coefi] = cinfo->Al;
+ }
+ }
+
+ /* Select MCU decoding routine */
+ if (cinfo->Ah == 0) {
+ if (is_DC_band)
+ entropy->pub.decode_mcu = decode_mcu_DC_first;
+ else
+ entropy->pub.decode_mcu = decode_mcu_AC_first;
+ } else {
+ if (is_DC_band)
+ entropy->pub.decode_mcu = decode_mcu_DC_refine;
+ else
+ entropy->pub.decode_mcu = decode_mcu_AC_refine;
+ }
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Make sure requested tables are present, and compute derived tables.
+ * We may build same derived table more than once, but it's not expensive.
+ */
+ if (is_DC_band) {
+ if (cinfo->Ah == 0) { /* DC refinement needs no table */
+ tbl = compptr->dc_tbl_no;
+ jpeg_make_d_derived_tbl(cinfo, TRUE, tbl,
+ & entropy->derived_tbls[tbl]);
+ }
+ } else {
+ tbl = compptr->ac_tbl_no;
+ jpeg_make_d_derived_tbl(cinfo, FALSE, tbl,
+ & entropy->derived_tbls[tbl]);
+ /* remember the single active table */
+ entropy->ac_derived_tbl = entropy->derived_tbls[tbl];
+ }
+ /* Initialize DC predictions to 0 */
+ entropy->saved.last_dc_val[ci] = 0;
+ }
+
+ /* Initialize bitread state variables */
+ entropy->bitstate.bits_left = 0;
+ entropy->bitstate.get_buffer = 0; /* unnecessary, but keeps Purify quiet */
+ entropy->pub.insufficient_data = FALSE;
+
+ /* Initialize private state variables */
+ entropy->saved.EOBRUN = 0;
+
+ /* Initialize restart counter */
+ entropy->restarts_to_go = cinfo->restart_interval;
+}
+
+
+/*
+ * Figure F.12: extend sign bit.
+ * On some machines, a shift and add will be faster than a table lookup.
+ */
+
+#ifdef AVOID_TABLES
+
+#define HUFF_EXTEND(x,s) ((x) < (1<<((s)-1)) ? (x) + (((-1)<<(s)) + 1) : (x))
+
+#else
+
+#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
+
+static const int extend_test[16] = /* entry n is 2**(n-1) */
+ { 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
+ 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000 };
+
+static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
+ { 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
+ ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
+ ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
+ ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1 };
+
+#endif /* AVOID_TABLES */
+
+
+/*
+ * Check for a restart marker & resynchronize decoder.
+ * Returns FALSE if must suspend.
+ */
+
+LOCAL(boolean)
+process_restart (j_decompress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ int ci;
+
+ /* Throw away any unused bits remaining in bit buffer; */
+ /* include any full bytes in next_marker's count of discarded bytes */
+ cinfo->marker->discarded_bytes += entropy->bitstate.bits_left / 8;
+ entropy->bitstate.bits_left = 0;
+
+ /* Advance past the RSTn marker */
+ if (! (*cinfo->marker->read_restart_marker) (cinfo))
+ return FALSE;
+
+ /* Re-initialize DC predictions to 0 */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++)
+ entropy->saved.last_dc_val[ci] = 0;
+ /* Re-init EOB run count, too */
+ entropy->saved.EOBRUN = 0;
+
+ /* Reset restart counter */
+ entropy->restarts_to_go = cinfo->restart_interval;
+
+ /* Reset out-of-data flag, unless read_restart_marker left us smack up
+ * against a marker. In that case we will end up treating the next data
+ * segment as empty, and we can avoid producing bogus output pixels by
+ * leaving the flag set.
+ */
+ if (cinfo->unread_marker == 0)
+ entropy->pub.insufficient_data = FALSE;
+
+ return TRUE;
+}
+
+
+/*
+ * Huffman MCU decoding.
+ * Each of these routines decodes and returns one MCU's worth of
+ * Huffman-compressed coefficients.
+ * The coefficients are reordered from zigzag order into natural array order,
+ * but are not dequantized.
+ *
+ * The i'th block of the MCU is stored into the block pointed to by
+ * MCU_data[i]. WE ASSUME THIS AREA IS INITIALLY ZEROED BY THE CALLER.
+ *
+ * We return FALSE if data source requested suspension. In that case no
+ * changes have been made to permanent state. (Exception: some output
+ * coefficients may already have been assigned. This is harmless for
+ * spectral selection, since we'll just re-assign them on the next call.
+ * Successive approximation AC refinement has to be more careful, however.)
+ */
+
+/*
+ * MCU decoding for DC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF(boolean)
+decode_mcu_DC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ int Al = cinfo->Al;
+ register int s, r;
+ int blkn, ci;
+ JBLOCKROW block;
+ BITREAD_STATE_VARS;
+ savable_state state;
+ d_derived_tbl * tbl;
+ jpeg_component_info * compptr;
+
+ /* Process restart marker if needed; may have to suspend */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0)
+ if (! process_restart(cinfo))
+ return FALSE;
+ }
+
+ /* If we've run out of data, just leave the MCU set to zeroes.
+ * This way, we return uniform gray for the remainder of the segment.
+ */
+ if (! entropy->pub.insufficient_data) {
+
+ /* Load up working state */
+ BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
+ ASSIGN_STATE(state, entropy->saved);
+
+ /* Outer loop handles each block in the MCU */
+
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ block = MCU_data[blkn];
+ ci = cinfo->MCU_membership[blkn];
+ compptr = cinfo->cur_comp_info[ci];
+ tbl = entropy->derived_tbls[compptr->dc_tbl_no];
+
+ /* Decode a single block's worth of coefficients */
+
+ /* Section F.2.2.1: decode the DC coefficient difference */
+ HUFF_DECODE(s, br_state, tbl, return FALSE, label1);
+ if (s) {
+ CHECK_BIT_BUFFER(br_state, s, return FALSE);
+ r = GET_BITS(s);
+ s = HUFF_EXTEND(r, s);
+ }
+
+ /* Convert DC difference to actual value, update last_dc_val */
+ s += state.last_dc_val[ci];
+ state.last_dc_val[ci] = s;
+ /* Scale and output the coefficient (assumes jpeg_natural_order[0]=0) */
+ (*block)[0] = (JCOEF) (s << Al);
+ }
+
+ /* Completed MCU, so update state */
+ BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+ ASSIGN_STATE(entropy->saved, state);
+ }
+
+ /* Account for restart interval (no-op if not using restarts) */
+ entropy->restarts_to_go--;
+
+ return TRUE;
+}
+
+
+/*
+ * MCU decoding for AC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF(boolean)
+decode_mcu_AC_first (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ int Se = cinfo->Se;
+ int Al = cinfo->Al;
+ register int s, k, r;
+ unsigned int EOBRUN;
+ JBLOCKROW block;
+ BITREAD_STATE_VARS;
+ d_derived_tbl * tbl;
+
+ /* Process restart marker if needed; may have to suspend */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0)
+ if (! process_restart(cinfo))
+ return FALSE;
+ }
+
+ /* If we've run out of data, just leave the MCU set to zeroes.
+ * This way, we return uniform gray for the remainder of the segment.
+ */
+ if (! entropy->pub.insufficient_data) {
+
+ /* Load up working state.
+ * We can avoid loading/saving bitread state if in an EOB run.
+ */
+ EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
+
+ /* There is always only one block per MCU */
+
+ if (EOBRUN > 0) /* if it's a band of zeroes... */
+ EOBRUN--; /* ...process it now (we do nothing) */
+ else {
+ BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
+ block = MCU_data[0];
+ tbl = entropy->ac_derived_tbl;
+
+ for (k = cinfo->Ss; k <= Se; k++) {
+ HUFF_DECODE(s, br_state, tbl, return FALSE, label2);
+ r = s >> 4;
+ s &= 15;
+ if (s) {
+ k += r;
+ CHECK_BIT_BUFFER(br_state, s, return FALSE);
+ r = GET_BITS(s);
+ s = HUFF_EXTEND(r, s);
+ /* Scale and output coefficient in natural (dezigzagged) order */
+ (*block)[jpeg_natural_order[k]] = (JCOEF) (s << Al);
+ } else {
+ if (r == 15) { /* ZRL */
+ k += 15; /* skip 15 zeroes in band */
+ } else { /* EOBr, run length is 2^r + appended bits */
+ EOBRUN = 1 << r;
+ if (r) { /* EOBr, r > 0 */
+ CHECK_BIT_BUFFER(br_state, r, return FALSE);
+ r = GET_BITS(r);
+ EOBRUN += r;
+ }
+ EOBRUN--; /* this band is processed at this moment */
+ break; /* force end-of-band */
+ }
+ }
+ }
+
+ BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+ }
+
+ /* Completed MCU, so update state */
+ entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
+ }
+
+ /* Account for restart interval (no-op if not using restarts) */
+ entropy->restarts_to_go--;
+
+ return TRUE;
+}
+
+
+/*
+ * MCU decoding for DC successive approximation refinement scan.
+ * Note: we assume such scans can be multi-component, although the spec
+ * is not very clear on the point.
+ */
+
+METHODDEF(boolean)
+decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
+ int blkn;
+ JBLOCKROW block;
+ BITREAD_STATE_VARS;
+
+ /* Process restart marker if needed; may have to suspend */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0)
+ if (! process_restart(cinfo))
+ return FALSE;
+ }
+
+ /* Not worth the cycles to check insufficient_data here,
+ * since we will not change the data anyway if we read zeroes.
+ */
+
+ /* Load up working state */
+ BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
+
+ /* Outer loop handles each block in the MCU */
+
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ block = MCU_data[blkn];
+
+ /* Encoded data is simply the next bit of the two's-complement DC value */
+ CHECK_BIT_BUFFER(br_state, 1, return FALSE);
+ if (GET_BITS(1))
+ (*block)[0] |= p1;
+ /* Note: since we use |=, repeating the assignment later is safe */
+ }
+
+ /* Completed MCU, so update state */
+ BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+
+ /* Account for restart interval (no-op if not using restarts) */
+ entropy->restarts_to_go--;
+
+ return TRUE;
+}
+
+
+/*
+ * MCU decoding for AC successive approximation refinement scan.
+ */
+
+METHODDEF(boolean)
+decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy;
+ int Se = cinfo->Se;
+ int p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */
+ int m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */
+ register int s, k, r;
+ unsigned int EOBRUN;
+ JBLOCKROW block;
+ JCOEFPTR thiscoef;
+ BITREAD_STATE_VARS;
+ d_derived_tbl * tbl;
+ int num_newnz;
+ int newnz_pos[DCTSIZE2];
+
+ /* Process restart marker if needed; may have to suspend */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0)
+ if (! process_restart(cinfo))
+ return FALSE;
+ }
+
+ /* If we've run out of data, don't modify the MCU.
+ */
+ if (! entropy->pub.insufficient_data) {
+
+ /* Load up working state */
+ BITREAD_LOAD_STATE(cinfo,entropy->bitstate);
+ EOBRUN = entropy->saved.EOBRUN; /* only part of saved state we need */
+
+ /* There is always only one block per MCU */
+ block = MCU_data[0];
+ tbl = entropy->ac_derived_tbl;
+
+ /* If we are forced to suspend, we must undo the assignments to any newly
+ * nonzero coefficients in the block, because otherwise we'd get confused
+ * next time about which coefficients were already nonzero.
+ * But we need not undo addition of bits to already-nonzero coefficients;
+ * instead, we can test the current bit to see if we already did it.
+ */
+ num_newnz = 0;
+
+ /* initialize coefficient loop counter to start of band */
+ k = cinfo->Ss;
+
+ if (EOBRUN == 0) {
+ for (; k <= Se; k++) {
+ HUFF_DECODE(s, br_state, tbl, goto undoit, label3);
+ r = s >> 4;
+ s &= 15;
+ if (s) {
+ if (s != 1) /* size of new coef should always be 1 */
+ WARNMS(cinfo, JWRN_HUFF_BAD_CODE);
+ CHECK_BIT_BUFFER(br_state, 1, goto undoit);
+ if (GET_BITS(1))
+ s = p1; /* newly nonzero coef is positive */
+ else
+ s = m1; /* newly nonzero coef is negative */
+ } else {
+ if (r != 15) {
+ EOBRUN = 1 << r; /* EOBr, run length is 2^r + appended bits */
+ if (r) {
+ CHECK_BIT_BUFFER(br_state, r, goto undoit);
+ r = GET_BITS(r);
+ EOBRUN += r;
+ }
+ break; /* rest of block is handled by EOB logic */
+ }
+ /* note s = 0 for processing ZRL */
+ }
+ /* Advance over already-nonzero coefs and r still-zero coefs,
+ * appending correction bits to the nonzeroes. A correction bit is 1
+ * if the absolute value of the coefficient must be increased.
+ */
+ do {
+ thiscoef = *block + jpeg_natural_order[k];
+ if (*thiscoef != 0) {
+ CHECK_BIT_BUFFER(br_state, 1, goto undoit);
+ if (GET_BITS(1)) {
+ if ((*thiscoef & p1) == 0) { /* do nothing if already set it */
+ if (*thiscoef >= 0)
+ *thiscoef += p1;
+ else
+ *thiscoef += m1;
+ }
+ }
+ } else {
+ if (--r < 0)
+ break; /* reached target zero coefficient */
+ }
+ k++;
+ } while (k <= Se);
+ if (s) {
+ int pos = jpeg_natural_order[k];
+ /* Output newly nonzero coefficient */
+ (*block)[pos] = (JCOEF) s;
+ /* Remember its position in case we have to suspend */
+ newnz_pos[num_newnz++] = pos;
+ }
+ }
+ }
+
+ if (EOBRUN > 0) {
+ /* Scan any remaining coefficient positions after the end-of-band
+ * (the last newly nonzero coefficient, if any). Append a correction
+ * bit to each already-nonzero coefficient. A correction bit is 1
+ * if the absolute value of the coefficient must be increased.
+ */
+ for (; k <= Se; k++) {
+ thiscoef = *block + jpeg_natural_order[k];
+ if (*thiscoef != 0) {
+ CHECK_BIT_BUFFER(br_state, 1, goto undoit);
+ if (GET_BITS(1)) {
+ if ((*thiscoef & p1) == 0) { /* do nothing if already changed it */
+ if (*thiscoef >= 0)
+ *thiscoef += p1;
+ else
+ *thiscoef += m1;
+ }
+ }
+ }
+ }
+ /* Count one block completed in EOB run */
+ EOBRUN--;
+ }
+
+ /* Completed MCU, so update state */
+ BITREAD_SAVE_STATE(cinfo,entropy->bitstate);
+ entropy->saved.EOBRUN = EOBRUN; /* only part of saved state we need */
+ }
+
+ /* Account for restart interval (no-op if not using restarts) */
+ entropy->restarts_to_go--;
+
+ return TRUE;
+
+undoit:
+ /* Re-zero any output coefficients that we made newly nonzero */
+ while (num_newnz > 0)
+ (*block)[newnz_pos[--num_newnz]] = 0;
+
+ return FALSE;
+}
+
+
+/*
+ * Module initialization routine for progressive Huffman entropy decoding.
+ */
+
+GLOBAL(void)
+jinit_phuff_decoder (j_decompress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy;
+ int *coef_bit_ptr;
+ int ci, i;
+
+ entropy = (phuff_entropy_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(phuff_entropy_decoder));
+ cinfo->entropy = (struct jpeg_entropy_decoder *) entropy;
+ entropy->pub.start_pass = start_pass_phuff_decoder;
+
+ /* Mark derived tables unallocated */
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ entropy->derived_tbls[i] = NULL;
+ }
+
+ /* Create progression status table */
+ cinfo->coef_bits = (int (*)[DCTSIZE2])
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ cinfo->num_components*DCTSIZE2*SIZEOF(int));
+ coef_bit_ptr = & cinfo->coef_bits[0][0];
+ for (ci = 0; ci < cinfo->num_components; ci++)
+ for (i = 0; i < DCTSIZE2; i++)
+ *coef_bit_ptr++ = -1;
+}
+
+#endif /* D_PROGRESSIVE_SUPPORTED */
--- /dev/null
+/*
+ * jdpostct.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the decompression postprocessing controller.
+ * This controller manages the upsampling, color conversion, and color
+ * quantization/reduction steps; specifically, it controls the buffering
+ * between upsample/color conversion and color quantization/reduction.
+ *
+ * If no color quantization/reduction is required, then this module has no
+ * work to do, and it just hands off to the upsample/color conversion code.
+ * An integrated upsample/convert/quantize process would replace this module
+ * entirely.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ struct jpeg_d_post_controller pub; /* public fields */
+
+ /* Color quantization source buffer: this holds output data from
+ * the upsample/color conversion step to be passed to the quantizer.
+ * For two-pass color quantization, we need a full-image buffer;
+ * for one-pass operation, a strip buffer is sufficient.
+ */
+ jvirt_sarray_ptr whole_image; /* virtual array, or NULL if one-pass */
+ JSAMPARRAY buffer; /* strip buffer, or current strip of virtual */
+ JDIMENSION strip_height; /* buffer size in rows */
+ /* for two-pass mode only: */
+ JDIMENSION starting_row; /* row # of first row in current strip */
+ JDIMENSION next_row; /* index of next row to fill/empty in strip */
+} my_post_controller;
+
+typedef my_post_controller * my_post_ptr;
+
+
+/* Forward declarations */
+METHODDEF(void) post_process_1pass
+ JPP((j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail));
+#ifdef QUANT_2PASS_SUPPORTED
+METHODDEF(void) post_process_prepass
+ JPP((j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail));
+METHODDEF(void) post_process_2pass
+ JPP((j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail));
+#endif
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_dpost (j_decompress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ my_post_ptr post = (my_post_ptr) cinfo->post;
+
+ switch (pass_mode) {
+ case JBUF_PASS_THRU:
+ if (cinfo->quantize_colors) {
+ /* Single-pass processing with color quantization. */
+ post->pub.post_process_data = post_process_1pass;
+ /* We could be doing buffered-image output before starting a 2-pass
+ * color quantization; in that case, jinit_d_post_controller did not
+ * allocate a strip buffer. Use the virtual-array buffer as workspace.
+ */
+ if (post->buffer == NULL) {
+ post->buffer = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, post->whole_image,
+ (JDIMENSION) 0, post->strip_height, TRUE);
+ }
+ } else {
+ /* For single-pass processing without color quantization,
+ * I have no work to do; just call the upsampler directly.
+ */
+ post->pub.post_process_data = cinfo->upsample->upsample;
+ }
+ break;
+#ifdef QUANT_2PASS_SUPPORTED
+ case JBUF_SAVE_AND_PASS:
+ /* First pass of 2-pass quantization */
+ if (post->whole_image == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ post->pub.post_process_data = post_process_prepass;
+ break;
+ case JBUF_CRANK_DEST:
+ /* Second pass of 2-pass quantization */
+ if (post->whole_image == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ post->pub.post_process_data = post_process_2pass;
+ break;
+#endif /* QUANT_2PASS_SUPPORTED */
+ default:
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ break;
+ }
+ post->starting_row = post->next_row = 0;
+}
+
+
+/*
+ * Process some data in the one-pass (strip buffer) case.
+ * This is used for color precision reduction as well as one-pass quantization.
+ */
+
+METHODDEF(void)
+post_process_1pass (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ my_post_ptr post = (my_post_ptr) cinfo->post;
+ JDIMENSION num_rows, max_rows;
+
+ /* Fill the buffer, but not more than what we can dump out in one go. */
+ /* Note we rely on the upsampler to detect bottom of image. */
+ max_rows = out_rows_avail - *out_row_ctr;
+ if (max_rows > post->strip_height)
+ max_rows = post->strip_height;
+ num_rows = 0;
+ (*cinfo->upsample->upsample) (cinfo,
+ input_buf, in_row_group_ctr, in_row_groups_avail,
+ post->buffer, &num_rows, max_rows);
+ /* Quantize and emit data. */
+ (*cinfo->cquantize->color_quantize) (cinfo,
+ post->buffer, output_buf + *out_row_ctr, (int) num_rows);
+ *out_row_ctr += num_rows;
+}
+
+
+#ifdef QUANT_2PASS_SUPPORTED
+
+/*
+ * Process some data in the first pass of 2-pass quantization.
+ */
+
+METHODDEF(void)
+post_process_prepass (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ my_post_ptr post = (my_post_ptr) cinfo->post;
+ JDIMENSION old_next_row, num_rows;
+
+ /* Reposition virtual buffer if at start of strip. */
+ if (post->next_row == 0) {
+ post->buffer = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, post->whole_image,
+ post->starting_row, post->strip_height, TRUE);
+ }
+
+ /* Upsample some data (up to a strip height's worth). */
+ old_next_row = post->next_row;
+ (*cinfo->upsample->upsample) (cinfo,
+ input_buf, in_row_group_ctr, in_row_groups_avail,
+ post->buffer, &post->next_row, post->strip_height);
+
+ /* Allow quantizer to scan new data. No data is emitted, */
+ /* but we advance out_row_ctr so outer loop can tell when we're done. */
+ if (post->next_row > old_next_row) {
+ num_rows = post->next_row - old_next_row;
+ (*cinfo->cquantize->color_quantize) (cinfo, post->buffer + old_next_row,
+ (JSAMPARRAY) NULL, (int) num_rows);
+ *out_row_ctr += num_rows;
+ }
+
+ /* Advance if we filled the strip. */
+ if (post->next_row >= post->strip_height) {
+ post->starting_row += post->strip_height;
+ post->next_row = 0;
+ }
+}
+
+
+/*
+ * Process some data in the second pass of 2-pass quantization.
+ */
+
+METHODDEF(void)
+post_process_2pass (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ my_post_ptr post = (my_post_ptr) cinfo->post;
+ JDIMENSION num_rows, max_rows;
+
+ /* Reposition virtual buffer if at start of strip. */
+ if (post->next_row == 0) {
+ post->buffer = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, post->whole_image,
+ post->starting_row, post->strip_height, FALSE);
+ }
+
+ /* Determine number of rows to emit. */
+ num_rows = post->strip_height - post->next_row; /* available in strip */
+ max_rows = out_rows_avail - *out_row_ctr; /* available in output area */
+ if (num_rows > max_rows)
+ num_rows = max_rows;
+ /* We have to check bottom of image here, can't depend on upsampler. */
+ max_rows = cinfo->output_height - post->starting_row;
+ if (num_rows > max_rows)
+ num_rows = max_rows;
+
+ /* Quantize and emit data. */
+ (*cinfo->cquantize->color_quantize) (cinfo,
+ post->buffer + post->next_row, output_buf + *out_row_ctr,
+ (int) num_rows);
+ *out_row_ctr += num_rows;
+
+ /* Advance if we filled the strip. */
+ post->next_row += num_rows;
+ if (post->next_row >= post->strip_height) {
+ post->starting_row += post->strip_height;
+ post->next_row = 0;
+ }
+}
+
+#endif /* QUANT_2PASS_SUPPORTED */
+
+
+/*
+ * Initialize postprocessing controller.
+ */
+
+GLOBAL(void)
+jinit_d_post_controller (j_decompress_ptr cinfo, boolean need_full_buffer)
+{
+ my_post_ptr post;
+
+ post = (my_post_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_post_controller));
+ cinfo->post = (struct jpeg_d_post_controller *) post;
+ post->pub.start_pass = start_pass_dpost;
+ post->whole_image = NULL; /* flag for no virtual arrays */
+ post->buffer = NULL; /* flag for no strip buffer */
+
+ /* Create the quantization buffer, if needed */
+ if (cinfo->quantize_colors) {
+ /* The buffer strip height is max_v_samp_factor, which is typically
+ * an efficient number of rows for upsampling to return.
+ * (In the presence of output rescaling, we might want to be smarter?)
+ */
+ post->strip_height = (JDIMENSION) cinfo->max_v_samp_factor;
+ if (need_full_buffer) {
+ /* Two-pass color quantization: need full-image storage. */
+ /* We round up the number of rows to a multiple of the strip height. */
+#ifdef QUANT_2PASS_SUPPORTED
+ post->whole_image = (*cinfo->mem->request_virt_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+ cinfo->output_width * cinfo->out_color_components,
+ (JDIMENSION) jround_up((long) cinfo->output_height,
+ (long) post->strip_height),
+ post->strip_height);
+#else
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+#endif /* QUANT_2PASS_SUPPORTED */
+ } else {
+ /* One-pass color quantization: just make a strip buffer. */
+ post->buffer = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ cinfo->output_width * cinfo->out_color_components,
+ post->strip_height);
+ }
+ }
+}
--- /dev/null
+/*
+ * jdsample.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains upsampling routines.
+ *
+ * Upsampling input data is counted in "row groups". A row group
+ * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
+ * sample rows of each component. Upsampling will normally produce
+ * max_v_samp_factor pixel rows from each row group (but this could vary
+ * if the upsampler is applying a scale factor of its own).
+ *
+ * An excellent reference for image resampling is
+ * Digital Image Warping, George Wolberg, 1990.
+ * Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Pointer to routine to upsample a single component */
+typedef JMETHOD(void, upsample1_ptr,
+ (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr));
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_upsampler pub; /* public fields */
+
+ /* Color conversion buffer. When using separate upsampling and color
+ * conversion steps, this buffer holds one upsampled row group until it
+ * has been color converted and output.
+ * Note: we do not allocate any storage for component(s) which are full-size,
+ * ie do not need rescaling. The corresponding entry of color_buf[] is
+ * simply set to point to the input data array, thereby avoiding copying.
+ */
+ JSAMPARRAY color_buf[MAX_COMPONENTS];
+
+ /* Per-component upsampling method pointers */
+ upsample1_ptr methods[MAX_COMPONENTS];
+
+ int next_row_out; /* counts rows emitted from color_buf */
+ JDIMENSION rows_to_go; /* counts rows remaining in image */
+
+ /* Height of an input row group for each component. */
+ int rowgroup_height[MAX_COMPONENTS];
+
+ /* These arrays save pixel expansion factors so that int_expand need not
+ * recompute them each time. They are unused for other upsampling methods.
+ */
+ UINT8 h_expand[MAX_COMPONENTS];
+ UINT8 v_expand[MAX_COMPONENTS];
+} my_upsampler;
+
+typedef my_upsampler * my_upsample_ptr;
+
+
+/*
+ * Initialize for an upsampling pass.
+ */
+
+METHODDEF(void)
+start_pass_upsample (j_decompress_ptr cinfo)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+
+ /* Mark the conversion buffer empty */
+ upsample->next_row_out = cinfo->max_v_samp_factor;
+ /* Initialize total-height counter for detecting bottom of image */
+ upsample->rows_to_go = cinfo->output_height;
+}
+
+
+/*
+ * Control routine to do upsampling (and color conversion).
+ *
+ * In this version we upsample each component independently.
+ * We upsample one row group into the conversion buffer, then apply
+ * color conversion a row at a time.
+ */
+
+METHODDEF(void)
+sep_upsample (j_decompress_ptr cinfo,
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ int ci;
+ jpeg_component_info * compptr;
+ JDIMENSION num_rows;
+
+ /* Fill the conversion buffer, if it's empty */
+ if (upsample->next_row_out >= cinfo->max_v_samp_factor) {
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Invoke per-component upsample method. Notice we pass a POINTER
+ * to color_buf[ci], so that fullsize_upsample can change it.
+ */
+ (*upsample->methods[ci]) (cinfo, compptr,
+ input_buf[ci] + (*in_row_group_ctr * upsample->rowgroup_height[ci]),
+ upsample->color_buf + ci);
+ }
+ upsample->next_row_out = 0;
+ }
+
+ /* Color-convert and emit rows */
+
+ /* How many we have in the buffer: */
+ num_rows = (JDIMENSION) (cinfo->max_v_samp_factor - upsample->next_row_out);
+ /* Not more than the distance to the end of the image. Need this test
+ * in case the image height is not a multiple of max_v_samp_factor:
+ */
+ if (num_rows > upsample->rows_to_go)
+ num_rows = upsample->rows_to_go;
+ /* And not more than what the client can accept: */
+ out_rows_avail -= *out_row_ctr;
+ if (num_rows > out_rows_avail)
+ num_rows = out_rows_avail;
+
+ (*cinfo->cconvert->color_convert) (cinfo, upsample->color_buf,
+ (JDIMENSION) upsample->next_row_out,
+ output_buf + *out_row_ctr,
+ (int) num_rows);
+
+ /* Adjust counts */
+ *out_row_ctr += num_rows;
+ upsample->rows_to_go -= num_rows;
+ upsample->next_row_out += num_rows;
+ /* When the buffer is emptied, declare this input row group consumed */
+ if (upsample->next_row_out >= cinfo->max_v_samp_factor)
+ (*in_row_group_ctr)++;
+}
+
+
+/*
+ * These are the routines invoked by sep_upsample to upsample pixel values
+ * of a single component. One row group is processed per call.
+ */
+
+
+/*
+ * For full-size components, we just make color_buf[ci] point at the
+ * input buffer, and thus avoid copying any data. Note that this is
+ * safe only because sep_upsample doesn't declare the input row group
+ * "consumed" until we are done color converting and emitting it.
+ */
+
+METHODDEF(void)
+fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ *output_data_ptr = input_data;
+}
+
+
+/*
+ * This is a no-op version used for "uninteresting" components.
+ * These components will not be referenced by color conversion.
+ */
+
+METHODDEF(void)
+noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ *output_data_ptr = NULL; /* safety check */
+}
+
+
+/*
+ * This version handles any integral sampling ratios.
+ * This is not used for typical JPEG files, so it need not be fast.
+ * Nor, for that matter, is it particularly accurate: the algorithm is
+ * simple replication of the input pixel onto the corresponding output
+ * pixels. The hi-falutin sampling literature refers to this as a
+ * "box filter". A box filter tends to introduce visible artifacts,
+ * so if you are actually going to use 3:1 or 4:1 sampling ratios
+ * you would be well advised to improve this code.
+ */
+
+METHODDEF(void)
+int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ JSAMPARRAY output_data = *output_data_ptr;
+ register JSAMPROW inptr, outptr;
+ register JSAMPLE invalue;
+ register int h;
+ JSAMPROW outend;
+ int h_expand, v_expand;
+ int inrow, outrow;
+
+ h_expand = upsample->h_expand[compptr->component_index];
+ v_expand = upsample->v_expand[compptr->component_index];
+
+ inrow = outrow = 0;
+ while (outrow < cinfo->max_v_samp_factor) {
+ /* Generate one output row with proper horizontal expansion */
+ inptr = input_data[inrow];
+ outptr = output_data[outrow];
+ outend = outptr + cinfo->output_width;
+ while (outptr < outend) {
+ invalue = *inptr++; /* don't need GETJSAMPLE() here */
+ for (h = h_expand; h > 0; h--) {
+ *outptr++ = invalue;
+ }
+ }
+ /* Generate any additional output rows by duplicating the first one */
+ if (v_expand > 1) {
+ jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
+ v_expand-1, cinfo->output_width);
+ }
+ inrow++;
+ outrow += v_expand;
+ }
+}
+
+
+/*
+ * Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
+ * It's still a box filter.
+ */
+
+METHODDEF(void)
+h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ JSAMPARRAY output_data = *output_data_ptr;
+ register JSAMPROW inptr, outptr;
+ register JSAMPLE invalue;
+ JSAMPROW outend;
+ int inrow;
+
+ for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
+ inptr = input_data[inrow];
+ outptr = output_data[inrow];
+ outend = outptr + cinfo->output_width;
+ while (outptr < outend) {
+ invalue = *inptr++; /* don't need GETJSAMPLE() here */
+ *outptr++ = invalue;
+ *outptr++ = invalue;
+ }
+ }
+}
+
+
+/*
+ * Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
+ * It's still a box filter.
+ */
+
+METHODDEF(void)
+h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ JSAMPARRAY output_data = *output_data_ptr;
+ register JSAMPROW inptr, outptr;
+ register JSAMPLE invalue;
+ JSAMPROW outend;
+ int inrow, outrow;
+
+ inrow = outrow = 0;
+ while (outrow < cinfo->max_v_samp_factor) {
+ inptr = input_data[inrow];
+ outptr = output_data[outrow];
+ outend = outptr + cinfo->output_width;
+ while (outptr < outend) {
+ invalue = *inptr++; /* don't need GETJSAMPLE() here */
+ *outptr++ = invalue;
+ *outptr++ = invalue;
+ }
+ jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
+ 1, cinfo->output_width);
+ inrow++;
+ outrow += 2;
+ }
+}
+
+
+/*
+ * Fancy processing for the common case of 2:1 horizontal and 1:1 vertical.
+ *
+ * The upsampling algorithm is linear interpolation between pixel centers,
+ * also known as a "triangle filter". This is a good compromise between
+ * speed and visual quality. The centers of the output pixels are 1/4 and 3/4
+ * of the way between input pixel centers.
+ *
+ * A note about the "bias" calculations: when rounding fractional values to
+ * integer, we do not want to always round 0.5 up to the next integer.
+ * If we did that, we'd introduce a noticeable bias towards larger values.
+ * Instead, this code is arranged so that 0.5 will be rounded up or down at
+ * alternate pixel locations (a simple ordered dither pattern).
+ */
+
+METHODDEF(void)
+h2v1_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ JSAMPARRAY output_data = *output_data_ptr;
+ register JSAMPROW inptr, outptr;
+ register int invalue;
+ register JDIMENSION colctr;
+ int inrow;
+
+ for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
+ inptr = input_data[inrow];
+ outptr = output_data[inrow];
+ /* Special case for first column */
+ invalue = GETJSAMPLE(*inptr++);
+ *outptr++ = (JSAMPLE) invalue;
+ *outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(*inptr) + 2) >> 2);
+
+ for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) {
+ /* General case: 3/4 * nearer pixel + 1/4 * further pixel */
+ invalue = GETJSAMPLE(*inptr++) * 3;
+ *outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(inptr[-2]) + 1) >> 2);
+ *outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(*inptr) + 2) >> 2);
+ }
+
+ /* Special case for last column */
+ invalue = GETJSAMPLE(*inptr);
+ *outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(inptr[-1]) + 1) >> 2);
+ *outptr++ = (JSAMPLE) invalue;
+ }
+}
+
+
+/*
+ * Fancy processing for the common case of 2:1 horizontal and 2:1 vertical.
+ * Again a triangle filter; see comments for h2v1 case, above.
+ *
+ * It is OK for us to reference the adjacent input rows because we demanded
+ * context from the main buffer controller (see initialization code).
+ */
+
+METHODDEF(void)
+h2v2_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
+{
+ JSAMPARRAY output_data = *output_data_ptr;
+ register JSAMPROW inptr0, inptr1, outptr;
+#if BITS_IN_JSAMPLE == 8
+ register int thiscolsum, lastcolsum, nextcolsum;
+#else
+ register INT32 thiscolsum, lastcolsum, nextcolsum;
+#endif
+ register JDIMENSION colctr;
+ int inrow, outrow, v;
+
+ inrow = outrow = 0;
+ while (outrow < cinfo->max_v_samp_factor) {
+ for (v = 0; v < 2; v++) {
+ /* inptr0 points to nearest input row, inptr1 points to next nearest */
+ inptr0 = input_data[inrow];
+ if (v == 0) /* next nearest is row above */
+ inptr1 = input_data[inrow-1];
+ else /* next nearest is row below */
+ inptr1 = input_data[inrow+1];
+ outptr = output_data[outrow++];
+
+ /* Special case for first column */
+ thiscolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
+ nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
+ *outptr++ = (JSAMPLE) ((thiscolsum * 4 + 8) >> 4);
+ *outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4);
+ lastcolsum = thiscolsum; thiscolsum = nextcolsum;
+
+ for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) {
+ /* General case: 3/4 * nearer pixel + 1/4 * further pixel in each */
+ /* dimension, thus 9/16, 3/16, 3/16, 1/16 overall */
+ nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
+ *outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4);
+ *outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4);
+ lastcolsum = thiscolsum; thiscolsum = nextcolsum;
+ }
+
+ /* Special case for last column */
+ *outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4);
+ *outptr++ = (JSAMPLE) ((thiscolsum * 4 + 7) >> 4);
+ }
+ inrow++;
+ }
+}
+
+
+/*
+ * Module initialization routine for upsampling.
+ */
+
+GLOBAL(void)
+jinit_upsampler (j_decompress_ptr cinfo)
+{
+ my_upsample_ptr upsample;
+ int ci;
+ jpeg_component_info * compptr;
+ boolean need_buffer, do_fancy;
+ int h_in_group, v_in_group, h_out_group, v_out_group;
+
+ upsample = (my_upsample_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_upsampler));
+ cinfo->upsample = (struct jpeg_upsampler *) upsample;
+ upsample->pub.start_pass = start_pass_upsample;
+ upsample->pub.upsample = sep_upsample;
+ upsample->pub.need_context_rows = FALSE; /* until we find out differently */
+
+ if (cinfo->CCIR601_sampling) /* this isn't supported */
+ ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
+
+ /* jdmainct.c doesn't support context rows when min_DCT_scaled_size = 1,
+ * so don't ask for it.
+ */
+ do_fancy = cinfo->do_fancy_upsampling && cinfo->min_DCT_scaled_size > 1;
+
+ /* Verify we can handle the sampling factors, select per-component methods,
+ * and create storage as needed.
+ */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Compute size of an "input group" after IDCT scaling. This many samples
+ * are to be converted to max_h_samp_factor * max_v_samp_factor pixels.
+ */
+ h_in_group = (compptr->h_samp_factor * compptr->DCT_scaled_size) /
+ cinfo->min_DCT_scaled_size;
+ v_in_group = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
+ cinfo->min_DCT_scaled_size;
+ h_out_group = cinfo->max_h_samp_factor;
+ v_out_group = cinfo->max_v_samp_factor;
+ upsample->rowgroup_height[ci] = v_in_group; /* save for use later */
+ need_buffer = TRUE;
+ if (! compptr->component_needed) {
+ /* Don't bother to upsample an uninteresting component. */
+ upsample->methods[ci] = noop_upsample;
+ need_buffer = FALSE;
+ } else if (h_in_group == h_out_group && v_in_group == v_out_group) {
+ /* Fullsize components can be processed without any work. */
+ upsample->methods[ci] = fullsize_upsample;
+ need_buffer = FALSE;
+ } else if (h_in_group * 2 == h_out_group &&
+ v_in_group == v_out_group) {
+ /* Special cases for 2h1v upsampling */
+ if (do_fancy && compptr->downsampled_width > 2)
+ upsample->methods[ci] = h2v1_fancy_upsample;
+ else
+ upsample->methods[ci] = h2v1_upsample;
+ } else if (h_in_group * 2 == h_out_group &&
+ v_in_group * 2 == v_out_group) {
+ /* Special cases for 2h2v upsampling */
+ if (do_fancy && compptr->downsampled_width > 2) {
+ upsample->methods[ci] = h2v2_fancy_upsample;
+ upsample->pub.need_context_rows = TRUE;
+ } else
+ upsample->methods[ci] = h2v2_upsample;
+ } else if ((h_out_group % h_in_group) == 0 &&
+ (v_out_group % v_in_group) == 0) {
+ /* Generic integral-factors upsampling method */
+ upsample->methods[ci] = int_upsample;
+ upsample->h_expand[ci] = (UINT8) (h_out_group / h_in_group);
+ upsample->v_expand[ci] = (UINT8) (v_out_group / v_in_group);
+ } else
+ ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
+ if (need_buffer) {
+ upsample->color_buf[ci] = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) jround_up((long) cinfo->output_width,
+ (long) cinfo->max_h_samp_factor),
+ (JDIMENSION) cinfo->max_v_samp_factor);
+ }
+ }
+}
--- /dev/null
+/*
+ * jdtrans.c
+ *
+ * Copyright (C) 1995-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains library routines for transcoding decompression,
+ * that is, reading raw DCT coefficient arrays from an input JPEG file.
+ * The routines in jdapimin.c will also be needed by a transcoder.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/* Forward declarations */
+LOCAL(void) transdecode_master_selection JPP((j_decompress_ptr cinfo));
+
+
+/*
+ * Read the coefficient arrays from a JPEG file.
+ * jpeg_read_header must be completed before calling this.
+ *
+ * The entire image is read into a set of virtual coefficient-block arrays,
+ * one per component. The return value is a pointer to the array of
+ * virtual-array descriptors. These can be manipulated directly via the
+ * JPEG memory manager, or handed off to jpeg_write_coefficients().
+ * To release the memory occupied by the virtual arrays, call
+ * jpeg_finish_decompress() when done with the data.
+ *
+ * An alternative usage is to simply obtain access to the coefficient arrays
+ * during a buffered-image-mode decompression operation. This is allowed
+ * after any jpeg_finish_output() call. The arrays can be accessed until
+ * jpeg_finish_decompress() is called. (Note that any call to the library
+ * may reposition the arrays, so don't rely on access_virt_barray() results
+ * to stay valid across library calls.)
+ *
+ * Returns NULL if suspended. This case need be checked only if
+ * a suspending data source is used.
+ */
+
+GLOBAL(jvirt_barray_ptr *)
+jpeg_read_coefficients (j_decompress_ptr cinfo)
+{
+ if (cinfo->global_state == DSTATE_READY) {
+ /* First call: initialize active modules */
+ transdecode_master_selection(cinfo);
+ cinfo->global_state = DSTATE_RDCOEFS;
+ }
+ if (cinfo->global_state == DSTATE_RDCOEFS) {
+ /* Absorb whole file into the coef buffer */
+ for (;;) {
+ int retcode;
+ /* Call progress monitor hook if present */
+ if (cinfo->progress != NULL)
+ (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
+ /* Absorb some more input */
+ retcode = (*cinfo->inputctl->consume_input) (cinfo);
+ if (retcode == JPEG_SUSPENDED)
+ return NULL;
+ if (retcode == JPEG_REACHED_EOI)
+ break;
+ /* Advance progress counter if appropriate */
+ if (cinfo->progress != NULL &&
+ (retcode == JPEG_ROW_COMPLETED || retcode == JPEG_REACHED_SOS)) {
+ if (++cinfo->progress->pass_counter >= cinfo->progress->pass_limit) {
+ /* startup underestimated number of scans; ratchet up one scan */
+ cinfo->progress->pass_limit += (long) cinfo->total_iMCU_rows;
+ }
+ }
+ }
+ /* Set state so that jpeg_finish_decompress does the right thing */
+ cinfo->global_state = DSTATE_STOPPING;
+ }
+ /* At this point we should be in state DSTATE_STOPPING if being used
+ * standalone, or in state DSTATE_BUFIMAGE if being invoked to get access
+ * to the coefficients during a full buffered-image-mode decompression.
+ */
+ if ((cinfo->global_state == DSTATE_STOPPING ||
+ cinfo->global_state == DSTATE_BUFIMAGE) && cinfo->buffered_image) {
+ return cinfo->coef->coef_arrays;
+ }
+ /* Oops, improper usage */
+ ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
+ return NULL; /* keep compiler happy */
+}
+
+
+/*
+ * Master selection of decompression modules for transcoding.
+ * This substitutes for jdmaster.c's initialization of the full decompressor.
+ */
+
+LOCAL(void)
+transdecode_master_selection (j_decompress_ptr cinfo)
+{
+ /* This is effectively a buffered-image operation. */
+ cinfo->buffered_image = TRUE;
+
+ /* Entropy decoding: either Huffman or arithmetic coding. */
+ if (cinfo->arith_code) {
+ ERREXIT(cinfo, JERR_ARITH_NOTIMPL);
+ } else {
+ if (cinfo->progressive_mode) {
+#ifdef D_PROGRESSIVE_SUPPORTED
+ jinit_phuff_decoder(cinfo);
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else
+ jinit_huff_decoder(cinfo);
+ }
+
+ /* Always get a full-image coefficient buffer. */
+ jinit_d_coef_controller(cinfo, TRUE);
+
+ /* We can now tell the memory manager to allocate virtual arrays. */
+ (*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
+
+ /* Initialize input side of decompressor to consume first scan. */
+ (*cinfo->inputctl->start_input_pass) (cinfo);
+
+ /* Initialize progress monitoring. */
+ if (cinfo->progress != NULL) {
+ int nscans;
+ /* Estimate number of scans to set pass_limit. */
+ if (cinfo->progressive_mode) {
+ /* Arbitrarily estimate 2 interleaved DC scans + 3 AC scans/component. */
+ nscans = 2 + 3 * cinfo->num_components;
+ } else if (cinfo->inputctl->has_multiple_scans) {
+ /* For a nonprogressive multiscan file, estimate 1 scan per component. */
+ nscans = cinfo->num_components;
+ } else {
+ nscans = 1;
+ }
+ cinfo->progress->pass_counter = 0L;
+ cinfo->progress->pass_limit = (long) cinfo->total_iMCU_rows * nscans;
+ cinfo->progress->completed_passes = 0;
+ cinfo->progress->total_passes = 1;
+ }
+}
--- /dev/null
+/*
+ * jerror.c
+ *
+ * Copyright (C) 1991-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains simple error-reporting and trace-message routines.
+ * These are suitable for Unix-like systems and others where writing to
+ * stderr is the right thing to do. Many applications will want to replace
+ * some or all of these routines.
+ *
+ * If you define USE_WINDOWS_MESSAGEBOX in jconfig.h or in the makefile,
+ * you get a Windows-specific hack to display error messages in a dialog box.
+ * It ain't much, but it beats dropping error messages into the bit bucket,
+ * which is what happens to output to stderr under most Windows C compilers.
+ *
+ * These routines are used by both the compression and decompression code.
+ */
+
+/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jversion12.h"
+#include "jerror12.h"
+
+#ifdef USE_WINDOWS_MESSAGEBOX
+#include <windows.h>
+#endif
+
+#ifndef EXIT_FAILURE /* define exit() codes if not provided */
+#define EXIT_FAILURE 1
+#endif
+
+
+/*
+ * Create the message string table.
+ * We do this from the master message list in jerror.h by re-reading
+ * jerror.h with a suitable definition for macro JMESSAGE.
+ * The message table is made an external symbol just in case any applications
+ * want to refer to it directly.
+ */
+
+#ifdef NEED_SHORT_EXTERNAL_NAMES
+#define jpeg_std_message_table jMsgTable
+#endif
+
+#define JMESSAGE(code,string) string ,
+
+const char * const jpeg_std_message_table[] = {
+#include "jerror.h"
+ NULL
+};
+
+
+/*
+ * Error exit handler: must not return to caller.
+ *
+ * Applications may override this if they want to get control back after
+ * an error. Typically one would longjmp somewhere instead of exiting.
+ * The setjmp buffer can be made a private field within an expanded error
+ * handler object. Note that the info needed to generate an error message
+ * is stored in the error object, so you can generate the message now or
+ * later, at your convenience.
+ * You should make sure that the JPEG object is cleaned up (with jpeg_abort
+ * or jpeg_destroy) at some point.
+ */
+
+METHODDEF(void)
+error_exit (j_common_ptr cinfo)
+{
+ /* Always display the message */
+ (*cinfo->err->output_message) (cinfo);
+
+ /* Let the memory manager delete any temp files before we die */
+ jpeg_destroy(cinfo);
+
+ exit(EXIT_FAILURE);
+}
+
+
+/*
+ * Actual output of an error or trace message.
+ * Applications may override this method to send JPEG messages somewhere
+ * other than stderr.
+ *
+ * On Windows, printing to stderr is generally completely useless,
+ * so we provide optional code to produce an error-dialog popup.
+ * Most Windows applications will still prefer to override this routine,
+ * but if they don't, it'll do something at least marginally useful.
+ *
+ * NOTE: to use the library in an environment that doesn't support the
+ * C stdio library, you may have to delete the call to fprintf() entirely,
+ * not just not use this routine.
+ */
+
+METHODDEF(void)
+output_message (j_common_ptr cinfo)
+{
+ char buffer[JMSG_LENGTH_MAX];
+
+ /* Create the message */
+ (*cinfo->err->format_message) (cinfo, buffer);
+
+#ifdef USE_WINDOWS_MESSAGEBOX
+ /* Display it in a message dialog box */
+ MessageBox(GetActiveWindow(), buffer, "JPEG Library Error",
+ MB_OK | MB_ICONERROR);
+#else
+ /* Send it to stderr, adding a newline */
+ fprintf(stderr, "%s\n", buffer);
+#endif
+}
+
+
+/*
+ * Decide whether to emit a trace or warning message.
+ * msg_level is one of:
+ * -1: recoverable corrupt-data warning, may want to abort.
+ * 0: important advisory messages (always display to user).
+ * 1: first level of tracing detail.
+ * 2,3,...: successively more detailed tracing messages.
+ * An application might override this method if it wanted to abort on warnings
+ * or change the policy about which messages to display.
+ */
+
+METHODDEF(void)
+emit_message (j_common_ptr cinfo, int msg_level)
+{
+ struct jpeg_error_mgr * err = cinfo->err;
+
+ if (msg_level < 0) {
+ /* It's a warning message. Since corrupt files may generate many warnings,
+ * the policy implemented here is to show only the first warning,
+ * unless trace_level >= 3.
+ */
+ if (err->num_warnings == 0 || err->trace_level >= 3)
+ (*err->output_message) (cinfo);
+ /* Always count warnings in num_warnings. */
+ err->num_warnings++;
+ } else {
+ /* It's a trace message. Show it if trace_level >= msg_level. */
+ if (err->trace_level >= msg_level)
+ (*err->output_message) (cinfo);
+ }
+}
+
+
+/*
+ * Format a message string for the most recent JPEG error or message.
+ * The message is stored into buffer, which should be at least JMSG_LENGTH_MAX
+ * characters. Note that no '\n' character is added to the string.
+ * Few applications should need to override this method.
+ */
+
+METHODDEF(void)
+format_message (j_common_ptr cinfo, char * buffer)
+{
+ struct jpeg_error_mgr * err = cinfo->err;
+ int msg_code = err->msg_code;
+ const char * msgtext = NULL;
+ const char * msgptr;
+ char ch;
+ boolean isstring;
+
+ /* Look up message string in proper table */
+ if (msg_code > 0 && msg_code <= err->last_jpeg_message) {
+ msgtext = err->jpeg_message_table[msg_code];
+ } else if (err->addon_message_table != NULL &&
+ msg_code >= err->first_addon_message &&
+ msg_code <= err->last_addon_message) {
+ msgtext = err->addon_message_table[msg_code - err->first_addon_message];
+ }
+
+ /* Defend against bogus message number */
+ if (msgtext == NULL) {
+ err->msg_parm.i[0] = msg_code;
+ msgtext = err->jpeg_message_table[0];
+ }
+
+ /* Check for string parameter, as indicated by %s in the message text */
+ isstring = FALSE;
+ msgptr = msgtext;
+ while ((ch = *msgptr++) != '\0') {
+ if (ch == '%') {
+ if (*msgptr == 's') isstring = TRUE;
+ break;
+ }
+ }
+
+ /* Format the message into the passed buffer */
+ if (isstring)
+ sprintf(buffer, msgtext, err->msg_parm.s);
+ else
+ sprintf(buffer, msgtext,
+ err->msg_parm.i[0], err->msg_parm.i[1],
+ err->msg_parm.i[2], err->msg_parm.i[3],
+ err->msg_parm.i[4], err->msg_parm.i[5],
+ err->msg_parm.i[6], err->msg_parm.i[7]);
+}
+
+
+/*
+ * Reset error state variables at start of a new image.
+ * This is called during compression startup to reset trace/error
+ * processing to default state, without losing any application-specific
+ * method pointers. An application might possibly want to override
+ * this method if it has additional error processing state.
+ */
+
+METHODDEF(void)
+reset_error_mgr (j_common_ptr cinfo)
+{
+ cinfo->err->num_warnings = 0;
+ /* trace_level is not reset since it is an application-supplied parameter */
+ cinfo->err->msg_code = 0; /* may be useful as a flag for "no error" */
+}
+
+
+/*
+ * Fill in the standard error-handling methods in a jpeg_error_mgr object.
+ * Typical call is:
+ * struct jpeg_compress_struct cinfo;
+ * struct jpeg_error_mgr err;
+ *
+ * cinfo.err = jpeg_std_error(&err);
+ * after which the application may override some of the methods.
+ */
+
+GLOBAL(struct jpeg_error_mgr *)
+jpeg_std_error (struct jpeg_error_mgr * err)
+{
+ err->error_exit = error_exit;
+ err->emit_message = emit_message;
+ err->output_message = output_message;
+ err->format_message = format_message;
+ err->reset_error_mgr = reset_error_mgr;
+
+ err->trace_level = 0; /* default = no tracing */
+ err->num_warnings = 0; /* no warnings emitted yet */
+ err->msg_code = 0; /* may be useful as a flag for "no error" */
+
+ /* Initialize message table pointers */
+ err->jpeg_message_table = jpeg_std_message_table;
+ err->last_jpeg_message = (int) JMSG_LASTMSGCODE - 1;
+
+ err->addon_message_table = NULL;
+ err->first_addon_message = 0; /* for safety */
+ err->last_addon_message = 0;
+
+ return err;
+}
--- /dev/null
+/*
+ * jfdctflt.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a floating-point implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * This implementation should be more accurate than either of the integer
+ * DCT implementations. However, it may not give the same results on all
+ * machines because of differences in roundoff behavior. Speed will depend
+ * on the hardware's floating point capacity.
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column. Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README). The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs. These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries. The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with a fixed-point
+ * implementation, accuracy is lost due to imprecise representation of the
+ * scaled quantization values. However, that problem does not arise if
+ * we use floating point arithmetic.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL(void)
+jpeg_fdct_float (FAST_FLOAT * data)
+{
+ FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ FAST_FLOAT tmp10, tmp11, tmp12, tmp13;
+ FAST_FLOAT z1, z2, z3, z4, z5, z11, z13;
+ FAST_FLOAT *dataptr;
+ int ctr;
+
+ /* Pass 1: process rows. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[0] + dataptr[7];
+ tmp7 = dataptr[0] - dataptr[7];
+ tmp1 = dataptr[1] + dataptr[6];
+ tmp6 = dataptr[1] - dataptr[6];
+ tmp2 = dataptr[2] + dataptr[5];
+ tmp5 = dataptr[2] - dataptr[5];
+ tmp3 = dataptr[3] + dataptr[4];
+ tmp4 = dataptr[3] - dataptr[4];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3; /* phase 2 */
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[0] = tmp10 + tmp11; /* phase 3 */
+ dataptr[4] = tmp10 - tmp11;
+
+ z1 = (tmp12 + tmp13) * ((FAST_FLOAT) 0.707106781); /* c4 */
+ dataptr[2] = tmp13 + z1; /* phase 5 */
+ dataptr[6] = tmp13 - z1;
+
+ /* Odd part */
+
+ tmp10 = tmp4 + tmp5; /* phase 2 */
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ /* The rotator is modified from fig 4-8 to avoid extra negations. */
+ z5 = (tmp10 - tmp12) * ((FAST_FLOAT) 0.382683433); /* c6 */
+ z2 = ((FAST_FLOAT) 0.541196100) * tmp10 + z5; /* c2-c6 */
+ z4 = ((FAST_FLOAT) 1.306562965) * tmp12 + z5; /* c2+c6 */
+ z3 = tmp11 * ((FAST_FLOAT) 0.707106781); /* c4 */
+
+ z11 = tmp7 + z3; /* phase 5 */
+ z13 = tmp7 - z3;
+
+ dataptr[5] = z13 + z2; /* phase 6 */
+ dataptr[3] = z13 - z2;
+ dataptr[1] = z11 + z4;
+ dataptr[7] = z11 - z4;
+
+ dataptr += DCTSIZE; /* advance pointer to next row */
+ }
+
+ /* Pass 2: process columns. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
+ tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
+ tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
+ tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
+ tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
+ tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
+ tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
+ tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3; /* phase 2 */
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[DCTSIZE*0] = tmp10 + tmp11; /* phase 3 */
+ dataptr[DCTSIZE*4] = tmp10 - tmp11;
+
+ z1 = (tmp12 + tmp13) * ((FAST_FLOAT) 0.707106781); /* c4 */
+ dataptr[DCTSIZE*2] = tmp13 + z1; /* phase 5 */
+ dataptr[DCTSIZE*6] = tmp13 - z1;
+
+ /* Odd part */
+
+ tmp10 = tmp4 + tmp5; /* phase 2 */
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ /* The rotator is modified from fig 4-8 to avoid extra negations. */
+ z5 = (tmp10 - tmp12) * ((FAST_FLOAT) 0.382683433); /* c6 */
+ z2 = ((FAST_FLOAT) 0.541196100) * tmp10 + z5; /* c2-c6 */
+ z4 = ((FAST_FLOAT) 1.306562965) * tmp12 + z5; /* c2+c6 */
+ z3 = tmp11 * ((FAST_FLOAT) 0.707106781); /* c4 */
+
+ z11 = tmp7 + z3; /* phase 5 */
+ z13 = tmp7 - z3;
+
+ dataptr[DCTSIZE*5] = z13 + z2; /* phase 6 */
+ dataptr[DCTSIZE*3] = z13 - z2;
+ dataptr[DCTSIZE*1] = z11 + z4;
+ dataptr[DCTSIZE*7] = z11 - z4;
+
+ dataptr++; /* advance pointer to next column */
+ }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */
--- /dev/null
+/*
+ * jfdctfst.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a fast, not so accurate integer implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column. Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README). The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs. These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries. The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with fixed-point math,
+ * accuracy is lost due to imprecise representation of the scaled
+ * quantization values. The smaller the quantization table entry, the less
+ * precise the scaled value, so this implementation does worse with high-
+ * quality-setting files than with low-quality ones.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef DCT_IFAST_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/* Scaling decisions are generally the same as in the LL&M algorithm;
+ * see jfdctint.c for more details. However, we choose to descale
+ * (right shift) multiplication products as soon as they are formed,
+ * rather than carrying additional fractional bits into subsequent additions.
+ * This compromises accuracy slightly, but it lets us save a few shifts.
+ * More importantly, 16-bit arithmetic is then adequate (for 8-bit samples)
+ * everywhere except in the multiplications proper; this saves a good deal
+ * of work on 16-bit-int machines.
+ *
+ * Again to save a few shifts, the intermediate results between pass 1 and
+ * pass 2 are not upscaled, but are represented only to integral precision.
+ *
+ * A final compromise is to represent the multiplicative constants to only
+ * 8 fractional bits, rather than 13. This saves some shifting work on some
+ * machines, and may also reduce the cost of multiplication (since there
+ * are fewer one-bits in the constants).
+ */
+
+#define CONST_BITS 8
+
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 8
+#define FIX_0_382683433 ((INT32) 98) /* FIX(0.382683433) */
+#define FIX_0_541196100 ((INT32) 139) /* FIX(0.541196100) */
+#define FIX_0_707106781 ((INT32) 181) /* FIX(0.707106781) */
+#define FIX_1_306562965 ((INT32) 334) /* FIX(1.306562965) */
+#else
+#define FIX_0_382683433 FIX(0.382683433)
+#define FIX_0_541196100 FIX(0.541196100)
+#define FIX_0_707106781 FIX(0.707106781)
+#define FIX_1_306562965 FIX(1.306562965)
+#endif
+
+
+/* We can gain a little more speed, with a further compromise in accuracy,
+ * by omitting the addition in a descaling shift. This yields an incorrectly
+ * rounded result half the time...
+ */
+
+#ifndef USE_ACCURATE_ROUNDING
+#undef DESCALE
+#define DESCALE(x,n) RIGHT_SHIFT(x, n)
+#endif
+
+
+/* Multiply a DCTELEM variable by an INT32 constant, and immediately
+ * descale to yield a DCTELEM result.
+ */
+
+#define MULTIPLY(var,const) ((DCTELEM) DESCALE((var) * (const), CONST_BITS))
+
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL(void)
+jpeg_fdct_ifast (DCTELEM * data)
+{
+ DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ DCTELEM tmp10, tmp11, tmp12, tmp13;
+ DCTELEM z1, z2, z3, z4, z5, z11, z13;
+ DCTELEM *dataptr;
+ int ctr;
+ SHIFT_TEMPS
+
+ /* Pass 1: process rows. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[0] + dataptr[7];
+ tmp7 = dataptr[0] - dataptr[7];
+ tmp1 = dataptr[1] + dataptr[6];
+ tmp6 = dataptr[1] - dataptr[6];
+ tmp2 = dataptr[2] + dataptr[5];
+ tmp5 = dataptr[2] - dataptr[5];
+ tmp3 = dataptr[3] + dataptr[4];
+ tmp4 = dataptr[3] - dataptr[4];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3; /* phase 2 */
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[0] = tmp10 + tmp11; /* phase 3 */
+ dataptr[4] = tmp10 - tmp11;
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781); /* c4 */
+ dataptr[2] = tmp13 + z1; /* phase 5 */
+ dataptr[6] = tmp13 - z1;
+
+ /* Odd part */
+
+ tmp10 = tmp4 + tmp5; /* phase 2 */
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ /* The rotator is modified from fig 4-8 to avoid extra negations. */
+ z5 = MULTIPLY(tmp10 - tmp12, FIX_0_382683433); /* c6 */
+ z2 = MULTIPLY(tmp10, FIX_0_541196100) + z5; /* c2-c6 */
+ z4 = MULTIPLY(tmp12, FIX_1_306562965) + z5; /* c2+c6 */
+ z3 = MULTIPLY(tmp11, FIX_0_707106781); /* c4 */
+
+ z11 = tmp7 + z3; /* phase 5 */
+ z13 = tmp7 - z3;
+
+ dataptr[5] = z13 + z2; /* phase 6 */
+ dataptr[3] = z13 - z2;
+ dataptr[1] = z11 + z4;
+ dataptr[7] = z11 - z4;
+
+ dataptr += DCTSIZE; /* advance pointer to next row */
+ }
+
+ /* Pass 2: process columns. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
+ tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
+ tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
+ tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
+ tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
+ tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
+ tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
+ tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
+
+ /* Even part */
+
+ tmp10 = tmp0 + tmp3; /* phase 2 */
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[DCTSIZE*0] = tmp10 + tmp11; /* phase 3 */
+ dataptr[DCTSIZE*4] = tmp10 - tmp11;
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_707106781); /* c4 */
+ dataptr[DCTSIZE*2] = tmp13 + z1; /* phase 5 */
+ dataptr[DCTSIZE*6] = tmp13 - z1;
+
+ /* Odd part */
+
+ tmp10 = tmp4 + tmp5; /* phase 2 */
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp6 + tmp7;
+
+ /* The rotator is modified from fig 4-8 to avoid extra negations. */
+ z5 = MULTIPLY(tmp10 - tmp12, FIX_0_382683433); /* c6 */
+ z2 = MULTIPLY(tmp10, FIX_0_541196100) + z5; /* c2-c6 */
+ z4 = MULTIPLY(tmp12, FIX_1_306562965) + z5; /* c2+c6 */
+ z3 = MULTIPLY(tmp11, FIX_0_707106781); /* c4 */
+
+ z11 = tmp7 + z3; /* phase 5 */
+ z13 = tmp7 - z3;
+
+ dataptr[DCTSIZE*5] = z13 + z2; /* phase 6 */
+ dataptr[DCTSIZE*3] = z13 - z2;
+ dataptr[DCTSIZE*1] = z11 + z4;
+ dataptr[DCTSIZE*7] = z11 - z4;
+
+ dataptr++; /* advance pointer to next column */
+ }
+}
+
+#endif /* DCT_IFAST_SUPPORTED */
--- /dev/null
+/*
+ * jfdctint.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a slow-but-accurate integer implementation of the
+ * forward DCT (Discrete Cosine Transform).
+ *
+ * A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
+ * on each column. Direct algorithms are also available, but they are
+ * much more complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on an algorithm described in
+ * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
+ * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
+ * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
+ * The primary algorithm described there uses 11 multiplies and 29 adds.
+ * We use their alternate method with 12 multiplies and 32 adds.
+ * The advantage of this method is that no data path contains more than one
+ * multiplication; this allows a very simple and accurate implementation in
+ * scaled fixed-point arithmetic, with a minimal number of shifts.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef DCT_ISLOW_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/*
+ * The poop on this scaling stuff is as follows:
+ *
+ * Each 1-D DCT step produces outputs which are a factor of sqrt(N)
+ * larger than the true DCT outputs. The final outputs are therefore
+ * a factor of N larger than desired; since N=8 this can be cured by
+ * a simple right shift at the end of the algorithm. The advantage of
+ * this arrangement is that we save two multiplications per 1-D DCT,
+ * because the y0 and y4 outputs need not be divided by sqrt(N).
+ * In the IJG code, this factor of 8 is removed by the quantization step
+ * (in jcdctmgr.c), NOT in this module.
+ *
+ * We have to do addition and subtraction of the integer inputs, which
+ * is no problem, and multiplication by fractional constants, which is
+ * a problem to do in integer arithmetic. We multiply all the constants
+ * by CONST_SCALE and convert them to integer constants (thus retaining
+ * CONST_BITS bits of precision in the constants). After doing a
+ * multiplication we have to divide the product by CONST_SCALE, with proper
+ * rounding, to produce the correct output. This division can be done
+ * cheaply as a right shift of CONST_BITS bits. We postpone shifting
+ * as long as possible so that partial sums can be added together with
+ * full fractional precision.
+ *
+ * The outputs of the first pass are scaled up by PASS1_BITS bits so that
+ * they are represented to better-than-integral precision. These outputs
+ * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
+ * with the recommended scaling. (For 12-bit sample data, the intermediate
+ * array is INT32 anyway.)
+ *
+ * To avoid overflow of the 32-bit intermediate results in pass 2, we must
+ * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
+ * shows that the values given below are the most effective.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS 13
+#define PASS1_BITS 2
+#else
+#define CONST_BITS 13
+#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 13
+#define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
+#define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
+#define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
+#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
+#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
+#define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
+#define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
+#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
+#define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
+#define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
+#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
+#define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
+#else
+#define FIX_0_298631336 FIX(0.298631336)
+#define FIX_0_390180644 FIX(0.390180644)
+#define FIX_0_541196100 FIX(0.541196100)
+#define FIX_0_765366865 FIX(0.765366865)
+#define FIX_0_899976223 FIX(0.899976223)
+#define FIX_1_175875602 FIX(1.175875602)
+#define FIX_1_501321110 FIX(1.501321110)
+#define FIX_1_847759065 FIX(1.847759065)
+#define FIX_1_961570560 FIX(1.961570560)
+#define FIX_2_053119869 FIX(2.053119869)
+#define FIX_2_562915447 FIX(2.562915447)
+#define FIX_3_072711026 FIX(3.072711026)
+#endif
+
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * For 8-bit samples with the recommended scaling, all the variable
+ * and constant values involved are no more than 16 bits wide, so a
+ * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
+ * For 12-bit samples, a full 32-bit multiplication will be needed.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
+#else
+#define MULTIPLY(var,const) ((var) * (const))
+#endif
+
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL(void)
+jpeg_fdct_islow (DCTELEM * data)
+{
+ INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ INT32 tmp10, tmp11, tmp12, tmp13;
+ INT32 z1, z2, z3, z4, z5;
+ DCTELEM *dataptr;
+ int ctr;
+ SHIFT_TEMPS
+
+ /* Pass 1: process rows. */
+ /* Note results are scaled up by sqrt(8) compared to a true DCT; */
+ /* furthermore, we scale the results by 2**PASS1_BITS. */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[0] + dataptr[7];
+ tmp7 = dataptr[0] - dataptr[7];
+ tmp1 = dataptr[1] + dataptr[6];
+ tmp6 = dataptr[1] - dataptr[6];
+ tmp2 = dataptr[2] + dataptr[5];
+ tmp5 = dataptr[2] - dataptr[5];
+ tmp3 = dataptr[3] + dataptr[4];
+ tmp4 = dataptr[3] - dataptr[4];
+
+ /* Even part per LL&M figure 1 --- note that published figure is faulty;
+ * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ */
+
+ tmp10 = tmp0 + tmp3;
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
+ dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
+ CONST_BITS-PASS1_BITS);
+ dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
+ CONST_BITS-PASS1_BITS);
+
+ /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
+ * cK represents cos(K*pi/16).
+ * i0..i3 in the paper are tmp4..tmp7 here.
+ */
+
+ z1 = tmp4 + tmp7;
+ z2 = tmp5 + tmp6;
+ z3 = tmp4 + tmp6;
+ z4 = tmp5 + tmp7;
+ z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
+
+ tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
+ tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
+ tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
+ z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
+ z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
+ z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+
+ z3 += z5;
+ z4 += z5;
+
+ dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
+ dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
+ dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
+ dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
+
+ dataptr += DCTSIZE; /* advance pointer to next row */
+ }
+
+ /* Pass 2: process columns.
+ * We remove the PASS1_BITS scaling, but leave the results scaled up
+ * by an overall factor of 8.
+ */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
+ tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
+ tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
+ tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
+ tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
+ tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
+ tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
+ tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
+
+ /* Even part per LL&M figure 1 --- note that published figure is faulty;
+ * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ */
+
+ tmp10 = tmp0 + tmp3;
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS);
+ dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS);
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
+ CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
+ CONST_BITS+PASS1_BITS);
+
+ /* Odd part per figure 8 --- note paper omits factor of sqrt(2).
+ * cK represents cos(K*pi/16).
+ * i0..i3 in the paper are tmp4..tmp7 here.
+ */
+
+ z1 = tmp4 + tmp7;
+ z2 = tmp5 + tmp6;
+ z3 = tmp4 + tmp6;
+ z4 = tmp5 + tmp7;
+ z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
+
+ tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
+ tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
+ tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
+ z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
+ z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
+ z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+
+ z3 += z5;
+ z4 += z5;
+
+ dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp4 + z1 + z3,
+ CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp5 + z2 + z4,
+ CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp6 + z2 + z3,
+ CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp7 + z1 + z4,
+ CONST_BITS+PASS1_BITS);
+
+ dataptr++; /* advance pointer to next column */
+ }
+}
+
+#endif /* DCT_ISLOW_SUPPORTED */
--- /dev/null
+/*
+ * jidctflt.c
+ *
+ * Copyright (C) 1994-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a floating-point implementation of the
+ * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
+ * must also perform dequantization of the input coefficients.
+ *
+ * This implementation should be more accurate than either of the integer
+ * IDCT implementations. However, it may not give the same results on all
+ * machines because of differences in roundoff behavior. Speed will depend
+ * on the hardware's floating point capacity.
+ *
+ * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
+ * on each row (or vice versa, but it's more convenient to emit a row at
+ * a time). Direct algorithms are also available, but they are much more
+ * complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README). The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs. These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries. The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with a fixed-point
+ * implementation, accuracy is lost due to imprecise representation of the
+ * scaled quantization values. However, that problem does not arise if
+ * we use floating point arithmetic.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef DCT_FLOAT_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce a float result.
+ */
+
+#define DEQUANTIZE(coef,quantval) (((FAST_FLOAT) (coef)) * (quantval))
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients.
+ */
+
+GLOBAL(void)
+jpeg_idct_float (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JCOEFPTR coef_block,
+ JSAMPARRAY output_buf, JDIMENSION output_col)
+{
+ FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ FAST_FLOAT tmp10, tmp11, tmp12, tmp13;
+ FAST_FLOAT z5, z10, z11, z12, z13;
+ JCOEFPTR inptr;
+ FLOAT_MULT_TYPE * quantptr;
+ FAST_FLOAT * wsptr;
+ JSAMPROW outptr;
+ JSAMPLE *range_limit = IDCT_range_limit(cinfo);
+ int ctr;
+ FAST_FLOAT workspace[DCTSIZE2]; /* buffers data between passes */
+ SHIFT_TEMPS
+
+ /* Pass 1: process columns from input, store into work array. */
+
+ inptr = coef_block;
+ quantptr = (FLOAT_MULT_TYPE *) compptr->dct_table;
+ wsptr = workspace;
+ for (ctr = DCTSIZE; ctr > 0; ctr--) {
+ /* Due to quantization, we will usually find that many of the input
+ * coefficients are zero, especially the AC terms. We can exploit this
+ * by short-circuiting the IDCT calculation for any column in which all
+ * the AC terms are zero. In that case each output is equal to the
+ * DC coefficient (with scale factor as needed).
+ * With typical images and quantization tables, half or more of the
+ * column DCT calculations can be simplified this way.
+ */
+
+ if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
+ inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 &&
+ inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 &&
+ inptr[DCTSIZE*7] == 0) {
+ /* AC terms all zero */
+ FAST_FLOAT dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+
+ wsptr[DCTSIZE*0] = dcval;
+ wsptr[DCTSIZE*1] = dcval;
+ wsptr[DCTSIZE*2] = dcval;
+ wsptr[DCTSIZE*3] = dcval;
+ wsptr[DCTSIZE*4] = dcval;
+ wsptr[DCTSIZE*5] = dcval;
+ wsptr[DCTSIZE*6] = dcval;
+ wsptr[DCTSIZE*7] = dcval;
+
+ inptr++; /* advance pointers to next column */
+ quantptr++;
+ wsptr++;
+ continue;
+ }
+
+ /* Even part */
+
+ tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+ tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
+ tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ tmp10 = tmp0 + tmp2; /* phase 3 */
+ tmp11 = tmp0 - tmp2;
+
+ tmp13 = tmp1 + tmp3; /* phases 5-3 */
+ tmp12 = (tmp1 - tmp3) * ((FAST_FLOAT) 1.414213562) - tmp13; /* 2*c4 */
+
+ tmp0 = tmp10 + tmp13; /* phase 2 */
+ tmp3 = tmp10 - tmp13;
+ tmp1 = tmp11 + tmp12;
+ tmp2 = tmp11 - tmp12;
+
+ /* Odd part */
+
+ tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
+ tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
+ tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
+ tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
+
+ z13 = tmp6 + tmp5; /* phase 6 */
+ z10 = tmp6 - tmp5;
+ z11 = tmp4 + tmp7;
+ z12 = tmp4 - tmp7;
+
+ tmp7 = z11 + z13; /* phase 5 */
+ tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562); /* 2*c4 */
+
+ z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */
+ tmp10 = ((FAST_FLOAT) 1.082392200) * z12 - z5; /* 2*(c2-c6) */
+ tmp12 = ((FAST_FLOAT) -2.613125930) * z10 + z5; /* -2*(c2+c6) */
+
+ tmp6 = tmp12 - tmp7; /* phase 2 */
+ tmp5 = tmp11 - tmp6;
+ tmp4 = tmp10 + tmp5;
+
+ wsptr[DCTSIZE*0] = tmp0 + tmp7;
+ wsptr[DCTSIZE*7] = tmp0 - tmp7;
+ wsptr[DCTSIZE*1] = tmp1 + tmp6;
+ wsptr[DCTSIZE*6] = tmp1 - tmp6;
+ wsptr[DCTSIZE*2] = tmp2 + tmp5;
+ wsptr[DCTSIZE*5] = tmp2 - tmp5;
+ wsptr[DCTSIZE*4] = tmp3 + tmp4;
+ wsptr[DCTSIZE*3] = tmp3 - tmp4;
+
+ inptr++; /* advance pointers to next column */
+ quantptr++;
+ wsptr++;
+ }
+
+ /* Pass 2: process rows from work array, store into output array. */
+ /* Note that we must descale the results by a factor of 8 == 2**3. */
+
+ wsptr = workspace;
+ for (ctr = 0; ctr < DCTSIZE; ctr++) {
+ outptr = output_buf[ctr] + output_col;
+ /* Rows of zeroes can be exploited in the same way as we did with columns.
+ * However, the column calculation has created many nonzero AC terms, so
+ * the simplification applies less often (typically 5% to 10% of the time).
+ * And testing floats for zero is relatively expensive, so we don't bother.
+ */
+
+ /* Even part */
+
+ tmp10 = wsptr[0] + wsptr[4];
+ tmp11 = wsptr[0] - wsptr[4];
+
+ tmp13 = wsptr[2] + wsptr[6];
+ tmp12 = (wsptr[2] - wsptr[6]) * ((FAST_FLOAT) 1.414213562) - tmp13;
+
+ tmp0 = tmp10 + tmp13;
+ tmp3 = tmp10 - tmp13;
+ tmp1 = tmp11 + tmp12;
+ tmp2 = tmp11 - tmp12;
+
+ /* Odd part */
+
+ z13 = wsptr[5] + wsptr[3];
+ z10 = wsptr[5] - wsptr[3];
+ z11 = wsptr[1] + wsptr[7];
+ z12 = wsptr[1] - wsptr[7];
+
+ tmp7 = z11 + z13;
+ tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562);
+
+ z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */
+ tmp10 = ((FAST_FLOAT) 1.082392200) * z12 - z5; /* 2*(c2-c6) */
+ tmp12 = ((FAST_FLOAT) -2.613125930) * z10 + z5; /* -2*(c2+c6) */
+
+ tmp6 = tmp12 - tmp7;
+ tmp5 = tmp11 - tmp6;
+ tmp4 = tmp10 + tmp5;
+
+ /* Final output stage: scale down by a factor of 8 and range-limit */
+
+ outptr[0] = range_limit[(int) DESCALE((INT32) (tmp0 + tmp7), 3)
+ & RANGE_MASK];
+ outptr[7] = range_limit[(int) DESCALE((INT32) (tmp0 - tmp7), 3)
+ & RANGE_MASK];
+ outptr[1] = range_limit[(int) DESCALE((INT32) (tmp1 + tmp6), 3)
+ & RANGE_MASK];
+ outptr[6] = range_limit[(int) DESCALE((INT32) (tmp1 - tmp6), 3)
+ & RANGE_MASK];
+ outptr[2] = range_limit[(int) DESCALE((INT32) (tmp2 + tmp5), 3)
+ & RANGE_MASK];
+ outptr[5] = range_limit[(int) DESCALE((INT32) (tmp2 - tmp5), 3)
+ & RANGE_MASK];
+ outptr[4] = range_limit[(int) DESCALE((INT32) (tmp3 + tmp4), 3)
+ & RANGE_MASK];
+ outptr[3] = range_limit[(int) DESCALE((INT32) (tmp3 - tmp4), 3)
+ & RANGE_MASK];
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ }
+}
+
+#endif /* DCT_FLOAT_SUPPORTED */
--- /dev/null
+/*
+ * jidctfst.c
+ *
+ * Copyright (C) 1994-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a fast, not so accurate integer implementation of the
+ * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
+ * must also perform dequantization of the input coefficients.
+ *
+ * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
+ * on each row (or vice versa, but it's more convenient to emit a row at
+ * a time). Direct algorithms are also available, but they are much more
+ * complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on Arai, Agui, and Nakajima's algorithm for
+ * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in
+ * Japanese, but the algorithm is described in the Pennebaker & Mitchell
+ * JPEG textbook (see REFERENCES section in file README). The following code
+ * is based directly on figure 4-8 in P&M.
+ * While an 8-point DCT cannot be done in less than 11 multiplies, it is
+ * possible to arrange the computation so that many of the multiplies are
+ * simple scalings of the final outputs. These multiplies can then be
+ * folded into the multiplications or divisions by the JPEG quantization
+ * table entries. The AA&N method leaves only 5 multiplies and 29 adds
+ * to be done in the DCT itself.
+ * The primary disadvantage of this method is that with fixed-point math,
+ * accuracy is lost due to imprecise representation of the scaled
+ * quantization values. The smaller the quantization table entry, the less
+ * precise the scaled value, so this implementation does worse with high-
+ * quality-setting files than with low-quality ones.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef DCT_IFAST_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/* Scaling decisions are generally the same as in the LL&M algorithm;
+ * see jidctint.c for more details. However, we choose to descale
+ * (right shift) multiplication products as soon as they are formed,
+ * rather than carrying additional fractional bits into subsequent additions.
+ * This compromises accuracy slightly, but it lets us save a few shifts.
+ * More importantly, 16-bit arithmetic is then adequate (for 8-bit samples)
+ * everywhere except in the multiplications proper; this saves a good deal
+ * of work on 16-bit-int machines.
+ *
+ * The dequantized coefficients are not integers because the AA&N scaling
+ * factors have been incorporated. We represent them scaled up by PASS1_BITS,
+ * so that the first and second IDCT rounds have the same input scaling.
+ * For 8-bit JSAMPLEs, we choose IFAST_SCALE_BITS = PASS1_BITS so as to
+ * avoid a descaling shift; this compromises accuracy rather drastically
+ * for small quantization table entries, but it saves a lot of shifts.
+ * For 12-bit JSAMPLEs, there's no hope of using 16x16 multiplies anyway,
+ * so we use a much larger scaling factor to preserve accuracy.
+ *
+ * A final compromise is to represent the multiplicative constants to only
+ * 8 fractional bits, rather than 13. This saves some shifting work on some
+ * machines, and may also reduce the cost of multiplication (since there
+ * are fewer one-bits in the constants).
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS 8
+#define PASS1_BITS 2
+#else
+#define CONST_BITS 8
+#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 8
+#define FIX_1_082392200 ((INT32) 277) /* FIX(1.082392200) */
+#define FIX_1_414213562 ((INT32) 362) /* FIX(1.414213562) */
+#define FIX_1_847759065 ((INT32) 473) /* FIX(1.847759065) */
+#define FIX_2_613125930 ((INT32) 669) /* FIX(2.613125930) */
+#else
+#define FIX_1_082392200 FIX(1.082392200)
+#define FIX_1_414213562 FIX(1.414213562)
+#define FIX_1_847759065 FIX(1.847759065)
+#define FIX_2_613125930 FIX(2.613125930)
+#endif
+
+
+/* We can gain a little more speed, with a further compromise in accuracy,
+ * by omitting the addition in a descaling shift. This yields an incorrectly
+ * rounded result half the time...
+ */
+
+#ifndef USE_ACCURATE_ROUNDING
+#undef DESCALE
+#define DESCALE(x,n) RIGHT_SHIFT(x, n)
+#endif
+
+
+/* Multiply a DCTELEM variable by an INT32 constant, and immediately
+ * descale to yield a DCTELEM result.
+ */
+
+#define MULTIPLY(var,const) ((DCTELEM) DESCALE((var) * (const), CONST_BITS))
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce a DCTELEM result. For 8-bit data a 16x16->16
+ * multiplication will do. For 12-bit data, the multiplier table is
+ * declared INT32, so a 32-bit multiply will be used.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define DEQUANTIZE(coef,quantval) (((IFAST_MULT_TYPE) (coef)) * (quantval))
+#else
+#define DEQUANTIZE(coef,quantval) \
+ DESCALE((coef)*(quantval), IFAST_SCALE_BITS-PASS1_BITS)
+#endif
+
+
+/* Like DESCALE, but applies to a DCTELEM and produces an int.
+ * We assume that int right shift is unsigned if INT32 right shift is.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define ISHIFT_TEMPS DCTELEM ishift_temp;
+#if BITS_IN_JSAMPLE == 8
+#define DCTELEMBITS 16 /* DCTELEM may be 16 or 32 bits */
+#else
+#define DCTELEMBITS 32 /* DCTELEM must be 32 bits */
+#endif
+#define IRIGHT_SHIFT(x,shft) \
+ ((ishift_temp = (x)) < 0 ? \
+ (ishift_temp >> (shft)) | ((~((DCTELEM) 0)) << (DCTELEMBITS-(shft))) : \
+ (ishift_temp >> (shft)))
+#else
+#define ISHIFT_TEMPS
+#define IRIGHT_SHIFT(x,shft) ((x) >> (shft))
+#endif
+
+#ifdef USE_ACCURATE_ROUNDING
+#define IDESCALE(x,n) ((int) IRIGHT_SHIFT((x) + (1 << ((n)-1)), n))
+#else
+#define IDESCALE(x,n) ((int) IRIGHT_SHIFT(x, n))
+#endif
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients.
+ */
+
+GLOBAL(void)
+jpeg_idct_ifast (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JCOEFPTR coef_block,
+ JSAMPARRAY output_buf, JDIMENSION output_col)
+{
+ DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ DCTELEM tmp10, tmp11, tmp12, tmp13;
+ DCTELEM z5, z10, z11, z12, z13;
+ JCOEFPTR inptr;
+ IFAST_MULT_TYPE * quantptr;
+ int * wsptr;
+ JSAMPROW outptr;
+ JSAMPLE *range_limit = IDCT_range_limit(cinfo);
+ int ctr;
+ int workspace[DCTSIZE2]; /* buffers data between passes */
+ SHIFT_TEMPS /* for DESCALE */
+ ISHIFT_TEMPS /* for IDESCALE */
+
+ /* Pass 1: process columns from input, store into work array. */
+
+ inptr = coef_block;
+ quantptr = (IFAST_MULT_TYPE *) compptr->dct_table;
+ wsptr = workspace;
+ for (ctr = DCTSIZE; ctr > 0; ctr--) {
+ /* Due to quantization, we will usually find that many of the input
+ * coefficients are zero, especially the AC terms. We can exploit this
+ * by short-circuiting the IDCT calculation for any column in which all
+ * the AC terms are zero. In that case each output is equal to the
+ * DC coefficient (with scale factor as needed).
+ * With typical images and quantization tables, half or more of the
+ * column DCT calculations can be simplified this way.
+ */
+
+ if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
+ inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 &&
+ inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 &&
+ inptr[DCTSIZE*7] == 0) {
+ /* AC terms all zero */
+ int dcval = (int) DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+
+ wsptr[DCTSIZE*0] = dcval;
+ wsptr[DCTSIZE*1] = dcval;
+ wsptr[DCTSIZE*2] = dcval;
+ wsptr[DCTSIZE*3] = dcval;
+ wsptr[DCTSIZE*4] = dcval;
+ wsptr[DCTSIZE*5] = dcval;
+ wsptr[DCTSIZE*6] = dcval;
+ wsptr[DCTSIZE*7] = dcval;
+
+ inptr++; /* advance pointers to next column */
+ quantptr++;
+ wsptr++;
+ continue;
+ }
+
+ /* Even part */
+
+ tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+ tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
+ tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ tmp10 = tmp0 + tmp2; /* phase 3 */
+ tmp11 = tmp0 - tmp2;
+
+ tmp13 = tmp1 + tmp3; /* phases 5-3 */
+ tmp12 = MULTIPLY(tmp1 - tmp3, FIX_1_414213562) - tmp13; /* 2*c4 */
+
+ tmp0 = tmp10 + tmp13; /* phase 2 */
+ tmp3 = tmp10 - tmp13;
+ tmp1 = tmp11 + tmp12;
+ tmp2 = tmp11 - tmp12;
+
+ /* Odd part */
+
+ tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
+ tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
+ tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
+ tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
+
+ z13 = tmp6 + tmp5; /* phase 6 */
+ z10 = tmp6 - tmp5;
+ z11 = tmp4 + tmp7;
+ z12 = tmp4 - tmp7;
+
+ tmp7 = z11 + z13; /* phase 5 */
+ tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562); /* 2*c4 */
+
+ z5 = MULTIPLY(z10 + z12, FIX_1_847759065); /* 2*c2 */
+ tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5; /* 2*(c2-c6) */
+ tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5; /* -2*(c2+c6) */
+
+ tmp6 = tmp12 - tmp7; /* phase 2 */
+ tmp5 = tmp11 - tmp6;
+ tmp4 = tmp10 + tmp5;
+
+ wsptr[DCTSIZE*0] = (int) (tmp0 + tmp7);
+ wsptr[DCTSIZE*7] = (int) (tmp0 - tmp7);
+ wsptr[DCTSIZE*1] = (int) (tmp1 + tmp6);
+ wsptr[DCTSIZE*6] = (int) (tmp1 - tmp6);
+ wsptr[DCTSIZE*2] = (int) (tmp2 + tmp5);
+ wsptr[DCTSIZE*5] = (int) (tmp2 - tmp5);
+ wsptr[DCTSIZE*4] = (int) (tmp3 + tmp4);
+ wsptr[DCTSIZE*3] = (int) (tmp3 - tmp4);
+
+ inptr++; /* advance pointers to next column */
+ quantptr++;
+ wsptr++;
+ }
+
+ /* Pass 2: process rows from work array, store into output array. */
+ /* Note that we must descale the results by a factor of 8 == 2**3, */
+ /* and also undo the PASS1_BITS scaling. */
+
+ wsptr = workspace;
+ for (ctr = 0; ctr < DCTSIZE; ctr++) {
+ outptr = output_buf[ctr] + output_col;
+ /* Rows of zeroes can be exploited in the same way as we did with columns.
+ * However, the column calculation has created many nonzero AC terms, so
+ * the simplification applies less often (typically 5% to 10% of the time).
+ * On machines with very fast multiplication, it's possible that the
+ * test takes more time than it's worth. In that case this section
+ * may be commented out.
+ */
+
+#ifndef NO_ZERO_ROW_TEST
+ if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 &&
+ wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
+ /* AC terms all zero */
+ JSAMPLE dcval = range_limit[IDESCALE(wsptr[0], PASS1_BITS+3)
+ & RANGE_MASK];
+
+ outptr[0] = dcval;
+ outptr[1] = dcval;
+ outptr[2] = dcval;
+ outptr[3] = dcval;
+ outptr[4] = dcval;
+ outptr[5] = dcval;
+ outptr[6] = dcval;
+ outptr[7] = dcval;
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ continue;
+ }
+#endif
+
+ /* Even part */
+
+ tmp10 = ((DCTELEM) wsptr[0] + (DCTELEM) wsptr[4]);
+ tmp11 = ((DCTELEM) wsptr[0] - (DCTELEM) wsptr[4]);
+
+ tmp13 = ((DCTELEM) wsptr[2] + (DCTELEM) wsptr[6]);
+ tmp12 = MULTIPLY((DCTELEM) wsptr[2] - (DCTELEM) wsptr[6], FIX_1_414213562)
+ - tmp13;
+
+ tmp0 = tmp10 + tmp13;
+ tmp3 = tmp10 - tmp13;
+ tmp1 = tmp11 + tmp12;
+ tmp2 = tmp11 - tmp12;
+
+ /* Odd part */
+
+ z13 = (DCTELEM) wsptr[5] + (DCTELEM) wsptr[3];
+ z10 = (DCTELEM) wsptr[5] - (DCTELEM) wsptr[3];
+ z11 = (DCTELEM) wsptr[1] + (DCTELEM) wsptr[7];
+ z12 = (DCTELEM) wsptr[1] - (DCTELEM) wsptr[7];
+
+ tmp7 = z11 + z13; /* phase 5 */
+ tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562); /* 2*c4 */
+
+ z5 = MULTIPLY(z10 + z12, FIX_1_847759065); /* 2*c2 */
+ tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5; /* 2*(c2-c6) */
+ tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5; /* -2*(c2+c6) */
+
+ tmp6 = tmp12 - tmp7; /* phase 2 */
+ tmp5 = tmp11 - tmp6;
+ tmp4 = tmp10 + tmp5;
+
+ /* Final output stage: scale down by a factor of 8 and range-limit */
+
+ outptr[0] = range_limit[IDESCALE(tmp0 + tmp7, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[7] = range_limit[IDESCALE(tmp0 - tmp7, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[1] = range_limit[IDESCALE(tmp1 + tmp6, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[6] = range_limit[IDESCALE(tmp1 - tmp6, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[2] = range_limit[IDESCALE(tmp2 + tmp5, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[5] = range_limit[IDESCALE(tmp2 - tmp5, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[4] = range_limit[IDESCALE(tmp3 + tmp4, PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[3] = range_limit[IDESCALE(tmp3 - tmp4, PASS1_BITS+3)
+ & RANGE_MASK];
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ }
+}
+
+#endif /* DCT_IFAST_SUPPORTED */
--- /dev/null
+/*
+ * jidctint.c
+ *
+ * Copyright (C) 1991-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains a slow-but-accurate integer implementation of the
+ * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
+ * must also perform dequantization of the input coefficients.
+ *
+ * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
+ * on each row (or vice versa, but it's more convenient to emit a row at
+ * a time). Direct algorithms are also available, but they are much more
+ * complex and seem not to be any faster when reduced to code.
+ *
+ * This implementation is based on an algorithm described in
+ * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT
+ * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics,
+ * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991.
+ * The primary algorithm described there uses 11 multiplies and 29 adds.
+ * We use their alternate method with 12 multiplies and 32 adds.
+ * The advantage of this method is that no data path contains more than one
+ * multiplication; this allows a very simple and accurate implementation in
+ * scaled fixed-point arithmetic, with a minimal number of shifts.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef DCT_ISLOW_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/*
+ * The poop on this scaling stuff is as follows:
+ *
+ * Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
+ * larger than the true IDCT outputs. The final outputs are therefore
+ * a factor of N larger than desired; since N=8 this can be cured by
+ * a simple right shift at the end of the algorithm. The advantage of
+ * this arrangement is that we save two multiplications per 1-D IDCT,
+ * because the y0 and y4 inputs need not be divided by sqrt(N).
+ *
+ * We have to do addition and subtraction of the integer inputs, which
+ * is no problem, and multiplication by fractional constants, which is
+ * a problem to do in integer arithmetic. We multiply all the constants
+ * by CONST_SCALE and convert them to integer constants (thus retaining
+ * CONST_BITS bits of precision in the constants). After doing a
+ * multiplication we have to divide the product by CONST_SCALE, with proper
+ * rounding, to produce the correct output. This division can be done
+ * cheaply as a right shift of CONST_BITS bits. We postpone shifting
+ * as long as possible so that partial sums can be added together with
+ * full fractional precision.
+ *
+ * The outputs of the first pass are scaled up by PASS1_BITS bits so that
+ * they are represented to better-than-integral precision. These outputs
+ * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
+ * with the recommended scaling. (To scale up 12-bit sample data further, an
+ * intermediate INT32 array would be needed.)
+ *
+ * To avoid overflow of the 32-bit intermediate results in pass 2, we must
+ * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
+ * shows that the values given below are the most effective.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS 13
+#define PASS1_BITS 2
+#else
+#define CONST_BITS 13
+#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 13
+#define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
+#define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
+#define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
+#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
+#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
+#define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
+#define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
+#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
+#define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
+#define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
+#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
+#define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
+#else
+#define FIX_0_298631336 FIX(0.298631336)
+#define FIX_0_390180644 FIX(0.390180644)
+#define FIX_0_541196100 FIX(0.541196100)
+#define FIX_0_765366865 FIX(0.765366865)
+#define FIX_0_899976223 FIX(0.899976223)
+#define FIX_1_175875602 FIX(1.175875602)
+#define FIX_1_501321110 FIX(1.501321110)
+#define FIX_1_847759065 FIX(1.847759065)
+#define FIX_1_961570560 FIX(1.961570560)
+#define FIX_2_053119869 FIX(2.053119869)
+#define FIX_2_562915447 FIX(2.562915447)
+#define FIX_3_072711026 FIX(3.072711026)
+#endif
+
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * For 8-bit samples with the recommended scaling, all the variable
+ * and constant values involved are no more than 16 bits wide, so a
+ * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
+ * For 12-bit samples, a full 32-bit multiplication will be needed.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
+#else
+#define MULTIPLY(var,const) ((var) * (const))
+#endif
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce an int result. In this module, both inputs and result
+ * are 16 bits or less, so either int or short multiply will work.
+ */
+
+#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients.
+ */
+
+GLOBAL(void)
+jpeg_idct_islow (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JCOEFPTR coef_block,
+ JSAMPARRAY output_buf, JDIMENSION output_col)
+{
+ INT32 tmp0, tmp1, tmp2, tmp3;
+ INT32 tmp10, tmp11, tmp12, tmp13;
+ INT32 z1, z2, z3, z4, z5;
+ JCOEFPTR inptr;
+ ISLOW_MULT_TYPE * quantptr;
+ int * wsptr;
+ JSAMPROW outptr;
+ JSAMPLE *range_limit = IDCT_range_limit(cinfo);
+ int ctr;
+ int workspace[DCTSIZE2]; /* buffers data between passes */
+ SHIFT_TEMPS
+
+ /* Pass 1: process columns from input, store into work array. */
+ /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
+ /* furthermore, we scale the results by 2**PASS1_BITS. */
+
+ inptr = coef_block;
+ quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+ wsptr = workspace;
+ for (ctr = DCTSIZE; ctr > 0; ctr--) {
+ /* Due to quantization, we will usually find that many of the input
+ * coefficients are zero, especially the AC terms. We can exploit this
+ * by short-circuiting the IDCT calculation for any column in which all
+ * the AC terms are zero. In that case each output is equal to the
+ * DC coefficient (with scale factor as needed).
+ * With typical images and quantization tables, half or more of the
+ * column DCT calculations can be simplified this way.
+ */
+
+ if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
+ inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 &&
+ inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 &&
+ inptr[DCTSIZE*7] == 0) {
+ /* AC terms all zero */
+ int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
+
+ wsptr[DCTSIZE*0] = dcval;
+ wsptr[DCTSIZE*1] = dcval;
+ wsptr[DCTSIZE*2] = dcval;
+ wsptr[DCTSIZE*3] = dcval;
+ wsptr[DCTSIZE*4] = dcval;
+ wsptr[DCTSIZE*5] = dcval;
+ wsptr[DCTSIZE*6] = dcval;
+ wsptr[DCTSIZE*7] = dcval;
+
+ inptr++; /* advance pointers to next column */
+ quantptr++;
+ wsptr++;
+ continue;
+ }
+
+ /* Even part: reverse the even part of the forward DCT. */
+ /* The rotator is sqrt(2)*c(-6). */
+
+ z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
+ tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
+ tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
+
+ z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
+
+ tmp0 = (z2 + z3) << CONST_BITS;
+ tmp1 = (z2 - z3) << CONST_BITS;
+
+ tmp10 = tmp0 + tmp3;
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ /* Odd part per figure 8; the matrix is unitary and hence its
+ * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
+ */
+
+ tmp0 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
+ tmp1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
+ tmp2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
+ tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
+
+ z1 = tmp0 + tmp3;
+ z2 = tmp1 + tmp2;
+ z3 = tmp0 + tmp2;
+ z4 = tmp1 + tmp3;
+ z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
+
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
+ z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
+ z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
+ z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+
+ z3 += z5;
+ z4 += z5;
+
+ tmp0 += z1 + z3;
+ tmp1 += z2 + z4;
+ tmp2 += z2 + z3;
+ tmp3 += z1 + z4;
+
+ /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
+
+ wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*7] = (int) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*1] = (int) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*6] = (int) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*5] = (int) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*3] = (int) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
+ wsptr[DCTSIZE*4] = (int) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
+
+ inptr++; /* advance pointers to next column */
+ quantptr++;
+ wsptr++;
+ }
+
+ /* Pass 2: process rows from work array, store into output array. */
+ /* Note that we must descale the results by a factor of 8 == 2**3, */
+ /* and also undo the PASS1_BITS scaling. */
+
+ wsptr = workspace;
+ for (ctr = 0; ctr < DCTSIZE; ctr++) {
+ outptr = output_buf[ctr] + output_col;
+ /* Rows of zeroes can be exploited in the same way as we did with columns.
+ * However, the column calculation has created many nonzero AC terms, so
+ * the simplification applies less often (typically 5% to 10% of the time).
+ * On machines with very fast multiplication, it's possible that the
+ * test takes more time than it's worth. In that case this section
+ * may be commented out.
+ */
+
+#ifndef NO_ZERO_ROW_TEST
+ if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 &&
+ wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
+ /* AC terms all zero */
+ JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
+ & RANGE_MASK];
+
+ outptr[0] = dcval;
+ outptr[1] = dcval;
+ outptr[2] = dcval;
+ outptr[3] = dcval;
+ outptr[4] = dcval;
+ outptr[5] = dcval;
+ outptr[6] = dcval;
+ outptr[7] = dcval;
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ continue;
+ }
+#endif
+
+ /* Even part: reverse the even part of the forward DCT. */
+ /* The rotator is sqrt(2)*c(-6). */
+
+ z2 = (INT32) wsptr[2];
+ z3 = (INT32) wsptr[6];
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
+ tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
+ tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
+
+ tmp0 = ((INT32) wsptr[0] + (INT32) wsptr[4]) << CONST_BITS;
+ tmp1 = ((INT32) wsptr[0] - (INT32) wsptr[4]) << CONST_BITS;
+
+ tmp10 = tmp0 + tmp3;
+ tmp13 = tmp0 - tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+
+ /* Odd part per figure 8; the matrix is unitary and hence its
+ * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
+ */
+
+ tmp0 = (INT32) wsptr[7];
+ tmp1 = (INT32) wsptr[5];
+ tmp2 = (INT32) wsptr[3];
+ tmp3 = (INT32) wsptr[1];
+
+ z1 = tmp0 + tmp3;
+ z2 = tmp1 + tmp2;
+ z3 = tmp0 + tmp2;
+ z4 = tmp1 + tmp3;
+ z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
+
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
+ z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
+ z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
+ z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+
+ z3 += z5;
+ z4 += z5;
+
+ tmp0 += z1 + z3;
+ tmp1 += z2 + z4;
+ tmp2 += z2 + z3;
+ tmp3 += z1 + z4;
+
+ /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
+
+ outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp3,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[7] = range_limit[(int) DESCALE(tmp10 - tmp3,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[1] = range_limit[(int) DESCALE(tmp11 + tmp2,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[6] = range_limit[(int) DESCALE(tmp11 - tmp2,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[2] = range_limit[(int) DESCALE(tmp12 + tmp1,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[5] = range_limit[(int) DESCALE(tmp12 - tmp1,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[3] = range_limit[(int) DESCALE(tmp13 + tmp0,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+ outptr[4] = range_limit[(int) DESCALE(tmp13 - tmp0,
+ CONST_BITS+PASS1_BITS+3)
+ & RANGE_MASK];
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ }
+}
+
+#endif /* DCT_ISLOW_SUPPORTED */
--- /dev/null
+/*
+ * jidctred.c
+ *
+ * Copyright (C) 1994-1998, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains inverse-DCT routines that produce reduced-size output:
+ * either 4x4, 2x2, or 1x1 pixels from an 8x8 DCT block.
+ *
+ * The implementation is based on the Loeffler, Ligtenberg and Moschytz (LL&M)
+ * algorithm used in jidctint.c. We simply replace each 8-to-8 1-D IDCT step
+ * with an 8-to-4 step that produces the four averages of two adjacent outputs
+ * (or an 8-to-2 step producing two averages of four outputs, for 2x2 output).
+ * These steps were derived by computing the corresponding values at the end
+ * of the normal LL&M code, then simplifying as much as possible.
+ *
+ * 1x1 is trivial: just take the DC coefficient divided by 8.
+ *
+ * See jidctint.c for additional comments.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jdct12.h" /* Private declarations for DCT subsystem */
+
+#ifdef IDCT_SCALING_SUPPORTED
+
+
+/*
+ * This module is specialized to the case DCTSIZE = 8.
+ */
+
+#if DCTSIZE != 8
+ Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+#endif
+
+
+/* Scaling is the same as in jidctint.c. */
+
+#if BITS_IN_JSAMPLE == 8
+#define CONST_BITS 13
+#define PASS1_BITS 2
+#else
+#define CONST_BITS 13
+#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
+#endif
+
+/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
+ * causing a lot of useless floating-point operations at run time.
+ * To get around this we use the following pre-calculated constants.
+ * If you change CONST_BITS you may want to add appropriate values.
+ * (With a reasonable C compiler, you can just rely on the FIX() macro...)
+ */
+
+#if CONST_BITS == 13
+#define FIX_0_211164243 ((INT32) 1730) /* FIX(0.211164243) */
+#define FIX_0_509795579 ((INT32) 4176) /* FIX(0.509795579) */
+#define FIX_0_601344887 ((INT32) 4926) /* FIX(0.601344887) */
+#define FIX_0_720959822 ((INT32) 5906) /* FIX(0.720959822) */
+#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
+#define FIX_0_850430095 ((INT32) 6967) /* FIX(0.850430095) */
+#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
+#define FIX_1_061594337 ((INT32) 8697) /* FIX(1.061594337) */
+#define FIX_1_272758580 ((INT32) 10426) /* FIX(1.272758580) */
+#define FIX_1_451774981 ((INT32) 11893) /* FIX(1.451774981) */
+#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
+#define FIX_2_172734803 ((INT32) 17799) /* FIX(2.172734803) */
+#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
+#define FIX_3_624509785 ((INT32) 29692) /* FIX(3.624509785) */
+#else
+#define FIX_0_211164243 FIX(0.211164243)
+#define FIX_0_509795579 FIX(0.509795579)
+#define FIX_0_601344887 FIX(0.601344887)
+#define FIX_0_720959822 FIX(0.720959822)
+#define FIX_0_765366865 FIX(0.765366865)
+#define FIX_0_850430095 FIX(0.850430095)
+#define FIX_0_899976223 FIX(0.899976223)
+#define FIX_1_061594337 FIX(1.061594337)
+#define FIX_1_272758580 FIX(1.272758580)
+#define FIX_1_451774981 FIX(1.451774981)
+#define FIX_1_847759065 FIX(1.847759065)
+#define FIX_2_172734803 FIX(2.172734803)
+#define FIX_2_562915447 FIX(2.562915447)
+#define FIX_3_624509785 FIX(3.624509785)
+#endif
+
+
+/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+ * For 8-bit samples with the recommended scaling, all the variable
+ * and constant values involved are no more than 16 bits wide, so a
+ * 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
+ * For 12-bit samples, a full 32-bit multiplication will be needed.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
+#else
+#define MULTIPLY(var,const) ((var) * (const))
+#endif
+
+
+/* Dequantize a coefficient by multiplying it by the multiplier-table
+ * entry; produce an int result. In this module, both inputs and result
+ * are 16 bits or less, so either int or short multiply will work.
+ */
+
+#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients,
+ * producing a reduced-size 4x4 output block.
+ */
+
+GLOBAL(void)
+jpeg_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JCOEFPTR coef_block,
+ JSAMPARRAY output_buf, JDIMENSION output_col)
+{
+ INT32 tmp0, tmp2, tmp10, tmp12;
+ INT32 z1, z2, z3, z4;
+ JCOEFPTR inptr;
+ ISLOW_MULT_TYPE * quantptr;
+ int * wsptr;
+ JSAMPROW outptr;
+ JSAMPLE *range_limit = IDCT_range_limit(cinfo);
+ int ctr;
+ int workspace[DCTSIZE*4]; /* buffers data between passes */
+ SHIFT_TEMPS
+
+ /* Pass 1: process columns from input, store into work array. */
+
+ inptr = coef_block;
+ quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+ wsptr = workspace;
+ for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) {
+ /* Don't bother to process column 4, because second pass won't use it */
+ if (ctr == DCTSIZE-4)
+ continue;
+ if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 &&
+ inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*5] == 0 &&
+ inptr[DCTSIZE*6] == 0 && inptr[DCTSIZE*7] == 0) {
+ /* AC terms all zero; we need not examine term 4 for 4x4 output */
+ int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
+
+ wsptr[DCTSIZE*0] = dcval;
+ wsptr[DCTSIZE*1] = dcval;
+ wsptr[DCTSIZE*2] = dcval;
+ wsptr[DCTSIZE*3] = dcval;
+
+ continue;
+ }
+
+ /* Even part */
+
+ tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+ tmp0 <<= (CONST_BITS+1);
+
+ z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ tmp2 = MULTIPLY(z2, FIX_1_847759065) + MULTIPLY(z3, - FIX_0_765366865);
+
+ tmp10 = tmp0 + tmp2;
+ tmp12 = tmp0 - tmp2;
+
+ /* Odd part */
+
+ z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
+ z2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
+ z4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
+
+ tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */
+ + MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */
+ + MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */
+ + MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */
+
+ tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */
+ + MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */
+ + MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */
+ + MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */
+
+ /* Final output stage */
+
+ wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp2, CONST_BITS-PASS1_BITS+1);
+ wsptr[DCTSIZE*3] = (int) DESCALE(tmp10 - tmp2, CONST_BITS-PASS1_BITS+1);
+ wsptr[DCTSIZE*1] = (int) DESCALE(tmp12 + tmp0, CONST_BITS-PASS1_BITS+1);
+ wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 - tmp0, CONST_BITS-PASS1_BITS+1);
+ }
+
+ /* Pass 2: process 4 rows from work array, store into output array. */
+
+ wsptr = workspace;
+ for (ctr = 0; ctr < 4; ctr++) {
+ outptr = output_buf[ctr] + output_col;
+ /* It's not clear whether a zero row test is worthwhile here ... */
+
+#ifndef NO_ZERO_ROW_TEST
+ if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 &&
+ wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
+ /* AC terms all zero */
+ JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
+ & RANGE_MASK];
+
+ outptr[0] = dcval;
+ outptr[1] = dcval;
+ outptr[2] = dcval;
+ outptr[3] = dcval;
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ continue;
+ }
+#endif
+
+ /* Even part */
+
+ tmp0 = ((INT32) wsptr[0]) << (CONST_BITS+1);
+
+ tmp2 = MULTIPLY((INT32) wsptr[2], FIX_1_847759065)
+ + MULTIPLY((INT32) wsptr[6], - FIX_0_765366865);
+
+ tmp10 = tmp0 + tmp2;
+ tmp12 = tmp0 - tmp2;
+
+ /* Odd part */
+
+ z1 = (INT32) wsptr[7];
+ z2 = (INT32) wsptr[5];
+ z3 = (INT32) wsptr[3];
+ z4 = (INT32) wsptr[1];
+
+ tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */
+ + MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */
+ + MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */
+ + MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */
+
+ tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */
+ + MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */
+ + MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */
+ + MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */
+
+ /* Final output stage */
+
+ outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp2,
+ CONST_BITS+PASS1_BITS+3+1)
+ & RANGE_MASK];
+ outptr[3] = range_limit[(int) DESCALE(tmp10 - tmp2,
+ CONST_BITS+PASS1_BITS+3+1)
+ & RANGE_MASK];
+ outptr[1] = range_limit[(int) DESCALE(tmp12 + tmp0,
+ CONST_BITS+PASS1_BITS+3+1)
+ & RANGE_MASK];
+ outptr[2] = range_limit[(int) DESCALE(tmp12 - tmp0,
+ CONST_BITS+PASS1_BITS+3+1)
+ & RANGE_MASK];
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ }
+}
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients,
+ * producing a reduced-size 2x2 output block.
+ */
+
+GLOBAL(void)
+jpeg_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JCOEFPTR coef_block,
+ JSAMPARRAY output_buf, JDIMENSION output_col)
+{
+ INT32 tmp0, tmp10, z1;
+ JCOEFPTR inptr;
+ ISLOW_MULT_TYPE * quantptr;
+ int * wsptr;
+ JSAMPROW outptr;
+ JSAMPLE *range_limit = IDCT_range_limit(cinfo);
+ int ctr;
+ int workspace[DCTSIZE*2]; /* buffers data between passes */
+ SHIFT_TEMPS
+
+ /* Pass 1: process columns from input, store into work array. */
+
+ inptr = coef_block;
+ quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+ wsptr = workspace;
+ for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) {
+ /* Don't bother to process columns 2,4,6 */
+ if (ctr == DCTSIZE-2 || ctr == DCTSIZE-4 || ctr == DCTSIZE-6)
+ continue;
+ if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*3] == 0 &&
+ inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*7] == 0) {
+ /* AC terms all zero; we need not examine terms 2,4,6 for 2x2 output */
+ int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
+
+ wsptr[DCTSIZE*0] = dcval;
+ wsptr[DCTSIZE*1] = dcval;
+
+ continue;
+ }
+
+ /* Even part */
+
+ z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
+ tmp10 = z1 << (CONST_BITS+2);
+
+ /* Odd part */
+
+ z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
+ tmp0 = MULTIPLY(z1, - FIX_0_720959822); /* sqrt(2) * (c7-c5+c3-c1) */
+ z1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
+ tmp0 += MULTIPLY(z1, FIX_0_850430095); /* sqrt(2) * (-c1+c3+c5+c7) */
+ z1 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
+ tmp0 += MULTIPLY(z1, - FIX_1_272758580); /* sqrt(2) * (-c1+c3-c5-c7) */
+ z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
+ tmp0 += MULTIPLY(z1, FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */
+
+ /* Final output stage */
+
+ wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp0, CONST_BITS-PASS1_BITS+2);
+ wsptr[DCTSIZE*1] = (int) DESCALE(tmp10 - tmp0, CONST_BITS-PASS1_BITS+2);
+ }
+
+ /* Pass 2: process 2 rows from work array, store into output array. */
+
+ wsptr = workspace;
+ for (ctr = 0; ctr < 2; ctr++) {
+ outptr = output_buf[ctr] + output_col;
+ /* It's not clear whether a zero row test is worthwhile here ... */
+
+#ifndef NO_ZERO_ROW_TEST
+ if (wsptr[1] == 0 && wsptr[3] == 0 && wsptr[5] == 0 && wsptr[7] == 0) {
+ /* AC terms all zero */
+ JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
+ & RANGE_MASK];
+
+ outptr[0] = dcval;
+ outptr[1] = dcval;
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ continue;
+ }
+#endif
+
+ /* Even part */
+
+ tmp10 = ((INT32) wsptr[0]) << (CONST_BITS+2);
+
+ /* Odd part */
+
+ tmp0 = MULTIPLY((INT32) wsptr[7], - FIX_0_720959822) /* sqrt(2) * (c7-c5+c3-c1) */
+ + MULTIPLY((INT32) wsptr[5], FIX_0_850430095) /* sqrt(2) * (-c1+c3+c5+c7) */
+ + MULTIPLY((INT32) wsptr[3], - FIX_1_272758580) /* sqrt(2) * (-c1+c3-c5-c7) */
+ + MULTIPLY((INT32) wsptr[1], FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */
+
+ /* Final output stage */
+
+ outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp0,
+ CONST_BITS+PASS1_BITS+3+2)
+ & RANGE_MASK];
+ outptr[1] = range_limit[(int) DESCALE(tmp10 - tmp0,
+ CONST_BITS+PASS1_BITS+3+2)
+ & RANGE_MASK];
+
+ wsptr += DCTSIZE; /* advance pointer to next row */
+ }
+}
+
+
+/*
+ * Perform dequantization and inverse DCT on one block of coefficients,
+ * producing a reduced-size 1x1 output block.
+ */
+
+GLOBAL(void)
+jpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
+ JCOEFPTR coef_block,
+ JSAMPARRAY output_buf, JDIMENSION output_col)
+{
+ int dcval;
+ ISLOW_MULT_TYPE * quantptr;
+ JSAMPLE *range_limit = IDCT_range_limit(cinfo);
+ SHIFT_TEMPS
+
+ /* We hardly need an inverse DCT routine for this: just take the
+ * average pixel value, which is one-eighth of the DC coefficient.
+ */
+ quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+ dcval = DEQUANTIZE(coef_block[0], quantptr[0]);
+ dcval = (int) DESCALE((INT32) dcval, 3);
+
+ output_buf[0][output_col] = range_limit[dcval & RANGE_MASK];
+}
+
+#endif /* IDCT_SCALING_SUPPORTED */
--- /dev/null
+/*
+ * jmemansi.c
+ *
+ * Copyright (C) 1992-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides a simple generic implementation of the system-
+ * dependent portion of the JPEG memory manager. This implementation
+ * assumes that you have the ANSI-standard library routine tmpfile().
+ * Also, the problem of determining the amount of memory available
+ * is shoved onto the user.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jmemsys12.h" /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP((size_t size));
+extern void free JPP((void *ptr));
+#endif
+
+#ifndef SEEK_SET /* pre-ANSI systems may not define this; */
+#define SEEK_SET 0 /* if not, assume 0 is correct */
+#endif
+
+
+/*
+ * Memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL(void *)
+jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL(void FAR *)
+jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void FAR *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM /* so can override from makefile */
+#define DEFAULT_MAX_MEM 1000000L /* default: one megabyte */
+#endif
+
+GLOBAL(long)
+jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
+ long max_bytes_needed, long already_allocated)
+{
+ return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed. You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+
+METHODDEF(void)
+read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ if (fseek(info->temp_file, file_offset, SEEK_SET))
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+ if (JFREAD(info->temp_file, buffer_address, byte_count)
+ != (size_t) byte_count)
+ ERREXIT(cinfo, JERR_TFILE_READ);
+}
+
+
+METHODDEF(void)
+write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ if (fseek(info->temp_file, file_offset, SEEK_SET))
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+ if (JFWRITE(info->temp_file, buffer_address, byte_count)
+ != (size_t) byte_count)
+ ERREXIT(cinfo, JERR_TFILE_WRITE);
+}
+
+
+METHODDEF(void)
+close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+ fclose(info->temp_file);
+ /* Since this implementation uses tmpfile() to create the file,
+ * no explicit file deletion is needed.
+ */
+}
+
+
+/*
+ * Initial opening of a backing-store object.
+ *
+ * This version uses tmpfile(), which constructs a suitable file name
+ * behind the scenes. We don't have to use info->temp_name[] at all;
+ * indeed, we can't even find out the actual name of the temp file.
+ */
+
+GLOBAL(void)
+jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ if ((info->temp_file = tmpfile()) == NULL)
+ ERREXITS(cinfo, JERR_TFILE_CREATE, "");
+ info->read_backing_store = read_backing_store;
+ info->write_backing_store = write_backing_store;
+ info->close_backing_store = close_backing_store;
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL(long)
+jpeg_mem_init (j_common_ptr cinfo)
+{
+ return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
+}
+
+GLOBAL(void)
+jpeg_mem_term (j_common_ptr cinfo)
+{
+ /* no work */
+}
--- /dev/null
+/*
+ * jmemdos.c
+ *
+ * Copyright (C) 1992-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides an MS-DOS-compatible implementation of the system-
+ * dependent portion of the JPEG memory manager. Temporary data can be
+ * stored in extended or expanded memory as well as in regular DOS files.
+ *
+ * If you use this file, you must be sure that NEED_FAR_POINTERS is defined
+ * if you compile in a small-data memory model; it should NOT be defined if
+ * you use a large-data memory model. This file is not recommended if you
+ * are using a flat-memory-space 386 environment such as DJGCC or Watcom C.
+ * Also, this code will NOT work if struct fields are aligned on greater than
+ * 2-byte boundaries.
+ *
+ * Based on code contributed by Ge' Weijers.
+ */
+
+/*
+ * If you have both extended and expanded memory, you may want to change the
+ * order in which they are tried in jopen_backing_store. On a 286 machine
+ * expanded memory is usually faster, since extended memory access involves
+ * an expensive protected-mode-and-back switch. On 386 and better, extended
+ * memory is usually faster. As distributed, the code tries extended memory
+ * first (what? not everyone has a 386? :-).
+ *
+ * You can disable use of extended/expanded memory entirely by altering these
+ * definitions or overriding them from the Makefile (eg, -DEMS_SUPPORTED=0).
+ */
+
+#ifndef XMS_SUPPORTED
+#define XMS_SUPPORTED 1
+#endif
+#ifndef EMS_SUPPORTED
+#define EMS_SUPPORTED 1
+#endif
+
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jmemsys12.h" /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare these */
+extern void * malloc JPP((size_t size));
+extern void free JPP((void *ptr));
+extern char * getenv JPP((const char * name));
+#endif
+
+#ifdef NEED_FAR_POINTERS
+
+#ifdef __TURBOC__
+/* These definitions work for Borland C (Turbo C) */
+#include <alloc.h> /* need farmalloc(), farfree() */
+#define far_malloc(x) farmalloc(x)
+#define far_free(x) farfree(x)
+#else
+/* These definitions work for Microsoft C and compatible compilers */
+#include <malloc.h> /* need _fmalloc(), _ffree() */
+#define far_malloc(x) _fmalloc(x)
+#define far_free(x) _ffree(x)
+#endif
+
+#else /* not NEED_FAR_POINTERS */
+
+#define far_malloc(x) malloc(x)
+#define far_free(x) free(x)
+
+#endif /* NEED_FAR_POINTERS */
+
+#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
+#define READ_BINARY "r"
+#else
+#define READ_BINARY "rb"
+#endif
+
+#ifndef USE_MSDOS_MEMMGR /* make sure user got configuration right */
+ You forgot to define USE_MSDOS_MEMMGR in jconfig.h. /* deliberate syntax error */
+#endif
+
+#if MAX_ALLOC_CHUNK >= 65535L /* make sure jconfig.h got this right */
+ MAX_ALLOC_CHUNK should be less than 64K. /* deliberate syntax error */
+#endif
+
+
+/*
+ * Declarations for assembly-language support routines (see jmemdosa.asm).
+ *
+ * The functions are declared "far" as are all their pointer arguments;
+ * this ensures the assembly source code will work regardless of the
+ * compiler memory model. We assume "short" is 16 bits, "long" is 32.
+ */
+
+typedef void far * XMSDRIVER; /* actually a pointer to code */
+typedef struct { /* registers for calling XMS driver */
+ unsigned short ax, dx, bx;
+ void far * ds_si;
+ } XMScontext;
+typedef struct { /* registers for calling EMS driver */
+ unsigned short ax, dx, bx;
+ void far * ds_si;
+ } EMScontext;
+
+extern short far jdos_open JPP((short far * handle, char far * filename));
+extern short far jdos_close JPP((short handle));
+extern short far jdos_seek JPP((short handle, long offset));
+extern short far jdos_read JPP((short handle, void far * buffer,
+ unsigned short count));
+extern short far jdos_write JPP((short handle, void far * buffer,
+ unsigned short count));
+extern void far jxms_getdriver JPP((XMSDRIVER far *));
+extern void far jxms_calldriver JPP((XMSDRIVER, XMScontext far *));
+extern short far jems_available JPP((void));
+extern void far jems_calldriver JPP((EMScontext far *));
+
+
+/*
+ * Selection of a file name for a temporary file.
+ * This is highly system-dependent, and you may want to customize it.
+ */
+
+static int next_file_num; /* to distinguish among several temp files */
+
+LOCAL(void)
+select_file_name (char * fname)
+{
+ const char * env;
+ char * ptr;
+ FILE * tfile;
+
+ /* Keep generating file names till we find one that's not in use */
+ for (;;) {
+ /* Get temp directory name from environment TMP or TEMP variable;
+ * if none, use "."
+ */
+ if ((env = (const char *) getenv("TMP")) == NULL)
+ if ((env = (const char *) getenv("TEMP")) == NULL)
+ env = ".";
+ if (*env == '\0') /* null string means "." */
+ env = ".";
+ ptr = fname; /* copy name to fname */
+ while (*env != '\0')
+ *ptr++ = *env++;
+ if (ptr[-1] != '\\' && ptr[-1] != '/')
+ *ptr++ = '\\'; /* append backslash if not in env variable */
+ /* Append a suitable file name */
+ next_file_num++; /* advance counter */
+ sprintf(ptr, "JPG%03d.TMP", next_file_num);
+ /* Probe to see if file name is already in use */
+ if ((tfile = fopen(fname, READ_BINARY)) == NULL)
+ break;
+ fclose(tfile); /* oops, it's there; close tfile & try again */
+ }
+}
+
+
+/*
+ * Near-memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL(void *)
+jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * "Large" objects are allocated in far memory, if possible
+ */
+
+GLOBAL(void FAR *)
+jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void FAR *) far_malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
+{
+ far_free(object);
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM /* so can override from makefile */
+#define DEFAULT_MAX_MEM 300000L /* for total usage about 450K */
+#endif
+
+GLOBAL(long)
+jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
+ long max_bytes_needed, long already_allocated)
+{
+ return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed. You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+/*
+ * For MS-DOS we support three types of backing storage:
+ * 1. Conventional DOS files. We access these by direct DOS calls rather
+ * than via the stdio package. This provides a bit better performance,
+ * but the real reason is that the buffers to be read or written are FAR.
+ * The stdio library for small-data memory models can't cope with that.
+ * 2. Extended memory, accessed per the XMS V2.0 specification.
+ * 3. Expanded memory, accessed per the LIM/EMS 4.0 specification.
+ * You'll need copies of those specs to make sense of the related code.
+ * The specs are available by Internet FTP from the SIMTEL archives
+ * (oak.oakland.edu and its various mirror sites). See files
+ * pub/msdos/microsoft/xms20.arc and pub/msdos/info/limems41.zip.
+ */
+
+
+/*
+ * Access methods for a DOS file.
+ */
+
+
+METHODDEF(void)
+read_file_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ if (jdos_seek(info->handle.file_handle, file_offset))
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+ /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */
+ if (byte_count > 65535L) /* safety check */
+ ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK);
+ if (jdos_read(info->handle.file_handle, buffer_address,
+ (unsigned short) byte_count))
+ ERREXIT(cinfo, JERR_TFILE_READ);
+}
+
+
+METHODDEF(void)
+write_file_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ if (jdos_seek(info->handle.file_handle, file_offset))
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+ /* Since MAX_ALLOC_CHUNK is less than 64K, byte_count will be too. */
+ if (byte_count > 65535L) /* safety check */
+ ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK);
+ if (jdos_write(info->handle.file_handle, buffer_address,
+ (unsigned short) byte_count))
+ ERREXIT(cinfo, JERR_TFILE_WRITE);
+}
+
+
+METHODDEF(void)
+close_file_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+ jdos_close(info->handle.file_handle); /* close the file */
+ remove(info->temp_name); /* delete the file */
+/* If your system doesn't have remove(), try unlink() instead.
+ * remove() is the ANSI-standard name for this function, but
+ * unlink() was more common in pre-ANSI systems.
+ */
+ TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name);
+}
+
+
+LOCAL(boolean)
+open_file_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ short handle;
+
+ select_file_name(info->temp_name);
+ if (jdos_open((short far *) & handle, (char far *) info->temp_name)) {
+ /* might as well exit since jpeg_open_backing_store will fail anyway */
+ ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
+ return FALSE;
+ }
+ info->handle.file_handle = handle;
+ info->read_backing_store = read_file_store;
+ info->write_backing_store = write_file_store;
+ info->close_backing_store = close_file_store;
+ TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
+ return TRUE; /* succeeded */
+}
+
+
+/*
+ * Access methods for extended memory.
+ */
+
+#if XMS_SUPPORTED
+
+static XMSDRIVER xms_driver; /* saved address of XMS driver */
+
+typedef union { /* either long offset or real-mode pointer */
+ long offset;
+ void far * ptr;
+ } XMSPTR;
+
+typedef struct { /* XMS move specification structure */
+ long length;
+ XMSH src_handle;
+ XMSPTR src;
+ XMSH dst_handle;
+ XMSPTR dst;
+ } XMSspec;
+
+#define ODD(X) (((X) & 1L) != 0)
+
+
+METHODDEF(void)
+read_xms_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ XMScontext ctx;
+ XMSspec spec;
+ char endbuffer[2];
+
+ /* The XMS driver can't cope with an odd length, so handle the last byte
+ * specially if byte_count is odd. We don't expect this to be common.
+ */
+
+ spec.length = byte_count & (~ 1L);
+ spec.src_handle = info->handle.xms_handle;
+ spec.src.offset = file_offset;
+ spec.dst_handle = 0;
+ spec.dst.ptr = buffer_address;
+
+ ctx.ds_si = (void far *) & spec;
+ ctx.ax = 0x0b00; /* EMB move */
+ jxms_calldriver(xms_driver, (XMScontext far *) & ctx);
+ if (ctx.ax != 1)
+ ERREXIT(cinfo, JERR_XMS_READ);
+
+ if (ODD(byte_count)) {
+ read_xms_store(cinfo, info, (void FAR *) endbuffer,
+ file_offset + byte_count - 1L, 2L);
+ ((char FAR *) buffer_address)[byte_count - 1L] = endbuffer[0];
+ }
+}
+
+
+METHODDEF(void)
+write_xms_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ XMScontext ctx;
+ XMSspec spec;
+ char endbuffer[2];
+
+ /* The XMS driver can't cope with an odd length, so handle the last byte
+ * specially if byte_count is odd. We don't expect this to be common.
+ */
+
+ spec.length = byte_count & (~ 1L);
+ spec.src_handle = 0;
+ spec.src.ptr = buffer_address;
+ spec.dst_handle = info->handle.xms_handle;
+ spec.dst.offset = file_offset;
+
+ ctx.ds_si = (void far *) & spec;
+ ctx.ax = 0x0b00; /* EMB move */
+ jxms_calldriver(xms_driver, (XMScontext far *) & ctx);
+ if (ctx.ax != 1)
+ ERREXIT(cinfo, JERR_XMS_WRITE);
+
+ if (ODD(byte_count)) {
+ read_xms_store(cinfo, info, (void FAR *) endbuffer,
+ file_offset + byte_count - 1L, 2L);
+ endbuffer[0] = ((char FAR *) buffer_address)[byte_count - 1L];
+ write_xms_store(cinfo, info, (void FAR *) endbuffer,
+ file_offset + byte_count - 1L, 2L);
+ }
+}
+
+
+METHODDEF(void)
+close_xms_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+ XMScontext ctx;
+
+ ctx.dx = info->handle.xms_handle;
+ ctx.ax = 0x0a00;
+ jxms_calldriver(xms_driver, (XMScontext far *) & ctx);
+ TRACEMS1(cinfo, 1, JTRC_XMS_CLOSE, info->handle.xms_handle);
+ /* we ignore any error return from the driver */
+}
+
+
+LOCAL(boolean)
+open_xms_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ XMScontext ctx;
+
+ /* Get address of XMS driver */
+ jxms_getdriver((XMSDRIVER far *) & xms_driver);
+ if (xms_driver == NULL)
+ return FALSE; /* no driver to be had */
+
+ /* Get version number, must be >= 2.00 */
+ ctx.ax = 0x0000;
+ jxms_calldriver(xms_driver, (XMScontext far *) & ctx);
+ if (ctx.ax < (unsigned short) 0x0200)
+ return FALSE;
+
+ /* Try to get space (expressed in kilobytes) */
+ ctx.dx = (unsigned short) ((total_bytes_needed + 1023L) >> 10);
+ ctx.ax = 0x0900;
+ jxms_calldriver(xms_driver, (XMScontext far *) & ctx);
+ if (ctx.ax != 1)
+ return FALSE;
+
+ /* Succeeded, save the handle and away we go */
+ info->handle.xms_handle = ctx.dx;
+ info->read_backing_store = read_xms_store;
+ info->write_backing_store = write_xms_store;
+ info->close_backing_store = close_xms_store;
+ TRACEMS1(cinfo, 1, JTRC_XMS_OPEN, ctx.dx);
+ return TRUE; /* succeeded */
+}
+
+#endif /* XMS_SUPPORTED */
+
+
+/*
+ * Access methods for expanded memory.
+ */
+
+#if EMS_SUPPORTED
+
+/* The EMS move specification structure requires word and long fields aligned
+ * at odd byte boundaries. Some compilers will align struct fields at even
+ * byte boundaries. While it's usually possible to force byte alignment,
+ * that causes an overall performance penalty and may pose problems in merging
+ * JPEG into a larger application. Instead we accept some rather dirty code
+ * here. Note this code would fail if the hardware did not allow odd-byte
+ * word & long accesses, but all 80x86 CPUs do.
+ */
+
+typedef void far * EMSPTR;
+
+typedef union { /* EMS move specification structure */
+ long length; /* It's easy to access first 4 bytes */
+ char bytes[18]; /* Misaligned fields in here! */
+ } EMSspec;
+
+/* Macros for accessing misaligned fields */
+#define FIELD_AT(spec,offset,type) (*((type *) &(spec.bytes[offset])))
+#define SRC_TYPE(spec) FIELD_AT(spec,4,char)
+#define SRC_HANDLE(spec) FIELD_AT(spec,5,EMSH)
+#define SRC_OFFSET(spec) FIELD_AT(spec,7,unsigned short)
+#define SRC_PAGE(spec) FIELD_AT(spec,9,unsigned short)
+#define SRC_PTR(spec) FIELD_AT(spec,7,EMSPTR)
+#define DST_TYPE(spec) FIELD_AT(spec,11,char)
+#define DST_HANDLE(spec) FIELD_AT(spec,12,EMSH)
+#define DST_OFFSET(spec) FIELD_AT(spec,14,unsigned short)
+#define DST_PAGE(spec) FIELD_AT(spec,16,unsigned short)
+#define DST_PTR(spec) FIELD_AT(spec,14,EMSPTR)
+
+#define EMSPAGESIZE 16384L /* gospel, see the EMS specs */
+
+#define HIBYTE(W) (((W) >> 8) & 0xFF)
+#define LOBYTE(W) ((W) & 0xFF)
+
+
+METHODDEF(void)
+read_ems_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ EMScontext ctx;
+ EMSspec spec;
+
+ spec.length = byte_count;
+ SRC_TYPE(spec) = 1;
+ SRC_HANDLE(spec) = info->handle.ems_handle;
+ SRC_PAGE(spec) = (unsigned short) (file_offset / EMSPAGESIZE);
+ SRC_OFFSET(spec) = (unsigned short) (file_offset % EMSPAGESIZE);
+ DST_TYPE(spec) = 0;
+ DST_HANDLE(spec) = 0;
+ DST_PTR(spec) = buffer_address;
+
+ ctx.ds_si = (void far *) & spec;
+ ctx.ax = 0x5700; /* move memory region */
+ jems_calldriver((EMScontext far *) & ctx);
+ if (HIBYTE(ctx.ax) != 0)
+ ERREXIT(cinfo, JERR_EMS_READ);
+}
+
+
+METHODDEF(void)
+write_ems_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ EMScontext ctx;
+ EMSspec spec;
+
+ spec.length = byte_count;
+ SRC_TYPE(spec) = 0;
+ SRC_HANDLE(spec) = 0;
+ SRC_PTR(spec) = buffer_address;
+ DST_TYPE(spec) = 1;
+ DST_HANDLE(spec) = info->handle.ems_handle;
+ DST_PAGE(spec) = (unsigned short) (file_offset / EMSPAGESIZE);
+ DST_OFFSET(spec) = (unsigned short) (file_offset % EMSPAGESIZE);
+
+ ctx.ds_si = (void far *) & spec;
+ ctx.ax = 0x5700; /* move memory region */
+ jems_calldriver((EMScontext far *) & ctx);
+ if (HIBYTE(ctx.ax) != 0)
+ ERREXIT(cinfo, JERR_EMS_WRITE);
+}
+
+
+METHODDEF(void)
+close_ems_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+ EMScontext ctx;
+
+ ctx.ax = 0x4500;
+ ctx.dx = info->handle.ems_handle;
+ jems_calldriver((EMScontext far *) & ctx);
+ TRACEMS1(cinfo, 1, JTRC_EMS_CLOSE, info->handle.ems_handle);
+ /* we ignore any error return from the driver */
+}
+
+
+LOCAL(boolean)
+open_ems_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ EMScontext ctx;
+
+ /* Is EMS driver there? */
+ if (! jems_available())
+ return FALSE;
+
+ /* Get status, make sure EMS is OK */
+ ctx.ax = 0x4000;
+ jems_calldriver((EMScontext far *) & ctx);
+ if (HIBYTE(ctx.ax) != 0)
+ return FALSE;
+
+ /* Get version, must be >= 4.0 */
+ ctx.ax = 0x4600;
+ jems_calldriver((EMScontext far *) & ctx);
+ if (HIBYTE(ctx.ax) != 0 || LOBYTE(ctx.ax) < 0x40)
+ return FALSE;
+
+ /* Try to allocate requested space */
+ ctx.ax = 0x4300;
+ ctx.bx = (unsigned short) ((total_bytes_needed + EMSPAGESIZE-1L) / EMSPAGESIZE);
+ jems_calldriver((EMScontext far *) & ctx);
+ if (HIBYTE(ctx.ax) != 0)
+ return FALSE;
+
+ /* Succeeded, save the handle and away we go */
+ info->handle.ems_handle = ctx.dx;
+ info->read_backing_store = read_ems_store;
+ info->write_backing_store = write_ems_store;
+ info->close_backing_store = close_ems_store;
+ TRACEMS1(cinfo, 1, JTRC_EMS_OPEN, ctx.dx);
+ return TRUE; /* succeeded */
+}
+
+#endif /* EMS_SUPPORTED */
+
+
+/*
+ * Initial opening of a backing-store object.
+ */
+
+GLOBAL(void)
+jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ /* Try extended memory, then expanded memory, then regular file. */
+#if XMS_SUPPORTED
+ if (open_xms_store(cinfo, info, total_bytes_needed))
+ return;
+#endif
+#if EMS_SUPPORTED
+ if (open_ems_store(cinfo, info, total_bytes_needed))
+ return;
+#endif
+ if (open_file_store(cinfo, info, total_bytes_needed))
+ return;
+ ERREXITS(cinfo, JERR_TFILE_CREATE, "");
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL(long)
+jpeg_mem_init (j_common_ptr cinfo)
+{
+ next_file_num = 0; /* initialize temp file name generator */
+ return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
+}
+
+GLOBAL(void)
+jpeg_mem_term (j_common_ptr cinfo)
+{
+ /* Microsoft C, at least in v6.00A, will not successfully reclaim freed
+ * blocks of size > 32Kbytes unless we give it a kick in the rear, like so:
+ */
+#ifdef NEED_FHEAPMIN
+ _fheapmin();
+#endif
+}
--- /dev/null
+/*
+ * jmemmac.c
+ *
+ * Copyright (C) 1992-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * jmemmac.c provides an Apple Macintosh implementation of the system-
+ * dependent portion of the JPEG memory manager.
+ *
+ * If you use jmemmac.c, then you must define USE_MAC_MEMMGR in the
+ * JPEG_INTERNALS part of jconfig.h.
+ *
+ * jmemmac.c uses the Macintosh toolbox routines NewPtr and DisposePtr
+ * instead of malloc and free. It accurately determines the amount of
+ * memory available by using CompactMem. Notice that if left to its
+ * own devices, this code can chew up all available space in the
+ * application's zone, with the exception of the rather small "slop"
+ * factor computed in jpeg_mem_available(). The application can ensure
+ * that more space is left over by reducing max_memory_to_use.
+ *
+ * Large images are swapped to disk using temporary files and System 7.0+'s
+ * temporary folder functionality.
+ *
+ * Note that jmemmac.c depends on two features of MacOS that were first
+ * introduced in System 7: FindFolder and the FSSpec-based calls.
+ * If your application uses jmemmac.c and is run under System 6 or earlier,
+ * and the jpeg library decides it needs a temporary file, it will abort,
+ * printing error messages about requiring System 7. (If no temporary files
+ * are created, it will run fine.)
+ *
+ * If you want to use jmemmac.c in an application that might be used with
+ * System 6 or earlier, then you should remove dependencies on FindFolder
+ * and the FSSpec calls. You will need to replace FindFolder with some
+ * other mechanism for finding a place to put temporary files, and you
+ * should replace the FSSpec calls with their HFS equivalents:
+ *
+ * FSpDelete -> HDelete
+ * FSpGetFInfo -> HGetFInfo
+ * FSpCreate -> HCreate
+ * FSpOpenDF -> HOpen *** Note: not HOpenDF ***
+ * FSMakeFSSpec -> (fill in spec by hand.)
+ *
+ * (Use HOpen instead of HOpenDF. HOpen is just a glue-interface to PBHOpen,
+ * which is on all HFS macs. HOpenDF is a System 7 addition which avoids the
+ * ages-old problem of names starting with a period.)
+ *
+ * Contributed by Sam Bushell (jsam@iagu.on.net) and
+ * Dan Gildor (gyld@in-touch.com).
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jmemsys12.h" /* import the system-dependent declarations */
+
+#ifndef USE_MAC_MEMMGR /* make sure user got configuration right */
+ You forgot to define USE_MAC_MEMMGR in jconfig.h. /* deliberate syntax error */
+#endif
+
+#include <Memory.h> /* we use the MacOS memory manager */
+#include <Files.h> /* we use the MacOS File stuff */
+#include <Folders.h> /* we use the MacOS HFS stuff */
+#include <Script.h> /* for smSystemScript */
+#include <Gestalt.h> /* we use Gestalt to test for specific functionality */
+
+#ifndef TEMP_FILE_NAME /* can override from jconfig.h or Makefile */
+#define TEMP_FILE_NAME "JPG%03d.TMP"
+#endif
+
+static int next_file_num; /* to distinguish among several temp files */
+
+
+/*
+ * Memory allocation and freeing are controlled by the MacOS library
+ * routines NewPtr() and DisposePtr(), which allocate fixed-address
+ * storage. Unfortunately, the IJG library isn't smart enough to cope
+ * with relocatable storage.
+ */
+
+GLOBAL(void *)
+jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void *) NewPtr(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
+{
+ DisposePtr((Ptr) object);
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: we include FAR keywords in the routine declarations simply for
+ * consistency with the rest of the IJG code; FAR should expand to empty
+ * on rational architectures like the Mac.
+ */
+
+GLOBAL(void FAR *)
+jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void FAR *) NewPtr(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
+{
+ DisposePtr((Ptr) object);
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ */
+
+GLOBAL(long)
+jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
+ long max_bytes_needed, long already_allocated)
+{
+ long limit = cinfo->mem->max_memory_to_use - already_allocated;
+ long slop, mem;
+
+ /* Don't ask for more than what application has told us we may use */
+ if (max_bytes_needed > limit && limit > 0)
+ max_bytes_needed = limit;
+ /* Find whether there's a big enough free block in the heap.
+ * CompactMem tries to create a contiguous block of the requested size,
+ * and then returns the size of the largest free block (which could be
+ * much more or much less than we asked for).
+ * We add some slop to ensure we don't use up all available memory.
+ */
+ slop = max_bytes_needed / 16 + 32768L;
+ mem = CompactMem(max_bytes_needed + slop) - slop;
+ if (mem < 0)
+ mem = 0; /* sigh, couldn't even get the slop */
+ /* Don't take more than the application says we can have */
+ if (mem > limit && limit > 0)
+ mem = limit;
+ return mem;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed. You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+
+METHODDEF(void)
+read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ long bytes = byte_count;
+ long retVal;
+
+ if ( SetFPos ( info->temp_file, fsFromStart, file_offset ) != noErr )
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+
+ retVal = FSRead ( info->temp_file, &bytes,
+ (unsigned char *) buffer_address );
+ if ( retVal != noErr || bytes != byte_count )
+ ERREXIT(cinfo, JERR_TFILE_READ);
+}
+
+
+METHODDEF(void)
+write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ long bytes = byte_count;
+ long retVal;
+
+ if ( SetFPos ( info->temp_file, fsFromStart, file_offset ) != noErr )
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+
+ retVal = FSWrite ( info->temp_file, &bytes,
+ (unsigned char *) buffer_address );
+ if ( retVal != noErr || bytes != byte_count )
+ ERREXIT(cinfo, JERR_TFILE_WRITE);
+}
+
+
+METHODDEF(void)
+close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+ FSClose ( info->temp_file );
+ FSpDelete ( &(info->tempSpec) );
+}
+
+
+/*
+ * Initial opening of a backing-store object.
+ *
+ * This version uses FindFolder to find the Temporary Items folder,
+ * and puts the temporary file in there.
+ */
+
+GLOBAL(void)
+jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ short tmpRef, vRefNum;
+ long dirID;
+ FInfo finderInfo;
+ FSSpec theSpec;
+ Str255 fName;
+ OSErr osErr;
+ long gestaltResponse = 0;
+
+ /* Check that FSSpec calls are available. */
+ osErr = Gestalt( gestaltFSAttr, &gestaltResponse );
+ if ( ( osErr != noErr )
+ || !( gestaltResponse & (1<<gestaltHasFSSpecCalls) ) )
+ ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required");
+ /* TO DO: add a proper error message to jerror.h. */
+
+ /* Check that FindFolder is available. */
+ osErr = Gestalt( gestaltFindFolderAttr, &gestaltResponse );
+ if ( ( osErr != noErr )
+ || !( gestaltResponse & (1<<gestaltFindFolderPresent) ) )
+ ERREXITS(cinfo, JERR_TFILE_CREATE, "- System 7.0 or later required.");
+ /* TO DO: add a proper error message to jerror.h. */
+
+ osErr = FindFolder ( kOnSystemDisk, kTemporaryFolderType, kCreateFolder,
+ &vRefNum, &dirID );
+ if ( osErr != noErr )
+ ERREXITS(cinfo, JERR_TFILE_CREATE, "- temporary items folder unavailable");
+ /* TO DO: Try putting the temp files somewhere else. */
+
+ /* Keep generating file names till we find one that's not in use */
+ for (;;) {
+ next_file_num++; /* advance counter */
+
+ sprintf(info->temp_name, TEMP_FILE_NAME, next_file_num);
+ strcpy ( (Ptr)fName+1, info->temp_name );
+ *fName = strlen (info->temp_name);
+ osErr = FSMakeFSSpec ( vRefNum, dirID, fName, &theSpec );
+
+ if ( (osErr = FSpGetFInfo ( &theSpec, &finderInfo ) ) != noErr )
+ break;
+ }
+
+ osErr = FSpCreate ( &theSpec, '????', '????', smSystemScript );
+ if ( osErr != noErr )
+ ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
+
+ osErr = FSpOpenDF ( &theSpec, fsRdWrPerm, &(info->temp_file) );
+ if ( osErr != noErr )
+ ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
+
+ info->tempSpec = theSpec;
+
+ info->read_backing_store = read_backing_store;
+ info->write_backing_store = write_backing_store;
+ info->close_backing_store = close_backing_store;
+ TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL(long)
+jpeg_mem_init (j_common_ptr cinfo)
+{
+ next_file_num = 0;
+
+ /* max_memory_to_use will be initialized to FreeMem()'s result;
+ * the calling application might later reduce it, for example
+ * to leave room to invoke multiple JPEG objects.
+ * Note that FreeMem returns the total number of free bytes;
+ * it may not be possible to allocate a single block of this size.
+ */
+ return FreeMem();
+}
+
+GLOBAL(void)
+jpeg_mem_term (j_common_ptr cinfo)
+{
+ /* no work */
+}
--- /dev/null
+/*
+ * jmemmgr.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains the JPEG system-independent memory management
+ * routines. This code is usable across a wide variety of machines; most
+ * of the system dependencies have been isolated in a separate file.
+ * The major functions provided here are:
+ * * pool-based allocation and freeing of memory;
+ * * policy decisions about how to divide available memory among the
+ * virtual arrays;
+ * * control logic for swapping virtual arrays between main memory and
+ * backing storage.
+ * The separate system-dependent file provides the actual backing-storage
+ * access code, and it contains the policy decision about how much total
+ * main memory to use.
+ * This file is system-dependent in the sense that some of its functions
+ * are unnecessary in some systems. For example, if there is enough virtual
+ * memory so that backing storage will never be used, much of the virtual
+ * array control logic could be removed. (Of course, if you have that much
+ * memory then you shouldn't care about a little bit of unused code...)
+ */
+
+#define JPEG_INTERNALS
+#define AM_MEMORY_MANAGER /* we define jvirt_Xarray_control structs */
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jmemsys12.h" /* import the system-dependent declarations */
+
+#ifndef NO_GETENV
+#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare getenv() */
+extern char * getenv JPP((const char * name));
+#endif
+#endif
+
+
+/*
+ * Some important notes:
+ * The allocation routines provided here must never return NULL.
+ * They should exit to error_exit if unsuccessful.
+ *
+ * It's not a good idea to try to merge the sarray and barray routines,
+ * even though they are textually almost the same, because samples are
+ * usually stored as bytes while coefficients are shorts or ints. Thus,
+ * in machines where byte pointers have a different representation from
+ * word pointers, the resulting machine code could not be the same.
+ */
+
+
+/*
+ * Many machines require storage alignment: longs must start on 4-byte
+ * boundaries, doubles on 8-byte boundaries, etc. On such machines, malloc()
+ * always returns pointers that are multiples of the worst-case alignment
+ * requirement, and we had better do so too.
+ * There isn't any really portable way to determine the worst-case alignment
+ * requirement. This module assumes that the alignment requirement is
+ * multiples of sizeof(ALIGN_TYPE).
+ * By default, we define ALIGN_TYPE as double. This is necessary on some
+ * workstations (where doubles really do need 8-byte alignment) and will work
+ * fine on nearly everything. If your machine has lesser alignment needs,
+ * you can save a few bytes by making ALIGN_TYPE smaller.
+ * The only place I know of where this will NOT work is certain Macintosh
+ * 680x0 compilers that define double as a 10-byte IEEE extended float.
+ * Doing 10-byte alignment is counterproductive because longwords won't be
+ * aligned well. Put "#define ALIGN_TYPE long" in jconfig.h if you have
+ * such a compiler.
+ */
+
+#ifndef ALIGN_TYPE /* so can override from jconfig.h */
+#define ALIGN_TYPE double
+#endif
+
+
+/*
+ * We allocate objects from "pools", where each pool is gotten with a single
+ * request to jpeg_get_small() or jpeg_get_large(). There is no per-object
+ * overhead within a pool, except for alignment padding. Each pool has a
+ * header with a link to the next pool of the same class.
+ * Small and large pool headers are identical except that the latter's
+ * link pointer must be FAR on 80x86 machines.
+ * Notice that the "real" header fields are union'ed with a dummy ALIGN_TYPE
+ * field. This forces the compiler to make SIZEOF(small_pool_hdr) a multiple
+ * of the alignment requirement of ALIGN_TYPE.
+ */
+
+typedef union small_pool_struct * small_pool_ptr;
+
+typedef union small_pool_struct {
+ struct {
+ small_pool_ptr next; /* next in list of pools */
+ size_t bytes_used; /* how many bytes already used within pool */
+ size_t bytes_left; /* bytes still available in this pool */
+ } hdr;
+ ALIGN_TYPE dummy; /* included in union to ensure alignment */
+} small_pool_hdr;
+
+typedef union large_pool_struct FAR * large_pool_ptr;
+
+typedef union large_pool_struct {
+ struct {
+ large_pool_ptr next; /* next in list of pools */
+ size_t bytes_used; /* how many bytes already used within pool */
+ size_t bytes_left; /* bytes still available in this pool */
+ } hdr;
+ ALIGN_TYPE dummy; /* included in union to ensure alignment */
+} large_pool_hdr;
+
+
+/*
+ * Here is the full definition of a memory manager object.
+ */
+
+typedef struct {
+ struct jpeg_memory_mgr pub; /* public fields */
+
+ /* Each pool identifier (lifetime class) names a linked list of pools. */
+ small_pool_ptr small_list[JPOOL_NUMPOOLS];
+ large_pool_ptr large_list[JPOOL_NUMPOOLS];
+
+ /* Since we only have one lifetime class of virtual arrays, only one
+ * linked list is necessary (for each datatype). Note that the virtual
+ * array control blocks being linked together are actually stored somewhere
+ * in the small-pool list.
+ */
+ jvirt_sarray_ptr virt_sarray_list;
+ jvirt_barray_ptr virt_barray_list;
+
+ /* This counts total space obtained from jpeg_get_small/large */
+ long total_space_allocated;
+
+ /* alloc_sarray and alloc_barray set this value for use by virtual
+ * array routines.
+ */
+ JDIMENSION last_rowsperchunk; /* from most recent alloc_sarray/barray */
+} my_memory_mgr;
+
+typedef my_memory_mgr * my_mem_ptr;
+
+
+/*
+ * The control blocks for virtual arrays.
+ * Note that these blocks are allocated in the "small" pool area.
+ * System-dependent info for the associated backing store (if any) is hidden
+ * inside the backing_store_info struct.
+ */
+
+struct jvirt_sarray_control {
+ JSAMPARRAY mem_buffer; /* => the in-memory buffer */
+ JDIMENSION rows_in_array; /* total virtual array height */
+ JDIMENSION samplesperrow; /* width of array (and of memory buffer) */
+ JDIMENSION maxaccess; /* max rows accessed by access_virt_sarray */
+ JDIMENSION rows_in_mem; /* height of memory buffer */
+ JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */
+ JDIMENSION cur_start_row; /* first logical row # in the buffer */
+ JDIMENSION first_undef_row; /* row # of first uninitialized row */
+ boolean pre_zero; /* pre-zero mode requested? */
+ boolean dirty; /* do current buffer contents need written? */
+ boolean b_s_open; /* is backing-store data valid? */
+ jvirt_sarray_ptr next; /* link to next virtual sarray control block */
+ backing_store_info b_s_info; /* System-dependent control info */
+};
+
+struct jvirt_barray_control {
+ JBLOCKARRAY mem_buffer; /* => the in-memory buffer */
+ JDIMENSION rows_in_array; /* total virtual array height */
+ JDIMENSION blocksperrow; /* width of array (and of memory buffer) */
+ JDIMENSION maxaccess; /* max rows accessed by access_virt_barray */
+ JDIMENSION rows_in_mem; /* height of memory buffer */
+ JDIMENSION rowsperchunk; /* allocation chunk size in mem_buffer */
+ JDIMENSION cur_start_row; /* first logical row # in the buffer */
+ JDIMENSION first_undef_row; /* row # of first uninitialized row */
+ boolean pre_zero; /* pre-zero mode requested? */
+ boolean dirty; /* do current buffer contents need written? */
+ boolean b_s_open; /* is backing-store data valid? */
+ jvirt_barray_ptr next; /* link to next virtual barray control block */
+ backing_store_info b_s_info; /* System-dependent control info */
+};
+
+
+#ifdef MEM_STATS /* optional extra stuff for statistics */
+
+LOCAL(void)
+print_mem_stats (j_common_ptr cinfo, int pool_id)
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ small_pool_ptr shdr_ptr;
+ large_pool_ptr lhdr_ptr;
+
+ /* Since this is only a debugging stub, we can cheat a little by using
+ * fprintf directly rather than going through the trace message code.
+ * This is helpful because message parm array can't handle longs.
+ */
+ fprintf(stderr, "Freeing pool %d, total space = %ld\n",
+ pool_id, mem->total_space_allocated);
+
+ for (lhdr_ptr = mem->large_list[pool_id]; lhdr_ptr != NULL;
+ lhdr_ptr = lhdr_ptr->hdr.next) {
+ fprintf(stderr, " Large chunk used %ld\n",
+ (long) lhdr_ptr->hdr.bytes_used);
+ }
+
+ for (shdr_ptr = mem->small_list[pool_id]; shdr_ptr != NULL;
+ shdr_ptr = shdr_ptr->hdr.next) {
+ fprintf(stderr, " Small chunk used %ld free %ld\n",
+ (long) shdr_ptr->hdr.bytes_used,
+ (long) shdr_ptr->hdr.bytes_left);
+ }
+}
+
+#endif /* MEM_STATS */
+
+
+LOCAL(void)
+out_of_memory (j_common_ptr cinfo, int which)
+/* Report an out-of-memory error and stop execution */
+/* If we compiled MEM_STATS support, report alloc requests before dying */
+{
+#ifdef MEM_STATS
+ cinfo->err->trace_level = 2; /* force self_destruct to report stats */
+#endif
+ ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, which);
+}
+
+
+/*
+ * Allocation of "small" objects.
+ *
+ * For these, we use pooled storage. When a new pool must be created,
+ * we try to get enough space for the current request plus a "slop" factor,
+ * where the slop will be the amount of leftover space in the new pool.
+ * The speed vs. space tradeoff is largely determined by the slop values.
+ * A different slop value is provided for each pool class (lifetime),
+ * and we also distinguish the first pool of a class from later ones.
+ * NOTE: the values given work fairly well on both 16- and 32-bit-int
+ * machines, but may be too small if longs are 64 bits or more.
+ */
+
+static const size_t first_pool_slop[JPOOL_NUMPOOLS] =
+{
+ 1600, /* first PERMANENT pool */
+ 16000 /* first IMAGE pool */
+};
+
+static const size_t extra_pool_slop[JPOOL_NUMPOOLS] =
+{
+ 0, /* additional PERMANENT pools */
+ 5000 /* additional IMAGE pools */
+};
+
+#define MIN_SLOP 50 /* greater than 0 to avoid futile looping */
+
+
+METHODDEF(void *)
+alloc_small (j_common_ptr cinfo, int pool_id, size_t sizeofobject)
+/* Allocate a "small" object */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ small_pool_ptr hdr_ptr, prev_hdr_ptr;
+ char * data_ptr;
+ size_t odd_bytes, min_request, slop;
+
+ /* Check for unsatisfiable request (do now to ensure no overflow below) */
+ if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(small_pool_hdr)))
+ out_of_memory(cinfo, 1); /* request exceeds malloc's ability */
+
+ /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */
+ odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE);
+ if (odd_bytes > 0)
+ sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes;
+
+ /* See if space is available in any existing pool */
+ if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
+ ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
+ prev_hdr_ptr = NULL;
+ hdr_ptr = mem->small_list[pool_id];
+ while (hdr_ptr != NULL) {
+ if (hdr_ptr->hdr.bytes_left >= sizeofobject)
+ break; /* found pool with enough space */
+ prev_hdr_ptr = hdr_ptr;
+ hdr_ptr = hdr_ptr->hdr.next;
+ }
+
+ /* Time to make a new pool? */
+ if (hdr_ptr == NULL) {
+ /* min_request is what we need now, slop is what will be leftover */
+ min_request = sizeofobject + SIZEOF(small_pool_hdr);
+ if (prev_hdr_ptr == NULL) /* first pool in class? */
+ slop = first_pool_slop[pool_id];
+ else
+ slop = extra_pool_slop[pool_id];
+ /* Don't ask for more than MAX_ALLOC_CHUNK */
+ if (slop > (size_t) (MAX_ALLOC_CHUNK-min_request))
+ slop = (size_t) (MAX_ALLOC_CHUNK-min_request);
+ /* Try to get space, if fail reduce slop and try again */
+ for (;;) {
+ hdr_ptr = (small_pool_ptr) jpeg_get_small(cinfo, min_request + slop);
+ if (hdr_ptr != NULL)
+ break;
+ slop /= 2;
+ if (slop < MIN_SLOP) /* give up when it gets real small */
+ out_of_memory(cinfo, 2); /* jpeg_get_small failed */
+ }
+ mem->total_space_allocated += min_request + slop;
+ /* Success, initialize the new pool header and add to end of list */
+ hdr_ptr->hdr.next = NULL;
+ hdr_ptr->hdr.bytes_used = 0;
+ hdr_ptr->hdr.bytes_left = sizeofobject + slop;
+ if (prev_hdr_ptr == NULL) /* first pool in class? */
+ mem->small_list[pool_id] = hdr_ptr;
+ else
+ prev_hdr_ptr->hdr.next = hdr_ptr;
+ }
+
+ /* OK, allocate the object from the current pool */
+ data_ptr = (char *) (hdr_ptr + 1); /* point to first data byte in pool */
+ data_ptr += hdr_ptr->hdr.bytes_used; /* point to place for object */
+ hdr_ptr->hdr.bytes_used += sizeofobject;
+ hdr_ptr->hdr.bytes_left -= sizeofobject;
+
+ return (void *) data_ptr;
+}
+
+
+/*
+ * Allocation of "large" objects.
+ *
+ * The external semantics of these are the same as "small" objects,
+ * except that FAR pointers are used on 80x86. However the pool
+ * management heuristics are quite different. We assume that each
+ * request is large enough that it may as well be passed directly to
+ * jpeg_get_large; the pool management just links everything together
+ * so that we can free it all on demand.
+ * Note: the major use of "large" objects is in JSAMPARRAY and JBLOCKARRAY
+ * structures. The routines that create these structures (see below)
+ * deliberately bunch rows together to ensure a large request size.
+ */
+
+METHODDEF(void FAR *)
+alloc_large (j_common_ptr cinfo, int pool_id, size_t sizeofobject)
+/* Allocate a "large" object */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ large_pool_ptr hdr_ptr;
+ size_t odd_bytes;
+
+ /* Check for unsatisfiable request (do now to ensure no overflow below) */
+ if (sizeofobject > (size_t) (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)))
+ out_of_memory(cinfo, 3); /* request exceeds malloc's ability */
+
+ /* Round up the requested size to a multiple of SIZEOF(ALIGN_TYPE) */
+ odd_bytes = sizeofobject % SIZEOF(ALIGN_TYPE);
+ if (odd_bytes > 0)
+ sizeofobject += SIZEOF(ALIGN_TYPE) - odd_bytes;
+
+ /* Always make a new pool */
+ if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
+ ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
+
+ hdr_ptr = (large_pool_ptr) jpeg_get_large(cinfo, sizeofobject +
+ SIZEOF(large_pool_hdr));
+ if (hdr_ptr == NULL)
+ out_of_memory(cinfo, 4); /* jpeg_get_large failed */
+ mem->total_space_allocated += sizeofobject + SIZEOF(large_pool_hdr);
+
+ /* Success, initialize the new pool header and add to list */
+ hdr_ptr->hdr.next = mem->large_list[pool_id];
+ /* We maintain space counts in each pool header for statistical purposes,
+ * even though they are not needed for allocation.
+ */
+ hdr_ptr->hdr.bytes_used = sizeofobject;
+ hdr_ptr->hdr.bytes_left = 0;
+ mem->large_list[pool_id] = hdr_ptr;
+
+ return (void FAR *) (hdr_ptr + 1); /* point to first data byte in pool */
+}
+
+
+/*
+ * Creation of 2-D sample arrays.
+ * The pointers are in near heap, the samples themselves in FAR heap.
+ *
+ * To minimize allocation overhead and to allow I/O of large contiguous
+ * blocks, we allocate the sample rows in groups of as many rows as possible
+ * without exceeding MAX_ALLOC_CHUNK total bytes per allocation request.
+ * NB: the virtual array control routines, later in this file, know about
+ * this chunking of rows. The rowsperchunk value is left in the mem manager
+ * object so that it can be saved away if this sarray is the workspace for
+ * a virtual array.
+ */
+
+METHODDEF(JSAMPARRAY)
+alloc_sarray (j_common_ptr cinfo, int pool_id,
+ JDIMENSION samplesperrow, JDIMENSION numrows)
+/* Allocate a 2-D sample array */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ JSAMPARRAY result;
+ JSAMPROW workspace;
+ JDIMENSION rowsperchunk, currow, i;
+ long ltemp;
+
+ /* Calculate max # of rows allowed in one allocation chunk */
+ ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) /
+ ((long) samplesperrow * SIZEOF(JSAMPLE));
+ if (ltemp <= 0)
+ ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
+ if (ltemp < (long) numrows)
+ rowsperchunk = (JDIMENSION) ltemp;
+ else
+ rowsperchunk = numrows;
+ mem->last_rowsperchunk = rowsperchunk;
+
+ /* Get space for row pointers (small object) */
+ result = (JSAMPARRAY) alloc_small(cinfo, pool_id,
+ (size_t) (numrows * SIZEOF(JSAMPROW)));
+
+ /* Get the rows themselves (large objects) */
+ currow = 0;
+ while (currow < numrows) {
+ rowsperchunk = MIN(rowsperchunk, numrows - currow);
+ workspace = (JSAMPROW) alloc_large(cinfo, pool_id,
+ (size_t) ((size_t) rowsperchunk * (size_t) samplesperrow
+ * SIZEOF(JSAMPLE)));
+ for (i = rowsperchunk; i > 0; i--) {
+ result[currow++] = workspace;
+ workspace += samplesperrow;
+ }
+ }
+
+ return result;
+}
+
+
+/*
+ * Creation of 2-D coefficient-block arrays.
+ * This is essentially the same as the code for sample arrays, above.
+ */
+
+METHODDEF(JBLOCKARRAY)
+alloc_barray (j_common_ptr cinfo, int pool_id,
+ JDIMENSION blocksperrow, JDIMENSION numrows)
+/* Allocate a 2-D coefficient-block array */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ JBLOCKARRAY result;
+ JBLOCKROW workspace;
+ JDIMENSION rowsperchunk, currow, i;
+ long ltemp;
+
+ /* Calculate max # of rows allowed in one allocation chunk */
+ ltemp = (MAX_ALLOC_CHUNK-SIZEOF(large_pool_hdr)) /
+ ((long) blocksperrow * SIZEOF(JBLOCK));
+ if (ltemp <= 0)
+ ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
+ if (ltemp < (long) numrows)
+ rowsperchunk = (JDIMENSION) ltemp;
+ else
+ rowsperchunk = numrows;
+ mem->last_rowsperchunk = rowsperchunk;
+
+ /* Get space for row pointers (small object) */
+ result = (JBLOCKARRAY) alloc_small(cinfo, pool_id,
+ (size_t) (numrows * SIZEOF(JBLOCKROW)));
+
+ /* Get the rows themselves (large objects) */
+ currow = 0;
+ while (currow < numrows) {
+ rowsperchunk = MIN(rowsperchunk, numrows - currow);
+ workspace = (JBLOCKROW) alloc_large(cinfo, pool_id,
+ (size_t) ((size_t) rowsperchunk * (size_t) blocksperrow
+ * SIZEOF(JBLOCK)));
+ for (i = rowsperchunk; i > 0; i--) {
+ result[currow++] = workspace;
+ workspace += blocksperrow;
+ }
+ }
+
+ return result;
+}
+
+
+/*
+ * About virtual array management:
+ *
+ * The above "normal" array routines are only used to allocate strip buffers
+ * (as wide as the image, but just a few rows high). Full-image-sized buffers
+ * are handled as "virtual" arrays. The array is still accessed a strip at a
+ * time, but the memory manager must save the whole array for repeated
+ * accesses. The intended implementation is that there is a strip buffer in
+ * memory (as high as is possible given the desired memory limit), plus a
+ * backing file that holds the rest of the array.
+ *
+ * The request_virt_array routines are told the total size of the image and
+ * the maximum number of rows that will be accessed at once. The in-memory
+ * buffer must be at least as large as the maxaccess value.
+ *
+ * The request routines create control blocks but not the in-memory buffers.
+ * That is postponed until realize_virt_arrays is called. At that time the
+ * total amount of space needed is known (approximately, anyway), so free
+ * memory can be divided up fairly.
+ *
+ * The access_virt_array routines are responsible for making a specific strip
+ * area accessible (after reading or writing the backing file, if necessary).
+ * Note that the access routines are told whether the caller intends to modify
+ * the accessed strip; during a read-only pass this saves having to rewrite
+ * data to disk. The access routines are also responsible for pre-zeroing
+ * any newly accessed rows, if pre-zeroing was requested.
+ *
+ * In current usage, the access requests are usually for nonoverlapping
+ * strips; that is, successive access start_row numbers differ by exactly
+ * num_rows = maxaccess. This means we can get good performance with simple
+ * buffer dump/reload logic, by making the in-memory buffer be a multiple
+ * of the access height; then there will never be accesses across bufferload
+ * boundaries. The code will still work with overlapping access requests,
+ * but it doesn't handle bufferload overlaps very efficiently.
+ */
+
+
+METHODDEF(jvirt_sarray_ptr)
+request_virt_sarray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
+ JDIMENSION samplesperrow, JDIMENSION numrows,
+ JDIMENSION maxaccess)
+/* Request a virtual 2-D sample array */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ jvirt_sarray_ptr result;
+
+ /* Only IMAGE-lifetime virtual arrays are currently supported */
+ if (pool_id != JPOOL_IMAGE)
+ ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
+
+ /* get control block */
+ result = (jvirt_sarray_ptr) alloc_small(cinfo, pool_id,
+ SIZEOF(struct jvirt_sarray_control));
+
+ result->mem_buffer = NULL; /* marks array not yet realized */
+ result->rows_in_array = numrows;
+ result->samplesperrow = samplesperrow;
+ result->maxaccess = maxaccess;
+ result->pre_zero = pre_zero;
+ result->b_s_open = FALSE; /* no associated backing-store object */
+ result->next = mem->virt_sarray_list; /* add to list of virtual arrays */
+ mem->virt_sarray_list = result;
+
+ return result;
+}
+
+
+METHODDEF(jvirt_barray_ptr)
+request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
+ JDIMENSION blocksperrow, JDIMENSION numrows,
+ JDIMENSION maxaccess)
+/* Request a virtual 2-D coefficient-block array */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ jvirt_barray_ptr result;
+
+ /* Only IMAGE-lifetime virtual arrays are currently supported */
+ if (pool_id != JPOOL_IMAGE)
+ ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
+
+ /* get control block */
+ result = (jvirt_barray_ptr) alloc_small(cinfo, pool_id,
+ SIZEOF(struct jvirt_barray_control));
+
+ result->mem_buffer = NULL; /* marks array not yet realized */
+ result->rows_in_array = numrows;
+ result->blocksperrow = blocksperrow;
+ result->maxaccess = maxaccess;
+ result->pre_zero = pre_zero;
+ result->b_s_open = FALSE; /* no associated backing-store object */
+ result->next = mem->virt_barray_list; /* add to list of virtual arrays */
+ mem->virt_barray_list = result;
+
+ return result;
+}
+
+
+METHODDEF(void)
+realize_virt_arrays (j_common_ptr cinfo)
+/* Allocate the in-memory buffers for any unrealized virtual arrays */
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ long space_per_minheight, maximum_space, avail_mem;
+ long minheights, max_minheights;
+ jvirt_sarray_ptr sptr;
+ jvirt_barray_ptr bptr;
+
+ /* Compute the minimum space needed (maxaccess rows in each buffer)
+ * and the maximum space needed (full image height in each buffer).
+ * These may be of use to the system-dependent jpeg_mem_available routine.
+ */
+ space_per_minheight = 0;
+ maximum_space = 0;
+ for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
+ if (sptr->mem_buffer == NULL) { /* if not realized yet */
+ space_per_minheight += (long) sptr->maxaccess *
+ (long) sptr->samplesperrow * SIZEOF(JSAMPLE);
+ maximum_space += (long) sptr->rows_in_array *
+ (long) sptr->samplesperrow * SIZEOF(JSAMPLE);
+ }
+ }
+ for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
+ if (bptr->mem_buffer == NULL) { /* if not realized yet */
+ space_per_minheight += (long) bptr->maxaccess *
+ (long) bptr->blocksperrow * SIZEOF(JBLOCK);
+ maximum_space += (long) bptr->rows_in_array *
+ (long) bptr->blocksperrow * SIZEOF(JBLOCK);
+ }
+ }
+
+ if (space_per_minheight <= 0)
+ return; /* no unrealized arrays, no work */
+
+ /* Determine amount of memory to actually use; this is system-dependent. */
+ avail_mem = jpeg_mem_available(cinfo, space_per_minheight, maximum_space,
+ mem->total_space_allocated);
+
+ /* If the maximum space needed is available, make all the buffers full
+ * height; otherwise parcel it out with the same number of minheights
+ * in each buffer.
+ */
+ if (avail_mem >= maximum_space)
+ max_minheights = 1000000000L;
+ else {
+ max_minheights = avail_mem / space_per_minheight;
+ /* If there doesn't seem to be enough space, try to get the minimum
+ * anyway. This allows a "stub" implementation of jpeg_mem_available().
+ */
+ if (max_minheights <= 0)
+ max_minheights = 1;
+ }
+
+ /* Allocate the in-memory buffers and initialize backing store as needed. */
+
+ for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
+ if (sptr->mem_buffer == NULL) { /* if not realized yet */
+ minheights = ((long) sptr->rows_in_array - 1L) / sptr->maxaccess + 1L;
+ if (minheights <= max_minheights) {
+ /* This buffer fits in memory */
+ sptr->rows_in_mem = sptr->rows_in_array;
+ } else {
+ /* It doesn't fit in memory, create backing store. */
+ sptr->rows_in_mem = (JDIMENSION) (max_minheights * sptr->maxaccess);
+ jpeg_open_backing_store(cinfo, & sptr->b_s_info,
+ (long) sptr->rows_in_array *
+ (long) sptr->samplesperrow *
+ (long) SIZEOF(JSAMPLE));
+ sptr->b_s_open = TRUE;
+ }
+ sptr->mem_buffer = alloc_sarray(cinfo, JPOOL_IMAGE,
+ sptr->samplesperrow, sptr->rows_in_mem);
+ sptr->rowsperchunk = mem->last_rowsperchunk;
+ sptr->cur_start_row = 0;
+ sptr->first_undef_row = 0;
+ sptr->dirty = FALSE;
+ }
+ }
+
+ for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
+ if (bptr->mem_buffer == NULL) { /* if not realized yet */
+ minheights = ((long) bptr->rows_in_array - 1L) / bptr->maxaccess + 1L;
+ if (minheights <= max_minheights) {
+ /* This buffer fits in memory */
+ bptr->rows_in_mem = bptr->rows_in_array;
+ } else {
+ /* It doesn't fit in memory, create backing store. */
+ bptr->rows_in_mem = (JDIMENSION) (max_minheights * bptr->maxaccess);
+ jpeg_open_backing_store(cinfo, & bptr->b_s_info,
+ (long) bptr->rows_in_array *
+ (long) bptr->blocksperrow *
+ (long) SIZEOF(JBLOCK));
+ bptr->b_s_open = TRUE;
+ }
+ bptr->mem_buffer = alloc_barray(cinfo, JPOOL_IMAGE,
+ bptr->blocksperrow, bptr->rows_in_mem);
+ bptr->rowsperchunk = mem->last_rowsperchunk;
+ bptr->cur_start_row = 0;
+ bptr->first_undef_row = 0;
+ bptr->dirty = FALSE;
+ }
+ }
+}
+
+
+LOCAL(void)
+do_sarray_io (j_common_ptr cinfo, jvirt_sarray_ptr ptr, boolean writing)
+/* Do backing store read or write of a virtual sample array */
+{
+ long bytesperrow, file_offset, byte_count, rows, thisrow, i;
+
+ bytesperrow = (long) ptr->samplesperrow * SIZEOF(JSAMPLE);
+ file_offset = ptr->cur_start_row * bytesperrow;
+ /* Loop to read or write each allocation chunk in mem_buffer */
+ for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) {
+ /* One chunk, but check for short chunk at end of buffer */
+ rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i);
+ /* Transfer no more than is currently defined */
+ thisrow = (long) ptr->cur_start_row + i;
+ rows = MIN(rows, (long) ptr->first_undef_row - thisrow);
+ /* Transfer no more than fits in file */
+ rows = MIN(rows, (long) ptr->rows_in_array - thisrow);
+ if (rows <= 0) /* this chunk might be past end of file! */
+ break;
+ byte_count = rows * bytesperrow;
+ if (writing)
+ (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info,
+ (void FAR *) ptr->mem_buffer[i],
+ file_offset, byte_count);
+ else
+ (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info,
+ (void FAR *) ptr->mem_buffer[i],
+ file_offset, byte_count);
+ file_offset += byte_count;
+ }
+}
+
+
+LOCAL(void)
+do_barray_io (j_common_ptr cinfo, jvirt_barray_ptr ptr, boolean writing)
+/* Do backing store read or write of a virtual coefficient-block array */
+{
+ long bytesperrow, file_offset, byte_count, rows, thisrow, i;
+
+ bytesperrow = (long) ptr->blocksperrow * SIZEOF(JBLOCK);
+ file_offset = ptr->cur_start_row * bytesperrow;
+ /* Loop to read or write each allocation chunk in mem_buffer */
+ for (i = 0; i < (long) ptr->rows_in_mem; i += ptr->rowsperchunk) {
+ /* One chunk, but check for short chunk at end of buffer */
+ rows = MIN((long) ptr->rowsperchunk, (long) ptr->rows_in_mem - i);
+ /* Transfer no more than is currently defined */
+ thisrow = (long) ptr->cur_start_row + i;
+ rows = MIN(rows, (long) ptr->first_undef_row - thisrow);
+ /* Transfer no more than fits in file */
+ rows = MIN(rows, (long) ptr->rows_in_array - thisrow);
+ if (rows <= 0) /* this chunk might be past end of file! */
+ break;
+ byte_count = rows * bytesperrow;
+ if (writing)
+ (*ptr->b_s_info.write_backing_store) (cinfo, & ptr->b_s_info,
+ (void FAR *) ptr->mem_buffer[i],
+ file_offset, byte_count);
+ else
+ (*ptr->b_s_info.read_backing_store) (cinfo, & ptr->b_s_info,
+ (void FAR *) ptr->mem_buffer[i],
+ file_offset, byte_count);
+ file_offset += byte_count;
+ }
+}
+
+
+METHODDEF(JSAMPARRAY)
+access_virt_sarray (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
+ JDIMENSION start_row, JDIMENSION num_rows,
+ boolean writable)
+/* Access the part of a virtual sample array starting at start_row */
+/* and extending for num_rows rows. writable is true if */
+/* caller intends to modify the accessed area. */
+{
+ JDIMENSION end_row = start_row + num_rows;
+ JDIMENSION undef_row;
+
+ /* debugging check */
+ if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess ||
+ ptr->mem_buffer == NULL)
+ ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
+
+ /* Make the desired part of the virtual array accessible */
+ if (start_row < ptr->cur_start_row ||
+ end_row > ptr->cur_start_row+ptr->rows_in_mem) {
+ if (! ptr->b_s_open)
+ ERREXIT(cinfo, JERR_VIRTUAL_BUG);
+ /* Flush old buffer contents if necessary */
+ if (ptr->dirty) {
+ do_sarray_io(cinfo, ptr, TRUE);
+ ptr->dirty = FALSE;
+ }
+ /* Decide what part of virtual array to access.
+ * Algorithm: if target address > current window, assume forward scan,
+ * load starting at target address. If target address < current window,
+ * assume backward scan, load so that target area is top of window.
+ * Note that when switching from forward write to forward read, will have
+ * start_row = 0, so the limiting case applies and we load from 0 anyway.
+ */
+ if (start_row > ptr->cur_start_row) {
+ ptr->cur_start_row = start_row;
+ } else {
+ /* use long arithmetic here to avoid overflow & unsigned problems */
+ long ltemp;
+
+ ltemp = (long) end_row - (long) ptr->rows_in_mem;
+ if (ltemp < 0)
+ ltemp = 0; /* don't fall off front end of file */
+ ptr->cur_start_row = (JDIMENSION) ltemp;
+ }
+ /* Read in the selected part of the array.
+ * During the initial write pass, we will do no actual read
+ * because the selected part is all undefined.
+ */
+ do_sarray_io(cinfo, ptr, FALSE);
+ }
+ /* Ensure the accessed part of the array is defined; prezero if needed.
+ * To improve locality of access, we only prezero the part of the array
+ * that the caller is about to access, not the entire in-memory array.
+ */
+ if (ptr->first_undef_row < end_row) {
+ if (ptr->first_undef_row < start_row) {
+ if (writable) /* writer skipped over a section of array */
+ ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
+ undef_row = start_row; /* but reader is allowed to read ahead */
+ } else {
+ undef_row = ptr->first_undef_row;
+ }
+ if (writable)
+ ptr->first_undef_row = end_row;
+ if (ptr->pre_zero) {
+ size_t bytesperrow = (size_t) ptr->samplesperrow * SIZEOF(JSAMPLE);
+ undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */
+ end_row -= ptr->cur_start_row;
+ while (undef_row < end_row) {
+ jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow);
+ undef_row++;
+ }
+ } else {
+ if (! writable) /* reader looking at undefined data */
+ ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
+ }
+ }
+ /* Flag the buffer dirty if caller will write in it */
+ if (writable)
+ ptr->dirty = TRUE;
+ /* Return address of proper part of the buffer */
+ return ptr->mem_buffer + (start_row - ptr->cur_start_row);
+}
+
+
+METHODDEF(JBLOCKARRAY)
+access_virt_barray (j_common_ptr cinfo, jvirt_barray_ptr ptr,
+ JDIMENSION start_row, JDIMENSION num_rows,
+ boolean writable)
+/* Access the part of a virtual block array starting at start_row */
+/* and extending for num_rows rows. writable is true if */
+/* caller intends to modify the accessed area. */
+{
+ JDIMENSION end_row = start_row + num_rows;
+ JDIMENSION undef_row;
+
+ /* debugging check */
+ if (end_row > ptr->rows_in_array || num_rows > ptr->maxaccess ||
+ ptr->mem_buffer == NULL)
+ ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
+
+ /* Make the desired part of the virtual array accessible */
+ if (start_row < ptr->cur_start_row ||
+ end_row > ptr->cur_start_row+ptr->rows_in_mem) {
+ if (! ptr->b_s_open)
+ ERREXIT(cinfo, JERR_VIRTUAL_BUG);
+ /* Flush old buffer contents if necessary */
+ if (ptr->dirty) {
+ do_barray_io(cinfo, ptr, TRUE);
+ ptr->dirty = FALSE;
+ }
+ /* Decide what part of virtual array to access.
+ * Algorithm: if target address > current window, assume forward scan,
+ * load starting at target address. If target address < current window,
+ * assume backward scan, load so that target area is top of window.
+ * Note that when switching from forward write to forward read, will have
+ * start_row = 0, so the limiting case applies and we load from 0 anyway.
+ */
+ if (start_row > ptr->cur_start_row) {
+ ptr->cur_start_row = start_row;
+ } else {
+ /* use long arithmetic here to avoid overflow & unsigned problems */
+ long ltemp;
+
+ ltemp = (long) end_row - (long) ptr->rows_in_mem;
+ if (ltemp < 0)
+ ltemp = 0; /* don't fall off front end of file */
+ ptr->cur_start_row = (JDIMENSION) ltemp;
+ }
+ /* Read in the selected part of the array.
+ * During the initial write pass, we will do no actual read
+ * because the selected part is all undefined.
+ */
+ do_barray_io(cinfo, ptr, FALSE);
+ }
+ /* Ensure the accessed part of the array is defined; prezero if needed.
+ * To improve locality of access, we only prezero the part of the array
+ * that the caller is about to access, not the entire in-memory array.
+ */
+ if (ptr->first_undef_row < end_row) {
+ if (ptr->first_undef_row < start_row) {
+ if (writable) /* writer skipped over a section of array */
+ ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
+ undef_row = start_row; /* but reader is allowed to read ahead */
+ } else {
+ undef_row = ptr->first_undef_row;
+ }
+ if (writable)
+ ptr->first_undef_row = end_row;
+ if (ptr->pre_zero) {
+ size_t bytesperrow = (size_t) ptr->blocksperrow * SIZEOF(JBLOCK);
+ undef_row -= ptr->cur_start_row; /* make indexes relative to buffer */
+ end_row -= ptr->cur_start_row;
+ while (undef_row < end_row) {
+ jzero_far((void FAR *) ptr->mem_buffer[undef_row], bytesperrow);
+ undef_row++;
+ }
+ } else {
+ if (! writable) /* reader looking at undefined data */
+ ERREXIT(cinfo, JERR_BAD_VIRTUAL_ACCESS);
+ }
+ }
+ /* Flag the buffer dirty if caller will write in it */
+ if (writable)
+ ptr->dirty = TRUE;
+ /* Return address of proper part of the buffer */
+ return ptr->mem_buffer + (start_row - ptr->cur_start_row);
+}
+
+
+/*
+ * Release all objects belonging to a specified pool.
+ */
+
+METHODDEF(void)
+free_pool (j_common_ptr cinfo, int pool_id)
+{
+ my_mem_ptr mem = (my_mem_ptr) cinfo->mem;
+ small_pool_ptr shdr_ptr;
+ large_pool_ptr lhdr_ptr;
+ size_t space_freed;
+
+ if (pool_id < 0 || pool_id >= JPOOL_NUMPOOLS)
+ ERREXIT1(cinfo, JERR_BAD_POOL_ID, pool_id); /* safety check */
+
+#ifdef MEM_STATS
+ if (cinfo->err->trace_level > 1)
+ print_mem_stats(cinfo, pool_id); /* print pool's memory usage statistics */
+#endif
+
+ /* If freeing IMAGE pool, close any virtual arrays first */
+ if (pool_id == JPOOL_IMAGE) {
+ jvirt_sarray_ptr sptr;
+ jvirt_barray_ptr bptr;
+
+ for (sptr = mem->virt_sarray_list; sptr != NULL; sptr = sptr->next) {
+ if (sptr->b_s_open) { /* there may be no backing store */
+ sptr->b_s_open = FALSE; /* prevent recursive close if error */
+ (*sptr->b_s_info.close_backing_store) (cinfo, & sptr->b_s_info);
+ }
+ }
+ mem->virt_sarray_list = NULL;
+ for (bptr = mem->virt_barray_list; bptr != NULL; bptr = bptr->next) {
+ if (bptr->b_s_open) { /* there may be no backing store */
+ bptr->b_s_open = FALSE; /* prevent recursive close if error */
+ (*bptr->b_s_info.close_backing_store) (cinfo, & bptr->b_s_info);
+ }
+ }
+ mem->virt_barray_list = NULL;
+ }
+
+ /* Release large objects */
+ lhdr_ptr = mem->large_list[pool_id];
+ mem->large_list[pool_id] = NULL;
+
+ while (lhdr_ptr != NULL) {
+ large_pool_ptr next_lhdr_ptr = lhdr_ptr->hdr.next;
+ space_freed = lhdr_ptr->hdr.bytes_used +
+ lhdr_ptr->hdr.bytes_left +
+ SIZEOF(large_pool_hdr);
+ jpeg_free_large(cinfo, (void FAR *) lhdr_ptr, space_freed);
+ mem->total_space_allocated -= space_freed;
+ lhdr_ptr = next_lhdr_ptr;
+ }
+
+ /* Release small objects */
+ shdr_ptr = mem->small_list[pool_id];
+ mem->small_list[pool_id] = NULL;
+
+ while (shdr_ptr != NULL) {
+ small_pool_ptr next_shdr_ptr = shdr_ptr->hdr.next;
+ space_freed = shdr_ptr->hdr.bytes_used +
+ shdr_ptr->hdr.bytes_left +
+ SIZEOF(small_pool_hdr);
+ jpeg_free_small(cinfo, (void *) shdr_ptr, space_freed);
+ mem->total_space_allocated -= space_freed;
+ shdr_ptr = next_shdr_ptr;
+ }
+}
+
+
+/*
+ * Close up shop entirely.
+ * Note that this cannot be called unless cinfo->mem is non-NULL.
+ */
+
+METHODDEF(void)
+self_destruct (j_common_ptr cinfo)
+{
+ int pool;
+
+ /* Close all backing store, release all memory.
+ * Releasing pools in reverse order might help avoid fragmentation
+ * with some (brain-damaged) malloc libraries.
+ */
+ for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) {
+ free_pool(cinfo, pool);
+ }
+
+ /* Release the memory manager control block too. */
+ jpeg_free_small(cinfo, (void *) cinfo->mem, SIZEOF(my_memory_mgr));
+ cinfo->mem = NULL; /* ensures I will be called only once */
+
+ jpeg_mem_term(cinfo); /* system-dependent cleanup */
+}
+
+
+/*
+ * Memory manager initialization.
+ * When this is called, only the error manager pointer is valid in cinfo!
+ */
+
+GLOBAL(void)
+jinit_memory_mgr (j_common_ptr cinfo)
+{
+ my_mem_ptr mem;
+ long max_to_use;
+ int pool;
+ size_t test_mac;
+
+ cinfo->mem = NULL; /* for safety if init fails */
+
+ /* Check for configuration errors.
+ * SIZEOF(ALIGN_TYPE) should be a power of 2; otherwise, it probably
+ * doesn't reflect any real hardware alignment requirement.
+ * The test is a little tricky: for X>0, X and X-1 have no one-bits
+ * in common if and only if X is a power of 2, ie has only one one-bit.
+ * Some compilers may give an "unreachable code" warning here; ignore it.
+ */
+ if ((SIZEOF(ALIGN_TYPE) & (SIZEOF(ALIGN_TYPE)-1)) != 0)
+ ERREXIT(cinfo, JERR_BAD_ALIGN_TYPE);
+ /* MAX_ALLOC_CHUNK must be representable as type size_t, and must be
+ * a multiple of SIZEOF(ALIGN_TYPE).
+ * Again, an "unreachable code" warning may be ignored here.
+ * But a "constant too large" warning means you need to fix MAX_ALLOC_CHUNK.
+ */
+ test_mac = (size_t) MAX_ALLOC_CHUNK;
+ if ((long) test_mac != MAX_ALLOC_CHUNK ||
+ (MAX_ALLOC_CHUNK % SIZEOF(ALIGN_TYPE)) != 0)
+ ERREXIT(cinfo, JERR_BAD_ALLOC_CHUNK);
+
+ max_to_use = jpeg_mem_init(cinfo); /* system-dependent initialization */
+
+ /* Attempt to allocate memory manager's control block */
+ mem = (my_mem_ptr) jpeg_get_small(cinfo, SIZEOF(my_memory_mgr));
+
+ if (mem == NULL) {
+ jpeg_mem_term(cinfo); /* system-dependent cleanup */
+ ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 0);
+ }
+
+ /* OK, fill in the method pointers */
+ mem->pub.alloc_small = alloc_small;
+ mem->pub.alloc_large = alloc_large;
+ mem->pub.alloc_sarray = alloc_sarray;
+ mem->pub.alloc_barray = alloc_barray;
+ mem->pub.request_virt_sarray = request_virt_sarray;
+ mem->pub.request_virt_barray = request_virt_barray;
+ mem->pub.realize_virt_arrays = realize_virt_arrays;
+ mem->pub.access_virt_sarray = access_virt_sarray;
+ mem->pub.access_virt_barray = access_virt_barray;
+ mem->pub.free_pool = free_pool;
+ mem->pub.self_destruct = self_destruct;
+
+ /* Make MAX_ALLOC_CHUNK accessible to other modules */
+ mem->pub.max_alloc_chunk = MAX_ALLOC_CHUNK;
+
+ /* Initialize working state */
+ mem->pub.max_memory_to_use = max_to_use;
+
+ for (pool = JPOOL_NUMPOOLS-1; pool >= JPOOL_PERMANENT; pool--) {
+ mem->small_list[pool] = NULL;
+ mem->large_list[pool] = NULL;
+ }
+ mem->virt_sarray_list = NULL;
+ mem->virt_barray_list = NULL;
+
+ mem->total_space_allocated = SIZEOF(my_memory_mgr);
+
+ /* Declare ourselves open for business */
+ cinfo->mem = & mem->pub;
+
+ /* Check for an environment variable JPEGMEM; if found, override the
+ * default max_memory setting from jpeg_mem_init. Note that the
+ * surrounding application may again override this value.
+ * If your system doesn't support getenv(), define NO_GETENV to disable
+ * this feature.
+ */
+#ifndef NO_GETENV
+ { char * memenv;
+
+ if ((memenv = getenv("JPEGMEM")) != NULL) {
+ char ch = 'x';
+
+ if (sscanf(memenv, "%ld%c", &max_to_use, &ch) > 0) {
+ if (ch == 'm' || ch == 'M')
+ max_to_use *= 1000L;
+ mem->pub.max_memory_to_use = max_to_use * 1000L;
+ }
+ }
+ }
+#endif
+
+}
--- /dev/null
+/*
+ * jmemname.c
+ *
+ * Copyright (C) 1992-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides a generic implementation of the system-dependent
+ * portion of the JPEG memory manager. This implementation assumes that
+ * you must explicitly construct a name for each temp file.
+ * Also, the problem of determining the amount of memory available
+ * is shoved onto the user.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jmemsys12.h" /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP((size_t size));
+extern void free JPP((void *ptr));
+#endif
+
+#ifndef SEEK_SET /* pre-ANSI systems may not define this; */
+#define SEEK_SET 0 /* if not, assume 0 is correct */
+#endif
+
+#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
+#define READ_BINARY "r"
+#define RW_BINARY "w+"
+#else
+#ifdef VMS /* VMS is very nonstandard */
+#define READ_BINARY "rb", "ctx=stm"
+#define RW_BINARY "w+b", "ctx=stm"
+#else /* standard ANSI-compliant case */
+#define READ_BINARY "rb"
+#define RW_BINARY "w+b"
+#endif
+#endif
+
+
+/*
+ * Selection of a file name for a temporary file.
+ * This is system-dependent!
+ *
+ * The code as given is suitable for most Unix systems, and it is easily
+ * modified for most non-Unix systems. Some notes:
+ * 1. The temp file is created in the directory named by TEMP_DIRECTORY.
+ * The default value is /usr/tmp, which is the conventional place for
+ * creating large temp files on Unix. On other systems you'll probably
+ * want to change the file location. You can do this by editing the
+ * #define, or (preferred) by defining TEMP_DIRECTORY in jconfig.h.
+ *
+ * 2. If you need to change the file name as well as its location,
+ * you can override the TEMP_FILE_NAME macro. (Note that this is
+ * actually a printf format string; it must contain %s and %d.)
+ * Few people should need to do this.
+ *
+ * 3. mktemp() is used to ensure that multiple processes running
+ * simultaneously won't select the same file names. If your system
+ * doesn't have mktemp(), define NO_MKTEMP to do it the hard way.
+ * (If you don't have <errno.h>, also define NO_ERRNO_H.)
+ *
+ * 4. You probably want to define NEED_SIGNAL_CATCHER so that cjpeg.c/djpeg.c
+ * will cause the temp files to be removed if you stop the program early.
+ */
+
+#ifndef TEMP_DIRECTORY /* can override from jconfig.h or Makefile */
+#define TEMP_DIRECTORY "/usr/tmp/" /* recommended setting for Unix */
+#endif
+
+static int next_file_num; /* to distinguish among several temp files */
+
+#ifdef NO_MKTEMP
+
+#ifndef TEMP_FILE_NAME /* can override from jconfig.h or Makefile */
+#define TEMP_FILE_NAME "%sJPG%03d.TMP"
+#endif
+
+#ifndef NO_ERRNO_H
+#include <errno.h> /* to define ENOENT */
+#endif
+
+/* ANSI C specifies that errno is a macro, but on older systems it's more
+ * likely to be a plain int variable. And not all versions of errno.h
+ * bother to declare it, so we have to in order to be most portable. Thus:
+ */
+#ifndef errno
+extern int errno;
+#endif
+
+
+LOCAL(void)
+select_file_name (char * fname)
+{
+ FILE * tfile;
+
+ /* Keep generating file names till we find one that's not in use */
+ for (;;) {
+ next_file_num++; /* advance counter */
+ sprintf(fname, TEMP_FILE_NAME, TEMP_DIRECTORY, next_file_num);
+ if ((tfile = fopen(fname, READ_BINARY)) == NULL) {
+ /* fopen could have failed for a reason other than the file not
+ * being there; for example, file there but unreadable.
+ * If <errno.h> isn't available, then we cannot test the cause.
+ */
+#ifdef ENOENT
+ if (errno != ENOENT)
+ continue;
+#endif
+ break;
+ }
+ fclose(tfile); /* oops, it's there; close tfile & try again */
+ }
+}
+
+#else /* ! NO_MKTEMP */
+
+/* Note that mktemp() requires the initial filename to end in six X's */
+#ifndef TEMP_FILE_NAME /* can override from jconfig.h or Makefile */
+#define TEMP_FILE_NAME "%sJPG%dXXXXXX"
+#endif
+
+LOCAL(void)
+select_file_name (char * fname)
+{
+ next_file_num++; /* advance counter */
+ sprintf(fname, TEMP_FILE_NAME, TEMP_DIRECTORY, next_file_num);
+ mktemp(fname); /* make sure file name is unique */
+ /* mktemp replaces the trailing XXXXXX with a unique string of characters */
+}
+
+#endif /* NO_MKTEMP */
+
+
+/*
+ * Memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL(void *)
+jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL(void FAR *)
+jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void FAR *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * It's impossible to do this in a portable way; our current solution is
+ * to make the user tell us (with a default value set at compile time).
+ * If you can actually get the available space, it's a good idea to subtract
+ * a slop factor of 5% or so.
+ */
+
+#ifndef DEFAULT_MAX_MEM /* so can override from makefile */
+#define DEFAULT_MAX_MEM 1000000L /* default: one megabyte */
+#endif
+
+GLOBAL(long)
+jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
+ long max_bytes_needed, long already_allocated)
+{
+ return cinfo->mem->max_memory_to_use - already_allocated;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Backing store objects are only used when the value returned by
+ * jpeg_mem_available is less than the total space needed. You can dispense
+ * with these routines if you have plenty of virtual memory; see jmemnobs.c.
+ */
+
+
+METHODDEF(void)
+read_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ if (fseek(info->temp_file, file_offset, SEEK_SET))
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+ if (JFREAD(info->temp_file, buffer_address, byte_count)
+ != (size_t) byte_count)
+ ERREXIT(cinfo, JERR_TFILE_READ);
+}
+
+
+METHODDEF(void)
+write_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ void FAR * buffer_address,
+ long file_offset, long byte_count)
+{
+ if (fseek(info->temp_file, file_offset, SEEK_SET))
+ ERREXIT(cinfo, JERR_TFILE_SEEK);
+ if (JFWRITE(info->temp_file, buffer_address, byte_count)
+ != (size_t) byte_count)
+ ERREXIT(cinfo, JERR_TFILE_WRITE);
+}
+
+
+METHODDEF(void)
+close_backing_store (j_common_ptr cinfo, backing_store_ptr info)
+{
+ fclose(info->temp_file); /* close the file */
+ unlink(info->temp_name); /* delete the file */
+/* If your system doesn't have unlink(), use remove() instead.
+ * remove() is the ANSI-standard name for this function, but if
+ * your system was ANSI you'd be using jmemansi.c, right?
+ */
+ TRACEMSS(cinfo, 1, JTRC_TFILE_CLOSE, info->temp_name);
+}
+
+
+/*
+ * Initial opening of a backing-store object.
+ */
+
+GLOBAL(void)
+jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ select_file_name(info->temp_name);
+ if ((info->temp_file = fopen(info->temp_name, RW_BINARY)) == NULL)
+ ERREXITS(cinfo, JERR_TFILE_CREATE, info->temp_name);
+ info->read_backing_store = read_backing_store;
+ info->write_backing_store = write_backing_store;
+ info->close_backing_store = close_backing_store;
+ TRACEMSS(cinfo, 1, JTRC_TFILE_OPEN, info->temp_name);
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required.
+ */
+
+GLOBAL(long)
+jpeg_mem_init (j_common_ptr cinfo)
+{
+ next_file_num = 0; /* initialize temp file name generator */
+ return DEFAULT_MAX_MEM; /* default for max_memory_to_use */
+}
+
+GLOBAL(void)
+jpeg_mem_term (j_common_ptr cinfo)
+{
+ /* no work */
+}
--- /dev/null
+/*
+ * jmemnobs.c
+ *
+ * Copyright (C) 1992-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file provides a really simple implementation of the system-
+ * dependent portion of the JPEG memory manager. This implementation
+ * assumes that no backing-store files are needed: all required space
+ * can be obtained from malloc().
+ * This is very portable in the sense that it'll compile on almost anything,
+ * but you'd better have lots of main memory (or virtual memory) if you want
+ * to process big images.
+ * Note that the max_memory_to_use option is ignored by this implementation.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "jmemsys12.h" /* import the system-dependent declarations */
+
+#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP((size_t size));
+extern void free JPP((void *ptr));
+#endif
+
+
+/*
+ * Memory allocation and freeing are controlled by the regular library
+ * routines malloc() and free().
+ */
+
+GLOBAL(void *)
+jpeg_get_small (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_small (j_common_ptr cinfo, void * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * "Large" objects are treated the same as "small" ones.
+ * NB: although we include FAR keywords in the routine declarations,
+ * this file won't actually work in 80x86 small/medium model; at least,
+ * you probably won't be able to process useful-size images in only 64KB.
+ */
+
+GLOBAL(void FAR *)
+jpeg_get_large (j_common_ptr cinfo, size_t sizeofobject)
+{
+ return (void FAR *) malloc(sizeofobject);
+}
+
+GLOBAL(void)
+jpeg_free_large (j_common_ptr cinfo, void FAR * object, size_t sizeofobject)
+{
+ free(object);
+}
+
+
+/*
+ * This routine computes the total memory space available for allocation.
+ * Here we always say, "we got all you want bud!"
+ */
+
+GLOBAL(long)
+jpeg_mem_available (j_common_ptr cinfo, long min_bytes_needed,
+ long max_bytes_needed, long already_allocated)
+{
+ return max_bytes_needed;
+}
+
+
+/*
+ * Backing store (temporary file) management.
+ * Since jpeg_mem_available always promised the moon,
+ * this should never be called and we can just error out.
+ */
+
+GLOBAL(void)
+jpeg_open_backing_store (j_common_ptr cinfo, backing_store_ptr info,
+ long total_bytes_needed)
+{
+ ERREXIT(cinfo, JERR_NO_BACKING_STORE);
+}
+
+
+/*
+ * These routines take care of any system-dependent initialization and
+ * cleanup required. Here, there isn't any.
+ */
+
+GLOBAL(long)
+jpeg_mem_init (j_common_ptr cinfo)
+{
+ return 0; /* just set max_memory_to_use to 0 */
+}
+
+GLOBAL(void)
+jpeg_mem_term (j_common_ptr cinfo)
+{
+ /* no work */
+}
--- /dev/null
+/*
+ * jquant1.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains 1-pass color quantization (color mapping) routines.
+ * These routines provide mapping to a fixed color map using equally spaced
+ * color values. Optional Floyd-Steinberg or ordered dithering is available.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+#ifdef QUANT_1PASS_SUPPORTED
+
+
+/*
+ * The main purpose of 1-pass quantization is to provide a fast, if not very
+ * high quality, colormapped output capability. A 2-pass quantizer usually
+ * gives better visual quality; however, for quantized grayscale output this
+ * quantizer is perfectly adequate. Dithering is highly recommended with this
+ * quantizer, though you can turn it off if you really want to.
+ *
+ * In 1-pass quantization the colormap must be chosen in advance of seeing the
+ * image. We use a map consisting of all combinations of Ncolors[i] color
+ * values for the i'th component. The Ncolors[] values are chosen so that
+ * their product, the total number of colors, is no more than that requested.
+ * (In most cases, the product will be somewhat less.)
+ *
+ * Since the colormap is orthogonal, the representative value for each color
+ * component can be determined without considering the other components;
+ * then these indexes can be combined into a colormap index by a standard
+ * N-dimensional-array-subscript calculation. Most of the arithmetic involved
+ * can be precalculated and stored in the lookup table colorindex[].
+ * colorindex[i][j] maps pixel value j in component i to the nearest
+ * representative value (grid plane) for that component; this index is
+ * multiplied by the array stride for component i, so that the
+ * index of the colormap entry closest to a given pixel value is just
+ * sum( colorindex[component-number][pixel-component-value] )
+ * Aside from being fast, this scheme allows for variable spacing between
+ * representative values with no additional lookup cost.
+ *
+ * If gamma correction has been applied in color conversion, it might be wise
+ * to adjust the color grid spacing so that the representative colors are
+ * equidistant in linear space. At this writing, gamma correction is not
+ * implemented by jdcolor, so nothing is done here.
+ */
+
+
+/* Declarations for ordered dithering.
+ *
+ * We use a standard 16x16 ordered dither array. The basic concept of ordered
+ * dithering is described in many references, for instance Dale Schumacher's
+ * chapter II.2 of Graphics Gems II (James Arvo, ed. Academic Press, 1991).
+ * In place of Schumacher's comparisons against a "threshold" value, we add a
+ * "dither" value to the input pixel and then round the result to the nearest
+ * output value. The dither value is equivalent to (0.5 - threshold) times
+ * the distance between output values. For ordered dithering, we assume that
+ * the output colors are equally spaced; if not, results will probably be
+ * worse, since the dither may be too much or too little at a given point.
+ *
+ * The normal calculation would be to form pixel value + dither, range-limit
+ * this to 0..MAXJSAMPLE, and then index into the colorindex table as usual.
+ * We can skip the separate range-limiting step by extending the colorindex
+ * table in both directions.
+ */
+
+#define ODITHER_SIZE 16 /* dimension of dither matrix */
+/* NB: if ODITHER_SIZE is not a power of 2, ODITHER_MASK uses will break */
+#define ODITHER_CELLS (ODITHER_SIZE*ODITHER_SIZE) /* # cells in matrix */
+#define ODITHER_MASK (ODITHER_SIZE-1) /* mask for wrapping around counters */
+
+typedef int ODITHER_MATRIX[ODITHER_SIZE][ODITHER_SIZE];
+typedef int (*ODITHER_MATRIX_PTR)[ODITHER_SIZE];
+
+static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = {
+ /* Bayer's order-4 dither array. Generated by the code given in
+ * Stephen Hawley's article "Ordered Dithering" in Graphics Gems I.
+ * The values in this array must range from 0 to ODITHER_CELLS-1.
+ */
+ { 0,192, 48,240, 12,204, 60,252, 3,195, 51,243, 15,207, 63,255 },
+ { 128, 64,176,112,140, 76,188,124,131, 67,179,115,143, 79,191,127 },
+ { 32,224, 16,208, 44,236, 28,220, 35,227, 19,211, 47,239, 31,223 },
+ { 160, 96,144, 80,172,108,156, 92,163, 99,147, 83,175,111,159, 95 },
+ { 8,200, 56,248, 4,196, 52,244, 11,203, 59,251, 7,199, 55,247 },
+ { 136, 72,184,120,132, 68,180,116,139, 75,187,123,135, 71,183,119 },
+ { 40,232, 24,216, 36,228, 20,212, 43,235, 27,219, 39,231, 23,215 },
+ { 168,104,152, 88,164,100,148, 84,171,107,155, 91,167,103,151, 87 },
+ { 2,194, 50,242, 14,206, 62,254, 1,193, 49,241, 13,205, 61,253 },
+ { 130, 66,178,114,142, 78,190,126,129, 65,177,113,141, 77,189,125 },
+ { 34,226, 18,210, 46,238, 30,222, 33,225, 17,209, 45,237, 29,221 },
+ { 162, 98,146, 82,174,110,158, 94,161, 97,145, 81,173,109,157, 93 },
+ { 10,202, 58,250, 6,198, 54,246, 9,201, 57,249, 5,197, 53,245 },
+ { 138, 74,186,122,134, 70,182,118,137, 73,185,121,133, 69,181,117 },
+ { 42,234, 26,218, 38,230, 22,214, 41,233, 25,217, 37,229, 21,213 },
+ { 170,106,154, 90,166,102,150, 86,169,105,153, 89,165,101,149, 85 }
+};
+
+
+/* Declarations for Floyd-Steinberg dithering.
+ *
+ * Errors are accumulated into the array fserrors[], at a resolution of
+ * 1/16th of a pixel count. The error at a given pixel is propagated
+ * to its not-yet-processed neighbors using the standard F-S fractions,
+ * ... (here) 7/16
+ * 3/16 5/16 1/16
+ * We work left-to-right on even rows, right-to-left on odd rows.
+ *
+ * We can get away with a single array (holding one row's worth of errors)
+ * by using it to store the current row's errors at pixel columns not yet
+ * processed, but the next row's errors at columns already processed. We
+ * need only a few extra variables to hold the errors immediately around the
+ * current column. (If we are lucky, those variables are in registers, but
+ * even if not, they're probably cheaper to access than array elements are.)
+ *
+ * The fserrors[] array is indexed [component#][position].
+ * We provide (#columns + 2) entries per component; the extra entry at each
+ * end saves us from special-casing the first and last pixels.
+ *
+ * Note: on a wide image, we might not have enough room in a PC's near data
+ * segment to hold the error array; so it is allocated with alloc_large.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+typedef INT16 FSERROR; /* 16 bits should be enough */
+typedef int LOCFSERROR; /* use 'int' for calculation temps */
+#else
+typedef INT32 FSERROR; /* may need more than 16 bits */
+typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */
+#endif
+
+typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */
+
+
+/* Private subobject */
+
+#define MAX_Q_COMPS 4 /* max components I can handle */
+
+typedef struct {
+ struct jpeg_color_quantizer pub; /* public fields */
+
+ /* Initially allocated colormap is saved here */
+ JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */
+ int sv_actual; /* number of entries in use */
+
+ JSAMPARRAY colorindex; /* Precomputed mapping for speed */
+ /* colorindex[i][j] = index of color closest to pixel value j in component i,
+ * premultiplied as described above. Since colormap indexes must fit into
+ * JSAMPLEs, the entries of this array will too.
+ */
+ boolean is_padded; /* is the colorindex padded for odither? */
+
+ int Ncolors[MAX_Q_COMPS]; /* # of values alloced to each component */
+
+ /* Variables for ordered dithering */
+ int row_index; /* cur row's vertical index in dither matrix */
+ ODITHER_MATRIX_PTR odither[MAX_Q_COMPS]; /* one dither array per component */
+
+ /* Variables for Floyd-Steinberg dithering */
+ FSERRPTR fserrors[MAX_Q_COMPS]; /* accumulated errors */
+ boolean on_odd_row; /* flag to remember which row we are on */
+} my_cquantizer;
+
+typedef my_cquantizer * my_cquantize_ptr;
+
+
+/*
+ * Policy-making subroutines for create_colormap and create_colorindex.
+ * These routines determine the colormap to be used. The rest of the module
+ * only assumes that the colormap is orthogonal.
+ *
+ * * select_ncolors decides how to divvy up the available colors
+ * among the components.
+ * * output_value defines the set of representative values for a component.
+ * * largest_input_value defines the mapping from input values to
+ * representative values for a component.
+ * Note that the latter two routines may impose different policies for
+ * different components, though this is not currently done.
+ */
+
+
+LOCAL(int)
+select_ncolors (j_decompress_ptr cinfo, int Ncolors[])
+/* Determine allocation of desired colors to components, */
+/* and fill in Ncolors[] array to indicate choice. */
+/* Return value is total number of colors (product of Ncolors[] values). */
+{
+ int nc = cinfo->out_color_components; /* number of color components */
+ int max_colors = cinfo->desired_number_of_colors;
+ int total_colors, iroot, i, j;
+ boolean changed;
+ long temp;
+ static const int RGB_order[3] = { RGB_GREEN, RGB_RED, RGB_BLUE };
+
+ /* We can allocate at least the nc'th root of max_colors per component. */
+ /* Compute floor(nc'th root of max_colors). */
+ iroot = 1;
+ do {
+ iroot++;
+ temp = iroot; /* set temp = iroot ** nc */
+ for (i = 1; i < nc; i++)
+ temp *= iroot;
+ } while (temp <= (long) max_colors); /* repeat till iroot exceeds root */
+ iroot--; /* now iroot = floor(root) */
+
+ /* Must have at least 2 color values per component */
+ if (iroot < 2)
+ ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, (int) temp);
+
+ /* Initialize to iroot color values for each component */
+ total_colors = 1;
+ for (i = 0; i < nc; i++) {
+ Ncolors[i] = iroot;
+ total_colors *= iroot;
+ }
+ /* We may be able to increment the count for one or more components without
+ * exceeding max_colors, though we know not all can be incremented.
+ * Sometimes, the first component can be incremented more than once!
+ * (Example: for 16 colors, we start at 2*2*2, go to 3*2*2, then 4*2*2.)
+ * In RGB colorspace, try to increment G first, then R, then B.
+ */
+ do {
+ changed = FALSE;
+ for (i = 0; i < nc; i++) {
+ j = (cinfo->out_color_space == JCS_RGB ? RGB_order[i] : i);
+ /* calculate new total_colors if Ncolors[j] is incremented */
+ temp = total_colors / Ncolors[j];
+ temp *= Ncolors[j]+1; /* done in long arith to avoid oflo */
+ if (temp > (long) max_colors)
+ break; /* won't fit, done with this pass */
+ Ncolors[j]++; /* OK, apply the increment */
+ total_colors = (int) temp;
+ changed = TRUE;
+ }
+ } while (changed);
+
+ return total_colors;
+}
+
+
+LOCAL(int)
+output_value (j_decompress_ptr cinfo, int ci, int j, int maxj)
+/* Return j'th output value, where j will range from 0 to maxj */
+/* The output values must fall in 0..MAXJSAMPLE in increasing order */
+{
+ /* We always provide values 0 and MAXJSAMPLE for each component;
+ * any additional values are equally spaced between these limits.
+ * (Forcing the upper and lower values to the limits ensures that
+ * dithering can't produce a color outside the selected gamut.)
+ */
+ return (int) (((INT32) j * MAXJSAMPLE + maxj/2) / maxj);
+}
+
+
+LOCAL(int)
+largest_input_value (j_decompress_ptr cinfo, int ci, int j, int maxj)
+/* Return largest input value that should map to j'th output value */
+/* Must have largest(j=0) >= 0, and largest(j=maxj) >= MAXJSAMPLE */
+{
+ /* Breakpoints are halfway between values returned by output_value */
+ return (int) (((INT32) (2*j + 1) * MAXJSAMPLE + maxj) / (2*maxj));
+}
+
+
+/*
+ * Create the colormap.
+ */
+
+LOCAL(void)
+create_colormap (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ JSAMPARRAY colormap; /* Created colormap */
+ int total_colors; /* Number of distinct output colors */
+ int i,j,k, nci, blksize, blkdist, ptr, val;
+
+ /* Select number of colors for each component */
+ total_colors = select_ncolors(cinfo, cquantize->Ncolors);
+
+ /* Report selected color counts */
+ if (cinfo->out_color_components == 3)
+ TRACEMS4(cinfo, 1, JTRC_QUANT_3_NCOLORS,
+ total_colors, cquantize->Ncolors[0],
+ cquantize->Ncolors[1], cquantize->Ncolors[2]);
+ else
+ TRACEMS1(cinfo, 1, JTRC_QUANT_NCOLORS, total_colors);
+
+ /* Allocate and fill in the colormap. */
+ /* The colors are ordered in the map in standard row-major order, */
+ /* i.e. rightmost (highest-indexed) color changes most rapidly. */
+
+ colormap = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) total_colors, (JDIMENSION) cinfo->out_color_components);
+
+ /* blksize is number of adjacent repeated entries for a component */
+ /* blkdist is distance between groups of identical entries for a component */
+ blkdist = total_colors;
+
+ for (i = 0; i < cinfo->out_color_components; i++) {
+ /* fill in colormap entries for i'th color component */
+ nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
+ blksize = blkdist / nci;
+ for (j = 0; j < nci; j++) {
+ /* Compute j'th output value (out of nci) for component */
+ val = output_value(cinfo, i, j, nci-1);
+ /* Fill in all colormap entries that have this value of this component */
+ for (ptr = j * blksize; ptr < total_colors; ptr += blkdist) {
+ /* fill in blksize entries beginning at ptr */
+ for (k = 0; k < blksize; k++)
+ colormap[i][ptr+k] = (JSAMPLE) val;
+ }
+ }
+ blkdist = blksize; /* blksize of this color is blkdist of next */
+ }
+
+ /* Save the colormap in private storage,
+ * where it will survive color quantization mode changes.
+ */
+ cquantize->sv_colormap = colormap;
+ cquantize->sv_actual = total_colors;
+}
+
+
+/*
+ * Create the color index table.
+ */
+
+LOCAL(void)
+create_colorindex (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ JSAMPROW indexptr;
+ int i,j,k, nci, blksize, val, pad;
+
+ /* For ordered dither, we pad the color index tables by MAXJSAMPLE in
+ * each direction (input index values can be -MAXJSAMPLE .. 2*MAXJSAMPLE).
+ * This is not necessary in the other dithering modes. However, we
+ * flag whether it was done in case user changes dithering mode.
+ */
+ if (cinfo->dither_mode == JDITHER_ORDERED) {
+ pad = MAXJSAMPLE*2;
+ cquantize->is_padded = TRUE;
+ } else {
+ pad = 0;
+ cquantize->is_padded = FALSE;
+ }
+
+ cquantize->colorindex = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) (MAXJSAMPLE+1 + pad),
+ (JDIMENSION) cinfo->out_color_components);
+
+ /* blksize is number of adjacent repeated entries for a component */
+ blksize = cquantize->sv_actual;
+
+ for (i = 0; i < cinfo->out_color_components; i++) {
+ /* fill in colorindex entries for i'th color component */
+ nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
+ blksize = blksize / nci;
+
+ /* adjust colorindex pointers to provide padding at negative indexes. */
+ if (pad)
+ cquantize->colorindex[i] += MAXJSAMPLE;
+
+ /* in loop, val = index of current output value, */
+ /* and k = largest j that maps to current val */
+ indexptr = cquantize->colorindex[i];
+ val = 0;
+ k = largest_input_value(cinfo, i, 0, nci-1);
+ for (j = 0; j <= MAXJSAMPLE; j++) {
+ while (j > k) /* advance val if past boundary */
+ k = largest_input_value(cinfo, i, ++val, nci-1);
+ /* premultiply so that no multiplication needed in main processing */
+ indexptr[j] = (JSAMPLE) (val * blksize);
+ }
+ /* Pad at both ends if necessary */
+ if (pad)
+ for (j = 1; j <= MAXJSAMPLE; j++) {
+ indexptr[-j] = indexptr[0];
+ indexptr[MAXJSAMPLE+j] = indexptr[MAXJSAMPLE];
+ }
+ }
+}
+
+
+/*
+ * Create an ordered-dither array for a component having ncolors
+ * distinct output values.
+ */
+
+LOCAL(ODITHER_MATRIX_PTR)
+make_odither_array (j_decompress_ptr cinfo, int ncolors)
+{
+ ODITHER_MATRIX_PTR odither;
+ int j,k;
+ INT32 num,den;
+
+ odither = (ODITHER_MATRIX_PTR)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(ODITHER_MATRIX));
+ /* The inter-value distance for this color is MAXJSAMPLE/(ncolors-1).
+ * Hence the dither value for the matrix cell with fill order f
+ * (f=0..N-1) should be (N-1-2*f)/(2*N) * MAXJSAMPLE/(ncolors-1).
+ * On 16-bit-int machine, be careful to avoid overflow.
+ */
+ den = 2 * ODITHER_CELLS * ((INT32) (ncolors - 1));
+ for (j = 0; j < ODITHER_SIZE; j++) {
+ for (k = 0; k < ODITHER_SIZE; k++) {
+ num = ((INT32) (ODITHER_CELLS-1 - 2*((int)base_dither_matrix[j][k])))
+ * MAXJSAMPLE;
+ /* Ensure round towards zero despite C's lack of consistency
+ * about rounding negative values in integer division...
+ */
+ odither[j][k] = (int) (num<0 ? -((-num)/den) : num/den);
+ }
+ }
+ return odither;
+}
+
+
+/*
+ * Create the ordered-dither tables.
+ * Components having the same number of representative colors may
+ * share a dither table.
+ */
+
+LOCAL(void)
+create_odither_tables (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ ODITHER_MATRIX_PTR odither;
+ int i, j, nci;
+
+ for (i = 0; i < cinfo->out_color_components; i++) {
+ nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
+ odither = NULL; /* search for matching prior component */
+ for (j = 0; j < i; j++) {
+ if (nci == cquantize->Ncolors[j]) {
+ odither = cquantize->odither[j];
+ break;
+ }
+ }
+ if (odither == NULL) /* need a new table? */
+ odither = make_odither_array(cinfo, nci);
+ cquantize->odither[i] = odither;
+ }
+}
+
+
+/*
+ * Map some rows of pixels to the output colormapped representation.
+ */
+
+METHODDEF(void)
+color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+ JSAMPARRAY output_buf, int num_rows)
+/* General case, no dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ JSAMPARRAY colorindex = cquantize->colorindex;
+ register int pixcode, ci;
+ register JSAMPROW ptrin, ptrout;
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+ register int nc = cinfo->out_color_components;
+
+ for (row = 0; row < num_rows; row++) {
+ ptrin = input_buf[row];
+ ptrout = output_buf[row];
+ for (col = width; col > 0; col--) {
+ pixcode = 0;
+ for (ci = 0; ci < nc; ci++) {
+ pixcode += GETJSAMPLE(colorindex[ci][GETJSAMPLE(*ptrin++)]);
+ }
+ *ptrout++ = (JSAMPLE) pixcode;
+ }
+ }
+}
+
+
+METHODDEF(void)
+color_quantize3 (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+ JSAMPARRAY output_buf, int num_rows)
+/* Fast path for out_color_components==3, no dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ register int pixcode;
+ register JSAMPROW ptrin, ptrout;
+ JSAMPROW colorindex0 = cquantize->colorindex[0];
+ JSAMPROW colorindex1 = cquantize->colorindex[1];
+ JSAMPROW colorindex2 = cquantize->colorindex[2];
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+
+ for (row = 0; row < num_rows; row++) {
+ ptrin = input_buf[row];
+ ptrout = output_buf[row];
+ for (col = width; col > 0; col--) {
+ pixcode = GETJSAMPLE(colorindex0[GETJSAMPLE(*ptrin++)]);
+ pixcode += GETJSAMPLE(colorindex1[GETJSAMPLE(*ptrin++)]);
+ pixcode += GETJSAMPLE(colorindex2[GETJSAMPLE(*ptrin++)]);
+ *ptrout++ = (JSAMPLE) pixcode;
+ }
+ }
+}
+
+
+METHODDEF(void)
+quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+ JSAMPARRAY output_buf, int num_rows)
+/* General case, with ordered dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ register JSAMPROW input_ptr;
+ register JSAMPROW output_ptr;
+ JSAMPROW colorindex_ci;
+ int * dither; /* points to active row of dither matrix */
+ int row_index, col_index; /* current indexes into dither matrix */
+ int nc = cinfo->out_color_components;
+ int ci;
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+
+ for (row = 0; row < num_rows; row++) {
+ /* Initialize output values to 0 so can process components separately */
+ jzero_far((void FAR *) output_buf[row],
+ (size_t) (width * SIZEOF(JSAMPLE)));
+ row_index = cquantize->row_index;
+ for (ci = 0; ci < nc; ci++) {
+ input_ptr = input_buf[row] + ci;
+ output_ptr = output_buf[row];
+ colorindex_ci = cquantize->colorindex[ci];
+ dither = cquantize->odither[ci][row_index];
+ col_index = 0;
+
+ for (col = width; col > 0; col--) {
+ /* Form pixel value + dither, range-limit to 0..MAXJSAMPLE,
+ * select output value, accumulate into output code for this pixel.
+ * Range-limiting need not be done explicitly, as we have extended
+ * the colorindex table to produce the right answers for out-of-range
+ * inputs. The maximum dither is +- MAXJSAMPLE; this sets the
+ * required amount of padding.
+ */
+ *output_ptr += colorindex_ci[GETJSAMPLE(*input_ptr)+dither[col_index]];
+ input_ptr += nc;
+ output_ptr++;
+ col_index = (col_index + 1) & ODITHER_MASK;
+ }
+ }
+ /* Advance row index for next row */
+ row_index = (row_index + 1) & ODITHER_MASK;
+ cquantize->row_index = row_index;
+ }
+}
+
+
+METHODDEF(void)
+quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+ JSAMPARRAY output_buf, int num_rows)
+/* Fast path for out_color_components==3, with ordered dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ register int pixcode;
+ register JSAMPROW input_ptr;
+ register JSAMPROW output_ptr;
+ JSAMPROW colorindex0 = cquantize->colorindex[0];
+ JSAMPROW colorindex1 = cquantize->colorindex[1];
+ JSAMPROW colorindex2 = cquantize->colorindex[2];
+ int * dither0; /* points to active row of dither matrix */
+ int * dither1;
+ int * dither2;
+ int row_index, col_index; /* current indexes into dither matrix */
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+
+ for (row = 0; row < num_rows; row++) {
+ row_index = cquantize->row_index;
+ input_ptr = input_buf[row];
+ output_ptr = output_buf[row];
+ dither0 = cquantize->odither[0][row_index];
+ dither1 = cquantize->odither[1][row_index];
+ dither2 = cquantize->odither[2][row_index];
+ col_index = 0;
+
+ for (col = width; col > 0; col--) {
+ pixcode = GETJSAMPLE(colorindex0[GETJSAMPLE(*input_ptr++) +
+ dither0[col_index]]);
+ pixcode += GETJSAMPLE(colorindex1[GETJSAMPLE(*input_ptr++) +
+ dither1[col_index]]);
+ pixcode += GETJSAMPLE(colorindex2[GETJSAMPLE(*input_ptr++) +
+ dither2[col_index]]);
+ *output_ptr++ = (JSAMPLE) pixcode;
+ col_index = (col_index + 1) & ODITHER_MASK;
+ }
+ row_index = (row_index + 1) & ODITHER_MASK;
+ cquantize->row_index = row_index;
+ }
+}
+
+
+METHODDEF(void)
+quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+ JSAMPARRAY output_buf, int num_rows)
+/* General case, with Floyd-Steinberg dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ register LOCFSERROR cur; /* current error or pixel value */
+ LOCFSERROR belowerr; /* error for pixel below cur */
+ LOCFSERROR bpreverr; /* error for below/prev col */
+ LOCFSERROR bnexterr; /* error for below/next col */
+ LOCFSERROR delta;
+ register FSERRPTR errorptr; /* => fserrors[] at column before current */
+ register JSAMPROW input_ptr;
+ register JSAMPROW output_ptr;
+ JSAMPROW colorindex_ci;
+ JSAMPROW colormap_ci;
+ int pixcode;
+ int nc = cinfo->out_color_components;
+ int dir; /* 1 for left-to-right, -1 for right-to-left */
+ int dirnc; /* dir * nc */
+ int ci;
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+ JSAMPLE *range_limit = cinfo->sample_range_limit;
+ SHIFT_TEMPS
+
+ for (row = 0; row < num_rows; row++) {
+ /* Initialize output values to 0 so can process components separately */
+ jzero_far((void FAR *) output_buf[row],
+ (size_t) (width * SIZEOF(JSAMPLE)));
+ for (ci = 0; ci < nc; ci++) {
+ input_ptr = input_buf[row] + ci;
+ output_ptr = output_buf[row];
+ if (cquantize->on_odd_row) {
+ /* work right to left in this row */
+ input_ptr += (width-1) * nc; /* so point to rightmost pixel */
+ output_ptr += width-1;
+ dir = -1;
+ dirnc = -nc;
+ errorptr = cquantize->fserrors[ci] + (width+1); /* => entry after last column */
+ } else {
+ /* work left to right in this row */
+ dir = 1;
+ dirnc = nc;
+ errorptr = cquantize->fserrors[ci]; /* => entry before first column */
+ }
+ colorindex_ci = cquantize->colorindex[ci];
+ colormap_ci = cquantize->sv_colormap[ci];
+ /* Preset error values: no error propagated to first pixel from left */
+ cur = 0;
+ /* and no error propagated to row below yet */
+ belowerr = bpreverr = 0;
+
+ for (col = width; col > 0; col--) {
+ /* cur holds the error propagated from the previous pixel on the
+ * current line. Add the error propagated from the previous line
+ * to form the complete error correction term for this pixel, and
+ * round the error term (which is expressed * 16) to an integer.
+ * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct
+ * for either sign of the error value.
+ * Note: errorptr points to *previous* column's array entry.
+ */
+ cur = RIGHT_SHIFT(cur + errorptr[dir] + 8, 4);
+ /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE.
+ * The maximum error is +- MAXJSAMPLE; this sets the required size
+ * of the range_limit array.
+ */
+ cur += GETJSAMPLE(*input_ptr);
+ cur = GETJSAMPLE(range_limit[cur]);
+ /* Select output value, accumulate into output code for this pixel */
+ pixcode = GETJSAMPLE(colorindex_ci[cur]);
+ *output_ptr += (JSAMPLE) pixcode;
+ /* Compute actual representation error at this pixel */
+ /* Note: we can do this even though we don't have the final */
+ /* pixel code, because the colormap is orthogonal. */
+ cur -= GETJSAMPLE(colormap_ci[pixcode]);
+ /* Compute error fractions to be propagated to adjacent pixels.
+ * Add these into the running sums, and simultaneously shift the
+ * next-line error sums left by 1 column.
+ */
+ bnexterr = cur;
+ delta = cur * 2;
+ cur += delta; /* form error * 3 */
+ errorptr[0] = (FSERROR) (bpreverr + cur);
+ cur += delta; /* form error * 5 */
+ bpreverr = belowerr + cur;
+ belowerr = bnexterr;
+ cur += delta; /* form error * 7 */
+ /* At this point cur contains the 7/16 error value to be propagated
+ * to the next pixel on the current line, and all the errors for the
+ * next line have been shifted over. We are therefore ready to move on.
+ */
+ input_ptr += dirnc; /* advance input ptr to next column */
+ output_ptr += dir; /* advance output ptr to next column */
+ errorptr += dir; /* advance errorptr to current column */
+ }
+ /* Post-loop cleanup: we must unload the final error value into the
+ * final fserrors[] entry. Note we need not unload belowerr because
+ * it is for the dummy column before or after the actual array.
+ */
+ errorptr[0] = (FSERROR) bpreverr; /* unload prev err into array */
+ }
+ cquantize->on_odd_row = (cquantize->on_odd_row ? FALSE : TRUE);
+ }
+}
+
+
+/*
+ * Allocate workspace for Floyd-Steinberg errors.
+ */
+
+LOCAL(void)
+alloc_fs_workspace (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ size_t arraysize;
+ int i;
+
+ arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR));
+ for (i = 0; i < cinfo->out_color_components; i++) {
+ cquantize->fserrors[i] = (FSERRPTR)
+ (*cinfo->mem->alloc_large)((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize);
+ }
+}
+
+
+/*
+ * Initialize for one-pass color quantization.
+ */
+
+METHODDEF(void)
+start_pass_1_quant (j_decompress_ptr cinfo, boolean is_pre_scan)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ size_t arraysize;
+ int i;
+
+ /* Install my colormap. */
+ cinfo->colormap = cquantize->sv_colormap;
+ cinfo->actual_number_of_colors = cquantize->sv_actual;
+
+ /* Initialize for desired dithering mode. */
+ switch (cinfo->dither_mode) {
+ case JDITHER_NONE:
+ if (cinfo->out_color_components == 3)
+ cquantize->pub.color_quantize = color_quantize3;
+ else
+ cquantize->pub.color_quantize = color_quantize;
+ break;
+ case JDITHER_ORDERED:
+ if (cinfo->out_color_components == 3)
+ cquantize->pub.color_quantize = quantize3_ord_dither;
+ else
+ cquantize->pub.color_quantize = quantize_ord_dither;
+ cquantize->row_index = 0; /* initialize state for ordered dither */
+ /* If user changed to ordered dither from another mode,
+ * we must recreate the color index table with padding.
+ * This will cost extra space, but probably isn't very likely.
+ */
+ if (! cquantize->is_padded)
+ create_colorindex(cinfo);
+ /* Create ordered-dither tables if we didn't already. */
+ if (cquantize->odither[0] == NULL)
+ create_odither_tables(cinfo);
+ break;
+ case JDITHER_FS:
+ cquantize->pub.color_quantize = quantize_fs_dither;
+ cquantize->on_odd_row = FALSE; /* initialize state for F-S dither */
+ /* Allocate Floyd-Steinberg workspace if didn't already. */
+ if (cquantize->fserrors[0] == NULL)
+ alloc_fs_workspace(cinfo);
+ /* Initialize the propagated errors to zero. */
+ arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR));
+ for (i = 0; i < cinfo->out_color_components; i++)
+ jzero_far((void FAR *) cquantize->fserrors[i], arraysize);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+ break;
+ }
+}
+
+
+/*
+ * Finish up at the end of the pass.
+ */
+
+METHODDEF(void)
+finish_pass_1_quant (j_decompress_ptr cinfo)
+{
+ /* no work in 1-pass case */
+}
+
+
+/*
+ * Switch to a new external colormap between output passes.
+ * Shouldn't get to this module!
+ */
+
+METHODDEF(void)
+new_color_map_1_quant (j_decompress_ptr cinfo)
+{
+ ERREXIT(cinfo, JERR_MODE_CHANGE);
+}
+
+
+/*
+ * Module initialization routine for 1-pass color quantization.
+ */
+
+GLOBAL(void)
+jinit_1pass_quantizer (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize;
+
+ cquantize = (my_cquantize_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_cquantizer));
+ cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize;
+ cquantize->pub.start_pass = start_pass_1_quant;
+ cquantize->pub.finish_pass = finish_pass_1_quant;
+ cquantize->pub.new_color_map = new_color_map_1_quant;
+ cquantize->fserrors[0] = NULL; /* Flag FS workspace not allocated */
+ cquantize->odither[0] = NULL; /* Also flag odither arrays not allocated */
+
+ /* Make sure my internal arrays won't overflow */
+ if (cinfo->out_color_components > MAX_Q_COMPS)
+ ERREXIT1(cinfo, JERR_QUANT_COMPONENTS, MAX_Q_COMPS);
+ /* Make sure colormap indexes can be represented by JSAMPLEs */
+ if (cinfo->desired_number_of_colors > (MAXJSAMPLE+1))
+ ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXJSAMPLE+1);
+
+ /* Create the colormap and color index table. */
+ create_colormap(cinfo);
+ create_colorindex(cinfo);
+
+ /* Allocate Floyd-Steinberg workspace now if requested.
+ * We do this now since it is FAR storage and may affect the memory
+ * manager's space calculations. If the user changes to FS dither
+ * mode in a later pass, we will allocate the space then, and will
+ * possibly overrun the max_memory_to_use setting.
+ */
+ if (cinfo->dither_mode == JDITHER_FS)
+ alloc_fs_workspace(cinfo);
+}
+
+#endif /* QUANT_1PASS_SUPPORTED */
--- /dev/null
+/*
+ * jquant2.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains 2-pass color quantization (color mapping) routines.
+ * These routines provide selection of a custom color map for an image,
+ * followed by mapping of the image to that color map, with optional
+ * Floyd-Steinberg dithering.
+ * It is also possible to use just the second pass to map to an arbitrary
+ * externally-given color map.
+ *
+ * Note: ordered dithering is not supported, since there isn't any fast
+ * way to compute intercolor distances; it's unclear that ordered dither's
+ * fundamental assumptions even hold with an irregularly spaced color map.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+#ifdef QUANT_2PASS_SUPPORTED
+
+
+/*
+ * This module implements the well-known Heckbert paradigm for color
+ * quantization. Most of the ideas used here can be traced back to
+ * Heckbert's seminal paper
+ * Heckbert, Paul. "Color Image Quantization for Frame Buffer Display",
+ * Proc. SIGGRAPH '82, Computer Graphics v.16 #3 (July 1982), pp 297-304.
+ *
+ * In the first pass over the image, we accumulate a histogram showing the
+ * usage count of each possible color. To keep the histogram to a reasonable
+ * size, we reduce the precision of the input; typical practice is to retain
+ * 5 or 6 bits per color, so that 8 or 4 different input values are counted
+ * in the same histogram cell.
+ *
+ * Next, the color-selection step begins with a box representing the whole
+ * color space, and repeatedly splits the "largest" remaining box until we
+ * have as many boxes as desired colors. Then the mean color in each
+ * remaining box becomes one of the possible output colors.
+ *
+ * The second pass over the image maps each input pixel to the closest output
+ * color (optionally after applying a Floyd-Steinberg dithering correction).
+ * This mapping is logically trivial, but making it go fast enough requires
+ * considerable care.
+ *
+ * Heckbert-style quantizers vary a good deal in their policies for choosing
+ * the "largest" box and deciding where to cut it. The particular policies
+ * used here have proved out well in experimental comparisons, but better ones
+ * may yet be found.
+ *
+ * In earlier versions of the IJG code, this module quantized in YCbCr color
+ * space, processing the raw upsampled data without a color conversion step.
+ * This allowed the color conversion math to be done only once per colormap
+ * entry, not once per pixel. However, that optimization precluded other
+ * useful optimizations (such as merging color conversion with upsampling)
+ * and it also interfered with desired capabilities such as quantizing to an
+ * externally-supplied colormap. We have therefore abandoned that approach.
+ * The present code works in the post-conversion color space, typically RGB.
+ *
+ * To improve the visual quality of the results, we actually work in scaled
+ * RGB space, giving G distances more weight than R, and R in turn more than
+ * B. To do everything in integer math, we must use integer scale factors.
+ * The 2/3/1 scale factors used here correspond loosely to the relative
+ * weights of the colors in the NTSC grayscale equation.
+ * If you want to use this code to quantize a non-RGB color space, you'll
+ * probably need to change these scale factors.
+ */
+
+#define R_SCALE 2 /* scale R distances by this much */
+#define G_SCALE 3 /* scale G distances by this much */
+#define B_SCALE 1 /* and B by this much */
+
+/* Relabel R/G/B as components 0/1/2, respecting the RGB ordering defined
+ * in jmorecfg.h. As the code stands, it will do the right thing for R,G,B
+ * and B,G,R orders. If you define some other weird order in jmorecfg.h,
+ * you'll get compile errors until you extend this logic. In that case
+ * you'll probably want to tweak the histogram sizes too.
+ */
+
+#if RGB_RED == 0
+#define C0_SCALE R_SCALE
+#endif
+#if RGB_BLUE == 0
+#define C0_SCALE B_SCALE
+#endif
+#if RGB_GREEN == 1
+#define C1_SCALE G_SCALE
+#endif
+#if RGB_RED == 2
+#define C2_SCALE R_SCALE
+#endif
+#if RGB_BLUE == 2
+#define C2_SCALE B_SCALE
+#endif
+
+
+/*
+ * First we have the histogram data structure and routines for creating it.
+ *
+ * The number of bits of precision can be adjusted by changing these symbols.
+ * We recommend keeping 6 bits for G and 5 each for R and B.
+ * If you have plenty of memory and cycles, 6 bits all around gives marginally
+ * better results; if you are short of memory, 5 bits all around will save
+ * some space but degrade the results.
+ * To maintain a fully accurate histogram, we'd need to allocate a "long"
+ * (preferably unsigned long) for each cell. In practice this is overkill;
+ * we can get by with 16 bits per cell. Few of the cell counts will overflow,
+ * and clamping those that do overflow to the maximum value will give close-
+ * enough results. This reduces the recommended histogram size from 256Kb
+ * to 128Kb, which is a useful savings on PC-class machines.
+ * (In the second pass the histogram space is re-used for pixel mapping data;
+ * in that capacity, each cell must be able to store zero to the number of
+ * desired colors. 16 bits/cell is plenty for that too.)
+ * Since the JPEG code is intended to run in small memory model on 80x86
+ * machines, we can't just allocate the histogram in one chunk. Instead
+ * of a true 3-D array, we use a row of pointers to 2-D arrays. Each
+ * pointer corresponds to a C0 value (typically 2^5 = 32 pointers) and
+ * each 2-D array has 2^6*2^5 = 2048 or 2^6*2^6 = 4096 entries. Note that
+ * on 80x86 machines, the pointer row is in near memory but the actual
+ * arrays are in far memory (same arrangement as we use for image arrays).
+ */
+
+#define MAXNUMCOLORS (MAXJSAMPLE+1) /* maximum size of colormap */
+
+/* These will do the right thing for either R,G,B or B,G,R color order,
+ * but you may not like the results for other color orders.
+ */
+#define HIST_C0_BITS 5 /* bits of precision in R/B histogram */
+#define HIST_C1_BITS 6 /* bits of precision in G histogram */
+#define HIST_C2_BITS 5 /* bits of precision in B/R histogram */
+
+/* Number of elements along histogram axes. */
+#define HIST_C0_ELEMS (1<<HIST_C0_BITS)
+#define HIST_C1_ELEMS (1<<HIST_C1_BITS)
+#define HIST_C2_ELEMS (1<<HIST_C2_BITS)
+
+/* These are the amounts to shift an input value to get a histogram index. */
+#define C0_SHIFT (BITS_IN_JSAMPLE-HIST_C0_BITS)
+#define C1_SHIFT (BITS_IN_JSAMPLE-HIST_C1_BITS)
+#define C2_SHIFT (BITS_IN_JSAMPLE-HIST_C2_BITS)
+
+
+typedef UINT16 histcell; /* histogram cell; prefer an unsigned type */
+
+typedef histcell FAR * histptr; /* for pointers to histogram cells */
+
+typedef histcell hist1d[HIST_C2_ELEMS]; /* typedefs for the array */
+typedef hist1d FAR * hist2d; /* type for the 2nd-level pointers */
+typedef hist2d * hist3d; /* type for top-level pointer */
+
+
+/* Declarations for Floyd-Steinberg dithering.
+ *
+ * Errors are accumulated into the array fserrors[], at a resolution of
+ * 1/16th of a pixel count. The error at a given pixel is propagated
+ * to its not-yet-processed neighbors using the standard F-S fractions,
+ * ... (here) 7/16
+ * 3/16 5/16 1/16
+ * We work left-to-right on even rows, right-to-left on odd rows.
+ *
+ * We can get away with a single array (holding one row's worth of errors)
+ * by using it to store the current row's errors at pixel columns not yet
+ * processed, but the next row's errors at columns already processed. We
+ * need only a few extra variables to hold the errors immediately around the
+ * current column. (If we are lucky, those variables are in registers, but
+ * even if not, they're probably cheaper to access than array elements are.)
+ *
+ * The fserrors[] array has (#columns + 2) entries; the extra entry at
+ * each end saves us from special-casing the first and last pixels.
+ * Each entry is three values long, one value for each color component.
+ *
+ * Note: on a wide image, we might not have enough room in a PC's near data
+ * segment to hold the error array; so it is allocated with alloc_large.
+ */
+
+#if BITS_IN_JSAMPLE == 8
+typedef INT16 FSERROR; /* 16 bits should be enough */
+typedef int LOCFSERROR; /* use 'int' for calculation temps */
+#else
+typedef INT32 FSERROR; /* may need more than 16 bits */
+typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */
+#endif
+
+typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */
+
+
+/* Private subobject */
+
+typedef struct {
+ struct jpeg_color_quantizer pub; /* public fields */
+
+ /* Space for the eventually created colormap is stashed here */
+ JSAMPARRAY sv_colormap; /* colormap allocated at init time */
+ int desired; /* desired # of colors = size of colormap */
+
+ /* Variables for accumulating image statistics */
+ hist3d histogram; /* pointer to the histogram */
+
+ boolean needs_zeroed; /* TRUE if next pass must zero histogram */
+
+ /* Variables for Floyd-Steinberg dithering */
+ FSERRPTR fserrors; /* accumulated errors */
+ boolean on_odd_row; /* flag to remember which row we are on */
+ int * error_limiter; /* table for clamping the applied error */
+} my_cquantizer;
+
+typedef my_cquantizer * my_cquantize_ptr;
+
+
+/*
+ * Prescan some rows of pixels.
+ * In this module the prescan simply updates the histogram, which has been
+ * initialized to zeroes by start_pass.
+ * An output_buf parameter is required by the method signature, but no data
+ * is actually output (in fact the buffer controller is probably passing a
+ * NULL pointer).
+ */
+
+METHODDEF(void)
+prescan_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
+ JSAMPARRAY output_buf, int num_rows)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ register JSAMPROW ptr;
+ register histptr histp;
+ register hist3d histogram = cquantize->histogram;
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+
+ for (row = 0; row < num_rows; row++) {
+ ptr = input_buf[row];
+ for (col = width; col > 0; col--) {
+ /* get pixel value and index into the histogram */
+ histp = & histogram[GETJSAMPLE(ptr[0]) >> C0_SHIFT]
+ [GETJSAMPLE(ptr[1]) >> C1_SHIFT]
+ [GETJSAMPLE(ptr[2]) >> C2_SHIFT];
+ /* increment, check for overflow and undo increment if so. */
+ if (++(*histp) <= 0)
+ (*histp)--;
+ ptr += 3;
+ }
+ }
+}
+
+
+/*
+ * Next we have the really interesting routines: selection of a colormap
+ * given the completed histogram.
+ * These routines work with a list of "boxes", each representing a rectangular
+ * subset of the input color space (to histogram precision).
+ */
+
+typedef struct {
+ /* The bounds of the box (inclusive); expressed as histogram indexes */
+ int c0min, c0max;
+ int c1min, c1max;
+ int c2min, c2max;
+ /* The volume (actually 2-norm) of the box */
+ INT32 volume;
+ /* The number of nonzero histogram cells within this box */
+ long colorcount;
+} box;
+
+typedef box * boxptr;
+
+
+LOCAL(boxptr)
+find_biggest_color_pop (boxptr boxlist, int numboxes)
+/* Find the splittable box with the largest color population */
+/* Returns NULL if no splittable boxes remain */
+{
+ register boxptr boxp;
+ register int i;
+ register long maxc = 0;
+ boxptr which = NULL;
+
+ for (i = 0, boxp = boxlist; i < numboxes; i++, boxp++) {
+ if (boxp->colorcount > maxc && boxp->volume > 0) {
+ which = boxp;
+ maxc = boxp->colorcount;
+ }
+ }
+ return which;
+}
+
+
+LOCAL(boxptr)
+find_biggest_volume (boxptr boxlist, int numboxes)
+/* Find the splittable box with the largest (scaled) volume */
+/* Returns NULL if no splittable boxes remain */
+{
+ register boxptr boxp;
+ register int i;
+ register INT32 maxv = 0;
+ boxptr which = NULL;
+
+ for (i = 0, boxp = boxlist; i < numboxes; i++, boxp++) {
+ if (boxp->volume > maxv) {
+ which = boxp;
+ maxv = boxp->volume;
+ }
+ }
+ return which;
+}
+
+
+LOCAL(void)
+update_box (j_decompress_ptr cinfo, boxptr boxp)
+/* Shrink the min/max bounds of a box to enclose only nonzero elements, */
+/* and recompute its volume and population */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ hist3d histogram = cquantize->histogram;
+ histptr histp;
+ int c0,c1,c2;
+ int c0min,c0max,c1min,c1max,c2min,c2max;
+ INT32 dist0,dist1,dist2;
+ long ccount;
+
+ c0min = boxp->c0min; c0max = boxp->c0max;
+ c1min = boxp->c1min; c1max = boxp->c1max;
+ c2min = boxp->c2min; c2max = boxp->c2max;
+
+ if (c0max > c0min)
+ for (c0 = c0min; c0 <= c0max; c0++)
+ for (c1 = c1min; c1 <= c1max; c1++) {
+ histp = & histogram[c0][c1][c2min];
+ for (c2 = c2min; c2 <= c2max; c2++)
+ if (*histp++ != 0) {
+ boxp->c0min = c0min = c0;
+ goto have_c0min;
+ }
+ }
+ have_c0min:
+ if (c0max > c0min)
+ for (c0 = c0max; c0 >= c0min; c0--)
+ for (c1 = c1min; c1 <= c1max; c1++) {
+ histp = & histogram[c0][c1][c2min];
+ for (c2 = c2min; c2 <= c2max; c2++)
+ if (*histp++ != 0) {
+ boxp->c0max = c0max = c0;
+ goto have_c0max;
+ }
+ }
+ have_c0max:
+ if (c1max > c1min)
+ for (c1 = c1min; c1 <= c1max; c1++)
+ for (c0 = c0min; c0 <= c0max; c0++) {
+ histp = & histogram[c0][c1][c2min];
+ for (c2 = c2min; c2 <= c2max; c2++)
+ if (*histp++ != 0) {
+ boxp->c1min = c1min = c1;
+ goto have_c1min;
+ }
+ }
+ have_c1min:
+ if (c1max > c1min)
+ for (c1 = c1max; c1 >= c1min; c1--)
+ for (c0 = c0min; c0 <= c0max; c0++) {
+ histp = & histogram[c0][c1][c2min];
+ for (c2 = c2min; c2 <= c2max; c2++)
+ if (*histp++ != 0) {
+ boxp->c1max = c1max = c1;
+ goto have_c1max;
+ }
+ }
+ have_c1max:
+ if (c2max > c2min)
+ for (c2 = c2min; c2 <= c2max; c2++)
+ for (c0 = c0min; c0 <= c0max; c0++) {
+ histp = & histogram[c0][c1min][c2];
+ for (c1 = c1min; c1 <= c1max; c1++, histp += HIST_C2_ELEMS)
+ if (*histp != 0) {
+ boxp->c2min = c2min = c2;
+ goto have_c2min;
+ }
+ }
+ have_c2min:
+ if (c2max > c2min)
+ for (c2 = c2max; c2 >= c2min; c2--)
+ for (c0 = c0min; c0 <= c0max; c0++) {
+ histp = & histogram[c0][c1min][c2];
+ for (c1 = c1min; c1 <= c1max; c1++, histp += HIST_C2_ELEMS)
+ if (*histp != 0) {
+ boxp->c2max = c2max = c2;
+ goto have_c2max;
+ }
+ }
+ have_c2max:
+
+ /* Update box volume.
+ * We use 2-norm rather than real volume here; this biases the method
+ * against making long narrow boxes, and it has the side benefit that
+ * a box is splittable iff norm > 0.
+ * Since the differences are expressed in histogram-cell units,
+ * we have to shift back to JSAMPLE units to get consistent distances;
+ * after which, we scale according to the selected distance scale factors.
+ */
+ dist0 = ((c0max - c0min) << C0_SHIFT) * C0_SCALE;
+ dist1 = ((c1max - c1min) << C1_SHIFT) * C1_SCALE;
+ dist2 = ((c2max - c2min) << C2_SHIFT) * C2_SCALE;
+ boxp->volume = dist0*dist0 + dist1*dist1 + dist2*dist2;
+
+ /* Now scan remaining volume of box and compute population */
+ ccount = 0;
+ for (c0 = c0min; c0 <= c0max; c0++)
+ for (c1 = c1min; c1 <= c1max; c1++) {
+ histp = & histogram[c0][c1][c2min];
+ for (c2 = c2min; c2 <= c2max; c2++, histp++)
+ if (*histp != 0) {
+ ccount++;
+ }
+ }
+ boxp->colorcount = ccount;
+}
+
+
+LOCAL(int)
+median_cut (j_decompress_ptr cinfo, boxptr boxlist, int numboxes,
+ int desired_colors)
+/* Repeatedly select and split the largest box until we have enough boxes */
+{
+ int n,lb;
+ int c0,c1,c2,cmax;
+ register boxptr b1,b2;
+
+ while (numboxes < desired_colors) {
+ /* Select box to split.
+ * Current algorithm: by population for first half, then by volume.
+ */
+ if (numboxes*2 <= desired_colors) {
+ b1 = find_biggest_color_pop(boxlist, numboxes);
+ } else {
+ b1 = find_biggest_volume(boxlist, numboxes);
+ }
+ if (b1 == NULL) /* no splittable boxes left! */
+ break;
+ b2 = &boxlist[numboxes]; /* where new box will go */
+ /* Copy the color bounds to the new box. */
+ b2->c0max = b1->c0max; b2->c1max = b1->c1max; b2->c2max = b1->c2max;
+ b2->c0min = b1->c0min; b2->c1min = b1->c1min; b2->c2min = b1->c2min;
+ /* Choose which axis to split the box on.
+ * Current algorithm: longest scaled axis.
+ * See notes in update_box about scaling distances.
+ */
+ c0 = ((b1->c0max - b1->c0min) << C0_SHIFT) * C0_SCALE;
+ c1 = ((b1->c1max - b1->c1min) << C1_SHIFT) * C1_SCALE;
+ c2 = ((b1->c2max - b1->c2min) << C2_SHIFT) * C2_SCALE;
+ /* We want to break any ties in favor of green, then red, blue last.
+ * This code does the right thing for R,G,B or B,G,R color orders only.
+ */
+#if RGB_RED == 0
+ cmax = c1; n = 1;
+ if (c0 > cmax) { cmax = c0; n = 0; }
+ if (c2 > cmax) { n = 2; }
+#else
+ cmax = c1; n = 1;
+ if (c2 > cmax) { cmax = c2; n = 2; }
+ if (c0 > cmax) { n = 0; }
+#endif
+ /* Choose split point along selected axis, and update box bounds.
+ * Current algorithm: split at halfway point.
+ * (Since the box has been shrunk to minimum volume,
+ * any split will produce two nonempty subboxes.)
+ * Note that lb value is max for lower box, so must be < old max.
+ */
+ switch (n) {
+ case 0:
+ lb = (b1->c0max + b1->c0min) / 2;
+ b1->c0max = lb;
+ b2->c0min = lb+1;
+ break;
+ case 1:
+ lb = (b1->c1max + b1->c1min) / 2;
+ b1->c1max = lb;
+ b2->c1min = lb+1;
+ break;
+ case 2:
+ lb = (b1->c2max + b1->c2min) / 2;
+ b1->c2max = lb;
+ b2->c2min = lb+1;
+ break;
+ }
+ /* Update stats for boxes */
+ update_box(cinfo, b1);
+ update_box(cinfo, b2);
+ numboxes++;
+ }
+ return numboxes;
+}
+
+
+LOCAL(void)
+compute_color (j_decompress_ptr cinfo, boxptr boxp, int icolor)
+/* Compute representative color for a box, put it in colormap[icolor] */
+{
+ /* Current algorithm: mean weighted by pixels (not colors) */
+ /* Note it is important to get the rounding correct! */
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ hist3d histogram = cquantize->histogram;
+ histptr histp;
+ int c0,c1,c2;
+ int c0min,c0max,c1min,c1max,c2min,c2max;
+ long count;
+ long total = 0;
+ long c0total = 0;
+ long c1total = 0;
+ long c2total = 0;
+
+ c0min = boxp->c0min; c0max = boxp->c0max;
+ c1min = boxp->c1min; c1max = boxp->c1max;
+ c2min = boxp->c2min; c2max = boxp->c2max;
+
+ for (c0 = c0min; c0 <= c0max; c0++)
+ for (c1 = c1min; c1 <= c1max; c1++) {
+ histp = & histogram[c0][c1][c2min];
+ for (c2 = c2min; c2 <= c2max; c2++) {
+ if ((count = *histp++) != 0) {
+ total += count;
+ c0total += ((c0 << C0_SHIFT) + ((1<<C0_SHIFT)>>1)) * count;
+ c1total += ((c1 << C1_SHIFT) + ((1<<C1_SHIFT)>>1)) * count;
+ c2total += ((c2 << C2_SHIFT) + ((1<<C2_SHIFT)>>1)) * count;
+ }
+ }
+ }
+
+ cinfo->colormap[0][icolor] = (JSAMPLE) ((c0total + (total>>1)) / total);
+ cinfo->colormap[1][icolor] = (JSAMPLE) ((c1total + (total>>1)) / total);
+ cinfo->colormap[2][icolor] = (JSAMPLE) ((c2total + (total>>1)) / total);
+}
+
+
+LOCAL(void)
+select_colors (j_decompress_ptr cinfo, int desired_colors)
+/* Master routine for color selection */
+{
+ boxptr boxlist;
+ int numboxes;
+ int i;
+
+ /* Allocate workspace for box list */
+ boxlist = (boxptr) (*cinfo->mem->alloc_small)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, desired_colors * SIZEOF(box));
+ /* Initialize one box containing whole space */
+ numboxes = 1;
+ boxlist[0].c0min = 0;
+ boxlist[0].c0max = MAXJSAMPLE >> C0_SHIFT;
+ boxlist[0].c1min = 0;
+ boxlist[0].c1max = MAXJSAMPLE >> C1_SHIFT;
+ boxlist[0].c2min = 0;
+ boxlist[0].c2max = MAXJSAMPLE >> C2_SHIFT;
+ /* Shrink it to actually-used volume and set its statistics */
+ update_box(cinfo, & boxlist[0]);
+ /* Perform median-cut to produce final box list */
+ numboxes = median_cut(cinfo, boxlist, numboxes, desired_colors);
+ /* Compute the representative color for each box, fill colormap */
+ for (i = 0; i < numboxes; i++)
+ compute_color(cinfo, & boxlist[i], i);
+ cinfo->actual_number_of_colors = numboxes;
+ TRACEMS1(cinfo, 1, JTRC_QUANT_SELECTED, numboxes);
+}
+
+
+/*
+ * These routines are concerned with the time-critical task of mapping input
+ * colors to the nearest color in the selected colormap.
+ *
+ * We re-use the histogram space as an "inverse color map", essentially a
+ * cache for the results of nearest-color searches. All colors within a
+ * histogram cell will be mapped to the same colormap entry, namely the one
+ * closest to the cell's center. This may not be quite the closest entry to
+ * the actual input color, but it's almost as good. A zero in the cache
+ * indicates we haven't found the nearest color for that cell yet; the array
+ * is cleared to zeroes before starting the mapping pass. When we find the
+ * nearest color for a cell, its colormap index plus one is recorded in the
+ * cache for future use. The pass2 scanning routines call fill_inverse_cmap
+ * when they need to use an unfilled entry in the cache.
+ *
+ * Our method of efficiently finding nearest colors is based on the "locally
+ * sorted search" idea described by Heckbert and on the incremental distance
+ * calculation described by Spencer W. Thomas in chapter III.1 of Graphics
+ * Gems II (James Arvo, ed. Academic Press, 1991). Thomas points out that
+ * the distances from a given colormap entry to each cell of the histogram can
+ * be computed quickly using an incremental method: the differences between
+ * distances to adjacent cells themselves differ by a constant. This allows a
+ * fairly fast implementation of the "brute force" approach of computing the
+ * distance from every colormap entry to every histogram cell. Unfortunately,
+ * it needs a work array to hold the best-distance-so-far for each histogram
+ * cell (because the inner loop has to be over cells, not colormap entries).
+ * The work array elements have to be INT32s, so the work array would need
+ * 256Kb at our recommended precision. This is not feasible in DOS machines.
+ *
+ * To get around these problems, we apply Thomas' method to compute the
+ * nearest colors for only the cells within a small subbox of the histogram.
+ * The work array need be only as big as the subbox, so the memory usage
+ * problem is solved. Furthermore, we need not fill subboxes that are never
+ * referenced in pass2; many images use only part of the color gamut, so a
+ * fair amount of work is saved. An additional advantage of this
+ * approach is that we can apply Heckbert's locality criterion to quickly
+ * eliminate colormap entries that are far away from the subbox; typically
+ * three-fourths of the colormap entries are rejected by Heckbert's criterion,
+ * and we need not compute their distances to individual cells in the subbox.
+ * The speed of this approach is heavily influenced by the subbox size: too
+ * small means too much overhead, too big loses because Heckbert's criterion
+ * can't eliminate as many colormap entries. Empirically the best subbox
+ * size seems to be about 1/512th of the histogram (1/8th in each direction).
+ *
+ * Thomas' article also describes a refined method which is asymptotically
+ * faster than the brute-force method, but it is also far more complex and
+ * cannot efficiently be applied to small subboxes. It is therefore not
+ * useful for programs intended to be portable to DOS machines. On machines
+ * with plenty of memory, filling the whole histogram in one shot with Thomas'
+ * refined method might be faster than the present code --- but then again,
+ * it might not be any faster, and it's certainly more complicated.
+ */
+
+
+/* log2(histogram cells in update box) for each axis; this can be adjusted */
+#define BOX_C0_LOG (HIST_C0_BITS-3)
+#define BOX_C1_LOG (HIST_C1_BITS-3)
+#define BOX_C2_LOG (HIST_C2_BITS-3)
+
+#define BOX_C0_ELEMS (1<<BOX_C0_LOG) /* # of hist cells in update box */
+#define BOX_C1_ELEMS (1<<BOX_C1_LOG)
+#define BOX_C2_ELEMS (1<<BOX_C2_LOG)
+
+#define BOX_C0_SHIFT (C0_SHIFT + BOX_C0_LOG)
+#define BOX_C1_SHIFT (C1_SHIFT + BOX_C1_LOG)
+#define BOX_C2_SHIFT (C2_SHIFT + BOX_C2_LOG)
+
+
+/*
+ * The next three routines implement inverse colormap filling. They could
+ * all be folded into one big routine, but splitting them up this way saves
+ * some stack space (the mindist[] and bestdist[] arrays need not coexist)
+ * and may allow some compilers to produce better code by registerizing more
+ * inner-loop variables.
+ */
+
+LOCAL(int)
+find_nearby_colors (j_decompress_ptr cinfo, int minc0, int minc1, int minc2,
+ JSAMPLE colorlist[])
+/* Locate the colormap entries close enough to an update box to be candidates
+ * for the nearest entry to some cell(s) in the update box. The update box
+ * is specified by the center coordinates of its first cell. The number of
+ * candidate colormap entries is returned, and their colormap indexes are
+ * placed in colorlist[].
+ * This routine uses Heckbert's "locally sorted search" criterion to select
+ * the colors that need further consideration.
+ */
+{
+ int numcolors = cinfo->actual_number_of_colors;
+ int maxc0, maxc1, maxc2;
+ int centerc0, centerc1, centerc2;
+ int i, x, ncolors;
+ INT32 minmaxdist, min_dist, max_dist, tdist;
+ INT32 mindist[MAXNUMCOLORS]; /* min distance to colormap entry i */
+
+ /* Compute true coordinates of update box's upper corner and center.
+ * Actually we compute the coordinates of the center of the upper-corner
+ * histogram cell, which are the upper bounds of the volume we care about.
+ * Note that since ">>" rounds down, the "center" values may be closer to
+ * min than to max; hence comparisons to them must be "<=", not "<".
+ */
+ maxc0 = minc0 + ((1 << BOX_C0_SHIFT) - (1 << C0_SHIFT));
+ centerc0 = (minc0 + maxc0) >> 1;
+ maxc1 = minc1 + ((1 << BOX_C1_SHIFT) - (1 << C1_SHIFT));
+ centerc1 = (minc1 + maxc1) >> 1;
+ maxc2 = minc2 + ((1 << BOX_C2_SHIFT) - (1 << C2_SHIFT));
+ centerc2 = (minc2 + maxc2) >> 1;
+
+ /* For each color in colormap, find:
+ * 1. its minimum squared-distance to any point in the update box
+ * (zero if color is within update box);
+ * 2. its maximum squared-distance to any point in the update box.
+ * Both of these can be found by considering only the corners of the box.
+ * We save the minimum distance for each color in mindist[];
+ * only the smallest maximum distance is of interest.
+ */
+ minmaxdist = 0x7FFFFFFFL;
+
+ for (i = 0; i < numcolors; i++) {
+ /* We compute the squared-c0-distance term, then add in the other two. */
+ x = GETJSAMPLE(cinfo->colormap[0][i]);
+ if (x < minc0) {
+ tdist = (x - minc0) * C0_SCALE;
+ min_dist = tdist*tdist;
+ tdist = (x - maxc0) * C0_SCALE;
+ max_dist = tdist*tdist;
+ } else if (x > maxc0) {
+ tdist = (x - maxc0) * C0_SCALE;
+ min_dist = tdist*tdist;
+ tdist = (x - minc0) * C0_SCALE;
+ max_dist = tdist*tdist;
+ } else {
+ /* within cell range so no contribution to min_dist */
+ min_dist = 0;
+ if (x <= centerc0) {
+ tdist = (x - maxc0) * C0_SCALE;
+ max_dist = tdist*tdist;
+ } else {
+ tdist = (x - minc0) * C0_SCALE;
+ max_dist = tdist*tdist;
+ }
+ }
+
+ x = GETJSAMPLE(cinfo->colormap[1][i]);
+ if (x < minc1) {
+ tdist = (x - minc1) * C1_SCALE;
+ min_dist += tdist*tdist;
+ tdist = (x - maxc1) * C1_SCALE;
+ max_dist += tdist*tdist;
+ } else if (x > maxc1) {
+ tdist = (x - maxc1) * C1_SCALE;
+ min_dist += tdist*tdist;
+ tdist = (x - minc1) * C1_SCALE;
+ max_dist += tdist*tdist;
+ } else {
+ /* within cell range so no contribution to min_dist */
+ if (x <= centerc1) {
+ tdist = (x - maxc1) * C1_SCALE;
+ max_dist += tdist*tdist;
+ } else {
+ tdist = (x - minc1) * C1_SCALE;
+ max_dist += tdist*tdist;
+ }
+ }
+
+ x = GETJSAMPLE(cinfo->colormap[2][i]);
+ if (x < minc2) {
+ tdist = (x - minc2) * C2_SCALE;
+ min_dist += tdist*tdist;
+ tdist = (x - maxc2) * C2_SCALE;
+ max_dist += tdist*tdist;
+ } else if (x > maxc2) {
+ tdist = (x - maxc2) * C2_SCALE;
+ min_dist += tdist*tdist;
+ tdist = (x - minc2) * C2_SCALE;
+ max_dist += tdist*tdist;
+ } else {
+ /* within cell range so no contribution to min_dist */
+ if (x <= centerc2) {
+ tdist = (x - maxc2) * C2_SCALE;
+ max_dist += tdist*tdist;
+ } else {
+ tdist = (x - minc2) * C2_SCALE;
+ max_dist += tdist*tdist;
+ }
+ }
+
+ mindist[i] = min_dist; /* save away the results */
+ if (max_dist < minmaxdist)
+ minmaxdist = max_dist;
+ }
+
+ /* Now we know that no cell in the update box is more than minmaxdist
+ * away from some colormap entry. Therefore, only colors that are
+ * within minmaxdist of some part of the box need be considered.
+ */
+ ncolors = 0;
+ for (i = 0; i < numcolors; i++) {
+ if (mindist[i] <= minmaxdist)
+ colorlist[ncolors++] = (JSAMPLE) i;
+ }
+ return ncolors;
+}
+
+
+LOCAL(void)
+find_best_colors (j_decompress_ptr cinfo, int minc0, int minc1, int minc2,
+ int numcolors, JSAMPLE colorlist[], JSAMPLE bestcolor[])
+/* Find the closest colormap entry for each cell in the update box,
+ * given the list of candidate colors prepared by find_nearby_colors.
+ * Return the indexes of the closest entries in the bestcolor[] array.
+ * This routine uses Thomas' incremental distance calculation method to
+ * find the distance from a colormap entry to successive cells in the box.
+ */
+{
+ int ic0, ic1, ic2;
+ int i, icolor;
+ register INT32 * bptr; /* pointer into bestdist[] array */
+ JSAMPLE * cptr; /* pointer into bestcolor[] array */
+ INT32 dist0, dist1; /* initial distance values */
+ register INT32 dist2; /* current distance in inner loop */
+ INT32 xx0, xx1; /* distance increments */
+ register INT32 xx2;
+ INT32 inc0, inc1, inc2; /* initial values for increments */
+ /* This array holds the distance to the nearest-so-far color for each cell */
+ INT32 bestdist[BOX_C0_ELEMS * BOX_C1_ELEMS * BOX_C2_ELEMS];
+
+ /* Initialize best-distance for each cell of the update box */
+ bptr = bestdist;
+ for (i = BOX_C0_ELEMS*BOX_C1_ELEMS*BOX_C2_ELEMS-1; i >= 0; i--)
+ *bptr++ = 0x7FFFFFFFL;
+
+ /* For each color selected by find_nearby_colors,
+ * compute its distance to the center of each cell in the box.
+ * If that's less than best-so-far, update best distance and color number.
+ */
+
+ /* Nominal steps between cell centers ("x" in Thomas article) */
+#define STEP_C0 ((1 << C0_SHIFT) * C0_SCALE)
+#define STEP_C1 ((1 << C1_SHIFT) * C1_SCALE)
+#define STEP_C2 ((1 << C2_SHIFT) * C2_SCALE)
+
+ for (i = 0; i < numcolors; i++) {
+ icolor = GETJSAMPLE(colorlist[i]);
+ /* Compute (square of) distance from minc0/c1/c2 to this color */
+ inc0 = (minc0 - GETJSAMPLE(cinfo->colormap[0][icolor])) * C0_SCALE;
+ dist0 = inc0*inc0;
+ inc1 = (minc1 - GETJSAMPLE(cinfo->colormap[1][icolor])) * C1_SCALE;
+ dist0 += inc1*inc1;
+ inc2 = (minc2 - GETJSAMPLE(cinfo->colormap[2][icolor])) * C2_SCALE;
+ dist0 += inc2*inc2;
+ /* Form the initial difference increments */
+ inc0 = inc0 * (2 * STEP_C0) + STEP_C0 * STEP_C0;
+ inc1 = inc1 * (2 * STEP_C1) + STEP_C1 * STEP_C1;
+ inc2 = inc2 * (2 * STEP_C2) + STEP_C2 * STEP_C2;
+ /* Now loop over all cells in box, updating distance per Thomas method */
+ bptr = bestdist;
+ cptr = bestcolor;
+ xx0 = inc0;
+ for (ic0 = BOX_C0_ELEMS-1; ic0 >= 0; ic0--) {
+ dist1 = dist0;
+ xx1 = inc1;
+ for (ic1 = BOX_C1_ELEMS-1; ic1 >= 0; ic1--) {
+ dist2 = dist1;
+ xx2 = inc2;
+ for (ic2 = BOX_C2_ELEMS-1; ic2 >= 0; ic2--) {
+ if (dist2 < *bptr) {
+ *bptr = dist2;
+ *cptr = (JSAMPLE) icolor;
+ }
+ dist2 += xx2;
+ xx2 += 2 * STEP_C2 * STEP_C2;
+ bptr++;
+ cptr++;
+ }
+ dist1 += xx1;
+ xx1 += 2 * STEP_C1 * STEP_C1;
+ }
+ dist0 += xx0;
+ xx0 += 2 * STEP_C0 * STEP_C0;
+ }
+ }
+}
+
+
+LOCAL(void)
+fill_inverse_cmap (j_decompress_ptr cinfo, int c0, int c1, int c2)
+/* Fill the inverse-colormap entries in the update box that contains */
+/* histogram cell c0/c1/c2. (Only that one cell MUST be filled, but */
+/* we can fill as many others as we wish.) */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ hist3d histogram = cquantize->histogram;
+ int minc0, minc1, minc2; /* lower left corner of update box */
+ int ic0, ic1, ic2;
+ register JSAMPLE * cptr; /* pointer into bestcolor[] array */
+ register histptr cachep; /* pointer into main cache array */
+ /* This array lists the candidate colormap indexes. */
+ JSAMPLE colorlist[MAXNUMCOLORS];
+ int numcolors; /* number of candidate colors */
+ /* This array holds the actually closest colormap index for each cell. */
+ JSAMPLE bestcolor[BOX_C0_ELEMS * BOX_C1_ELEMS * BOX_C2_ELEMS];
+
+ /* Convert cell coordinates to update box ID */
+ c0 >>= BOX_C0_LOG;
+ c1 >>= BOX_C1_LOG;
+ c2 >>= BOX_C2_LOG;
+
+ /* Compute true coordinates of update box's origin corner.
+ * Actually we compute the coordinates of the center of the corner
+ * histogram cell, which are the lower bounds of the volume we care about.
+ */
+ minc0 = (c0 << BOX_C0_SHIFT) + ((1 << C0_SHIFT) >> 1);
+ minc1 = (c1 << BOX_C1_SHIFT) + ((1 << C1_SHIFT) >> 1);
+ minc2 = (c2 << BOX_C2_SHIFT) + ((1 << C2_SHIFT) >> 1);
+
+ /* Determine which colormap entries are close enough to be candidates
+ * for the nearest entry to some cell in the update box.
+ */
+ numcolors = find_nearby_colors(cinfo, minc0, minc1, minc2, colorlist);
+
+ /* Determine the actually nearest colors. */
+ find_best_colors(cinfo, minc0, minc1, minc2, numcolors, colorlist,
+ bestcolor);
+
+ /* Save the best color numbers (plus 1) in the main cache array */
+ c0 <<= BOX_C0_LOG; /* convert ID back to base cell indexes */
+ c1 <<= BOX_C1_LOG;
+ c2 <<= BOX_C2_LOG;
+ cptr = bestcolor;
+ for (ic0 = 0; ic0 < BOX_C0_ELEMS; ic0++) {
+ for (ic1 = 0; ic1 < BOX_C1_ELEMS; ic1++) {
+ cachep = & histogram[c0+ic0][c1+ic1][c2];
+ for (ic2 = 0; ic2 < BOX_C2_ELEMS; ic2++) {
+ *cachep++ = (histcell) (GETJSAMPLE(*cptr++) + 1);
+ }
+ }
+ }
+}
+
+
+/*
+ * Map some rows of pixels to the output colormapped representation.
+ */
+
+METHODDEF(void)
+pass2_no_dither (j_decompress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPARRAY output_buf, int num_rows)
+/* This version performs no dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ hist3d histogram = cquantize->histogram;
+ register JSAMPROW inptr, outptr;
+ register histptr cachep;
+ register int c0, c1, c2;
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+
+ for (row = 0; row < num_rows; row++) {
+ inptr = input_buf[row];
+ outptr = output_buf[row];
+ for (col = width; col > 0; col--) {
+ /* get pixel value and index into the cache */
+ c0 = GETJSAMPLE(*inptr++) >> C0_SHIFT;
+ c1 = GETJSAMPLE(*inptr++) >> C1_SHIFT;
+ c2 = GETJSAMPLE(*inptr++) >> C2_SHIFT;
+ cachep = & histogram[c0][c1][c2];
+ /* If we have not seen this color before, find nearest colormap entry */
+ /* and update the cache */
+ if (*cachep == 0)
+ fill_inverse_cmap(cinfo, c0,c1,c2);
+ /* Now emit the colormap index for this cell */
+ *outptr++ = (JSAMPLE) (*cachep - 1);
+ }
+ }
+}
+
+
+METHODDEF(void)
+pass2_fs_dither (j_decompress_ptr cinfo,
+ JSAMPARRAY input_buf, JSAMPARRAY output_buf, int num_rows)
+/* This version performs Floyd-Steinberg dithering */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ hist3d histogram = cquantize->histogram;
+ register LOCFSERROR cur0, cur1, cur2; /* current error or pixel value */
+ LOCFSERROR belowerr0, belowerr1, belowerr2; /* error for pixel below cur */
+ LOCFSERROR bpreverr0, bpreverr1, bpreverr2; /* error for below/prev col */
+ register FSERRPTR errorptr; /* => fserrors[] at column before current */
+ JSAMPROW inptr; /* => current input pixel */
+ JSAMPROW outptr; /* => current output pixel */
+ histptr cachep;
+ int dir; /* +1 or -1 depending on direction */
+ int dir3; /* 3*dir, for advancing inptr & errorptr */
+ int row;
+ JDIMENSION col;
+ JDIMENSION width = cinfo->output_width;
+ JSAMPLE *range_limit = cinfo->sample_range_limit;
+ int *error_limit = cquantize->error_limiter;
+ JSAMPROW colormap0 = cinfo->colormap[0];
+ JSAMPROW colormap1 = cinfo->colormap[1];
+ JSAMPROW colormap2 = cinfo->colormap[2];
+ SHIFT_TEMPS
+
+ for (row = 0; row < num_rows; row++) {
+ inptr = input_buf[row];
+ outptr = output_buf[row];
+ if (cquantize->on_odd_row) {
+ /* work right to left in this row */
+ inptr += (width-1) * 3; /* so point to rightmost pixel */
+ outptr += width-1;
+ dir = -1;
+ dir3 = -3;
+ errorptr = cquantize->fserrors + (width+1)*3; /* => entry after last column */
+ cquantize->on_odd_row = FALSE; /* flip for next time */
+ } else {
+ /* work left to right in this row */
+ dir = 1;
+ dir3 = 3;
+ errorptr = cquantize->fserrors; /* => entry before first real column */
+ cquantize->on_odd_row = TRUE; /* flip for next time */
+ }
+ /* Preset error values: no error propagated to first pixel from left */
+ cur0 = cur1 = cur2 = 0;
+ /* and no error propagated to row below yet */
+ belowerr0 = belowerr1 = belowerr2 = 0;
+ bpreverr0 = bpreverr1 = bpreverr2 = 0;
+
+ for (col = width; col > 0; col--) {
+ /* curN holds the error propagated from the previous pixel on the
+ * current line. Add the error propagated from the previous line
+ * to form the complete error correction term for this pixel, and
+ * round the error term (which is expressed * 16) to an integer.
+ * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct
+ * for either sign of the error value.
+ * Note: errorptr points to *previous* column's array entry.
+ */
+ cur0 = RIGHT_SHIFT(cur0 + errorptr[dir3+0] + 8, 4);
+ cur1 = RIGHT_SHIFT(cur1 + errorptr[dir3+1] + 8, 4);
+ cur2 = RIGHT_SHIFT(cur2 + errorptr[dir3+2] + 8, 4);
+ /* Limit the error using transfer function set by init_error_limit.
+ * See comments with init_error_limit for rationale.
+ */
+ cur0 = error_limit[cur0];
+ cur1 = error_limit[cur1];
+ cur2 = error_limit[cur2];
+ /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE.
+ * The maximum error is +- MAXJSAMPLE (or less with error limiting);
+ * this sets the required size of the range_limit array.
+ */
+ cur0 += GETJSAMPLE(inptr[0]);
+ cur1 += GETJSAMPLE(inptr[1]);
+ cur2 += GETJSAMPLE(inptr[2]);
+ cur0 = GETJSAMPLE(range_limit[cur0]);
+ cur1 = GETJSAMPLE(range_limit[cur1]);
+ cur2 = GETJSAMPLE(range_limit[cur2]);
+ /* Index into the cache with adjusted pixel value */
+ cachep = & histogram[cur0>>C0_SHIFT][cur1>>C1_SHIFT][cur2>>C2_SHIFT];
+ /* If we have not seen this color before, find nearest colormap */
+ /* entry and update the cache */
+ if (*cachep == 0)
+ fill_inverse_cmap(cinfo, cur0>>C0_SHIFT,cur1>>C1_SHIFT,cur2>>C2_SHIFT);
+ /* Now emit the colormap index for this cell */
+ { register int pixcode = *cachep - 1;
+ *outptr = (JSAMPLE) pixcode;
+ /* Compute representation error for this pixel */
+ cur0 -= GETJSAMPLE(colormap0[pixcode]);
+ cur1 -= GETJSAMPLE(colormap1[pixcode]);
+ cur2 -= GETJSAMPLE(colormap2[pixcode]);
+ }
+ /* Compute error fractions to be propagated to adjacent pixels.
+ * Add these into the running sums, and simultaneously shift the
+ * next-line error sums left by 1 column.
+ */
+ { register LOCFSERROR bnexterr, delta;
+
+ bnexterr = cur0; /* Process component 0 */
+ delta = cur0 * 2;
+ cur0 += delta; /* form error * 3 */
+ errorptr[0] = (FSERROR) (bpreverr0 + cur0);
+ cur0 += delta; /* form error * 5 */
+ bpreverr0 = belowerr0 + cur0;
+ belowerr0 = bnexterr;
+ cur0 += delta; /* form error * 7 */
+ bnexterr = cur1; /* Process component 1 */
+ delta = cur1 * 2;
+ cur1 += delta; /* form error * 3 */
+ errorptr[1] = (FSERROR) (bpreverr1 + cur1);
+ cur1 += delta; /* form error * 5 */
+ bpreverr1 = belowerr1 + cur1;
+ belowerr1 = bnexterr;
+ cur1 += delta; /* form error * 7 */
+ bnexterr = cur2; /* Process component 2 */
+ delta = cur2 * 2;
+ cur2 += delta; /* form error * 3 */
+ errorptr[2] = (FSERROR) (bpreverr2 + cur2);
+ cur2 += delta; /* form error * 5 */
+ bpreverr2 = belowerr2 + cur2;
+ belowerr2 = bnexterr;
+ cur2 += delta; /* form error * 7 */
+ }
+ /* At this point curN contains the 7/16 error value to be propagated
+ * to the next pixel on the current line, and all the errors for the
+ * next line have been shifted over. We are therefore ready to move on.
+ */
+ inptr += dir3; /* Advance pixel pointers to next column */
+ outptr += dir;
+ errorptr += dir3; /* advance errorptr to current column */
+ }
+ /* Post-loop cleanup: we must unload the final error values into the
+ * final fserrors[] entry. Note we need not unload belowerrN because
+ * it is for the dummy column before or after the actual array.
+ */
+ errorptr[0] = (FSERROR) bpreverr0; /* unload prev errs into array */
+ errorptr[1] = (FSERROR) bpreverr1;
+ errorptr[2] = (FSERROR) bpreverr2;
+ }
+}
+
+
+/*
+ * Initialize the error-limiting transfer function (lookup table).
+ * The raw F-S error computation can potentially compute error values of up to
+ * +- MAXJSAMPLE. But we want the maximum correction applied to a pixel to be
+ * much less, otherwise obviously wrong pixels will be created. (Typical
+ * effects include weird fringes at color-area boundaries, isolated bright
+ * pixels in a dark area, etc.) The standard advice for avoiding this problem
+ * is to ensure that the "corners" of the color cube are allocated as output
+ * colors; then repeated errors in the same direction cannot cause cascading
+ * error buildup. However, that only prevents the error from getting
+ * completely out of hand; Aaron Giles reports that error limiting improves
+ * the results even with corner colors allocated.
+ * A simple clamping of the error values to about +- MAXJSAMPLE/8 works pretty
+ * well, but the smoother transfer function used below is even better. Thanks
+ * to Aaron Giles for this idea.
+ */
+
+LOCAL(void)
+init_error_limit (j_decompress_ptr cinfo)
+/* Allocate and fill in the error_limiter table */
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ int * table;
+ int in, out;
+
+ table = (int *) (*cinfo->mem->alloc_small)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE*2+1) * SIZEOF(int));
+ table += MAXJSAMPLE; /* so can index -MAXJSAMPLE .. +MAXJSAMPLE */
+ cquantize->error_limiter = table;
+
+#define STEPSIZE ((MAXJSAMPLE+1)/16)
+ /* Map errors 1:1 up to +- MAXJSAMPLE/16 */
+ out = 0;
+ for (in = 0; in < STEPSIZE; in++, out++) {
+ table[in] = out; table[-in] = -out;
+ }
+ /* Map errors 1:2 up to +- 3*MAXJSAMPLE/16 */
+ for (; in < STEPSIZE*3; in++, out += (in&1) ? 0 : 1) {
+ table[in] = out; table[-in] = -out;
+ }
+ /* Clamp the rest to final out value (which is (MAXJSAMPLE+1)/8) */
+ for (; in <= MAXJSAMPLE; in++) {
+ table[in] = out; table[-in] = -out;
+ }
+#undef STEPSIZE
+}
+
+
+/*
+ * Finish up at the end of each pass.
+ */
+
+METHODDEF(void)
+finish_pass1 (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+
+ /* Select the representative colors and fill in cinfo->colormap */
+ cinfo->colormap = cquantize->sv_colormap;
+ select_colors(cinfo, cquantize->desired);
+ /* Force next pass to zero the color index table */
+ cquantize->needs_zeroed = TRUE;
+}
+
+
+METHODDEF(void)
+finish_pass2 (j_decompress_ptr cinfo)
+{
+ /* no work */
+}
+
+
+/*
+ * Initialize for each processing pass.
+ */
+
+METHODDEF(void)
+start_pass_2_quant (j_decompress_ptr cinfo, boolean is_pre_scan)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+ hist3d histogram = cquantize->histogram;
+ int i;
+
+ /* Only F-S dithering or no dithering is supported. */
+ /* If user asks for ordered dither, give him F-S. */
+ if (cinfo->dither_mode != JDITHER_NONE)
+ cinfo->dither_mode = JDITHER_FS;
+
+ if (is_pre_scan) {
+ /* Set up method pointers */
+ cquantize->pub.color_quantize = prescan_quantize;
+ cquantize->pub.finish_pass = finish_pass1;
+ cquantize->needs_zeroed = TRUE; /* Always zero histogram */
+ } else {
+ /* Set up method pointers */
+ if (cinfo->dither_mode == JDITHER_FS)
+ cquantize->pub.color_quantize = pass2_fs_dither;
+ else
+ cquantize->pub.color_quantize = pass2_no_dither;
+ cquantize->pub.finish_pass = finish_pass2;
+
+ /* Make sure color count is acceptable */
+ i = cinfo->actual_number_of_colors;
+ if (i < 1)
+ ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, 1);
+ if (i > MAXNUMCOLORS)
+ ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS);
+
+ if (cinfo->dither_mode == JDITHER_FS) {
+ size_t arraysize = (size_t) ((cinfo->output_width + 2) *
+ (3 * SIZEOF(FSERROR)));
+ /* Allocate Floyd-Steinberg workspace if we didn't already. */
+ if (cquantize->fserrors == NULL)
+ cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize);
+ /* Initialize the propagated errors to zero. */
+ jzero_far((void FAR *) cquantize->fserrors, arraysize);
+ /* Make the error-limit table if we didn't already. */
+ if (cquantize->error_limiter == NULL)
+ init_error_limit(cinfo);
+ cquantize->on_odd_row = FALSE;
+ }
+
+ }
+ /* Zero the histogram or inverse color map, if necessary */
+ if (cquantize->needs_zeroed) {
+ for (i = 0; i < HIST_C0_ELEMS; i++) {
+ jzero_far((void FAR *) histogram[i],
+ HIST_C1_ELEMS*HIST_C2_ELEMS * SIZEOF(histcell));
+ }
+ cquantize->needs_zeroed = FALSE;
+ }
+}
+
+
+/*
+ * Switch to a new external colormap between output passes.
+ */
+
+METHODDEF(void)
+new_color_map_2_quant (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
+
+ /* Reset the inverse color map */
+ cquantize->needs_zeroed = TRUE;
+}
+
+
+/*
+ * Module initialization routine for 2-pass color quantization.
+ */
+
+GLOBAL(void)
+jinit_2pass_quantizer (j_decompress_ptr cinfo)
+{
+ my_cquantize_ptr cquantize;
+ int i;
+
+ cquantize = (my_cquantize_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(my_cquantizer));
+ cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize;
+ cquantize->pub.start_pass = start_pass_2_quant;
+ cquantize->pub.new_color_map = new_color_map_2_quant;
+ cquantize->fserrors = NULL; /* flag optional arrays not allocated */
+ cquantize->error_limiter = NULL;
+
+ /* Make sure jdmaster didn't give me a case I can't handle */
+ if (cinfo->out_color_components != 3)
+ ERREXIT(cinfo, JERR_NOTIMPL);
+
+ /* Allocate the histogram/inverse colormap storage */
+ cquantize->histogram = (hist3d) (*cinfo->mem->alloc_small)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, HIST_C0_ELEMS * SIZEOF(hist2d));
+ for (i = 0; i < HIST_C0_ELEMS; i++) {
+ cquantize->histogram[i] = (hist2d) (*cinfo->mem->alloc_large)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ HIST_C1_ELEMS*HIST_C2_ELEMS * SIZEOF(histcell));
+ }
+ cquantize->needs_zeroed = TRUE; /* histogram is garbage now */
+
+ /* Allocate storage for the completed colormap, if required.
+ * We do this now since it is FAR storage and may affect
+ * the memory manager's space calculations.
+ */
+ if (cinfo->enable_2pass_quant) {
+ /* Make sure color count is acceptable */
+ int desired = cinfo->desired_number_of_colors;
+ /* Lower bound on # of colors ... somewhat arbitrary as long as > 0 */
+ if (desired < 8)
+ ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, 8);
+ /* Make sure colormap indexes can be represented by JSAMPLEs */
+ if (desired > MAXNUMCOLORS)
+ ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS);
+ cquantize->sv_colormap = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo,JPOOL_IMAGE, (JDIMENSION) desired, (JDIMENSION) 3);
+ cquantize->desired = desired;
+ } else
+ cquantize->sv_colormap = NULL;
+
+ /* Only F-S dithering or no dithering is supported. */
+ /* If user asks for ordered dither, give him F-S. */
+ if (cinfo->dither_mode != JDITHER_NONE)
+ cinfo->dither_mode = JDITHER_FS;
+
+ /* Allocate Floyd-Steinberg workspace if necessary.
+ * This isn't really needed until pass 2, but again it is FAR storage.
+ * Although we will cope with a later change in dither_mode,
+ * we do not promise to honor max_memory_to_use if dither_mode changes.
+ */
+ if (cinfo->dither_mode == JDITHER_FS) {
+ cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (size_t) ((cinfo->output_width + 2) * (3 * SIZEOF(FSERROR))));
+ /* Might as well create the error-limiting table too. */
+ init_error_limit(cinfo);
+ }
+}
+
+#endif /* QUANT_2PASS_SUPPORTED */
--- /dev/null
+/*
+ * jutils.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains tables and miscellaneous utility routines needed
+ * for both compression and decompression.
+ * Note we prefix all global names with "j" to minimize conflicts with
+ * a surrounding application.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude12.h"
+#include "jpeglib12.h"
+
+
+/*
+ * jpeg_zigzag_order[i] is the zigzag-order position of the i'th element
+ * of a DCT block read in natural order (left to right, top to bottom).
+ */
+
+#if 0 /* This table is not actually needed in v6a */
+
+const int jpeg_zigzag_order[DCTSIZE2] = {
+ 0, 1, 5, 6, 14, 15, 27, 28,
+ 2, 4, 7, 13, 16, 26, 29, 42,
+ 3, 8, 12, 17, 25, 30, 41, 43,
+ 9, 11, 18, 24, 31, 40, 44, 53,
+ 10, 19, 23, 32, 39, 45, 52, 54,
+ 20, 22, 33, 38, 46, 51, 55, 60,
+ 21, 34, 37, 47, 50, 56, 59, 61,
+ 35, 36, 48, 49, 57, 58, 62, 63
+};
+
+#endif
+
+/*
+ * jpeg_natural_order[i] is the natural-order position of the i'th element
+ * of zigzag order.
+ *
+ * When reading corrupted data, the Huffman decoders could attempt
+ * to reference an entry beyond the end of this array (if the decoded
+ * zero run length reaches past the end of the block). To prevent
+ * wild stores without adding an inner-loop test, we put some extra
+ * "63"s after the real entries. This will cause the extra coefficient
+ * to be stored in location 63 of the block, not somewhere random.
+ * The worst case would be a run-length of 15, which means we need 16
+ * fake entries.
+ */
+
+const int jpeg_natural_order[DCTSIZE2+16] = {
+ 0, 1, 8, 16, 9, 2, 3, 10,
+ 17, 24, 32, 25, 18, 11, 4, 5,
+ 12, 19, 26, 33, 40, 48, 41, 34,
+ 27, 20, 13, 6, 7, 14, 21, 28,
+ 35, 42, 49, 56, 57, 50, 43, 36,
+ 29, 22, 15, 23, 30, 37, 44, 51,
+ 58, 59, 52, 45, 38, 31, 39, 46,
+ 53, 60, 61, 54, 47, 55, 62, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63, /* extra entries for safety in decoder */
+ 63, 63, 63, 63, 63, 63, 63, 63
+};
+
+
+/*
+ * Arithmetic utilities
+ */
+
+GLOBAL(long)
+jdiv_round_up (long a, long b)
+/* Compute a/b rounded up to next integer, ie, ceil(a/b) */
+/* Assumes a >= 0, b > 0 */
+{
+ return (a + b - 1L) / b;
+}
+
+
+GLOBAL(long)
+jround_up (long a, long b)
+/* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
+/* Assumes a >= 0, b > 0 */
+{
+ a += b - 1L;
+ return a - (a % b);
+}
+
+
+/* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
+ * and coefficient-block arrays. This won't work on 80x86 because the arrays
+ * are FAR and we're assuming a small-pointer memory model. However, some
+ * DOS compilers provide far-pointer versions of memcpy() and memset() even
+ * in the small-model libraries. These will be used if USE_FMEM is defined.
+ * Otherwise, the routines below do it the hard way. (The performance cost
+ * is not all that great, because these routines aren't very heavily used.)
+ */
+
+#ifndef NEED_FAR_POINTERS /* normal case, same as regular macros */
+#define FMEMCOPY(dest,src,size) MEMCOPY(dest,src,size)
+#define FMEMZERO(target,size) MEMZERO(target,size)
+#else /* 80x86 case, define if we can */
+#ifdef USE_FMEM
+#define FMEMCOPY(dest,src,size) _fmemcpy((void FAR *)(dest), (const void FAR *)(src), (size_t)(size))
+#define FMEMZERO(target,size) _fmemset((void FAR *)(target), 0, (size_t)(size))
+#endif
+#endif
+
+
+GLOBAL(void)
+jcopy_sample_rows (JSAMPARRAY input_array, int source_row,
+ JSAMPARRAY output_array, int dest_row,
+ int num_rows, JDIMENSION num_cols)
+/* Copy some rows of samples from one place to another.
+ * num_rows rows are copied from input_array[source_row++]
+ * to output_array[dest_row++]; these areas may overlap for duplication.
+ * The source and destination arrays must be at least as wide as num_cols.
+ */
+{
+ register JSAMPROW inptr, outptr;
+#ifdef FMEMCOPY
+ register size_t count = (size_t) (num_cols * SIZEOF(JSAMPLE));
+#else
+ register JDIMENSION count;
+#endif
+ register int row;
+
+ input_array += source_row;
+ output_array += dest_row;
+
+ for (row = num_rows; row > 0; row--) {
+ inptr = *input_array++;
+ outptr = *output_array++;
+#ifdef FMEMCOPY
+ FMEMCOPY(outptr, inptr, count);
+#else
+ for (count = num_cols; count > 0; count--)
+ *outptr++ = *inptr++; /* needn't bother with GETJSAMPLE() here */
+#endif
+ }
+}
+
+
+GLOBAL(void)
+jcopy_block_row (JBLOCKROW input_row, JBLOCKROW output_row,
+ JDIMENSION num_blocks)
+/* Copy a row of coefficient blocks from one place to another. */
+{
+#ifdef FMEMCOPY
+ FMEMCOPY(output_row, input_row, num_blocks * (DCTSIZE2 * SIZEOF(JCOEF)));
+#else
+ register JCOEFPTR inptr, outptr;
+ register long count;
+
+ inptr = (JCOEFPTR) input_row;
+ outptr = (JCOEFPTR) output_row;
+ for (count = (long) num_blocks * DCTSIZE2; count > 0; count--) {
+ *outptr++ = *inptr++;
+ }
+#endif
+}
+
+
+GLOBAL(void)
+jzero_far (void FAR * target, size_t bytestozero)
+/* Zero out a chunk of FAR memory. */
+/* This might be sample-array data, block-array data, or alloc_large data. */
+{
+#ifdef FMEMZERO
+ FMEMZERO(target, bytestozero);
+#else
+ register char FAR * ptr = (char FAR *) target;
+ register size_t count;
+
+ for (count = bytestozero; count > 0; count--) {
+ *ptr++ = 0;
+ }
+#endif
+}
--- /dev/null
+/*
+ * rdbmp.c
+ *
+ * Copyright (C) 1994-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to read input images in Microsoft "BMP"
+ * format (MS Windows 3.x, OS/2 1.x, and OS/2 2.x flavors).
+ * Currently, only 8-bit and 24-bit images are supported, not 1-bit or
+ * 4-bit (feeding such low-depth images into JPEG would be silly anyway).
+ * Also, we don't support RLE-compressed files.
+ *
+ * These routines may need modification for non-Unix environments or
+ * specialized applications. As they stand, they assume input from
+ * an ordinary stdio stream. They further assume that reading begins
+ * at the start of the file; start_input may need work if the
+ * user interface has already read some data (e.g., to determine that
+ * the file is indeed BMP format).
+ *
+ * This code contributed by James Arthur Boucher.
+ */
+
+#include "cdjpeg12.h" /* Common decls for cjpeg/djpeg applications */
+
+#ifdef BMP_SUPPORTED
+
+
+/* Macros to deal with unsigned chars as efficiently as compiler allows */
+
+#ifdef HAVE_UNSIGNED_CHAR
+typedef unsigned char U_CHAR;
+#define UCH(x) ((int) (x))
+#else /* !HAVE_UNSIGNED_CHAR */
+#ifdef CHAR_IS_UNSIGNED
+typedef char U_CHAR;
+#define UCH(x) ((int) (x))
+#else
+typedef char U_CHAR;
+#define UCH(x) ((int) (x) & 0xFF)
+#endif
+#endif /* HAVE_UNSIGNED_CHAR */
+
+
+#define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
+
+
+/* Private version of data source object */
+
+typedef struct _bmp_source_struct * bmp_source_ptr;
+
+typedef struct _bmp_source_struct {
+ struct cjpeg_source_struct pub; /* public fields */
+
+ j_compress_ptr cinfo; /* back link saves passing separate parm */
+
+ JSAMPARRAY colormap; /* BMP colormap (converted to my format) */
+
+ jvirt_sarray_ptr whole_image; /* Needed to reverse row order */
+ JDIMENSION source_row; /* Current source row number */
+ JDIMENSION row_width; /* Physical width of scanlines in file */
+
+ int bits_per_pixel; /* remembers 8- or 24-bit format */
+} bmp_source_struct;
+
+
+LOCAL(int)
+read_byte (bmp_source_ptr sinfo)
+/* Read next byte from BMP file */
+{
+ register FILE *infile = sinfo->pub.input_file;
+ register int c;
+
+ if ((c = getc(infile)) == EOF)
+ ERREXIT(sinfo->cinfo, JERR_INPUT_EOF);
+ return c;
+}
+
+
+LOCAL(void)
+read_colormap (bmp_source_ptr sinfo, int cmaplen, int mapentrysize)
+/* Read the colormap from a BMP file */
+{
+ int i;
+
+ switch (mapentrysize) {
+ case 3:
+ /* BGR format (occurs in OS/2 files) */
+ for (i = 0; i < cmaplen; i++) {
+ sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
+ }
+ break;
+ case 4:
+ /* BGR0 format (occurs in MS Windows files) */
+ for (i = 0; i < cmaplen; i++) {
+ sinfo->colormap[2][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[1][i] = (JSAMPLE) read_byte(sinfo);
+ sinfo->colormap[0][i] = (JSAMPLE) read_byte(sinfo);
+ (void) read_byte(sinfo);
+ }
+ break;
+ default:
+ ERREXIT(sinfo->cinfo, JERR_BMP_BADCMAP);
+ break;
+ }
+}
+
+
+/*
+ * Read one row of pixels.
+ * The image has been read into the whole_image array, but is otherwise
+ * unprocessed. We must read it out in top-to-bottom row order, and if
+ * it is an 8-bit image, we must expand colormapped pixels to 24bit format.
+ */
+
+METHODDEF(JDIMENSION)
+get_8bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+/* This version is for reading 8-bit colormap indexes */
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ register JSAMPARRAY colormap = source->colormap;
+ JSAMPARRAY image_ptr;
+ register int t;
+ register JSAMPROW inptr, outptr;
+ register JDIMENSION col;
+
+ /* Fetch next row from virtual array */
+ source->source_row--;
+ image_ptr = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->whole_image,
+ source->source_row, (JDIMENSION) 1, FALSE);
+
+ /* Expand the colormap indexes to real data */
+ inptr = image_ptr[0];
+ outptr = source->pub.buffer[0];
+ for (col = cinfo->image_width; col > 0; col--) {
+ t = GETJSAMPLE(*inptr++);
+ *outptr++ = colormap[0][t]; /* can omit GETJSAMPLE() safely */
+ *outptr++ = colormap[1][t];
+ *outptr++ = colormap[2][t];
+ }
+
+ return 1;
+}
+
+
+METHODDEF(JDIMENSION)
+get_24bit_row (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+/* This version is for reading 24-bit pixels */
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ JSAMPARRAY image_ptr;
+ register JSAMPROW inptr, outptr;
+ register JDIMENSION col;
+
+ /* Fetch next row from virtual array */
+ source->source_row--;
+ image_ptr = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->whole_image,
+ source->source_row, (JDIMENSION) 1, FALSE);
+
+ /* Transfer data. Note source values are in BGR order
+ * (even though Microsoft's own documents say the opposite).
+ */
+ inptr = image_ptr[0];
+ outptr = source->pub.buffer[0];
+ for (col = cinfo->image_width; col > 0; col--) {
+ outptr[2] = *inptr++; /* can omit GETJSAMPLE() safely */
+ outptr[1] = *inptr++;
+ outptr[0] = *inptr++;
+ outptr += 3;
+ }
+
+ return 1;
+}
+
+
+/*
+ * This method loads the image into whole_image during the first call on
+ * get_pixel_rows. The get_pixel_rows pointer is then adjusted to call
+ * get_8bit_row or get_24bit_row on subsequent calls.
+ */
+
+METHODDEF(JDIMENSION)
+preload_image (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ register FILE *infile = source->pub.input_file;
+ register int c;
+ register JSAMPROW out_ptr;
+ JSAMPARRAY image_ptr;
+ JDIMENSION row, col;
+ cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
+
+ /* Read the data into a virtual array in input-file row order. */
+ for (row = 0; row < cinfo->image_height; row++) {
+ if (progress != NULL) {
+ progress->pub.pass_counter = (long) row;
+ progress->pub.pass_limit = (long) cinfo->image_height;
+ (*progress->pub.progress_monitor) ((j_common_ptr) cinfo);
+ }
+ image_ptr = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, source->whole_image,
+ row, (JDIMENSION) 1, TRUE);
+ out_ptr = image_ptr[0];
+ for (col = source->row_width; col > 0; col--) {
+ /* inline copy of read_byte() for speed */
+ if ((c = getc(infile)) == EOF)
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ *out_ptr++ = (JSAMPLE) c;
+ }
+ }
+ if (progress != NULL)
+ progress->completed_extra_passes++;
+
+ /* Set up to read from the virtual array in top-to-bottom order */
+ switch (source->bits_per_pixel) {
+ case 8:
+ source->pub.get_pixel_rows = get_8bit_row;
+ break;
+ case 24:
+ source->pub.get_pixel_rows = get_24bit_row;
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADDEPTH);
+ }
+ source->source_row = cinfo->image_height;
+
+ /* And read the first row */
+ return (*source->pub.get_pixel_rows) (cinfo, sinfo);
+}
+
+
+/*
+ * Read the file header; return image size and component count.
+ */
+
+METHODDEF(void)
+start_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+{
+ bmp_source_ptr source = (bmp_source_ptr) sinfo;
+ U_CHAR bmpfileheader[14];
+ U_CHAR bmpinfoheader[64];
+#define GET_2B(array,offset) ((unsigned int) UCH(array[offset]) + \
+ (((unsigned int) UCH(array[offset+1])) << 8))
+#define GET_4B(array,offset) ((INT32) UCH(array[offset]) + \
+ (((INT32) UCH(array[offset+1])) << 8) + \
+ (((INT32) UCH(array[offset+2])) << 16) + \
+ (((INT32) UCH(array[offset+3])) << 24))
+ INT32 bfOffBits;
+ INT32 headerSize;
+ INT32 biWidth = 0; /* initialize to avoid compiler warning */
+ INT32 biHeight = 0;
+ unsigned int biPlanes;
+ INT32 biCompression;
+ INT32 biXPelsPerMeter,biYPelsPerMeter;
+ INT32 biClrUsed = 0;
+ int mapentrysize = 0; /* 0 indicates no colormap */
+ INT32 bPad;
+ JDIMENSION row_width;
+
+ /* Read and verify the bitmap file header */
+ if (! ReadOK(source->pub.input_file, bmpfileheader, 14))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ if (GET_2B(bmpfileheader,0) != 0x4D42) /* 'BM' */
+ ERREXIT(cinfo, JERR_BMP_NOT);
+ bfOffBits = (INT32) GET_4B(bmpfileheader,10);
+ /* We ignore the remaining fileheader fields */
+
+ /* The infoheader might be 12 bytes (OS/2 1.x), 40 bytes (Windows),
+ * or 64 bytes (OS/2 2.x). Check the first 4 bytes to find out which.
+ */
+ if (! ReadOK(source->pub.input_file, bmpinfoheader, 4))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+ headerSize = (INT32) GET_4B(bmpinfoheader,0);
+ if (headerSize < 12 || headerSize > 64)
+ ERREXIT(cinfo, JERR_BMP_BADHEADER);
+ if (! ReadOK(source->pub.input_file, bmpinfoheader+4, headerSize-4))
+ ERREXIT(cinfo, JERR_INPUT_EOF);
+
+ switch ((int) headerSize) {
+ case 12:
+ /* Decode OS/2 1.x header (Microsoft calls this a BITMAPCOREHEADER) */
+ biWidth = (INT32) GET_2B(bmpinfoheader,4);
+ biHeight = (INT32) GET_2B(bmpinfoheader,6);
+ biPlanes = GET_2B(bmpinfoheader,8);
+ source->bits_per_pixel = (int) GET_2B(bmpinfoheader,10);
+
+ switch (source->bits_per_pixel) {
+ case 8: /* colormapped image */
+ mapentrysize = 3; /* OS/2 uses RGBTRIPLE colormap */
+ TRACEMS2(cinfo, 1, JTRC_BMP_OS2_MAPPED, (int) biWidth, (int) biHeight);
+ break;
+ case 24: /* RGB image */
+ TRACEMS2(cinfo, 1, JTRC_BMP_OS2, (int) biWidth, (int) biHeight);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADDEPTH);
+ break;
+ }
+ if (biPlanes != 1)
+ ERREXIT(cinfo, JERR_BMP_BADPLANES);
+ break;
+ case 40:
+ case 64:
+ /* Decode Windows 3.x header (Microsoft calls this a BITMAPINFOHEADER) */
+ /* or OS/2 2.x header, which has additional fields that we ignore */
+ biWidth = GET_4B(bmpinfoheader,4);
+ biHeight = GET_4B(bmpinfoheader,8);
+ biPlanes = GET_2B(bmpinfoheader,12);
+ source->bits_per_pixel = (int) GET_2B(bmpinfoheader,14);
+ biCompression = GET_4B(bmpinfoheader,16);
+ biXPelsPerMeter = GET_4B(bmpinfoheader,24);
+ biYPelsPerMeter = GET_4B(bmpinfoheader,28);
+ biClrUsed = GET_4B(bmpinfoheader,32);
+ /* biSizeImage, biClrImportant fields are ignored */
+
+ switch (source->bits_per_pixel) {
+ case 8: /* colormapped image */
+ mapentrysize = 4; /* Windows uses RGBQUAD colormap */
+ TRACEMS2(cinfo, 1, JTRC_BMP_MAPPED, (int) biWidth, (int) biHeight);
+ break;
+ case 24: /* RGB image */
+ TRACEMS2(cinfo, 1, JTRC_BMP, (int) biWidth, (int) biHeight);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADDEPTH);
+ break;
+ }
+ if (biPlanes != 1)
+ ERREXIT(cinfo, JERR_BMP_BADPLANES);
+ if (biCompression != 0)
+ ERREXIT(cinfo, JERR_BMP_COMPRESSED);
+
+ if (biXPelsPerMeter > 0 && biYPelsPerMeter > 0) {
+ /* Set JFIF density parameters from the BMP data */
+ cinfo->X_density = (UINT16) (biXPelsPerMeter/100); /* 100 cm per meter */
+ cinfo->Y_density = (UINT16) (biYPelsPerMeter/100);
+ cinfo->density_unit = 2; /* dots/cm */
+ }
+ break;
+ default:
+ ERREXIT(cinfo, JERR_BMP_BADHEADER);
+ break;
+ }
+
+ /* Compute distance to bitmap data --- will adjust for colormap below */
+ bPad = bfOffBits - (headerSize + 14);
+
+ /* Read the colormap, if any */
+ if (mapentrysize > 0) {
+ if (biClrUsed <= 0)
+ biClrUsed = 256; /* assume it's 256 */
+ else if (biClrUsed > 256)
+ ERREXIT(cinfo, JERR_BMP_BADCMAP);
+ /* Allocate space to store the colormap */
+ source->colormap = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) biClrUsed, (JDIMENSION) 3);
+ /* and read it from the file */
+ read_colormap(source, (int) biClrUsed, mapentrysize);
+ /* account for size of colormap */
+ bPad -= biClrUsed * mapentrysize;
+ }
+
+ /* Skip any remaining pad bytes */
+ if (bPad < 0) /* incorrect bfOffBits value? */
+ ERREXIT(cinfo, JERR_BMP_BADHEADER);
+ while (--bPad >= 0) {
+ (void) read_byte(source);
+ }
+
+ /* Compute row width in file, including padding to 4-byte boundary */
+ if (source->bits_per_pixel == 24)
+ row_width = (JDIMENSION) (biWidth * 3);
+ else
+ row_width = (JDIMENSION) biWidth;
+ while ((row_width & 3) != 0) row_width++;
+ source->row_width = row_width;
+
+ /* Allocate space for inversion array, prepare for preload pass */
+ source->whole_image = (*cinfo->mem->request_virt_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+ row_width, (JDIMENSION) biHeight, (JDIMENSION) 1);
+ source->pub.get_pixel_rows = preload_image;
+ if (cinfo->progress != NULL) {
+ cd_progress_ptr progress = (cd_progress_ptr) cinfo->progress;
+ progress->total_extra_passes++; /* count file input as separate pass */
+ }
+
+ /* Allocate one-row buffer for returned data */
+ source->pub.buffer = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) (biWidth * 3), (JDIMENSION) 1);
+ source->pub.buffer_height = 1;
+
+ cinfo->in_color_space = JCS_RGB;
+ cinfo->input_components = 3;
+ cinfo->data_precision = 8;
+ cinfo->image_width = (JDIMENSION) biWidth;
+ cinfo->image_height = (JDIMENSION) biHeight;
+}
+
+
+/*
+ * Finish up at the end of the file.
+ */
+
+METHODDEF(void)
+finish_input_bmp (j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
+{
+ /* no work */
+}
+
+
+/*
+ * The module selection routine for BMP format input.
+ */
+
+GLOBAL(cjpeg_source_ptr)
+jinit_read_bmp (j_compress_ptr cinfo)
+{
+ bmp_source_ptr source;
+
+ /* Create module interface object */
+ source = (bmp_source_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(bmp_source_struct));
+ source->cinfo = cinfo; /* make back link for subroutines */
+ /* Fill in method ptrs, except get_pixel_rows which start_input sets */
+ source->pub.start_input = start_input_bmp;
+ source->pub.finish_input = finish_input_bmp;
+
+ return (cjpeg_source_ptr) source;
+}
+
+#endif /* BMP_SUPPORTED */
--- /dev/null
+/*
+ * rdgif.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to read input images in GIF format.
+ *
+ *****************************************************************************
+ * NOTE: to avoid entanglements with Unisys' patent on LZW compression, *
+ * the ability to read GIF files has been removed from the IJG distribution. *
+ * Sorry about that. *
+ *****************************************************************************
+ *
+ * We are required to state that
+ * "The Graphics Interchange Format(c) is the Copyright property of
+ * CompuServe Incorporated. GIF(sm) is a Service Mark property of
+ * CompuServe Incorporated."
+ */
+
+#include "cdjpeg12.h" /* Common decls for cjpeg/djpeg applications */
+
+#ifdef GIF_SUPPORTED
+
+/*
+ * The module selection routine for GIF format input.
+ */
+
+GLOBAL(cjpeg_source_ptr)
+jinit_read_gif (j_compress_ptr cinfo)
+{
+ fprintf(stderr, "GIF input is unsupported for legal reasons. Sorry.\n");
+ exit(EXIT_FAILURE);
+ return NULL; /* keep compiler happy */
+}
+
+#endif /* GIF_SUPPORTED */
--- /dev/null
+/*
+ * rdswitch.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to process some of cjpeg's more complicated
+ * command-line switches. Switches processed here are:
+ * -qtables file Read quantization tables from text file
+ * -scans file Read scan script from text file
+ * -qslots N[,N,...] Set component quantization table selectors
+ * -sample HxV[,HxV,...] Set component sampling factors
+ */
+
+#include "cdjpeg12.h" /* Common decls for cjpeg/djpeg applications */
+#include <ctype.h> /* to declare isdigit(), isspace() */
+
+
+LOCAL(int)
+text_getc (FILE * file)
+/* Read next char, skipping over any comments (# to end of line) */
+/* A comment/newline sequence is returned as a newline */
+{
+ register int ch;
+
+ ch = getc(file);
+ if (ch == '#') {
+ do {
+ ch = getc(file);
+ } while (ch != '\n' && ch != EOF);
+ }
+ return ch;
+}
+
+
+LOCAL(boolean)
+read_text_integer (FILE * file, long * result, int * termchar)
+/* Read an unsigned decimal integer from a file, store it in result */
+/* Reads one trailing character after the integer; returns it in termchar */
+{
+ register int ch;
+ register long val;
+
+ /* Skip any leading whitespace, detect EOF */
+ do {
+ ch = text_getc(file);
+ if (ch == EOF) {
+ *termchar = ch;
+ return FALSE;
+ }
+ } while (isspace(ch));
+
+ if (! isdigit(ch)) {
+ *termchar = ch;
+ return FALSE;
+ }
+
+ val = ch - '0';
+ while ((ch = text_getc(file)) != EOF) {
+ if (! isdigit(ch))
+ break;
+ val *= 10;
+ val += ch - '0';
+ }
+ *result = val;
+ *termchar = ch;
+ return TRUE;
+}
+
+
+GLOBAL(boolean)
+read_quant_tables (j_compress_ptr cinfo, char * filename,
+ int scale_factor, boolean force_baseline)
+/* Read a set of quantization tables from the specified file.
+ * The file is plain ASCII text: decimal numbers with whitespace between.
+ * Comments preceded by '#' may be included in the file.
+ * There may be one to NUM_QUANT_TBLS tables in the file, each of 64 values.
+ * The tables are implicitly numbered 0,1,etc.
+ * NOTE: does not affect the qslots mapping, which will default to selecting
+ * table 0 for luminance (or primary) components, 1 for chrominance components.
+ * You must use -qslots if you want a different component->table mapping.
+ */
+{
+ FILE * fp;
+ int tblno, i, termchar;
+ long val;
+ unsigned int table[DCTSIZE2];
+
+ if ((fp = fopen(filename, "r")) == NULL) {
+ fprintf(stderr, "Can't open table file %s\n", filename);
+ return FALSE;
+ }
+ tblno = 0;
+
+ while (read_text_integer(fp, &val, &termchar)) { /* read 1st element of table */
+ if (tblno >= NUM_QUANT_TBLS) {
+ fprintf(stderr, "Too many tables in file %s\n", filename);
+ fclose(fp);
+ return FALSE;
+ }
+ table[0] = (unsigned int) val;
+ for (i = 1; i < DCTSIZE2; i++) {
+ if (! read_text_integer(fp, &val, &termchar)) {
+ fprintf(stderr, "Invalid table data in file %s\n", filename);
+ fclose(fp);
+ return FALSE;
+ }
+ table[i] = (unsigned int) val;
+ }
+ jpeg_add_quant_table(cinfo, tblno, table, scale_factor, force_baseline);
+ tblno++;
+ }
+
+ if (termchar != EOF) {
+ fprintf(stderr, "Non-numeric data in file %s\n", filename);
+ fclose(fp);
+ return FALSE;
+ }
+
+ fclose(fp);
+ return TRUE;
+}
+
+
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+
+LOCAL(boolean)
+read_scan_integer (FILE * file, long * result, int * termchar)
+/* Variant of read_text_integer that always looks for a non-space termchar;
+ * this simplifies parsing of punctuation in scan scripts.
+ */
+{
+ register int ch;
+
+ if (! read_text_integer(file, result, termchar))
+ return FALSE;
+ ch = *termchar;
+ while (ch != EOF && isspace(ch))
+ ch = text_getc(file);
+ if (isdigit(ch)) { /* oops, put it back */
+ if (ungetc(ch, file) == EOF)
+ return FALSE;
+ ch = ' ';
+ } else {
+ /* Any separators other than ';' and ':' are ignored;
+ * this allows user to insert commas, etc, if desired.
+ */
+ if (ch != EOF && ch != ';' && ch != ':')
+ ch = ' ';
+ }
+ *termchar = ch;
+ return TRUE;
+}
+
+
+GLOBAL(boolean)
+read_scan_script (j_compress_ptr cinfo, char * filename)
+/* Read a scan script from the specified text file.
+ * Each entry in the file defines one scan to be emitted.
+ * Entries are separated by semicolons ';'.
+ * An entry contains one to four component indexes,
+ * optionally followed by a colon ':' and four progressive-JPEG parameters.
+ * The component indexes denote which component(s) are to be transmitted
+ * in the current scan. The first component has index 0.
+ * Sequential JPEG is used if the progressive-JPEG parameters are omitted.
+ * The file is free format text: any whitespace may appear between numbers
+ * and the ':' and ';' punctuation marks. Also, other punctuation (such
+ * as commas or dashes) can be placed between numbers if desired.
+ * Comments preceded by '#' may be included in the file.
+ * Note: we do very little validity checking here;
+ * jcmaster.c will validate the script parameters.
+ */
+{
+ FILE * fp;
+ int scanno, ncomps, termchar;
+ long val;
+ jpeg_scan_info * scanptr;
+#define MAX_SCANS 100 /* quite arbitrary limit */
+ jpeg_scan_info scans[MAX_SCANS];
+
+ if ((fp = fopen(filename, "r")) == NULL) {
+ fprintf(stderr, "Can't open scan definition file %s\n", filename);
+ return FALSE;
+ }
+ scanptr = scans;
+ scanno = 0;
+
+ while (read_scan_integer(fp, &val, &termchar)) {
+ if (scanno >= MAX_SCANS) {
+ fprintf(stderr, "Too many scans defined in file %s\n", filename);
+ fclose(fp);
+ return FALSE;
+ }
+ scanptr->component_index[0] = (int) val;
+ ncomps = 1;
+ while (termchar == ' ') {
+ if (ncomps >= MAX_COMPS_IN_SCAN) {
+ fprintf(stderr, "Too many components in one scan in file %s\n",
+ filename);
+ fclose(fp);
+ return FALSE;
+ }
+ if (! read_scan_integer(fp, &val, &termchar))
+ goto bogus;
+ scanptr->component_index[ncomps] = (int) val;
+ ncomps++;
+ }
+ scanptr->comps_in_scan = ncomps;
+ if (termchar == ':') {
+ if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
+ goto bogus;
+ scanptr->Ss = (int) val;
+ if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
+ goto bogus;
+ scanptr->Se = (int) val;
+ if (! read_scan_integer(fp, &val, &termchar) || termchar != ' ')
+ goto bogus;
+ scanptr->Ah = (int) val;
+ if (! read_scan_integer(fp, &val, &termchar))
+ goto bogus;
+ scanptr->Al = (int) val;
+ } else {
+ /* set non-progressive parameters */
+ scanptr->Ss = 0;
+ scanptr->Se = DCTSIZE2-1;
+ scanptr->Ah = 0;
+ scanptr->Al = 0;
+ }
+ if (termchar != ';' && termchar != EOF) {
+bogus:
+ fprintf(stderr, "Invalid scan entry format in file %s\n", filename);
+ fclose(fp);
+ return FALSE;
+ }
+ scanptr++, scanno++;
+ }
+
+ if (termchar != EOF) {
+ fprintf(stderr, "Non-numeric data in file %s\n", filename);
+ fclose(fp);
+ return FALSE;
+ }
+
+ if (scanno > 0) {
+ /* Stash completed scan list in cinfo structure.
+ * NOTE: for cjpeg's use, JPOOL_IMAGE is the right lifetime for this data,
+ * but if you want to compress multiple images you'd want JPOOL_PERMANENT.
+ */
+ scanptr = (jpeg_scan_info *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ scanno * SIZEOF(jpeg_scan_info));
+ MEMCOPY(scanptr, scans, scanno * SIZEOF(jpeg_scan_info));
+ cinfo->scan_info = scanptr;
+ cinfo->num_scans = scanno;
+ }
+
+ fclose(fp);
+ return TRUE;
+}
+
+#endif /* C_MULTISCAN_FILES_SUPPORTED */
+
+
+GLOBAL(boolean)
+set_quant_slots (j_compress_ptr cinfo, char *arg)
+/* Process a quantization-table-selectors parameter string, of the form
+ * N[,N,...]
+ * If there are more components than parameters, the last value is replicated.
+ */
+{
+ int val = 0; /* default table # */
+ int ci;
+ char ch;
+
+ for (ci = 0; ci < MAX_COMPONENTS; ci++) {
+ if (*arg) {
+ ch = ','; /* if not set by sscanf, will be ',' */
+ if (sscanf(arg, "%d%c", &val, &ch) < 1)
+ return FALSE;
+ if (ch != ',') /* syntax check */
+ return FALSE;
+ if (val < 0 || val >= NUM_QUANT_TBLS) {
+ fprintf(stderr, "JPEG quantization tables are numbered 0..%d\n",
+ NUM_QUANT_TBLS-1);
+ return FALSE;
+ }
+ cinfo->comp_info[ci].quant_tbl_no = val;
+ while (*arg && *arg++ != ',') /* advance to next segment of arg string */
+ ;
+ } else {
+ /* reached end of parameter, set remaining components to last table */
+ cinfo->comp_info[ci].quant_tbl_no = val;
+ }
+ }
+ return TRUE;
+}
+
+
+GLOBAL(boolean)
+set_sample_factors (j_compress_ptr cinfo, char *arg)
+/* Process a sample-factors parameter string, of the form
+ * HxV[,HxV,...]
+ * If there are more components than parameters, "1x1" is assumed for the rest.
+ */
+{
+ int ci, val1, val2;
+ char ch1, ch2;
+
+ for (ci = 0; ci < MAX_COMPONENTS; ci++) {
+ if (*arg) {
+ ch2 = ','; /* if not set by sscanf, will be ',' */
+ if (sscanf(arg, "%d%c%d%c", &val1, &ch1, &val2, &ch2) < 3)
+ return FALSE;
+ if ((ch1 != 'x' && ch1 != 'X') || ch2 != ',') /* syntax check */
+ return FALSE;
+ if (val1 <= 0 || val1 > 4 || val2 <= 0 || val2 > 4) {
+ fprintf(stderr, "JPEG sampling factors must be 1..4\n");
+ return FALSE;
+ }
+ cinfo->comp_info[ci].h_samp_factor = val1;
+ cinfo->comp_info[ci].v_samp_factor = val2;
+ while (*arg && *arg++ != ',') /* advance to next segment of arg string */
+ ;
+ } else {
+ /* reached end of parameter, set remaining components to 1x1 sampling */
+ cinfo->comp_info[ci].h_samp_factor = 1;
+ cinfo->comp_info[ci].v_samp_factor = 1;
+ }
+ }
+ return TRUE;
+}
--- /dev/null
+/*
+ * transupp.c
+ *
+ * Copyright (C) 1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains image transformation routines and other utility code
+ * used by the jpegtran sample application. These are NOT part of the core
+ * JPEG library. But we keep these routines separate from jpegtran.c to
+ * ease the task of maintaining jpegtran-like programs that have other user
+ * interfaces.
+ */
+
+/* Although this file really shouldn't have access to the library internals,
+ * it's helpful to let it call jround_up() and jcopy_block_row().
+ */
+#define JPEG_INTERNALS
+
+#include "jinclude12.h"
+#include "jpeglib12.h"
+#include "transupp12.h" /* My own external interface */
+
+
+#if TRANSFORMS_SUPPORTED
+
+/*
+ * Lossless image transformation routines. These routines work on DCT
+ * coefficient arrays and thus do not require any lossy decompression
+ * or recompression of the image.
+ * Thanks to Guido Vollbeding for the initial design and code of this feature.
+ *
+ * Horizontal flipping is done in-place, using a single top-to-bottom
+ * pass through the virtual source array. It will thus be much the
+ * fastest option for images larger than main memory.
+ *
+ * The other routines require a set of destination virtual arrays, so they
+ * need twice as much memory as jpegtran normally does. The destination
+ * arrays are always written in normal scan order (top to bottom) because
+ * the virtual array manager expects this. The source arrays will be scanned
+ * in the corresponding order, which means multiple passes through the source
+ * arrays for most of the transforms. That could result in much thrashing
+ * if the image is larger than main memory.
+ *
+ * Some notes about the operating environment of the individual transform
+ * routines:
+ * 1. Both the source and destination virtual arrays are allocated from the
+ * source JPEG object, and therefore should be manipulated by calling the
+ * source's memory manager.
+ * 2. The destination's component count should be used. It may be smaller
+ * than the source's when forcing to grayscale.
+ * 3. Likewise the destination's sampling factors should be used. When
+ * forcing to grayscale the destination's sampling factors will be all 1,
+ * and we may as well take that as the effective iMCU size.
+ * 4. When "trim" is in effect, the destination's dimensions will be the
+ * trimmed values but the source's will be untrimmed.
+ * 5. All the routines assume that the source and destination buffers are
+ * padded out to a full iMCU boundary. This is true, although for the
+ * source buffer it is an undocumented property of jdcoefct.c.
+ * Notes 2,3,4 boil down to this: generally we should use the destination's
+ * dimensions and ignore the source's.
+ */
+
+
+LOCAL(void)
+do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays)
+/* Horizontal flip; done in-place, so no separate dest array is required */
+{
+ JDIMENSION MCU_cols, comp_width, blk_x, blk_y;
+ int ci, k, offset_y;
+ JBLOCKARRAY buffer;
+ JCOEFPTR ptr1, ptr2;
+ JCOEF temp1, temp2;
+ jpeg_component_info *compptr;
+
+ /* Horizontal mirroring of DCT blocks is accomplished by swapping
+ * pairs of blocks in-place. Within a DCT block, we perform horizontal
+ * mirroring by changing the signs of odd-numbered columns.
+ * Partial iMCUs at the right edge are left untouched.
+ */
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ for (blk_y = 0; blk_y < compptr->height_in_blocks;
+ blk_y += compptr->v_samp_factor) {
+ buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
+ ptr1 = buffer[offset_y][blk_x];
+ ptr2 = buffer[offset_y][comp_width - blk_x - 1];
+ /* this unrolled loop doesn't need to know which row it's on... */
+ for (k = 0; k < DCTSIZE2; k += 2) {
+ temp1 = *ptr1; /* swap even column */
+ temp2 = *ptr2;
+ *ptr1++ = temp2;
+ *ptr2++ = temp1;
+ temp1 = *ptr1; /* swap odd column with sign change */
+ temp2 = *ptr2;
+ *ptr1++ = -temp2;
+ *ptr2++ = -temp1;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* Vertical flip */
+{
+ JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JBLOCKROW src_row_ptr, dst_row_ptr;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* We output into a separate array because we can't touch different
+ * rows of the source virtual array simultaneously. Otherwise, this
+ * is a pretty straightforward analog of horizontal flip.
+ * Within a DCT block, vertical mirroring is done by changing the signs
+ * of odd-numbered rows.
+ * Partial iMCUs at the bottom edge are copied verbatim.
+ */
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ if (dst_blk_y < comp_height) {
+ /* Row is within the mirrorable area. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+ comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ } else {
+ /* Bottom-edge blocks will be copied verbatim. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ if (dst_blk_y < comp_height) {
+ /* Row is within the mirrorable area. */
+ dst_row_ptr = dst_buffer[offset_y];
+ src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[dst_blk_x];
+ for (i = 0; i < DCTSIZE; i += 2) {
+ /* copy even row */
+ for (j = 0; j < DCTSIZE; j++)
+ *dst_ptr++ = *src_ptr++;
+ /* copy odd row with sign change */
+ for (j = 0; j < DCTSIZE; j++)
+ *dst_ptr++ = - *src_ptr++;
+ }
+ }
+ } else {
+ /* Just copy row verbatim. */
+ jcopy_block_row(src_buffer[offset_y], dst_buffer[offset_y],
+ compptr->width_in_blocks);
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* Transpose source into destination */
+{
+ JDIMENSION dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* Transposing pixels within a block just requires transposing the
+ * DCT coefficients.
+ * Partial iMCUs at the edges require no special treatment; we simply
+ * process all the available DCT blocks for every component.
+ */
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* 90 degree rotation is equivalent to
+ * 1. Transposing the image;
+ * 2. Horizontal mirroring.
+ * These two steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* Because of the horizontal mirror step, we can't process partial iMCUs
+ * at the (output) right edge properly. They just get transposed and
+ * not mirrored.
+ */
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ if (dst_blk_x < comp_width) {
+ /* Block is within the mirrorable area. */
+ dst_ptr = dst_buffer[offset_y]
+ [comp_width - dst_blk_x - offset_x - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ i++;
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ } else {
+ /* Edge blocks are transposed but not mirrored. */
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* 270 degree rotation is equivalent to
+ * 1. Horizontal mirroring;
+ * 2. Transposing the image.
+ * These two steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* Because of the horizontal mirror step, we can't process partial iMCUs
+ * at the (output) bottom edge properly. They just get transposed and
+ * not mirrored.
+ */
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ if (dst_blk_y < comp_height) {
+ /* Block is within the mirrorable area. */
+ src_ptr = src_buffer[offset_x]
+ [comp_height - dst_blk_y - offset_y - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ j++;
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ }
+ } else {
+ /* Edge blocks are transposed but not mirrored. */
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* 180 degree rotation is equivalent to
+ * 1. Vertical mirroring;
+ * 2. Horizontal mirroring.
+ * These two steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JBLOCKROW src_row_ptr, dst_row_ptr;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ if (dst_blk_y < comp_height) {
+ /* Row is within the vertically mirrorable area. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+ comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ } else {
+ /* Bottom-edge rows are only mirrored horizontally. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ if (dst_blk_y < comp_height) {
+ /* Row is within the mirrorable area. */
+ dst_row_ptr = dst_buffer[offset_y];
+ src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+ /* Process the blocks that can be mirrored both ways. */
+ for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
+ for (i = 0; i < DCTSIZE; i += 2) {
+ /* For even row, negate every odd column. */
+ for (j = 0; j < DCTSIZE; j += 2) {
+ *dst_ptr++ = *src_ptr++;
+ *dst_ptr++ = - *src_ptr++;
+ }
+ /* For odd row, negate every even column. */
+ for (j = 0; j < DCTSIZE; j += 2) {
+ *dst_ptr++ = - *src_ptr++;
+ *dst_ptr++ = *src_ptr++;
+ }
+ }
+ }
+ /* Any remaining right-edge blocks are only mirrored vertically. */
+ for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[dst_blk_x];
+ for (i = 0; i < DCTSIZE; i += 2) {
+ for (j = 0; j < DCTSIZE; j++)
+ *dst_ptr++ = *src_ptr++;
+ for (j = 0; j < DCTSIZE; j++)
+ *dst_ptr++ = - *src_ptr++;
+ }
+ }
+ } else {
+ /* Remaining rows are just mirrored horizontally. */
+ dst_row_ptr = dst_buffer[offset_y];
+ src_row_ptr = src_buffer[offset_y];
+ /* Process the blocks that can be mirrored. */
+ for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
+ for (i = 0; i < DCTSIZE2; i += 2) {
+ *dst_ptr++ = *src_ptr++;
+ *dst_ptr++ = - *src_ptr++;
+ }
+ }
+ /* Any remaining right-edge blocks are only copied. */
+ for (; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[dst_blk_x];
+ for (i = 0; i < DCTSIZE2; i++)
+ *dst_ptr++ = *src_ptr++;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* Transverse transpose is equivalent to
+ * 1. 180 degree rotation;
+ * 2. Transposition;
+ * or
+ * 1. Horizontal mirroring;
+ * 2. Transposition;
+ * 3. Horizontal mirroring.
+ * These steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ if (dst_blk_y < comp_height) {
+ src_ptr = src_buffer[offset_x]
+ [comp_height - dst_blk_y - offset_y - 1];
+ if (dst_blk_x < comp_width) {
+ /* Block is within the mirrorable area. */
+ dst_ptr = dst_buffer[offset_y]
+ [comp_width - dst_blk_x - offset_x - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ j++;
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ i++;
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ j++;
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ } else {
+ /* Right-edge blocks are mirrored in y only */
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ j++;
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ } else {
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ if (dst_blk_x < comp_width) {
+ /* Bottom-edge blocks are mirrored in x only */
+ dst_ptr = dst_buffer[offset_y]
+ [comp_width - dst_blk_x - offset_x - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ i++;
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ } else {
+ /* At lower right corner, just transpose, no mirroring */
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+
+/* Request any required workspace.
+ *
+ * We allocate the workspace virtual arrays from the source decompression
+ * object, so that all the arrays (both the original data and the workspace)
+ * will be taken into account while making memory management decisions.
+ * Hence, this routine must be called after jpeg_read_header (which reads
+ * the image dimensions) and before jpeg_read_coefficients (which realizes
+ * the source's virtual arrays).
+ */
+
+GLOBAL(void)
+jtransform_request_workspace (j_decompress_ptr srcinfo,
+ jpeg_transform_info *info)
+{
+ jvirt_barray_ptr *coef_arrays = NULL;
+ jpeg_component_info *compptr;
+ int ci;
+
+ if (info->force_grayscale &&
+ srcinfo->jpeg_color_space == JCS_YCbCr &&
+ srcinfo->num_components == 3) {
+ /* We'll only process the first component */
+ info->num_components = 1;
+ } else {
+ /* Process all the components */
+ info->num_components = srcinfo->num_components;
+ }
+
+ switch (info->transform) {
+ case JXFORM_NONE:
+ case JXFORM_FLIP_H:
+ /* Don't need a workspace array */
+ break;
+ case JXFORM_FLIP_V:
+ case JXFORM_ROT_180:
+ /* Need workspace arrays having same dimensions as source image.
+ * Note that we allocate arrays padded out to the next iMCU boundary,
+ * so that transform routines need not worry about missing edge blocks.
+ */
+ coef_arrays = (jvirt_barray_ptr *)
+ (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
+ SIZEOF(jvirt_barray_ptr) * info->num_components);
+ for (ci = 0; ci < info->num_components; ci++) {
+ compptr = srcinfo->comp_info + ci;
+ coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
+ ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
+ (JDIMENSION) jround_up((long) compptr->width_in_blocks,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) compptr->v_samp_factor);
+ }
+ break;
+ case JXFORM_TRANSPOSE:
+ case JXFORM_TRANSVERSE:
+ case JXFORM_ROT_90:
+ case JXFORM_ROT_270:
+ /* Need workspace arrays having transposed dimensions.
+ * Note that we allocate arrays padded out to the next iMCU boundary,
+ * so that transform routines need not worry about missing edge blocks.
+ */
+ coef_arrays = (jvirt_barray_ptr *)
+ (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
+ SIZEOF(jvirt_barray_ptr) * info->num_components);
+ for (ci = 0; ci < info->num_components; ci++) {
+ compptr = srcinfo->comp_info + ci;
+ coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
+ ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->width_in_blocks,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) compptr->h_samp_factor);
+ }
+ break;
+ }
+ info->workspace_coef_arrays = coef_arrays;
+}
+
+
+/* Transpose destination image parameters */
+
+LOCAL(void)
+transpose_critical_parameters (j_compress_ptr dstinfo)
+{
+ int tblno, i, j, ci, itemp;
+ jpeg_component_info *compptr;
+ JQUANT_TBL *qtblptr;
+ JDIMENSION dtemp;
+ UINT16 qtemp;
+
+ /* Transpose basic image dimensions */
+ dtemp = dstinfo->image_width;
+ dstinfo->image_width = dstinfo->image_height;
+ dstinfo->image_height = dtemp;
+
+ /* Transpose sampling factors */
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ itemp = compptr->h_samp_factor;
+ compptr->h_samp_factor = compptr->v_samp_factor;
+ compptr->v_samp_factor = itemp;
+ }
+
+ /* Transpose quantization tables */
+ for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
+ qtblptr = dstinfo->quant_tbl_ptrs[tblno];
+ if (qtblptr != NULL) {
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < i; j++) {
+ qtemp = qtblptr->quantval[i*DCTSIZE+j];
+ qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
+ qtblptr->quantval[j*DCTSIZE+i] = qtemp;
+ }
+ }
+ }
+ }
+}
+
+
+/* Trim off any partial iMCUs on the indicated destination edge */
+
+LOCAL(void)
+trim_right_edge (j_compress_ptr dstinfo)
+{
+ int ci, max_h_samp_factor;
+ JDIMENSION MCU_cols;
+
+ /* We have to compute max_h_samp_factor ourselves,
+ * because it hasn't been set yet in the destination
+ * (and we don't want to use the source's value).
+ */
+ max_h_samp_factor = 1;
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ int h_samp_factor = dstinfo->comp_info[ci].h_samp_factor;
+ max_h_samp_factor = MAX(max_h_samp_factor, h_samp_factor);
+ }
+ MCU_cols = dstinfo->image_width / (max_h_samp_factor * DCTSIZE);
+ if (MCU_cols > 0) /* can't trim to 0 pixels */
+ dstinfo->image_width = MCU_cols * (max_h_samp_factor * DCTSIZE);
+}
+
+LOCAL(void)
+trim_bottom_edge (j_compress_ptr dstinfo)
+{
+ int ci, max_v_samp_factor;
+ JDIMENSION MCU_rows;
+
+ /* We have to compute max_v_samp_factor ourselves,
+ * because it hasn't been set yet in the destination
+ * (and we don't want to use the source's value).
+ */
+ max_v_samp_factor = 1;
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ int v_samp_factor = dstinfo->comp_info[ci].v_samp_factor;
+ max_v_samp_factor = MAX(max_v_samp_factor, v_samp_factor);
+ }
+ MCU_rows = dstinfo->image_height / (max_v_samp_factor * DCTSIZE);
+ if (MCU_rows > 0) /* can't trim to 0 pixels */
+ dstinfo->image_height = MCU_rows * (max_v_samp_factor * DCTSIZE);
+}
+
+
+/* Adjust output image parameters as needed.
+ *
+ * This must be called after jpeg_copy_critical_parameters()
+ * and before jpeg_write_coefficients().
+ *
+ * The return value is the set of virtual coefficient arrays to be written
+ * (either the ones allocated by jtransform_request_workspace, or the
+ * original source data arrays). The caller will need to pass this value
+ * to jpeg_write_coefficients().
+ */
+
+GLOBAL(jvirt_barray_ptr *)
+jtransform_adjust_parameters (j_decompress_ptr srcinfo,
+ j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jpeg_transform_info *info)
+{
+ /* If force-to-grayscale is requested, adjust destination parameters */
+ if (info->force_grayscale) {
+ /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
+ * properly. Among other things, the target h_samp_factor & v_samp_factor
+ * will get set to 1, which typically won't match the source.
+ * In fact we do this even if the source is already grayscale; that
+ * provides an easy way of coercing a grayscale JPEG with funny sampling
+ * factors to the customary 1,1. (Some decoders fail on other factors.)
+ */
+ if ((dstinfo->jpeg_color_space == JCS_YCbCr &&
+ dstinfo->num_components == 3) ||
+ (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
+ dstinfo->num_components == 1)) {
+ /* We have to preserve the source's quantization table number. */
+ int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
+ jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
+ dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
+ } else {
+ /* Sorry, can't do it */
+ ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
+ }
+ }
+
+ /* Correct the destination's image dimensions etc if necessary */
+ switch (info->transform) {
+ case JXFORM_NONE:
+ /* Nothing to do */
+ break;
+ case JXFORM_FLIP_H:
+ if (info->trim)
+ trim_right_edge(dstinfo);
+ break;
+ case JXFORM_FLIP_V:
+ if (info->trim)
+ trim_bottom_edge(dstinfo);
+ break;
+ case JXFORM_TRANSPOSE:
+ transpose_critical_parameters(dstinfo);
+ /* transpose does NOT have to trim anything */
+ break;
+ case JXFORM_TRANSVERSE:
+ transpose_critical_parameters(dstinfo);
+ if (info->trim) {
+ trim_right_edge(dstinfo);
+ trim_bottom_edge(dstinfo);
+ }
+ break;
+ case JXFORM_ROT_90:
+ transpose_critical_parameters(dstinfo);
+ if (info->trim)
+ trim_right_edge(dstinfo);
+ break;
+ case JXFORM_ROT_180:
+ if (info->trim) {
+ trim_right_edge(dstinfo);
+ trim_bottom_edge(dstinfo);
+ }
+ break;
+ case JXFORM_ROT_270:
+ transpose_critical_parameters(dstinfo);
+ if (info->trim)
+ trim_bottom_edge(dstinfo);
+ break;
+ }
+
+ /* Return the appropriate output data set */
+ if (info->workspace_coef_arrays != NULL)
+ return info->workspace_coef_arrays;
+ return src_coef_arrays;
+}
+
+
+/* Execute the actual transformation, if any.
+ *
+ * This must be called *after* jpeg_write_coefficients, because it depends
+ * on jpeg_write_coefficients to have computed subsidiary values such as
+ * the per-component width and height fields in the destination object.
+ *
+ * Note that some transformations will modify the source data arrays!
+ */
+
+GLOBAL(void)
+jtransform_execute_transformation (j_decompress_ptr srcinfo,
+ j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jpeg_transform_info *info)
+{
+ jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
+
+ switch (info->transform) {
+ case JXFORM_NONE:
+ break;
+ case JXFORM_FLIP_H:
+ do_flip_h(srcinfo, dstinfo, src_coef_arrays);
+ break;
+ case JXFORM_FLIP_V:
+ do_flip_v(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_TRANSPOSE:
+ do_transpose(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_TRANSVERSE:
+ do_transverse(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_ROT_90:
+ do_rot_90(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_ROT_180:
+ do_rot_180(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_ROT_270:
+ do_rot_270(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ }
+}
+
+#endif /* TRANSFORMS_SUPPORTED */
+
+
+/* Setup decompression object to save desired markers in memory.
+ * This must be called before jpeg_read_header() to have the desired effect.
+ */
+
+GLOBAL(void)
+jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
+{
+#ifdef SAVE_MARKERS_SUPPORTED
+ int m;
+
+ /* Save comments except under NONE option */
+ if (option != JCOPYOPT_NONE) {
+ jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
+ }
+ /* Save all types of APPn markers iff ALL option */
+ if (option == JCOPYOPT_ALL) {
+ for (m = 0; m < 16; m++)
+ jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
+ }
+#endif /* SAVE_MARKERS_SUPPORTED */
+}
+
+/* Copy markers saved in the given source object to the destination object.
+ * This should be called just after jpeg_start_compress() or
+ * jpeg_write_coefficients().
+ * Note that those routines will have written the SOI, and also the
+ * JFIF APP0 or Adobe APP14 markers if selected.
+ */
+
+GLOBAL(void)
+jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ JCOPY_OPTION option)
+{
+ jpeg_saved_marker_ptr marker;
+
+ /* In the current implementation, we don't actually need to examine the
+ * option flag here; we just copy everything that got saved.
+ * But to avoid confusion, we do not output JFIF and Adobe APP14 markers
+ * if the encoder library already wrote one.
+ */
+ for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
+ if (dstinfo->write_JFIF_header &&
+ marker->marker == JPEG_APP0 &&
+ marker->data_length >= 5 &&
+ GETJOCTET(marker->data[0]) == 0x4A &&
+ GETJOCTET(marker->data[1]) == 0x46 &&
+ GETJOCTET(marker->data[2]) == 0x49 &&
+ GETJOCTET(marker->data[3]) == 0x46 &&
+ GETJOCTET(marker->data[4]) == 0)
+ continue; /* reject duplicate JFIF */
+ if (dstinfo->write_Adobe_marker &&
+ marker->marker == JPEG_APP0+14 &&
+ marker->data_length >= 5 &&
+ GETJOCTET(marker->data[0]) == 0x41 &&
+ GETJOCTET(marker->data[1]) == 0x64 &&
+ GETJOCTET(marker->data[2]) == 0x6F &&
+ GETJOCTET(marker->data[3]) == 0x62 &&
+ GETJOCTET(marker->data[4]) == 0x65)
+ continue; /* reject duplicate Adobe */
+#ifdef NEED_FAR_POINTERS
+ /* We could use jpeg_write_marker if the data weren't FAR... */
+ {
+ unsigned int i;
+ jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
+ for (i = 0; i < marker->data_length; i++)
+ jpeg_write_m_byte(dstinfo, marker->data[i]);
+ }
+#else
+ jpeg_write_marker(dstinfo, marker->marker,
+ marker->data, marker->data_length);
+#endif
+ }
+}
--- /dev/null
+/*
+ * wrgif.c
+ *
+ * Copyright (C) 1991-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to write output images in GIF format.
+ *
+ **************************************************************************
+ * NOTE: to avoid entanglements with Unisys' patent on LZW compression, *
+ * this code has been modified to output "uncompressed GIF" files. *
+ * There is no trace of the LZW algorithm in this file. *
+ **************************************************************************
+ *
+ * These routines may need modification for non-Unix environments or
+ * specialized applications. As they stand, they assume output to
+ * an ordinary stdio stream.
+ */
+
+/*
+ * This code is loosely based on ppmtogif from the PBMPLUS distribution
+ * of Feb. 1991. That file contains the following copyright notice:
+ * Based on GIFENCODE by David Rowley <mgardi@watdscu.waterloo.edu>.
+ * Lempel-Ziv compression based on "compress" by Spencer W. Thomas et al.
+ * Copyright (C) 1989 by Jef Poskanzer.
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose and without fee is hereby granted, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation. This software is provided "as is" without express or
+ * implied warranty.
+ *
+ * We are also required to state that
+ * "The Graphics Interchange Format(c) is the Copyright property of
+ * CompuServe Incorporated. GIF(sm) is a Service Mark property of
+ * CompuServe Incorporated."
+ */
+
+#include "cdjpeg12.h" /* Common decls for cjpeg/djpeg applications */
+
+#ifdef GIF_SUPPORTED
+
+
+/* Private version of data destination object */
+
+typedef struct {
+ struct djpeg_dest_struct pub; /* public fields */
+
+ j_decompress_ptr cinfo; /* back link saves passing separate parm */
+
+ /* State for packing variable-width codes into a bitstream */
+ int n_bits; /* current number of bits/code */
+ int maxcode; /* maximum code, given n_bits */
+ INT32 cur_accum; /* holds bits not yet output */
+ int cur_bits; /* # of bits in cur_accum */
+
+ /* State for GIF code assignment */
+ int ClearCode; /* clear code (doesn't change) */
+ int EOFCode; /* EOF code (ditto) */
+ int code_counter; /* counts output symbols */
+
+ /* GIF data packet construction buffer */
+ int bytesinpkt; /* # of bytes in current packet */
+ char packetbuf[256]; /* workspace for accumulating packet */
+
+} gif_dest_struct;
+
+typedef gif_dest_struct * gif_dest_ptr;
+
+/* Largest value that will fit in N bits */
+#define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
+
+
+/*
+ * Routines to package finished data bytes into GIF data blocks.
+ * A data block consists of a count byte (1..255) and that many data bytes.
+ */
+
+LOCAL(void)
+flush_packet (gif_dest_ptr dinfo)
+/* flush any accumulated data */
+{
+ if (dinfo->bytesinpkt > 0) { /* never write zero-length packet */
+ dinfo->packetbuf[0] = (char) dinfo->bytesinpkt++;
+ if (JFWRITE(dinfo->pub.output_file, dinfo->packetbuf, dinfo->bytesinpkt)
+ != (size_t) dinfo->bytesinpkt)
+ ERREXIT(dinfo->cinfo, JERR_FILE_WRITE);
+ dinfo->bytesinpkt = 0;
+ }
+}
+
+
+/* Add a character to current packet; flush to disk if necessary */
+#define CHAR_OUT(dinfo,c) \
+ { (dinfo)->packetbuf[++(dinfo)->bytesinpkt] = (char) (c); \
+ if ((dinfo)->bytesinpkt >= 255) \
+ flush_packet(dinfo); \
+ }
+
+
+/* Routine to convert variable-width codes into a byte stream */
+
+LOCAL(void)
+output (gif_dest_ptr dinfo, int code)
+/* Emit a code of n_bits bits */
+/* Uses cur_accum and cur_bits to reblock into 8-bit bytes */
+{
+ dinfo->cur_accum |= ((INT32) code) << dinfo->cur_bits;
+ dinfo->cur_bits += dinfo->n_bits;
+
+ while (dinfo->cur_bits >= 8) {
+ CHAR_OUT(dinfo, dinfo->cur_accum & 0xFF);
+ dinfo->cur_accum >>= 8;
+ dinfo->cur_bits -= 8;
+ }
+}
+
+
+/* The pseudo-compression algorithm.
+ *
+ * In this module we simply output each pixel value as a separate symbol;
+ * thus, no compression occurs. In fact, there is expansion of one bit per
+ * pixel, because we use a symbol width one bit wider than the pixel width.
+ *
+ * GIF ordinarily uses variable-width symbols, and the decoder will expect
+ * to ratchet up the symbol width after a fixed number of symbols.
+ * To simplify the logic and keep the expansion penalty down, we emit a
+ * GIF Clear code to reset the decoder just before the width would ratchet up.
+ * Thus, all the symbols in the output file will have the same bit width.
+ * Note that emitting the Clear codes at the right times is a mere matter of
+ * counting output symbols and is in no way dependent on the LZW patent.
+ *
+ * With a small basic pixel width (low color count), Clear codes will be
+ * needed very frequently, causing the file to expand even more. So this
+ * simplistic approach wouldn't work too well on bilevel images, for example.
+ * But for output of JPEG conversions the pixel width will usually be 8 bits
+ * (129 to 256 colors), so the overhead added by Clear symbols is only about
+ * one symbol in every 256.
+ */
+
+LOCAL(void)
+compress_init (gif_dest_ptr dinfo, int i_bits)
+/* Initialize pseudo-compressor */
+{
+ /* init all the state variables */
+ dinfo->n_bits = i_bits;
+ dinfo->maxcode = MAXCODE(dinfo->n_bits);
+ dinfo->ClearCode = (1 << (i_bits - 1));
+ dinfo->EOFCode = dinfo->ClearCode + 1;
+ dinfo->code_counter = dinfo->ClearCode + 2;
+ /* init output buffering vars */
+ dinfo->bytesinpkt = 0;
+ dinfo->cur_accum = 0;
+ dinfo->cur_bits = 0;
+ /* GIF specifies an initial Clear code */
+ output(dinfo, dinfo->ClearCode);
+}
+
+
+LOCAL(void)
+compress_pixel (gif_dest_ptr dinfo, int c)
+/* Accept and "compress" one pixel value.
+ * The given value must be less than n_bits wide.
+ */
+{
+ /* Output the given pixel value as a symbol. */
+ output(dinfo, c);
+ /* Issue Clear codes often enough to keep the reader from ratcheting up
+ * its symbol size.
+ */
+ if (dinfo->code_counter < dinfo->maxcode) {
+ dinfo->code_counter++;
+ } else {
+ output(dinfo, dinfo->ClearCode);
+ dinfo->code_counter = dinfo->ClearCode + 2; /* reset the counter */
+ }
+}
+
+
+LOCAL(void)
+compress_term (gif_dest_ptr dinfo)
+/* Clean up at end */
+{
+ /* Send an EOF code */
+ output(dinfo, dinfo->EOFCode);
+ /* Flush the bit-packing buffer */
+ if (dinfo->cur_bits > 0) {
+ CHAR_OUT(dinfo, dinfo->cur_accum & 0xFF);
+ }
+ /* Flush the packet buffer */
+ flush_packet(dinfo);
+}
+
+
+/* GIF header construction */
+
+
+LOCAL(void)
+put_word (gif_dest_ptr dinfo, unsigned int w)
+/* Emit a 16-bit word, LSB first */
+{
+ putc(w & 0xFF, dinfo->pub.output_file);
+ putc((w >> 8) & 0xFF, dinfo->pub.output_file);
+}
+
+
+LOCAL(void)
+put_3bytes (gif_dest_ptr dinfo, int val)
+/* Emit 3 copies of same byte value --- handy subr for colormap construction */
+{
+ putc(val, dinfo->pub.output_file);
+ putc(val, dinfo->pub.output_file);
+ putc(val, dinfo->pub.output_file);
+}
+
+
+LOCAL(void)
+emit_header (gif_dest_ptr dinfo, int num_colors, JSAMPARRAY colormap)
+/* Output the GIF file header, including color map */
+/* If colormap==NULL, synthesize a gray-scale colormap */
+{
+ int BitsPerPixel, ColorMapSize, InitCodeSize, FlagByte;
+ int cshift = dinfo->cinfo->data_precision - 8;
+ int i;
+
+ if (num_colors > 256)
+ ERREXIT1(dinfo->cinfo, JERR_TOO_MANY_COLORS, num_colors);
+ /* Compute bits/pixel and related values */
+ BitsPerPixel = 1;
+ while (num_colors > (1 << BitsPerPixel))
+ BitsPerPixel++;
+ ColorMapSize = 1 << BitsPerPixel;
+ if (BitsPerPixel <= 1)
+ InitCodeSize = 2;
+ else
+ InitCodeSize = BitsPerPixel;
+ /*
+ * Write the GIF header.
+ * Note that we generate a plain GIF87 header for maximum compatibility.
+ */
+ putc('G', dinfo->pub.output_file);
+ putc('I', dinfo->pub.output_file);
+ putc('F', dinfo->pub.output_file);
+ putc('8', dinfo->pub.output_file);
+ putc('7', dinfo->pub.output_file);
+ putc('a', dinfo->pub.output_file);
+ /* Write the Logical Screen Descriptor */
+ put_word(dinfo, (unsigned int) dinfo->cinfo->output_width);
+ put_word(dinfo, (unsigned int) dinfo->cinfo->output_height);
+ FlagByte = 0x80; /* Yes, there is a global color table */
+ FlagByte |= (BitsPerPixel-1) << 4; /* color resolution */
+ FlagByte |= (BitsPerPixel-1); /* size of global color table */
+ putc(FlagByte, dinfo->pub.output_file);
+ putc(0, dinfo->pub.output_file); /* Background color index */
+ putc(0, dinfo->pub.output_file); /* Reserved (aspect ratio in GIF89) */
+ /* Write the Global Color Map */
+ /* If the color map is more than 8 bits precision, */
+ /* we reduce it to 8 bits by shifting */
+ for (i=0; i < ColorMapSize; i++) {
+ if (i < num_colors) {
+ if (colormap != NULL) {
+ if (dinfo->cinfo->out_color_space == JCS_RGB) {
+ /* Normal case: RGB color map */
+ putc(GETJSAMPLE(colormap[0][i]) >> cshift, dinfo->pub.output_file);
+ putc(GETJSAMPLE(colormap[1][i]) >> cshift, dinfo->pub.output_file);
+ putc(GETJSAMPLE(colormap[2][i]) >> cshift, dinfo->pub.output_file);
+ } else {
+ /* Grayscale "color map": possible if quantizing grayscale image */
+ put_3bytes(dinfo, GETJSAMPLE(colormap[0][i]) >> cshift);
+ }
+ } else {
+ /* Create a gray-scale map of num_colors values, range 0..255 */
+ put_3bytes(dinfo, (i * 255 + (num_colors-1)/2) / (num_colors-1));
+ }
+ } else {
+ /* fill out the map to a power of 2 */
+ put_3bytes(dinfo, 0);
+ }
+ }
+ /* Write image separator and Image Descriptor */
+ putc(',', dinfo->pub.output_file); /* separator */
+ put_word(dinfo, 0); /* left/top offset */
+ put_word(dinfo, 0);
+ put_word(dinfo, (unsigned int) dinfo->cinfo->output_width); /* image size */
+ put_word(dinfo, (unsigned int) dinfo->cinfo->output_height);
+ /* flag byte: not interlaced, no local color map */
+ putc(0x00, dinfo->pub.output_file);
+ /* Write Initial Code Size byte */
+ putc(InitCodeSize, dinfo->pub.output_file);
+
+ /* Initialize for "compression" of image data */
+ compress_init(dinfo, InitCodeSize+1);
+}
+
+
+/*
+ * Startup: write the file header.
+ */
+
+METHODDEF(void)
+start_output_gif (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
+{
+ gif_dest_ptr dest = (gif_dest_ptr) dinfo;
+
+ if (cinfo->quantize_colors)
+ emit_header(dest, cinfo->actual_number_of_colors, cinfo->colormap);
+ else
+ emit_header(dest, 256, (JSAMPARRAY) NULL);
+}
+
+
+/*
+ * Write some pixel data.
+ * In this module rows_supplied will always be 1.
+ */
+
+METHODDEF(void)
+put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
+ JDIMENSION rows_supplied)
+{
+ gif_dest_ptr dest = (gif_dest_ptr) dinfo;
+ register JSAMPROW ptr;
+ register JDIMENSION col;
+
+ ptr = dest->pub.buffer[0];
+ for (col = cinfo->output_width; col > 0; col--) {
+ compress_pixel(dest, GETJSAMPLE(*ptr++));
+ }
+}
+
+
+/*
+ * Finish up at the end of the file.
+ */
+
+METHODDEF(void)
+finish_output_gif (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
+{
+ gif_dest_ptr dest = (gif_dest_ptr) dinfo;
+
+ /* Flush "compression" mechanism */
+ compress_term(dest);
+ /* Write a zero-length data block to end the series */
+ putc(0, dest->pub.output_file);
+ /* Write the GIF terminator mark */
+ putc(';', dest->pub.output_file);
+ /* Make sure we wrote the output file OK */
+ fflush(dest->pub.output_file);
+ if (ferror(dest->pub.output_file))
+ ERREXIT(cinfo, JERR_FILE_WRITE);
+}
+
+
+/*
+ * The module selection routine for GIF format output.
+ */
+
+GLOBAL(djpeg_dest_ptr)
+jinit_write_gif (j_decompress_ptr cinfo)
+{
+ gif_dest_ptr dest;
+
+ /* Create module interface object, fill in method pointers */
+ dest = (gif_dest_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(gif_dest_struct));
+ dest->cinfo = cinfo; /* make back link for subroutines */
+ dest->pub.start_output = start_output_gif;
+ dest->pub.put_pixel_rows = put_pixel_rows;
+ dest->pub.finish_output = finish_output_gif;
+
+ if (cinfo->out_color_space != JCS_GRAYSCALE &&
+ cinfo->out_color_space != JCS_RGB)
+ ERREXIT(cinfo, JERR_GIF_COLORSPACE);
+
+ /* Force quantization if color or if > 8 bits input */
+ if (cinfo->out_color_space != JCS_GRAYSCALE || cinfo->data_precision > 8) {
+ /* Force quantization to at most 256 colors */
+ cinfo->quantize_colors = TRUE;
+ if (cinfo->desired_number_of_colors > 256)
+ cinfo->desired_number_of_colors = 256;
+ }
+
+ /* Calculate output image dimensions so we can allocate space */
+ jpeg_calc_output_dimensions(cinfo);
+
+ if (cinfo->output_components != 1) /* safety check: just one component? */
+ ERREXIT(cinfo, JERR_GIF_BUG);
+
+ /* Create decompressor output buffer. */
+ dest->pub.buffer = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, cinfo->output_width, (JDIMENSION) 1);
+ dest->pub.buffer_height = 1;
+
+ return (djpeg_dest_ptr) dest;
+}
+
+#endif /* GIF_SUPPORTED */
--- /dev/null
+/*
+ * wrppm.c
+ *
+ * Copyright (C) 1991-1996, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains routines to write output images in PPM/PGM format.
+ * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
+ * The PBMPLUS library is NOT required to compile this software
+ * (but it is highly useful as a set of PPM image manipulation programs).
+ *
+ * These routines may need modification for non-Unix environments or
+ * specialized applications. As they stand, they assume output to
+ * an ordinary stdio stream.
+ */
+
+#include "cdjpeg12.h" /* Common decls for cjpeg/djpeg applications */
+
+#ifdef PPM_SUPPORTED
+
+
+/*
+ * For 12-bit JPEG data, we either downscale the values to 8 bits
+ * (to write standard byte-per-sample PPM/PGM files), or output
+ * nonstandard word-per-sample PPM/PGM files. Downscaling is done
+ * if PPM_NORAWWORD is defined (this can be done in the Makefile
+ * or in jconfig.h).
+ * (When the core library supports data precision reduction, a cleaner
+ * implementation will be to ask for that instead.)
+ */
+
+#if BITS_IN_JSAMPLE == 8
+#define PUTPPMSAMPLE(ptr,v) *ptr++ = (char) (v)
+#define BYTESPERSAMPLE 1
+#define PPM_MAXVAL 255
+#else
+#ifdef PPM_NORAWWORD
+#define PUTPPMSAMPLE(ptr,v) *ptr++ = (char) ((v) >> (BITS_IN_JSAMPLE-8))
+#define BYTESPERSAMPLE 1
+#define PPM_MAXVAL 255
+#else
+/* The word-per-sample format always puts the LSB first. */
+#define PUTPPMSAMPLE(ptr,v) \
+ { register int val_ = v; \
+ *ptr++ = (char) (val_ & 0xFF); \
+ *ptr++ = (char) ((val_ >> 8) & 0xFF); \
+ }
+#define BYTESPERSAMPLE 2
+#define PPM_MAXVAL ((1<<BITS_IN_JSAMPLE)-1)
+#endif
+#endif
+
+
+/*
+ * When JSAMPLE is the same size as char, we can just fwrite() the
+ * decompressed data to the PPM or PGM file. On PCs, in order to make this
+ * work the output buffer must be allocated in near data space, because we are
+ * assuming small-data memory model wherein fwrite() can't reach far memory.
+ * If you need to process very wide images on a PC, you might have to compile
+ * in large-memory model, or else replace fwrite() with a putc() loop ---
+ * which will be much slower.
+ */
+
+
+/* Private version of data destination object */
+
+typedef struct {
+ struct djpeg_dest_struct pub; /* public fields */
+
+ /* Usually these two pointers point to the same place: */
+ char *iobuffer; /* fwrite's I/O buffer */
+ JSAMPROW pixrow; /* decompressor output buffer */
+ size_t buffer_width; /* width of I/O buffer */
+ JDIMENSION samples_per_row; /* JSAMPLEs per output row */
+} ppm_dest_struct;
+
+typedef ppm_dest_struct * ppm_dest_ptr;
+
+
+/*
+ * Write some pixel data.
+ * In this module rows_supplied will always be 1.
+ *
+ * put_pixel_rows handles the "normal" 8-bit case where the decompressor
+ * output buffer is physically the same as the fwrite buffer.
+ */
+
+METHODDEF(void)
+put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
+ JDIMENSION rows_supplied)
+{
+ ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
+
+ (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
+}
+
+
+/*
+ * This code is used when we have to copy the data and apply a pixel
+ * format translation. Typically this only happens in 12-bit mode.
+ */
+
+METHODDEF(void)
+copy_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
+ JDIMENSION rows_supplied)
+{
+ ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
+ register char * bufferptr;
+ register JSAMPROW ptr;
+ register JDIMENSION col;
+
+ ptr = dest->pub.buffer[0];
+ bufferptr = dest->iobuffer;
+ for (col = dest->samples_per_row; col > 0; col--) {
+ PUTPPMSAMPLE(bufferptr, GETJSAMPLE(*ptr++));
+ }
+ (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
+}
+
+
+/*
+ * Write some pixel data when color quantization is in effect.
+ * We have to demap the color index values to straight data.
+ */
+
+METHODDEF(void)
+put_demapped_rgb (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
+ JDIMENSION rows_supplied)
+{
+ ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
+ register char * bufferptr;
+ register int pixval;
+ register JSAMPROW ptr;
+ register JSAMPROW color_map0 = cinfo->colormap[0];
+ register JSAMPROW color_map1 = cinfo->colormap[1];
+ register JSAMPROW color_map2 = cinfo->colormap[2];
+ register JDIMENSION col;
+
+ ptr = dest->pub.buffer[0];
+ bufferptr = dest->iobuffer;
+ for (col = cinfo->output_width; col > 0; col--) {
+ pixval = GETJSAMPLE(*ptr++);
+ PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map0[pixval]));
+ PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map1[pixval]));
+ PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map2[pixval]));
+ }
+ (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
+}
+
+
+METHODDEF(void)
+put_demapped_gray (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
+ JDIMENSION rows_supplied)
+{
+ ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
+ register char * bufferptr;
+ register JSAMPROW ptr;
+ register JSAMPROW color_map = cinfo->colormap[0];
+ register JDIMENSION col;
+
+ ptr = dest->pub.buffer[0];
+ bufferptr = dest->iobuffer;
+ for (col = cinfo->output_width; col > 0; col--) {
+ PUTPPMSAMPLE(bufferptr, GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]));
+ }
+ (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
+}
+
+
+/*
+ * Startup: write the file header.
+ */
+
+METHODDEF(void)
+start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
+{
+ ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
+
+ /* Emit file header */
+ switch (cinfo->out_color_space) {
+ case JCS_GRAYSCALE:
+ /* emit header for raw PGM format */
+ fprintf(dest->pub.output_file, "P5\n%ld %ld\n%d\n",
+ (long) cinfo->output_width, (long) cinfo->output_height,
+ PPM_MAXVAL);
+ break;
+ case JCS_RGB:
+ /* emit header for raw PPM format */
+ fprintf(dest->pub.output_file, "P6\n%ld %ld\n%d\n",
+ (long) cinfo->output_width, (long) cinfo->output_height,
+ PPM_MAXVAL);
+ break;
+ default:
+ ERREXIT(cinfo, JERR_PPM_COLORSPACE);
+ }
+}
+
+
+/*
+ * Finish up at the end of the file.
+ */
+
+METHODDEF(void)
+finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
+{
+ /* Make sure we wrote the output file OK */
+ fflush(dinfo->output_file);
+ if (ferror(dinfo->output_file))
+ ERREXIT(cinfo, JERR_FILE_WRITE);
+}
+
+
+/*
+ * The module selection routine for PPM format output.
+ */
+
+GLOBAL(djpeg_dest_ptr)
+jinit_write_ppm (j_decompress_ptr cinfo)
+{
+ ppm_dest_ptr dest;
+
+ /* Create module interface object, fill in method pointers */
+ dest = (ppm_dest_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(ppm_dest_struct));
+ dest->pub.start_output = start_output_ppm;
+ dest->pub.finish_output = finish_output_ppm;
+
+ /* Calculate output image dimensions so we can allocate space */
+ jpeg_calc_output_dimensions(cinfo);
+
+ /* Create physical I/O buffer. Note we make this near on a PC. */
+ dest->samples_per_row = cinfo->output_width * cinfo->out_color_components;
+ dest->buffer_width = dest->samples_per_row * (BYTESPERSAMPLE * SIZEOF(char));
+ dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
+
+ if (cinfo->quantize_colors || BITS_IN_JSAMPLE != 8 ||
+ SIZEOF(JSAMPLE) != SIZEOF(char)) {
+ /* When quantizing, we need an output buffer for colormap indexes
+ * that's separate from the physical I/O buffer. We also need a
+ * separate buffer if pixel format translation must take place.
+ */
+ dest->pub.buffer = (*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ cinfo->output_width * cinfo->output_components, (JDIMENSION) 1);
+ dest->pub.buffer_height = 1;
+ if (! cinfo->quantize_colors)
+ dest->pub.put_pixel_rows = copy_pixel_rows;
+ else if (cinfo->out_color_space == JCS_GRAYSCALE)
+ dest->pub.put_pixel_rows = put_demapped_gray;
+ else
+ dest->pub.put_pixel_rows = put_demapped_rgb;
+ } else {
+ /* We will fwrite() directly from decompressor output buffer. */
+ /* Synthesize a JSAMPARRAY pointer structure */
+ /* Cast here implies near->far pointer conversion on PCs */
+ dest->pixrow = (JSAMPROW) dest->iobuffer;
+ dest->pub.buffer = & dest->pixrow;
+ dest->pub.buffer_height = 1;
+ dest->pub.put_pixel_rows = put_pixel_rows;
+ }
+
+ return (djpeg_dest_ptr) dest;
+}
+
+#endif /* PPM_SUPPORTED */
projects / gdcm.git / commitdiff