--- /dev/null
+/*
+ * jcdiffct.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 the difference buffer controller for compression.
+ * This controller is the top level of the lossless JPEG compressor proper.
+ * The difference buffer lies between prediction/differencing and entropy
+ * encoding.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jlossls.h" /* Private declarations for lossless codec */
+
+
+#ifdef C_LOSSLESS_SUPPORTED
+
+/* We use a full-image sample buffer when doing Huffman optimization,
+ * and also for writing multiple-scan JPEG files. In all cases, the
+ * full-image buffer is filled during the first pass, and the scaling,
+ * prediction and differencing steps are run during subsequent passes.
+ */
+#ifdef ENTROPY_OPT_SUPPORTED
+#define FULL_SAMP_BUFFER_SUPPORTED
+#else
+#ifdef C_MULTISCAN_FILES_SUPPORTED
+#define FULL_SAMP_BUFFER_SUPPORTED
+#endif
+#endif
+
+
+/* Private buffer controller object */
+
+typedef struct {
+ 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 */
+
+ JSAMPROW cur_row[MAX_COMPONENTS]; /* row of point transformed samples */
+ JSAMPROW prev_row[MAX_COMPONENTS]; /* previous row of Pt'd samples */
+ JDIFFARRAY diff_buf[MAX_COMPONENTS]; /* iMCU row of differences */
+
+ /* In multi-pass modes, we need a virtual sample array for each component. */
+ jvirt_sarray_ptr whole_image[MAX_COMPONENTS];
+} c_diff_controller;
+
+typedef c_diff_controller * c_diff_ptr;
+
+
+/* Forward declarations */
+METHODDEF(boolean) compress_data
+ JPP((j_compress_ptr cinfo, JSAMPIMAGE input_buf));
+#ifdef FULL_SAMP_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 */
+{
+ j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+ c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+
+ /* 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) {
+ diff->MCU_rows_per_iMCU_row = 1;
+ } else {
+ if (diff->iMCU_row_num < (cinfo->total_iMCU_rows-1))
+ diff->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor;
+ else
+ diff->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height;
+ }
+
+ diff->mcu_ctr = 0;
+ diff->MCU_vert_offset = 0;
+}
+
+
+/*
+ * Initialize for a processing pass.
+ */
+
+METHODDEF(void)
+start_pass_diff (j_compress_ptr cinfo, J_BUF_MODE pass_mode)
+{
+ j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+ c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+
+ diff->iMCU_row_num = 0;
+ start_iMCU_row(cinfo);
+
+ switch (pass_mode) {
+ case JBUF_PASS_THRU:
+ if (diff->whole_image[0] != NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ losslsc->pub.compress_data = compress_data;
+ break;
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+ case JBUF_SAVE_AND_PASS:
+ if (diff->whole_image[0] == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ losslsc->pub.compress_data = compress_first_pass;
+ break;
+ case JBUF_CRANK_DEST:
+ if (diff->whole_image[0] == NULL)
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ losslsc->pub.compress_data = compress_output;
+ break;
+#endif
+ default:
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+ break;
+ }
+}
+
+
+#define SWAP_ROWS(rowa,rowb) {JSAMPROW temp; temp=rowa; rowa=rowb; rowb=temp;}
+
+/*
+ * 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 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)
+{
+ j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+ c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+ JDIMENSION MCU_col_num; /* index of current MCU within row */
+ JDIMENSION MCU_count; /* number of MCUs encoded */
+ /* JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1; */
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ int comp, ci, yoffset, samp_row, samp_rows, samps_across;
+ jpeg_component_info *compptr;
+
+ /* Loop to write as much as one whole iMCU row */
+ for (yoffset = diff->MCU_vert_offset; yoffset < diff->MCU_rows_per_iMCU_row;
+ yoffset++) {
+
+ MCU_col_num = diff->mcu_ctr;
+
+ /* Scale and predict each scanline of the MCU-row separately.
+ *
+ * Note: We only do this if we are at the start of a MCU-row, ie,
+ * we don't want to reprocess a row suspended by the output.
+ */
+ if (MCU_col_num == 0) {
+ for (comp = 0; comp < cinfo->comps_in_scan; comp++) {
+ compptr = cinfo->cur_comp_info[comp];
+ ci = compptr->component_index;
+ if (diff->iMCU_row_num < last_iMCU_row)
+ samp_rows = compptr->v_samp_factor;
+ else {
+ /* NB: can't use last_row_height here, since may not be set! */
+ samp_rows = (int) (compptr->height_in_data_units % compptr->v_samp_factor);
+ if (samp_rows == 0) samp_rows = compptr->v_samp_factor;
+ else {
+ /* Fill dummy difference rows at the bottom edge with zeros, which
+ * will encode to the smallest amount of data.
+ */
+ for (samp_row = samp_rows; samp_row < compptr->v_samp_factor;
+ samp_row++)
+ MEMZERO(diff->diff_buf[ci][samp_row],
+ jround_up((long) compptr->width_in_data_units,
+ (long) compptr->h_samp_factor) * SIZEOF(JDIFF));
+ }
+ }
+ samps_across = compptr->width_in_data_units;
+
+ for (samp_row = 0; samp_row < samp_rows; samp_row++) {
+ (*losslsc->scaler_scale) (cinfo,
+ input_buf[ci][samp_row],
+ diff->cur_row[ci], samps_across);
+ (*losslsc->predict_difference[ci]) (cinfo, ci,
+ diff->cur_row[ci],
+ diff->prev_row[ci],
+ diff->diff_buf[ci][samp_row],
+ samps_across);
+ SWAP_ROWS(diff->cur_row[ci], diff->prev_row[ci]);
+ }
+ }
+ }
+
+ /* Try to write the MCU-row (or remaining portion of suspended MCU-row). */
+ MCU_count =
+ (*losslsc->entropy_encode_mcus) (cinfo,
+ diff->diff_buf, yoffset, MCU_col_num,
+ cinfo->MCUs_per_row - MCU_col_num);
+ if (MCU_count != cinfo->MCUs_per_row - MCU_col_num) {
+ /* Suspension forced; update state counters and exit */
+ diff->MCU_vert_offset = yoffset;
+ diff->mcu_ctr += MCU_col_num;
+ return FALSE;
+ }
+
+ /* Completed an MCU row, but perhaps not an iMCU row */
+ diff->mcu_ctr = 0;
+ }
+
+ /* Completed the iMCU row, advance counters for next one */
+ diff->iMCU_row_num++;
+ start_iMCU_row(cinfo);
+ return TRUE;
+}
+
+
+#ifdef FULL_SAMP_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 rows for each component in the image.
+ * This amount of data is read from the source buffer and saved into the
+ * virtual arrays.
+ *
+ * We must also emit the data to the compressor. 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 loaded into the virtual arrays in this pass. However, it may be that
+ * only a subset of the components are emitted to the compressor 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)
+{
+ j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+ c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+ JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
+ JDIMENSION samps_across;
+ int ci, samp_row, samp_rows;
+ JSAMPARRAY buffer[MAX_COMPONENTS];
+ jpeg_component_info *compptr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ /* Align the virtual buffers for this component. */
+ buffer[ci] = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, diff->whole_image[ci],
+ diff->iMCU_row_num * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+
+ /* Count non-dummy sample rows in this iMCU row. */
+ if (diff->iMCU_row_num < last_iMCU_row)
+ samp_rows = compptr->v_samp_factor;
+ else {
+ /* NB: can't use last_row_height here, since may not be set! */
+ samp_rows = (int) (compptr->height_in_data_units % compptr->v_samp_factor);
+ if (samp_rows == 0) samp_rows = compptr->v_samp_factor;
+ }
+ samps_across = compptr->width_in_data_units;
+
+ /* Perform point transform scaling and prediction/differencing for all
+ * non-dummy rows in this iMCU row. Each call on these functions
+ * process a complete row of samples.
+ */
+ for (samp_row = 0; samp_row < samp_rows; samp_row++) {
+ MEMCOPY(buffer[ci][samp_row], input_buf[ci][samp_row],
+ samps_across * SIZEOF(JSAMPLE));
+ }
+ }
+
+ /* 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 compressor, 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 rows for each component in the scan.
+ * The data is obtained from the virtual arrays and fed to the compressor.
+ * 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)
+{
+ j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+ c_diff_ptr diff = (c_diff_ptr) losslsc->diff_private;
+ /* JDIMENSION MCU_col_num; */ /* index of current MCU within row */
+ /* JDIMENSION MCU_count; */ /* number of MCUs encoded */
+ int comp, ci /* , yoffset */ ;
+ JSAMPARRAY buffer[MAX_COMPONENTS];
+ jpeg_component_info *compptr;
+ (void)input_buf;
+
+ /* 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 (comp = 0; comp < cinfo->comps_in_scan; comp++) {
+ compptr = cinfo->cur_comp_info[comp];
+ ci = compptr->component_index;
+ buffer[ci] = (*cinfo->mem->access_virt_sarray)
+ ((j_common_ptr) cinfo, diff->whole_image[ci],
+ diff->iMCU_row_num * compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+
+ return compress_data(cinfo, buffer);
+}
+
+#endif /* FULL_SAMP_BUFFER_SUPPORTED */
+
+
+/*
+ * Initialize difference buffer controller.
+ */
+
+GLOBAL(void)
+jinit_c_diff_controller (j_compress_ptr cinfo, boolean need_full_buffer)
+{
+ j_lossless_c_ptr losslsc = (j_lossless_c_ptr) cinfo->codec;
+ c_diff_ptr diff;
+ int ci, row;
+ jpeg_component_info *compptr;
+
+ diff = (c_diff_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(c_diff_controller));
+ losslsc->diff_private = (void *) diff;
+ losslsc->diff_start_pass = start_pass_diff;
+
+ /* Create the prediction row buffers. */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ diff->cur_row[ci] = *(*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) 1);
+ diff->prev_row[ci] = *(*cinfo->mem->alloc_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) 1);
+ }
+
+ /* Create the difference buffer. */
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ diff->diff_buf[ci] = (*cinfo->mem->alloc_darray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) compptr->v_samp_factor);
+ /* Prefill difference rows with zeros. We do this because only actual
+ * data is placed in the buffers during prediction/differencing, leaving
+ * any dummy differences at the right edge as zeros, which will encode
+ * to the smallest amount of data.
+ */
+ for (row = 0; row < compptr->v_samp_factor; row++)
+ MEMZERO(diff->diff_buf[ci][row],
+ jround_up((long) compptr->width_in_data_units,
+ (long) compptr->h_samp_factor) * SIZEOF(JDIFF));
+ }
+
+ /* Create the sample buffer. */
+ if (need_full_buffer) {
+#ifdef FULL_SAMP_BUFFER_SUPPORTED
+ /* Allocate a full-image virtual array for each component, */
+ /* padded to a multiple of samp_factor differences in each direction. */
+ int ci;
+ jpeg_component_info *compptr;
+
+ for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
+ ci++, compptr++) {
+ diff->whole_image[ci] = (*cinfo->mem->request_virt_sarray)
+ ((j_common_ptr) cinfo, JPOOL_IMAGE, FALSE,
+ (JDIMENSION) jround_up((long) compptr->width_in_data_units,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->height_in_data_units,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) compptr->v_samp_factor);
+ }
+#else
+ ERREXIT(cinfo, JERR_BAD_BUFFER_MODE);
+#endif
+ } else
+ diff->whole_image[0] = NULL; /* flag for no virtual arrays */
+}
+
+#endif /* C_LOSSLESS_SUPPORTED */
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff