+/*
+ * jcshuff.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 Huffman entropy encoding routines for sequential JPEG.
+ *
+ * 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 "jinclude.h"
+#include "jpeglib.h"
+#include "jlossy.h" /* Private declarations for lossy codec */
+#include "jchuff.h" /* Declarations shared with jc*huff.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 {
+ 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
+} shuff_entropy_encoder;
+
+typedef shuff_entropy_encoder * shuff_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)
+{
+ j_lossy_c_ptr lossyc = (j_lossy_c_ptr) cinfo->codec;
+ shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyc->entropy_private;
+ int ci, dctbl, actbl;
+ jpeg_component_info * compptr;
+
+ if (gather_statistics) {
+#ifdef ENTROPY_OPT_SUPPORTED
+ lossyc->entropy_encode_mcu = encode_mcu_gather;
+ lossyc->pub.entropy_finish_pass = finish_pass_gather;
+#else
+ ERREXIT(cinfo, JERR_NOT_COMPILED);
+#endif
+ } else {
+ lossyc->entropy_encode_mcu = encode_mcu_huff;
+ lossyc->pub.entropy_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;
+}
+
+
+/* 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)
+{
+ j_lossy_c_ptr lossyc = (j_lossy_c_ptr) cinfo->codec;
+ shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyc->entropy_private;
+ 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->data_units_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)
+{
+ j_lossy_c_ptr lossyc = (j_lossy_c_ptr) cinfo->codec;
+ shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyc->entropy_private;
+ 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)
+{
+ j_lossy_c_ptr lossyc = (j_lossy_c_ptr) cinfo->codec;
+ shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyc->entropy_private;
+ 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->data_units_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;
+}
+
+
+/*
+ * Finish up a statistics-gathering pass and create the new Huffman tables.
+ */
+
+METHODDEF(void)
+finish_pass_gather (j_compress_ptr cinfo)
+{
+ j_lossy_c_ptr lossyc = (j_lossy_c_ptr) cinfo->codec;
+ shuff_entropy_ptr entropy = (shuff_entropy_ptr) lossyc->entropy_private;
+ 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 */
+
+
+METHODDEF(boolean)
+need_optimization_pass (j_compress_ptr cinfo)
+{
+ return TRUE;
+}
+
+
+/*
+ * Module initialization routine for Huffman entropy encoding.
+ */
+
+GLOBAL(void)
+jinit_shuff_encoder (j_compress_ptr cinfo)
+{
+ j_lossy_c_ptr lossyc = (j_lossy_c_ptr) cinfo->codec;
+ shuff_entropy_ptr entropy;
+ int i;
+
+ entropy = (shuff_entropy_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
+ SIZEOF(shuff_entropy_encoder));
+ lossyc->entropy_private = (struct jpeg_entropy_encoder *) entropy;
+ lossyc->pub.entropy_start_pass = start_pass_huff;
+ lossyc->pub.need_optimization_pass = need_optimization_pass;
+
+ /* 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
+ }
+}
git://git.creatis.insa-lyon.fr / gdcm.git / commitdiff