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Diffstat (limited to 'src/libjpeg/jcphuff.c')
| -rw-r--r-- | src/libjpeg/jcphuff.c | 833 |
1 files changed, 0 insertions, 833 deletions
diff --git a/src/libjpeg/jcphuff.c b/src/libjpeg/jcphuff.c deleted file mode 100644 index 07f9178..0000000 --- a/src/libjpeg/jcphuff.c +++ /dev/null @@ -1,833 +0,0 @@ -/* - * 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 "jinclude.h" -#include "jpeglib.h" -#include "jchuff.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 */ |