| Index: third_party/libjpeg_turbo/jdphuff.c
|
| ===================================================================
|
| --- third_party/libjpeg_turbo/jdphuff.c (revision 0)
|
| +++ third_party/libjpeg_turbo/jdphuff.c (revision 0)
|
| @@ -0,0 +1,668 @@
|
| +/*
|
| + * 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 "jinclude.h"
|
| +#include "jpeglib.h"
|
| +#include "jdhuff.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 */
|
|
|