diff options
Diffstat (limited to 'core/src/fxcodec/libjpeg/fpdfapi_jdphuff.c')
-rw-r--r-- | core/src/fxcodec/libjpeg/fpdfapi_jdphuff.c | 1342 |
1 files changed, 671 insertions, 671 deletions
diff --git a/core/src/fxcodec/libjpeg/fpdfapi_jdphuff.c b/core/src/fxcodec/libjpeg/fpdfapi_jdphuff.c index 3c19d0ab24..128e412662 100644 --- a/core/src/fxcodec/libjpeg/fpdfapi_jdphuff.c +++ b/core/src/fxcodec/libjpeg/fpdfapi_jdphuff.c @@ -1,671 +1,671 @@ -#if !defined(_FX_JPEG_TURBO_)
-/*
- * 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 */
-
-#endif //_FX_JPEG_TURBO_
+#if !defined(_FX_JPEG_TURBO_) +/* + * 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 */ + +#endif //_FX_JPEG_TURBO_ |