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 */ |