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Diffstat (limited to 'plugins/FreeImage/src/LibJPEG/jdarith.c')
| -rw-r--r-- | plugins/FreeImage/src/LibJPEG/jdarith.c | 776 |
1 files changed, 0 insertions, 776 deletions
diff --git a/plugins/FreeImage/src/LibJPEG/jdarith.c b/plugins/FreeImage/src/LibJPEG/jdarith.c deleted file mode 100644 index 092f8af5fe..0000000000 --- a/plugins/FreeImage/src/LibJPEG/jdarith.c +++ /dev/null @@ -1,776 +0,0 @@ -/* - * jdarith.c - * - * Developed 1997-2011 by Guido Vollbeding. - * 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 portable arithmetic entropy decoding routines for JPEG - * (implementing the ISO/IEC IS 10918-1 and CCITT Recommendation ITU-T T.81). - * - * Both sequential and progressive modes are supported in this single module. - * - * Suspension is not currently supported in this module. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" - - -/* Expanded entropy decoder object for arithmetic decoding. */ - -typedef struct { - struct jpeg_entropy_decoder pub; /* public fields */ - - INT32 c; /* C register, base of coding interval + input bit buffer */ - INT32 a; /* A register, normalized size of coding interval */ - int ct; /* bit shift counter, # of bits left in bit buffer part of C */ - /* init: ct = -16 */ - /* run: ct = 0..7 */ - /* error: ct = -1 */ - int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ - int dc_context[MAX_COMPS_IN_SCAN]; /* context index for DC conditioning */ - - unsigned int restarts_to_go; /* MCUs left in this restart interval */ - - /* Pointers to statistics areas (these workspaces have image lifespan) */ - unsigned char * dc_stats[NUM_ARITH_TBLS]; - unsigned char * ac_stats[NUM_ARITH_TBLS]; - - /* Statistics bin for coding with fixed probability 0.5 */ - unsigned char fixed_bin[4]; -} arith_entropy_decoder; - -typedef arith_entropy_decoder * arith_entropy_ptr; - -/* The following two definitions specify the allocation chunk size - * for the statistics area. - * According to sections F.1.4.4.1.3 and F.1.4.4.2, we need at least - * 49 statistics bins for DC, and 245 statistics bins for AC coding. - * - * We use a compact representation with 1 byte per statistics bin, - * thus the numbers directly represent byte sizes. - * This 1 byte per statistics bin contains the meaning of the MPS - * (more probable symbol) in the highest bit (mask 0x80), and the - * index into the probability estimation state machine table - * in the lower bits (mask 0x7F). - */ - -#define DC_STAT_BINS 64 -#define AC_STAT_BINS 256 - - -LOCAL(int) -get_byte (j_decompress_ptr cinfo) -/* Read next input byte; we do not support suspension in this module. */ -{ - struct jpeg_source_mgr * src = cinfo->src; - - if (src->bytes_in_buffer == 0) - if (! (*src->fill_input_buffer) (cinfo)) - ERREXIT(cinfo, JERR_CANT_SUSPEND); - src->bytes_in_buffer--; - return GETJOCTET(*src->next_input_byte++); -} - - -/* - * The core arithmetic decoding routine (common in JPEG and JBIG). - * This needs to go as fast as possible. - * Machine-dependent optimization facilities - * are not utilized in this portable implementation. - * However, this code should be fairly efficient and - * may be a good base for further optimizations anyway. - * - * Return value is 0 or 1 (binary decision). - * - * Note: I've changed the handling of the code base & bit - * buffer register C compared to other implementations - * based on the standards layout & procedures. - * While it also contains both the actual base of the - * coding interval (16 bits) and the next-bits buffer, - * the cut-point between these two parts is floating - * (instead of fixed) with the bit shift counter CT. - * Thus, we also need only one (variable instead of - * fixed size) shift for the LPS/MPS decision, and - * we can get away with any renormalization update - * of C (except for new data insertion, of course). - * - * I've also introduced a new scheme for accessing - * the probability estimation state machine table, - * derived from Markus Kuhn's JBIG implementation. - */ - -LOCAL(int) -arith_decode (j_decompress_ptr cinfo, unsigned char *st) -{ - register arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; - register unsigned char nl, nm; - register INT32 qe, temp; - register int sv, data; - - /* Renormalization & data input per section D.2.6 */ - while (e->a < 0x8000L) { - if (--e->ct < 0) { - /* Need to fetch next data byte */ - if (cinfo->unread_marker) - data = 0; /* stuff zero data */ - else { - data = get_byte(cinfo); /* read next input byte */ - if (data == 0xFF) { /* zero stuff or marker code */ - do data = get_byte(cinfo); - while (data == 0xFF); /* swallow extra 0xFF bytes */ - if (data == 0) - data = 0xFF; /* discard stuffed zero byte */ - else { - /* Note: Different from the Huffman decoder, hitting - * a marker while processing the compressed data - * segment is legal in arithmetic coding. - * The convention is to supply zero data - * then until decoding is complete. - */ - cinfo->unread_marker = data; - data = 0; - } - } - } - e->c = (e->c << 8) | data; /* insert data into C register */ - if ((e->ct += 8) < 0) /* update bit shift counter */ - /* Need more initial bytes */ - if (++e->ct == 0) - /* Got 2 initial bytes -> re-init A and exit loop */ - e->a = 0x8000L; /* => e->a = 0x10000L after loop exit */ - } - e->a <<= 1; - } - - /* Fetch values from our compact representation of Table D.3(D.2): - * Qe values and probability estimation state machine - */ - sv = *st; - qe = jpeg_aritab[sv & 0x7F]; /* => Qe_Value */ - nl = qe & 0xFF; qe >>= 8; /* Next_Index_LPS + Switch_MPS */ - nm = qe & 0xFF; qe >>= 8; /* Next_Index_MPS */ - - /* Decode & estimation procedures per sections D.2.4 & D.2.5 */ - temp = e->a - qe; - e->a = temp; - temp <<= e->ct; - if (e->c >= temp) { - e->c -= temp; - /* Conditional LPS (less probable symbol) exchange */ - if (e->a < qe) { - e->a = qe; - *st = (sv & 0x80) ^ nm; /* Estimate_after_MPS */ - } else { - e->a = qe; - *st = (sv & 0x80) ^ nl; /* Estimate_after_LPS */ - sv ^= 0x80; /* Exchange LPS/MPS */ - } - } else if (e->a < 0x8000L) { - /* Conditional MPS (more probable symbol) exchange */ - if (e->a < qe) { - *st = (sv & 0x80) ^ nl; /* Estimate_after_LPS */ - sv ^= 0x80; /* Exchange LPS/MPS */ - } else { - *st = (sv & 0x80) ^ nm; /* Estimate_after_MPS */ - } - } - - return sv >> 7; -} - - -/* - * Check for a restart marker & resynchronize decoder. - */ - -LOCAL(void) -process_restart (j_decompress_ptr cinfo) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - int ci; - jpeg_component_info * compptr; - - /* Advance past the RSTn marker */ - if (! (*cinfo->marker->read_restart_marker) (cinfo)) - ERREXIT(cinfo, JERR_CANT_SUSPEND); - - /* Re-initialize statistics areas */ - for (ci = 0; ci < cinfo->comps_in_scan; ci++) { - compptr = cinfo->cur_comp_info[ci]; - if (! cinfo->progressive_mode || (cinfo->Ss == 0 && cinfo->Ah == 0)) { - MEMZERO(entropy->dc_stats[compptr->dc_tbl_no], DC_STAT_BINS); - /* Reset DC predictions to 0 */ - entropy->last_dc_val[ci] = 0; - entropy->dc_context[ci] = 0; - } - if ((! cinfo->progressive_mode && cinfo->lim_Se) || - (cinfo->progressive_mode && cinfo->Ss)) { - MEMZERO(entropy->ac_stats[compptr->ac_tbl_no], AC_STAT_BINS); - } - } - - /* Reset arithmetic decoding variables */ - entropy->c = 0; - entropy->a = 0; - entropy->ct = -16; /* force reading 2 initial bytes to fill C */ - - /* Reset restart counter */ - entropy->restarts_to_go = cinfo->restart_interval; -} - - -/* - * Arithmetic MCU decoding. - * Each of these routines decodes and returns one MCU's worth of - * arithmetic-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. - */ - -/* - * 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) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - JBLOCKROW block; - unsigned char *st; - int blkn, ci, tbl, sign; - int v, m; - - /* Process restart marker if needed */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) - process_restart(cinfo); - entropy->restarts_to_go--; - } - - if (entropy->ct == -1) return TRUE; /* if error do nothing */ - - /* 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]; - tbl = cinfo->cur_comp_info[ci]->dc_tbl_no; - - /* Sections F.2.4.1 & F.1.4.4.1: Decoding of DC coefficients */ - - /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ - st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; - - /* Figure F.19: Decode_DC_DIFF */ - if (arith_decode(cinfo, st) == 0) - entropy->dc_context[ci] = 0; - else { - /* Figure F.21: Decoding nonzero value v */ - /* Figure F.22: Decoding the sign of v */ - sign = arith_decode(cinfo, st + 1); - st += 2; st += sign; - /* Figure F.23: Decoding the magnitude category of v */ - if ((m = arith_decode(cinfo, st)) != 0) { - st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ - while (arith_decode(cinfo, st)) { - if ((m <<= 1) == 0x8000) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* magnitude overflow */ - return TRUE; - } - st += 1; - } - } - /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ - if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) - entropy->dc_context[ci] = 0; /* zero diff category */ - else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) - entropy->dc_context[ci] = 12 + (sign * 4); /* large diff category */ - else - entropy->dc_context[ci] = 4 + (sign * 4); /* small diff category */ - v = m; - /* Figure F.24: Decoding the magnitude bit pattern of v */ - st += 14; - while (m >>= 1) - if (arith_decode(cinfo, st)) v |= m; - v += 1; if (sign) v = -v; - entropy->last_dc_val[ci] += v; - } - - /* Scale and output the DC coefficient (assumes jpeg_natural_order[0]=0) */ - (*block)[0] = (JCOEF) (entropy->last_dc_val[ci] << cinfo->Al); - } - - 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) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - JBLOCKROW block; - unsigned char *st; - int tbl, sign, k; - int v, m; - const int * natural_order; - - /* Process restart marker if needed */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) - process_restart(cinfo); - entropy->restarts_to_go--; - } - - if (entropy->ct == -1) return TRUE; /* if error do nothing */ - - natural_order = cinfo->natural_order; - - /* There is always only one block per MCU */ - block = MCU_data[0]; - tbl = cinfo->cur_comp_info[0]->ac_tbl_no; - - /* Sections F.2.4.2 & F.1.4.4.2: Decoding of AC coefficients */ - - /* Figure F.20: Decode_AC_coefficients */ - for (k = cinfo->Ss; k <= cinfo->Se; k++) { - st = entropy->ac_stats[tbl] + 3 * (k - 1); - if (arith_decode(cinfo, st)) break; /* EOB flag */ - while (arith_decode(cinfo, st + 1) == 0) { - st += 3; k++; - if (k > cinfo->Se) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* spectral overflow */ - return TRUE; - } - } - /* Figure F.21: Decoding nonzero value v */ - /* Figure F.22: Decoding the sign of v */ - sign = arith_decode(cinfo, entropy->fixed_bin); - st += 2; - /* Figure F.23: Decoding the magnitude category of v */ - if ((m = arith_decode(cinfo, st)) != 0) { - if (arith_decode(cinfo, st)) { - m <<= 1; - st = entropy->ac_stats[tbl] + - (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); - while (arith_decode(cinfo, st)) { - if ((m <<= 1) == 0x8000) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* magnitude overflow */ - return TRUE; - } - st += 1; - } - } - } - v = m; - /* Figure F.24: Decoding the magnitude bit pattern of v */ - st += 14; - while (m >>= 1) - if (arith_decode(cinfo, st)) v |= m; - v += 1; if (sign) v = -v; - /* Scale and output coefficient in natural (dezigzagged) order */ - (*block)[natural_order[k]] = (JCOEF) (v << cinfo->Al); - } - - return TRUE; -} - - -/* - * MCU decoding for DC successive approximation refinement scan. - */ - -METHODDEF(boolean) -decode_mcu_DC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - unsigned char *st; - int p1, blkn; - - /* Process restart marker if needed */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) - process_restart(cinfo); - entropy->restarts_to_go--; - } - - st = entropy->fixed_bin; /* use fixed probability estimation */ - p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */ - - /* Outer loop handles each block in the MCU */ - - for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { - /* Encoded data is simply the next bit of the two's-complement DC value */ - if (arith_decode(cinfo, st)) - MCU_data[blkn][0][0] |= p1; - } - - return TRUE; -} - - -/* - * MCU decoding for AC successive approximation refinement scan. - */ - -METHODDEF(boolean) -decode_mcu_AC_refine (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - JBLOCKROW block; - JCOEFPTR thiscoef; - unsigned char *st; - int tbl, k, kex; - int p1, m1; - const int * natural_order; - - /* Process restart marker if needed */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) - process_restart(cinfo); - entropy->restarts_to_go--; - } - - if (entropy->ct == -1) return TRUE; /* if error do nothing */ - - natural_order = cinfo->natural_order; - - /* There is always only one block per MCU */ - block = MCU_data[0]; - tbl = cinfo->cur_comp_info[0]->ac_tbl_no; - - p1 = 1 << cinfo->Al; /* 1 in the bit position being coded */ - m1 = (-1) << cinfo->Al; /* -1 in the bit position being coded */ - - /* Establish EOBx (previous stage end-of-block) index */ - for (kex = cinfo->Se; kex > 0; kex--) - if ((*block)[natural_order[kex]]) break; - - for (k = cinfo->Ss; k <= cinfo->Se; k++) { - st = entropy->ac_stats[tbl] + 3 * (k - 1); - if (k > kex) - if (arith_decode(cinfo, st)) break; /* EOB flag */ - for (;;) { - thiscoef = *block + natural_order[k]; - if (*thiscoef) { /* previously nonzero coef */ - if (arith_decode(cinfo, st + 2)) { - if (*thiscoef < 0) - *thiscoef += m1; - else - *thiscoef += p1; - } - break; - } - if (arith_decode(cinfo, st + 1)) { /* newly nonzero coef */ - if (arith_decode(cinfo, entropy->fixed_bin)) - *thiscoef = m1; - else - *thiscoef = p1; - break; - } - st += 3; k++; - if (k > cinfo->Se) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* spectral overflow */ - return TRUE; - } - } - } - - return TRUE; -} - - -/* - * Decode one MCU's worth of arithmetic-compressed coefficients. - */ - -METHODDEF(boolean) -decode_mcu (j_decompress_ptr cinfo, JBLOCKROW *MCU_data) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - jpeg_component_info * compptr; - JBLOCKROW block; - unsigned char *st; - int blkn, ci, tbl, sign, k; - int v, m; - const int * natural_order; - - /* Process restart marker if needed */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) - process_restart(cinfo); - entropy->restarts_to_go--; - } - - if (entropy->ct == -1) return TRUE; /* if error do nothing */ - - natural_order = cinfo->natural_order; - - /* 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]; - - /* Sections F.2.4.1 & F.1.4.4.1: Decoding of DC coefficients */ - - tbl = compptr->dc_tbl_no; - - /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ - st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; - - /* Figure F.19: Decode_DC_DIFF */ - if (arith_decode(cinfo, st) == 0) - entropy->dc_context[ci] = 0; - else { - /* Figure F.21: Decoding nonzero value v */ - /* Figure F.22: Decoding the sign of v */ - sign = arith_decode(cinfo, st + 1); - st += 2; st += sign; - /* Figure F.23: Decoding the magnitude category of v */ - if ((m = arith_decode(cinfo, st)) != 0) { - st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ - while (arith_decode(cinfo, st)) { - if ((m <<= 1) == 0x8000) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* magnitude overflow */ - return TRUE; - } - st += 1; - } - } - /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ - if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) - entropy->dc_context[ci] = 0; /* zero diff category */ - else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) - entropy->dc_context[ci] = 12 + (sign * 4); /* large diff category */ - else - entropy->dc_context[ci] = 4 + (sign * 4); /* small diff category */ - v = m; - /* Figure F.24: Decoding the magnitude bit pattern of v */ - st += 14; - while (m >>= 1) - if (arith_decode(cinfo, st)) v |= m; - v += 1; if (sign) v = -v; - entropy->last_dc_val[ci] += v; - } - - (*block)[0] = (JCOEF) entropy->last_dc_val[ci]; - - /* Sections F.2.4.2 & F.1.4.4.2: Decoding of AC coefficients */ - - if (cinfo->lim_Se == 0) continue; - tbl = compptr->ac_tbl_no; - k = 0; - - /* Figure F.20: Decode_AC_coefficients */ - do { - st = entropy->ac_stats[tbl] + 3 * k; - if (arith_decode(cinfo, st)) break; /* EOB flag */ - for (;;) { - k++; - if (arith_decode(cinfo, st + 1)) break; - st += 3; - if (k >= cinfo->lim_Se) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* spectral overflow */ - return TRUE; - } - } - /* Figure F.21: Decoding nonzero value v */ - /* Figure F.22: Decoding the sign of v */ - sign = arith_decode(cinfo, entropy->fixed_bin); - st += 2; - /* Figure F.23: Decoding the magnitude category of v */ - if ((m = arith_decode(cinfo, st)) != 0) { - if (arith_decode(cinfo, st)) { - m <<= 1; - st = entropy->ac_stats[tbl] + - (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); - while (arith_decode(cinfo, st)) { - if ((m <<= 1) == 0x8000) { - WARNMS(cinfo, JWRN_ARITH_BAD_CODE); - entropy->ct = -1; /* magnitude overflow */ - return TRUE; - } - st += 1; - } - } - } - v = m; - /* Figure F.24: Decoding the magnitude bit pattern of v */ - st += 14; - while (m >>= 1) - if (arith_decode(cinfo, st)) v |= m; - v += 1; if (sign) v = -v; - (*block)[natural_order[k]] = (JCOEF) v; - } while (k < cinfo->lim_Se); - } - - return TRUE; -} - - -/* - * Initialize for an arithmetic-compressed scan. - */ - -METHODDEF(void) -start_pass (j_decompress_ptr cinfo) -{ - arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; - int ci, tbl; - jpeg_component_info * compptr; - - if (cinfo->progressive_mode) { - /* Validate progressive scan parameters */ - if (cinfo->Ss == 0) { - if (cinfo->Se != 0) - goto bad; - } else { - /* need not check Ss/Se < 0 since they came from unsigned bytes */ - if (cinfo->Se < cinfo->Ss || cinfo->Se > cinfo->lim_Se) - goto bad; - /* AC scans may have only one component */ - if (cinfo->comps_in_scan != 1) - goto bad; - } - if (cinfo->Ah != 0) { - /* Successive approximation refinement scan: must have Al = Ah-1. */ - if (cinfo->Ah-1 != cinfo->Al) - goto bad; - } - if (cinfo->Al > 13) { /* need not check for < 0 */ - 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 coefi, cindex = cinfo->cur_comp_info[ci]->component_index; - int *coef_bit_ptr = & cinfo->coef_bits[cindex][0]; - if (cinfo->Ss && 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 (cinfo->Ss == 0) - entropy->pub.decode_mcu = decode_mcu_DC_first; - else - entropy->pub.decode_mcu = decode_mcu_AC_first; - } else { - if (cinfo->Ss == 0) - entropy->pub.decode_mcu = decode_mcu_DC_refine; - else - entropy->pub.decode_mcu = decode_mcu_AC_refine; - } - } else { - /* Check that the scan parameters Ss, Se, Ah/Al are OK for sequential JPEG. - * This ought to be an error condition, but we make it a warning. - */ - if (cinfo->Ss != 0 || cinfo->Ah != 0 || cinfo->Al != 0 || - (cinfo->Se < DCTSIZE2 && cinfo->Se != cinfo->lim_Se)) - WARNMS(cinfo, JWRN_NOT_SEQUENTIAL); - /* Select MCU decoding routine */ - entropy->pub.decode_mcu = decode_mcu; - } - - /* Allocate & initialize requested statistics areas */ - for (ci = 0; ci < cinfo->comps_in_scan; ci++) { - compptr = cinfo->cur_comp_info[ci]; - if (! cinfo->progressive_mode || (cinfo->Ss == 0 && cinfo->Ah == 0)) { - tbl = compptr->dc_tbl_no; - if (tbl < 0 || tbl >= NUM_ARITH_TBLS) - ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); - if (entropy->dc_stats[tbl] == NULL) - entropy->dc_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) - ((j_common_ptr) cinfo, JPOOL_IMAGE, DC_STAT_BINS); - MEMZERO(entropy->dc_stats[tbl], DC_STAT_BINS); - /* Initialize DC predictions to 0 */ - entropy->last_dc_val[ci] = 0; - entropy->dc_context[ci] = 0; - } - if ((! cinfo->progressive_mode && cinfo->lim_Se) || - (cinfo->progressive_mode && cinfo->Ss)) { - tbl = compptr->ac_tbl_no; - if (tbl < 0 || tbl >= NUM_ARITH_TBLS) - ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); - if (entropy->ac_stats[tbl] == NULL) - entropy->ac_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) - ((j_common_ptr) cinfo, JPOOL_IMAGE, AC_STAT_BINS); - MEMZERO(entropy->ac_stats[tbl], AC_STAT_BINS); - } - } - - /* Initialize arithmetic decoding variables */ - entropy->c = 0; - entropy->a = 0; - entropy->ct = -16; /* force reading 2 initial bytes to fill C */ - - /* Initialize restart counter */ - entropy->restarts_to_go = cinfo->restart_interval; -} - - -/* - * Module initialization routine for arithmetic entropy decoding. - */ - -GLOBAL(void) -jinit_arith_decoder (j_decompress_ptr cinfo) -{ - arith_entropy_ptr entropy; - int i; - - entropy = (arith_entropy_ptr) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - SIZEOF(arith_entropy_decoder)); - cinfo->entropy = (struct jpeg_entropy_decoder *) entropy; - entropy->pub.start_pass = start_pass; - - /* Mark tables unallocated */ - for (i = 0; i < NUM_ARITH_TBLS; i++) { - entropy->dc_stats[i] = NULL; - entropy->ac_stats[i] = NULL; - } - - /* Initialize index for fixed probability estimation */ - entropy->fixed_bin[0] = 113; - - if (cinfo->progressive_mode) { - /* Create progression status table */ - int *coef_bit_ptr, ci; - 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; - } -} |