diff options
Diffstat (limited to 'src/libjpeg')
| -rw-r--r-- | src/libjpeg/jaricom.c | 148 | ||||
| -rw-r--r-- | src/libjpeg/jcarith.c | 921 | ||||
| -rw-r--r-- | src/libjpeg/jchuff.h | 47 | ||||
| -rw-r--r-- | src/libjpeg/jcphuff.c | 833 | ||||
| -rw-r--r-- | src/libjpeg/jdarith.c | 762 | ||||
| -rw-r--r-- | src/libjpeg/jdhuff.h | 201 | ||||
| -rw-r--r-- | src/libjpeg/jdphuff.c | 668 | ||||
| -rw-r--r-- | src/libjpeg/jidctred.c | 398 |
8 files changed, 1831 insertions, 2147 deletions
diff --git a/src/libjpeg/jaricom.c b/src/libjpeg/jaricom.c new file mode 100644 index 0000000..9e51ed5 --- /dev/null +++ b/src/libjpeg/jaricom.c @@ -0,0 +1,148 @@ +/* + * jaricom.c + * + * Developed 1997 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 probability estimation tables for common use in + * arithmetic entropy encoding and decoding routines. + * + * This data represents Table D.2 in the JPEG spec (ISO/IEC IS 10918-1 + * and CCITT Recommendation ITU-T T.81) and Table 24 in the JBIG spec + * (ISO/IEC IS 11544 and CCITT Recommendation ITU-T T.82). + */ + +#define JPEG_INTERNALS +#include "jinclude.h" +#include "jpeglib.h" + +/* The following #define specifies the packing of the four components + * into the compact INT32 representation. + * Note that this formula must match the actual arithmetic encoder + * and decoder implementation. The implementation has to be changed + * if this formula is changed. + * The current organization is leaned on Markus Kuhn's JBIG + * implementation (jbig_tab.c). + */ + +#define V(a,b,c,d) (((INT32)a << 16) | ((INT32)c << 8) | ((INT32)d << 7) | b) + +const INT32 jaritab[113] = { +/* + * Index, Qe_Value, Next_Index_LPS, Next_Index_MPS, Switch_MPS + */ +/* 0 */ V( 0x5a1d, 1, 1, 1 ), +/* 1 */ V( 0x2586, 14, 2, 0 ), +/* 2 */ V( 0x1114, 16, 3, 0 ), +/* 3 */ V( 0x080b, 18, 4, 0 ), +/* 4 */ V( 0x03d8, 20, 5, 0 ), +/* 5 */ V( 0x01da, 23, 6, 0 ), +/* 6 */ V( 0x00e5, 25, 7, 0 ), +/* 7 */ V( 0x006f, 28, 8, 0 ), +/* 8 */ V( 0x0036, 30, 9, 0 ), +/* 9 */ V( 0x001a, 33, 10, 0 ), +/* 10 */ V( 0x000d, 35, 11, 0 ), +/* 11 */ V( 0x0006, 9, 12, 0 ), +/* 12 */ V( 0x0003, 10, 13, 0 ), +/* 13 */ V( 0x0001, 12, 13, 0 ), +/* 14 */ V( 0x5a7f, 15, 15, 1 ), +/* 15 */ V( 0x3f25, 36, 16, 0 ), +/* 16 */ V( 0x2cf2, 38, 17, 0 ), +/* 17 */ V( 0x207c, 39, 18, 0 ), +/* 18 */ V( 0x17b9, 40, 19, 0 ), +/* 19 */ V( 0x1182, 42, 20, 0 ), +/* 20 */ V( 0x0cef, 43, 21, 0 ), +/* 21 */ V( 0x09a1, 45, 22, 0 ), +/* 22 */ V( 0x072f, 46, 23, 0 ), +/* 23 */ V( 0x055c, 48, 24, 0 ), +/* 24 */ V( 0x0406, 49, 25, 0 ), +/* 25 */ V( 0x0303, 51, 26, 0 ), +/* 26 */ V( 0x0240, 52, 27, 0 ), +/* 27 */ V( 0x01b1, 54, 28, 0 ), +/* 28 */ V( 0x0144, 56, 29, 0 ), +/* 29 */ V( 0x00f5, 57, 30, 0 ), +/* 30 */ V( 0x00b7, 59, 31, 0 ), +/* 31 */ V( 0x008a, 60, 32, 0 ), +/* 32 */ V( 0x0068, 62, 33, 0 ), +/* 33 */ V( 0x004e, 63, 34, 0 ), +/* 34 */ V( 0x003b, 32, 35, 0 ), +/* 35 */ V( 0x002c, 33, 9, 0 ), +/* 36 */ V( 0x5ae1, 37, 37, 1 ), +/* 37 */ V( 0x484c, 64, 38, 0 ), +/* 38 */ V( 0x3a0d, 65, 39, 0 ), +/* 39 */ V( 0x2ef1, 67, 40, 0 ), +/* 40 */ V( 0x261f, 68, 41, 0 ), +/* 41 */ V( 0x1f33, 69, 42, 0 ), +/* 42 */ V( 0x19a8, 70, 43, 0 ), +/* 43 */ V( 0x1518, 72, 44, 0 ), +/* 44 */ V( 0x1177, 73, 45, 0 ), +/* 45 */ V( 0x0e74, 74, 46, 0 ), +/* 46 */ V( 0x0bfb, 75, 47, 0 ), +/* 47 */ V( 0x09f8, 77, 48, 0 ), +/* 48 */ V( 0x0861, 78, 49, 0 ), +/* 49 */ V( 0x0706, 79, 50, 0 ), +/* 50 */ V( 0x05cd, 48, 51, 0 ), +/* 51 */ V( 0x04de, 50, 52, 0 ), +/* 52 */ V( 0x040f, 50, 53, 0 ), +/* 53 */ V( 0x0363, 51, 54, 0 ), +/* 54 */ V( 0x02d4, 52, 55, 0 ), +/* 55 */ V( 0x025c, 53, 56, 0 ), +/* 56 */ V( 0x01f8, 54, 57, 0 ), +/* 57 */ V( 0x01a4, 55, 58, 0 ), +/* 58 */ V( 0x0160, 56, 59, 0 ), +/* 59 */ V( 0x0125, 57, 60, 0 ), +/* 60 */ V( 0x00f6, 58, 61, 0 ), +/* 61 */ V( 0x00cb, 59, 62, 0 ), +/* 62 */ V( 0x00ab, 61, 63, 0 ), +/* 63 */ V( 0x008f, 61, 32, 0 ), +/* 64 */ V( 0x5b12, 65, 65, 1 ), +/* 65 */ V( 0x4d04, 80, 66, 0 ), +/* 66 */ V( 0x412c, 81, 67, 0 ), +/* 67 */ V( 0x37d8, 82, 68, 0 ), +/* 68 */ V( 0x2fe8, 83, 69, 0 ), +/* 69 */ V( 0x293c, 84, 70, 0 ), +/* 70 */ V( 0x2379, 86, 71, 0 ), +/* 71 */ V( 0x1edf, 87, 72, 0 ), +/* 72 */ V( 0x1aa9, 87, 73, 0 ), +/* 73 */ V( 0x174e, 72, 74, 0 ), +/* 74 */ V( 0x1424, 72, 75, 0 ), +/* 75 */ V( 0x119c, 74, 76, 0 ), +/* 76 */ V( 0x0f6b, 74, 77, 0 ), +/* 77 */ V( 0x0d51, 75, 78, 0 ), +/* 78 */ V( 0x0bb6, 77, 79, 0 ), +/* 79 */ V( 0x0a40, 77, 48, 0 ), +/* 80 */ V( 0x5832, 80, 81, 1 ), +/* 81 */ V( 0x4d1c, 88, 82, 0 ), +/* 82 */ V( 0x438e, 89, 83, 0 ), +/* 83 */ V( 0x3bdd, 90, 84, 0 ), +/* 84 */ V( 0x34ee, 91, 85, 0 ), +/* 85 */ V( 0x2eae, 92, 86, 0 ), +/* 86 */ V( 0x299a, 93, 87, 0 ), +/* 87 */ V( 0x2516, 86, 71, 0 ), +/* 88 */ V( 0x5570, 88, 89, 1 ), +/* 89 */ V( 0x4ca9, 95, 90, 0 ), +/* 90 */ V( 0x44d9, 96, 91, 0 ), +/* 91 */ V( 0x3e22, 97, 92, 0 ), +/* 92 */ V( 0x3824, 99, 93, 0 ), +/* 93 */ V( 0x32b4, 99, 94, 0 ), +/* 94 */ V( 0x2e17, 93, 86, 0 ), +/* 95 */ V( 0x56a8, 95, 96, 1 ), +/* 96 */ V( 0x4f46, 101, 97, 0 ), +/* 97 */ V( 0x47e5, 102, 98, 0 ), +/* 98 */ V( 0x41cf, 103, 99, 0 ), +/* 99 */ V( 0x3c3d, 104, 100, 0 ), +/* 100 */ V( 0x375e, 99, 93, 0 ), +/* 101 */ V( 0x5231, 105, 102, 0 ), +/* 102 */ V( 0x4c0f, 106, 103, 0 ), +/* 103 */ V( 0x4639, 107, 104, 0 ), +/* 104 */ V( 0x415e, 103, 99, 0 ), +/* 105 */ V( 0x5627, 105, 106, 1 ), +/* 106 */ V( 0x50e7, 108, 107, 0 ), +/* 107 */ V( 0x4b85, 109, 103, 0 ), +/* 108 */ V( 0x5597, 110, 109, 0 ), +/* 109 */ V( 0x504f, 111, 107, 0 ), +/* 110 */ V( 0x5a10, 110, 111, 1 ), +/* 111 */ V( 0x5522, 112, 109, 0 ), +/* 112 */ V( 0x59eb, 112, 111, 1 ) +}; diff --git a/src/libjpeg/jcarith.c b/src/libjpeg/jcarith.c new file mode 100644 index 0000000..945a817 --- /dev/null +++ b/src/libjpeg/jcarith.c @@ -0,0 +1,921 @@ +/* + * jcarith.c + * + * Developed 1997 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 encoding 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 encoder object for arithmetic encoding. */ + +typedef struct { + struct jpeg_entropy_encoder pub; /* public fields */ + + INT32 c; /* C register, base of coding interval, layout as in sec. D.1.3 */ + INT32 a; /* A register, normalized size of coding interval */ + INT32 sc; /* counter for stacked 0xFF values which might overflow */ + INT32 zc; /* counter for pending 0x00 output values which might * + * be discarded at the end ("Pacman" termination) */ + int ct; /* bit shift counter, determines when next byte will be written */ + int buffer; /* buffer for most recent output byte != 0xFF */ + + 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 */ + int next_restart_num; /* next restart number to write (0-7) */ + + /* Pointers to statistics areas (these workspaces have image lifespan) */ + unsigned char * dc_stats[NUM_ARITH_TBLS]; + unsigned char * ac_stats[NUM_ARITH_TBLS]; +} arith_entropy_encoder; + +typedef arith_entropy_encoder * 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. + * Note that we use one additional AC bin for codings with fixed + * probability (0.5), thus the minimum number for AC is 246. + * + * 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 + +/* NOTE: Uncomment the following #define if you want to use the + * given formula for calculating the AC conditioning parameter Kx + * for spectral selection progressive coding in section G.1.3.2 + * of the spec (Kx = Kmin + SRL (8 + Se - Kmin) 4). + * Although the spec and P&M authors claim that this "has proven + * to give good results for 8 bit precision samples", I'm not + * convinced yet that this is really beneficial. + * Early tests gave only very marginal compression enhancements + * (a few - around 5 or so - bytes even for very large files), + * which would turn out rather negative if we'd suppress the + * DAC (Define Arithmetic Conditioning) marker segments for + * the default parameters in the future. + * Note that currently the marker writing module emits 12-byte + * DAC segments for a full-component scan in a color image. + * This is not worth worrying about IMHO. However, since the + * spec defines the default values to be used if the tables + * are omitted (unlike Huffman tables, which are required + * anyway), one might optimize this behaviour in the future, + * and then it would be disadvantageous to use custom tables if + * they don't provide sufficient gain to exceed the DAC size. + * + * On the other hand, I'd consider it as a reasonable result + * that the conditioning has no significant influence on the + * compression performance. This means that the basic + * statistical model is already rather stable. + * + * Thus, at the moment, we use the default conditioning values + * anyway, and do not use the custom formula. + * +#define CALCULATE_SPECTRAL_CONDITIONING + */ + +/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32. + * We assume that int right shift is unsigned if INT32 right shift is, + * which should be safe. + */ + +#ifdef RIGHT_SHIFT_IS_UNSIGNED +#define ISHIFT_TEMPS int ishift_temp; +#define IRIGHT_SHIFT(x,shft) \ + ((ishift_temp = (x)) < 0 ? \ + (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ + (ishift_temp >> (shft))) +#else +#define ISHIFT_TEMPS +#define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) +#endif + + +LOCAL(void) +emit_byte (int val, j_compress_ptr cinfo) +/* Write next output byte; we do not support suspension in this module. */ +{ + struct jpeg_destination_mgr * dest = cinfo->dest; + + *dest->next_output_byte++ = (JOCTET) val; + if (--dest->free_in_buffer == 0) + if (! (*dest->empty_output_buffer) (cinfo)) + ERREXIT(cinfo, JERR_CANT_SUSPEND); +} + + +/* + * Finish up at the end of an arithmetic-compressed scan. + */ + +METHODDEF(void) +finish_pass (j_compress_ptr cinfo) +{ + arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; + INT32 temp; + + /* Section D.1.8: Termination of encoding */ + + /* Find the e->c in the coding interval with the largest + * number of trailing zero bits */ + if ((temp = (e->a - 1 + e->c) & 0xFFFF0000L) < e->c) + e->c = temp + 0x8000L; + else + e->c = temp; + /* Send remaining bytes to output */ + e->c <<= e->ct; + if (e->c & 0xF8000000L) { + /* One final overflow has to be handled */ + if (e->buffer >= 0) { + if (e->zc) + do emit_byte(0x00, cinfo); + while (--e->zc); + emit_byte(e->buffer + 1, cinfo); + if (e->buffer + 1 == 0xFF) + emit_byte(0x00, cinfo); + } + e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ + e->sc = 0; + } else { + if (e->buffer == 0) + ++e->zc; + else if (e->buffer >= 0) { + if (e->zc) + do emit_byte(0x00, cinfo); + while (--e->zc); + emit_byte(e->buffer, cinfo); + } + if (e->sc) { + if (e->zc) + do emit_byte(0x00, cinfo); + while (--e->zc); + do { + emit_byte(0xFF, cinfo); + emit_byte(0x00, cinfo); + } while (--e->sc); + } + } + /* Output final bytes only if they are not 0x00 */ + if (e->c & 0x7FFF800L) { + if (e->zc) /* output final pending zero bytes */ + do emit_byte(0x00, cinfo); + while (--e->zc); + emit_byte((e->c >> 19) & 0xFF, cinfo); + if (((e->c >> 19) & 0xFF) == 0xFF) + emit_byte(0x00, cinfo); + if (e->c & 0x7F800L) { + emit_byte((e->c >> 11) & 0xFF, cinfo); + if (((e->c >> 11) & 0xFF) == 0xFF) + emit_byte(0x00, cinfo); + } + } +} + + +/* + * The core arithmetic encoding 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. + * + * Parameter 'val' to be encoded may be 0 or 1 (binary decision). + * + * Note: I've added full "Pacman" termination support to the + * byte output routines, which is equivalent to the optional + * Discard_final_zeros procedure (Figure D.15) in the spec. + * Thus, we always produce the shortest possible output + * stream compliant to the spec (no trailing zero bytes, + * except for FF stuffing). + * + * I've also introduced a new scheme for accessing + * the probability estimation state machine table, + * derived from Markus Kuhn's JBIG implementation. + */ + +LOCAL(void) +arith_encode (j_compress_ptr cinfo, unsigned char *st, int val) +{ + extern const INT32 jaritab[]; + register arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; + register unsigned char nl, nm; + register INT32 qe, temp; + register int sv; + + /* Fetch values from our compact representation of Table D.2: + * Qe values and probability estimation state machine + */ + sv = *st; + qe = jaritab[sv & 0x7F]; /* => Qe_Value */ + nl = qe & 0xFF; qe >>= 8; /* Next_Index_LPS + Switch_MPS */ + nm = qe & 0xFF; qe >>= 8; /* Next_Index_MPS */ + + /* Encode & estimation procedures per sections D.1.4 & D.1.5 */ + e->a -= qe; + if (val != (sv >> 7)) { + /* Encode the less probable symbol */ + if (e->a >= qe) { + /* If the interval size (qe) for the less probable symbol (LPS) + * is larger than the interval size for the MPS, then exchange + * the two symbols for coding efficiency, otherwise code the LPS + * as usual: */ + e->c += e->a; + e->a = qe; + } + *st = (sv & 0x80) ^ nl; /* Estimate_after_LPS */ + } else { + /* Encode the more probable symbol */ + if (e->a >= 0x8000L) + return; /* A >= 0x8000 -> ready, no renormalization required */ + if (e->a < qe) { + /* If the interval size (qe) for the less probable symbol (LPS) + * is larger than the interval size for the MPS, then exchange + * the two symbols for coding efficiency: */ + e->c += e->a; + e->a = qe; + } + *st = (sv & 0x80) ^ nm; /* Estimate_after_MPS */ + } + + /* Renormalization & data output per section D.1.6 */ + do { + e->a <<= 1; + e->c <<= 1; + if (--e->ct == 0) { + /* Another byte is ready for output */ + temp = e->c >> 19; + if (temp > 0xFF) { + /* Handle overflow over all stacked 0xFF bytes */ + if (e->buffer >= 0) { + if (e->zc) + do emit_byte(0x00, cinfo); + while (--e->zc); + emit_byte(e->buffer + 1, cinfo); + if (e->buffer + 1 == 0xFF) + emit_byte(0x00, cinfo); + } + e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ + e->sc = 0; + /* Note: The 3 spacer bits in the C register guarantee + * that the new buffer byte can't be 0xFF here + * (see page 160 in the P&M JPEG book). */ + e->buffer = temp & 0xFF; /* new output byte, might overflow later */ + } else if (temp == 0xFF) { + ++e->sc; /* stack 0xFF byte (which might overflow later) */ + } else { + /* Output all stacked 0xFF bytes, they will not overflow any more */ + if (e->buffer == 0) + ++e->zc; + else if (e->buffer >= 0) { + if (e->zc) + do emit_byte(0x00, cinfo); + while (--e->zc); + emit_byte(e->buffer, cinfo); + } + if (e->sc) { + if (e->zc) + do emit_byte(0x00, cinfo); + while (--e->zc); + do { + emit_byte(0xFF, cinfo); + emit_byte(0x00, cinfo); + } while (--e->sc); + } + e->buffer = temp & 0xFF; /* new output byte (can still overflow) */ + } + e->c &= 0x7FFFFL; + e->ct += 8; + } + } while (e->a < 0x8000L); +} + + +/* + * Emit a restart marker & resynchronize predictions. + */ + +LOCAL(void) +emit_restart (j_compress_ptr cinfo, int restart_num) +{ + arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; + int ci; + jpeg_component_info * compptr; + + finish_pass(cinfo); + + emit_byte(0xFF, cinfo); + emit_byte(JPEG_RST0 + restart_num, cinfo); + + for (ci = 0; ci < cinfo->comps_in_scan; ci++) { + compptr = cinfo->cur_comp_info[ci]; + /* Re-initialize statistics areas */ + if (cinfo->progressive_mode == 0 || (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 == 0 || cinfo->Ss) { + MEMZERO(entropy->ac_stats[compptr->ac_tbl_no], AC_STAT_BINS); + } + } + + /* Reset arithmetic encoding variables */ + entropy->c = 0; + entropy->a = 0x10000L; + entropy->sc = 0; + entropy->zc = 0; + entropy->ct = 11; + entropy->buffer = -1; /* empty */ +} + + +/* + * MCU encoding for DC initial scan (either spectral selection, + * or first pass of successive approximation). + */ + +METHODDEF(boolean) +encode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) +{ + arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; + JBLOCKROW block; + unsigned char *st; + int blkn, ci, tbl; + int v, v2, m; + ISHIFT_TEMPS + + /* Emit restart marker if needed */ + if (cinfo->restart_interval) { + if (entropy->restarts_to_go == 0) { + emit_restart(cinfo, entropy->next_restart_num); + entropy->restarts_to_go = cinfo->restart_interval; + entropy->next_restart_num++; + entropy->next_restart_num &= 7; + } + entropy->restarts_to_go--; + } + + /* Encode the MCU data blocks */ + 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; + + /* Compute the DC value after the required point transform by Al. + * This is simply an arithmetic right shift. + */ + m = IRIGHT_SHIFT((int) ((*block)[0]), cinfo->Al); + + /* Sections F.1.4.1 & F.1.4.4.1: Encoding 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.4: Encode_DC_DIFF */ + if ((v = m - entropy->last_dc_val[ci]) == 0) { + arith_encode(cinfo, st, 0); + entropy->dc_context[ci] = 0; /* zero diff category */ + } else { + entropy->last_dc_val[ci] = m; + arith_encode(cinfo, st, 1); + /* Figure F.6: Encoding nonzero value v */ + /* Figure F.7: Encoding the sign of v */ + if (v > 0) { + arith_encode(cinfo, st + 1, 0); /* Table F.4: SS = S0 + 1 */ + st += 2; /* Table F.4: SP = S0 + 2 */ + entropy->dc_context[ci] = 4; /* small positive diff category */ + } else { + v = -v; + arith_encode(cinfo, st + 1, 1); /* Table F.4: SS = S0 + 1 */ + st += 3; /* Table F.4: SN = S0 + 3 */ + entropy->dc_context[ci] = 8; /* small negative diff category */ + } + /* Figure F.8: Encoding the magnitude category of v */ + m = 0; + if (v -= 1) { + arith_encode(cinfo, st, 1); + m = 1; + v2 = v; + st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ + while (v2 >>= 1) { + arith_encode(cinfo, st, 1); + m <<= 1; + st += 1; + } + } + arith_encode(cinfo, st, 0); + /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ + if (m < (int) (((INT32) 1 << cinfo->arith_dc_L[tbl]) >> 1)) + entropy->dc_context[ci] = 0; /* zero diff category */ + else if (m > (int) (((INT32) 1 << cinfo->arith_dc_U[tbl]) >> 1)) + entropy->dc_context[ci] += 8; /* large diff category */ + /* Figure F.9: Encoding the magnitude bit pattern of v */ + st += 14; + while (m >>= 1) + arith_encode(cinfo, st, (m & v) ? 1 : 0); + } + } + + return TRUE; +} + + +/* + * MCU encoding for AC initial scan (either spectral selection, + * or first pass of successive approximation). + */ + +METHODDEF(boolean) +encode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) +{ + arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; + JBLOCKROW block; + unsigned char *st; + int tbl, k, ke; + int v, v2, m; + + /* Emit restart marker if needed */ + if (cinfo->restart_interval) { + if (entropy->restarts_to_go == 0) { + emit_restart(cinfo, entropy->next_restart_num); + entropy->restarts_to_go = cinfo->restart_interval; + entropy->next_restart_num++; + entropy->next_restart_num &= 7; + } + entropy->restarts_to_go--; + } + + /* Encode the MCU data block */ + block = MCU_data[0]; + tbl = cinfo->cur_comp_info[0]->ac_tbl_no; + + /* Sections F.1.4.2 & F.1.4.4.2: Encoding of AC coefficients */ + + /* Establish EOB (end-of-block) index */ + for (ke = cinfo->Se + 1; ke > 1; ke--) + /* We must apply the point transform by Al. For AC coefficients this + * is an integer division with rounding towards 0. To do this portably + * in C, we shift after obtaining the absolute value. + */ + if ((v = (*block)[jpeg_natural_order[ke - 1]]) >= 0) { + if (v >>= cinfo->Al) break; + } else { + v = -v; + if (v >>= cinfo->Al) break; + } + + /* Figure F.5: Encode_AC_Coefficients */ + for (k = cinfo->Ss; k < ke; k++) { + st = entropy->ac_stats[tbl] + 3 * (k - 1); + arith_encode(cinfo, st, 0); /* EOB decision */ + entropy->ac_stats[tbl][245] = 0; + for (;;) { + if ((v = (*block)[jpeg_natural_order[k]]) >= 0) { + if (v >>= cinfo->Al) { + arith_encode(cinfo, st + 1, 1); + arith_encode(cinfo, entropy->ac_stats[tbl] + 245, 0); + break; + } + } else { + v = -v; + if (v >>= cinfo->Al) { + arith_encode(cinfo, st + 1, 1); + arith_encode(cinfo, entropy->ac_stats[tbl] + 245, 1); + break; + } + } + arith_encode(cinfo, st + 1, 0); st += 3; k++; + } + st += 2; + /* Figure F.8: Encoding the magnitude category of v */ + m = 0; + if (v -= 1) { + arith_encode(cinfo, st, 1); + m = 1; + v2 = v; + if (v2 >>= 1) { + arith_encode(cinfo, st, 1); + m <<= 1; + st = entropy->ac_stats[tbl] + + (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); + while (v2 >>= 1) { + arith_encode(cinfo, st, 1); + m <<= 1; + st += 1; + } + } + } + arith_encode(cinfo, st, 0); + /* Figure F.9: Encoding the magnitude bit pattern of v */ + st += 14; + while (m >>= 1) + arith_encode(cinfo, st, (m & v) ? 1 : 0); + } + /* Encode EOB decision only if k <= cinfo->Se */ + if (k <= cinfo->Se) { + st = entropy->ac_stats[tbl] + 3 * (k - 1); + arith_encode(cinfo, st, 1); + } + + return TRUE; +} + + +/* + * MCU encoding for DC successive approximation refinement scan. + */ + +METHODDEF(boolean) +encode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) +{ + arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; + unsigned char st[4]; + int Al, blkn; + + /* Emit restart marker if needed */ + if (cinfo->restart_interval) { + if (entropy->restarts_to_go == 0) { + emit_restart(cinfo, entropy->next_restart_num); + entropy->restarts_to_go = cinfo->restart_interval; + entropy->next_restart_num++; + entropy->next_restart_num &= 7; + } + entropy->restarts_to_go--; + } + + Al = cinfo->Al; + + /* Encode the MCU data blocks */ + for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { + st[0] = 0; /* use fixed probability estimation */ + /* We simply emit the Al'th bit of the DC coefficient value. */ + arith_encode(cinfo, st, (MCU_data[blkn][0][0] >> Al) & 1); + } + + return TRUE; +} + + +/* + * MCU encoding for AC successive approximation refinement scan. + */ + +METHODDEF(boolean) +encode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) +{ + arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; + JBLOCKROW block; + unsigned char *st; + int tbl, k, ke, kex; + int v; + + /* Emit restart marker if needed */ + if (cinfo->restart_interval) { + if (entropy->restarts_to_go == 0) { + emit_restart(cinfo, entropy->next_restart_num); + entropy->restarts_to_go = cinfo->restart_interval; + entropy->next_restart_num++; + entropy->next_restart_num &= 7; + } + entropy->restarts_to_go--; + } + + /* Encode the MCU data block */ + block = MCU_data[0]; + tbl = cinfo->cur_comp_info[0]->ac_tbl_no; + + /* Section G.1.3.3: Encoding of AC coefficients */ + + /* Establish EOB (end-of-block) index */ + for (ke = cinfo->Se + 1; ke > 1; ke--) + /* We must apply the point transform by Al. For AC coefficients this + * is an integer division with rounding towards 0. To do this portably + * in C, we shift after obtaining the absolute value. + */ + if ((v = (*block)[jpeg_natural_order[ke - 1]]) >= 0) { + if (v >>= cinfo->Al) break; + } else { + v = -v; + if (v >>= cinfo->Al) break; + } + + /* Establish EOBx (previous stage end-of-block) index */ + for (kex = ke; kex > 1; kex--) + if ((v = (*block)[jpeg_natural_order[kex - 1]]) >= 0) { + if (v >>= cinfo->Ah) break; + } else { + v = -v; + if (v >>= cinfo->Ah) break; + } + + /* Figure G.10: Encode_AC_Coefficients_SA */ + for (k = cinfo->Ss; k < ke; k++) { + st = entropy->ac_stats[tbl] + 3 * (k - 1); + if (k >= kex) + arith_encode(cinfo, st, 0); /* EOB decision */ + entropy->ac_stats[tbl][245] = 0; + for (;;) { + if ((v = (*block)[jpeg_natural_order[k]]) >= 0) { + if (v >>= cinfo->Al) { + if (v >> 1) /* previously nonzero coef */ + arith_encode(cinfo, st + 2, (v & 1)); + else { /* newly nonzero coef */ + arith_encode(cinfo, st + 1, 1); + arith_encode(cinfo, entropy->ac_stats[tbl] + 245, 0); + } + break; + } + } else { + v = -v; + if (v >>= cinfo->Al) { + if (v >> 1) /* previously nonzero coef */ + arith_encode(cinfo, st + 2, (v & 1)); + else { /* newly nonzero coef */ + arith_encode(cinfo, st + 1, 1); + arith_encode(cinfo, entropy->ac_stats[tbl] + 245, 1); + } + break; + } + } + arith_encode(cinfo, st + 1, 0); st += 3; k++; + } + } + /* Encode EOB decision only if k <= cinfo->Se */ + if (k <= cinfo->Se) { + st = entropy->ac_stats[tbl] + 3 * (k - 1); + arith_encode(cinfo, st, 1); + } + + return TRUE; +} + + +/* + * Encode and output one MCU's worth of arithmetic-compressed coefficients. + */ + +METHODDEF(boolean) +encode_mcu (j_compress_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, k, ke; + int v, v2, m; + + /* Emit restart marker if needed */ + if (cinfo->restart_interval) { + if (entropy->restarts_to_go == 0) { + emit_restart(cinfo, entropy->next_restart_num); + entropy->restarts_to_go = cinfo->restart_interval; + entropy->next_restart_num++; + entropy->next_restart_num &= 7; + } + entropy->restarts_to_go--; + } + + /* Encode the MCU data blocks */ + for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { + block = MCU_data[blkn]; + ci = cinfo->MCU_membership[blkn]; + compptr = cinfo->cur_comp_info[ci]; + + /* Sections F.1.4.1 & F.1.4.4.1: Encoding 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.4: Encode_DC_DIFF */ + if ((v = (*block)[0] - entropy->last_dc_val[ci]) == 0) { + arith_encode(cinfo, st, 0); + entropy->dc_context[ci] = 0; /* zero diff category */ + } else { + entropy->last_dc_val[ci] = (*block)[0]; + arith_encode(cinfo, st, 1); + /* Figure F.6: Encoding nonzero value v */ + /* Figure F.7: Encoding the sign of v */ + if (v > 0) { + arith_encode(cinfo, st + 1, 0); /* Table F.4: SS = S0 + 1 */ + st += 2; /* Table F.4: SP = S0 + 2 */ + entropy->dc_context[ci] = 4; /* small positive diff category */ + } else { + v = -v; + arith_encode(cinfo, st + 1, 1); /* Table F.4: SS = S0 + 1 */ + st += 3; /* Table F.4: SN = S0 + 3 */ + entropy->dc_context[ci] = 8; /* small negative diff category */ + } + /* Figure F.8: Encoding the magnitude category of v */ + m = 0; + if (v -= 1) { + arith_encode(cinfo, st, 1); + m = 1; + v2 = v; + st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ + while (v2 >>= 1) { + arith_encode(cinfo, st, 1); + m <<= 1; + st += 1; + } + } + arith_encode(cinfo, st, 0); + /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ + if (m < (int) (((INT32) 1 << cinfo->arith_dc_L[tbl]) >> 1)) + entropy->dc_context[ci] = 0; /* zero diff category */ + else if (m > (int) (((INT32) 1 << cinfo->arith_dc_U[tbl]) >> 1)) + entropy->dc_context[ci] += 8; /* large diff category */ + /* Figure F.9: Encoding the magnitude bit pattern of v */ + st += 14; + while (m >>= 1) + arith_encode(cinfo, st, (m & v) ? 1 : 0); + } + + /* Sections F.1.4.2 & F.1.4.4.2: Encoding of AC coefficients */ + + tbl = compptr->ac_tbl_no; + + /* Establish EOB (end-of-block) index */ + for (ke = DCTSIZE2; ke > 1; ke--) + if ((*block)[jpeg_natural_order[ke - 1]]) break; + + /* Figure F.5: Encode_AC_Coefficients */ + for (k = 1; k < ke; k++) { + st = entropy->ac_stats[tbl] + 3 * (k - 1); + arith_encode(cinfo, st, 0); /* EOB decision */ + while ((v = (*block)[jpeg_natural_order[k]]) == 0) { + arith_encode(cinfo, st + 1, 0); st += 3; k++; + } + arith_encode(cinfo, st + 1, 1); + /* Figure F.6: Encoding nonzero value v */ + /* Figure F.7: Encoding the sign of v */ + entropy->ac_stats[tbl][245] = 0; + if (v > 0) { + arith_encode(cinfo, entropy->ac_stats[tbl] + 245, 0); + } else { + v = -v; + arith_encode(cinfo, entropy->ac_stats[tbl] + 245, 1); + } + st += 2; + /* Figure F.8: Encoding the magnitude category of v */ + m = 0; + if (v -= 1) { + arith_encode(cinfo, st, 1); + m = 1; + v2 = v; + if (v2 >>= 1) { + arith_encode(cinfo, st, 1); + m <<= 1; + st = entropy->ac_stats[tbl] + + (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); + while (v2 >>= 1) { + arith_encode(cinfo, st, 1); + m <<= 1; + st += 1; + } + } + } + arith_encode(cinfo, st, 0); + /* Figure F.9: Encoding the magnitude bit pattern of v */ + st += 14; + while (m >>= 1) + arith_encode(cinfo, st, (m & v) ? 1 : 0); + } + /* Encode EOB decision only if k < DCTSIZE2 */ + if (k < DCTSIZE2) { + st = entropy->ac_stats[tbl] + 3 * (k - 1); + arith_encode(cinfo, st, 1); + } + } + + return TRUE; +} + + +/* + * Initialize for an arithmetic-compressed scan. + */ + +METHODDEF(void) +start_pass (j_compress_ptr cinfo, boolean gather_statistics) +{ + arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; + int ci, tbl; + jpeg_component_info * compptr; + + if (gather_statistics) + /* Make sure to avoid that in the master control logic! + * We are fully adaptive here and need no extra + * statistics gathering pass! + */ + ERREXIT(cinfo, JERR_NOT_COMPILED); + + /* We assume jcmaster.c already validated the progressive scan parameters. */ + + /* Select execution routines */ + if (cinfo->progressive_mode) { + if (cinfo->Ah == 0) { + if (cinfo->Ss == 0) + entropy->pub.encode_mcu = encode_mcu_DC_first; + else + entropy->pub.encode_mcu = encode_mcu_AC_first; + } else { + if (cinfo->Ss == 0) + entropy->pub.encode_mcu = encode_mcu_DC_refine; + else + entropy->pub.encode_mcu = encode_mcu_AC_refine; + } + } else + entropy->pub.encode_mcu = encode_mcu; + + for (ci = 0; ci < cinfo->comps_in_scan; ci++) { + compptr = cinfo->cur_comp_info[ci]; + /* Allocate & initialize requested statistics areas */ + if (cinfo->progressive_mode == 0 || (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 == 0 || 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); +#ifdef CALCULATE_SPECTRAL_CONDITIONING + if (cinfo->progressive_mode) + /* Section G.1.3.2: Set appropriate arithmetic conditioning value Kx */ + cinfo->arith_ac_K[tbl] = cinfo->Ss + ((8 + cinfo->Se - cinfo->Ss) >> 4); +#endif + } + } + + /* Initialize arithmetic encoding variables */ + entropy->c = 0; + entropy->a = 0x10000L; + entropy->sc = 0; + entropy->zc = 0; + entropy->ct = 11; + entropy->buffer = -1; /* empty */ + + /* Initialize restart stuff */ + entropy->restarts_to_go = cinfo->restart_interval; + entropy->next_restart_num = 0; +} + + +/* + * Module initialization routine for arithmetic entropy encoding. + */ + +GLOBAL(void) +jinit_arith_encoder (j_compress_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_encoder)); + cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; + entropy->pub.start_pass = start_pass; + entropy->pub.finish_pass = finish_pass; + + /* Mark tables unallocated */ + for (i = 0; i < NUM_ARITH_TBLS; i++) { + entropy->dc_stats[i] = NULL; + entropy->ac_stats[i] = NULL; + } +} diff --git a/src/libjpeg/jchuff.h b/src/libjpeg/jchuff.h deleted file mode 100644 index a9599fc..0000000 --- a/src/libjpeg/jchuff.h +++ /dev/null @@ -1,47 +0,0 @@ -/* - * jchuff.h - * - * Copyright (C) 1991-1997, 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 declarations for Huffman entropy encoding routines - * that are shared between the sequential encoder (jchuff.c) and the - * progressive encoder (jcphuff.c). No other modules need to see these. - */ - -/* The legal range of a DCT coefficient is - * -1024 .. +1023 for 8-bit data; - * -16384 .. +16383 for 12-bit data. - * Hence the magnitude should always fit in 10 or 14 bits respectively. - */ - -#if BITS_IN_JSAMPLE == 8 -#define MAX_COEF_BITS 10 -#else -#define MAX_COEF_BITS 14 -#endif - -/* Derived data constructed for each Huffman table */ - -typedef struct { - unsigned int ehufco[256]; /* code for each symbol */ - char ehufsi[256]; /* length of code for each symbol */ - /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */ -} c_derived_tbl; - -/* Short forms of external names for systems with brain-damaged linkers. */ - -#ifdef NEED_SHORT_EXTERNAL_NAMES -#define jpeg_make_c_derived_tbl jMkCDerived -#define jpeg_gen_optimal_table jGenOptTbl -#endif /* NEED_SHORT_EXTERNAL_NAMES */ - -/* Expand a Huffman table definition into the derived format */ -EXTERN(void) jpeg_make_c_derived_tbl - JPP((j_compress_ptr cinfo, boolean isDC, int tblno, - c_derived_tbl ** pdtbl)); - -/* Generate an optimal table definition given the specified counts */ -EXTERN(void) jpeg_gen_optimal_table - JPP((j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[])); diff --git a/src/libjpeg/jcphuff.c b/src/libjpeg/jcphuff.c deleted file mode 100644 index 07f9178..0000000 --- a/src/libjpeg/jcphuff.c +++ /dev/null @@ -1,833 +0,0 @@ -/* - * jcphuff.c - * - * Copyright (C) 1995-1997, Thomas G. Lane. - * This file is part of the Independent JPEG Group's software. - * For conditions of distribution and use, see the accompanying README file. - * - * This file contains Huffman entropy encoding routines for progressive JPEG. - * - * We do not support output suspension in this module, since the library - * currently does not allow multiple-scan files to be written with output - * suspension. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" -#include "jchuff.h" /* Declarations shared with jchuff.c */ - -#ifdef C_PROGRESSIVE_SUPPORTED - -/* Expanded entropy encoder object for progressive Huffman encoding. */ - -typedef struct { - struct jpeg_entropy_encoder pub; /* public fields */ - - /* Mode flag: TRUE for optimization, FALSE for actual data output */ - boolean gather_statistics; - - /* Bit-level coding status. - * next_output_byte/free_in_buffer are local copies of cinfo->dest fields. - */ - JOCTET * next_output_byte; /* => next byte to write in buffer */ - size_t free_in_buffer; /* # of byte spaces remaining in buffer */ - INT32 put_buffer; /* current bit-accumulation buffer */ - int put_bits; /* # of bits now in it */ - j_compress_ptr cinfo; /* link to cinfo (needed for dump_buffer) */ - - /* Coding status for DC components */ - int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ - - /* Coding status for AC components */ - int ac_tbl_no; /* the table number of the single component */ - unsigned int EOBRUN; /* run length of EOBs */ - unsigned int BE; /* # of buffered correction bits before MCU */ - char * bit_buffer; /* buffer for correction bits (1 per char) */ - /* packing correction bits tightly would save some space but cost time... */ - - unsigned int restarts_to_go; /* MCUs left in this restart interval */ - int next_restart_num; /* next restart number to write (0-7) */ - - /* Pointers to derived tables (these workspaces have image lifespan). - * Since any one scan codes only DC or only AC, we only need one set - * of tables, not one for DC and one for AC. - */ - c_derived_tbl * derived_tbls[NUM_HUFF_TBLS]; - - /* Statistics tables for optimization; again, one set is enough */ - long * count_ptrs[NUM_HUFF_TBLS]; -} phuff_entropy_encoder; - -typedef phuff_entropy_encoder * phuff_entropy_ptr; - -/* MAX_CORR_BITS is the number of bits the AC refinement correction-bit - * buffer can hold. Larger sizes may slightly improve compression, but - * 1000 is already well into the realm of overkill. - * The minimum safe size is 64 bits. - */ - -#define MAX_CORR_BITS 1000 /* Max # of correction bits I can buffer */ - -/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32. - * We assume that int right shift is unsigned if INT32 right shift is, - * which should be safe. - */ - -#ifdef RIGHT_SHIFT_IS_UNSIGNED -#define ISHIFT_TEMPS int ishift_temp; -#define IRIGHT_SHIFT(x,shft) \ - ((ishift_temp = (x)) < 0 ? \ - (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ - (ishift_temp >> (shft))) -#else -#define ISHIFT_TEMPS -#define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) -#endif - -/* Forward declarations */ -METHODDEF(boolean) encode_mcu_DC_first JPP((j_compress_ptr cinfo, - JBLOCKROW *MCU_data)); -METHODDEF(boolean) encode_mcu_AC_first JPP((j_compress_ptr cinfo, - JBLOCKROW *MCU_data)); -METHODDEF(boolean) encode_mcu_DC_refine JPP((j_compress_ptr cinfo, - JBLOCKROW *MCU_data)); -METHODDEF(boolean) encode_mcu_AC_refine JPP((j_compress_ptr cinfo, - JBLOCKROW *MCU_data)); -METHODDEF(void) finish_pass_phuff JPP((j_compress_ptr cinfo)); -METHODDEF(void) finish_pass_gather_phuff JPP((j_compress_ptr cinfo)); - - -/* - * Initialize for a Huffman-compressed scan using progressive JPEG. - */ - -METHODDEF(void) -start_pass_phuff (j_compress_ptr cinfo, boolean gather_statistics) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - boolean is_DC_band; - int ci, tbl; - jpeg_component_info * compptr; - - entropy->cinfo = cinfo; - entropy->gather_statistics = gather_statistics; - - is_DC_band = (cinfo->Ss == 0); - - /* We assume jcmaster.c already validated the scan parameters. */ - - /* Select execution routines */ - if (cinfo->Ah == 0) { - if (is_DC_band) - entropy->pub.encode_mcu = encode_mcu_DC_first; - else - entropy->pub.encode_mcu = encode_mcu_AC_first; - } else { - if (is_DC_band) - entropy->pub.encode_mcu = encode_mcu_DC_refine; - else { - entropy->pub.encode_mcu = encode_mcu_AC_refine; - /* AC refinement needs a correction bit buffer */ - if (entropy->bit_buffer == NULL) - entropy->bit_buffer = (char *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - MAX_CORR_BITS * SIZEOF(char)); - } - } - if (gather_statistics) - entropy->pub.finish_pass = finish_pass_gather_phuff; - else - entropy->pub.finish_pass = finish_pass_phuff; - - /* Only DC coefficients may be interleaved, so cinfo->comps_in_scan = 1 - * for AC coefficients. - */ - for (ci = 0; ci < cinfo->comps_in_scan; ci++) { - compptr = cinfo->cur_comp_info[ci]; - /* Initialize DC predictions to 0 */ - entropy->last_dc_val[ci] = 0; - /* Get table index */ - if (is_DC_band) { - if (cinfo->Ah != 0) /* DC refinement needs no table */ - continue; - tbl = compptr->dc_tbl_no; - } else { - entropy->ac_tbl_no = tbl = compptr->ac_tbl_no; - } - if (gather_statistics) { - /* Check for invalid table index */ - /* (make_c_derived_tbl does this in the other path) */ - if (tbl < 0 || tbl >= NUM_HUFF_TBLS) - ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl); - /* Allocate and zero the statistics tables */ - /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */ - if (entropy->count_ptrs[tbl] == NULL) - entropy->count_ptrs[tbl] = (long *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - 257 * SIZEOF(long)); - MEMZERO(entropy->count_ptrs[tbl], 257 * SIZEOF(long)); - } else { - /* Compute derived values for Huffman table */ - /* We may do this more than once for a table, but it's not expensive */ - jpeg_make_c_derived_tbl(cinfo, is_DC_band, tbl, - & entropy->derived_tbls[tbl]); - } - } - - /* Initialize AC stuff */ - entropy->EOBRUN = 0; - entropy->BE = 0; - - /* Initialize bit buffer to empty */ - entropy->put_buffer = 0; - entropy->put_bits = 0; - - /* Initialize restart stuff */ - entropy->restarts_to_go = cinfo->restart_interval; - entropy->next_restart_num = 0; -} - - -/* Outputting bytes to the file. - * NB: these must be called only when actually outputting, - * that is, entropy->gather_statistics == FALSE. - */ - -/* Emit a byte */ -#define emit_byte(entropy,val) \ - { *(entropy)->next_output_byte++ = (JOCTET) (val); \ - if (--(entropy)->free_in_buffer == 0) \ - dump_buffer(entropy); } - - -LOCAL(void) -dump_buffer (phuff_entropy_ptr entropy) -/* Empty the output buffer; we do not support suspension in this module. */ -{ - struct jpeg_destination_mgr * dest = entropy->cinfo->dest; - - if (! (*dest->empty_output_buffer) (entropy->cinfo)) - ERREXIT(entropy->cinfo, JERR_CANT_SUSPEND); - /* After a successful buffer dump, must reset buffer pointers */ - entropy->next_output_byte = dest->next_output_byte; - entropy->free_in_buffer = dest->free_in_buffer; -} - - -/* Outputting bits to the file */ - -/* Only the right 24 bits of put_buffer are used; the valid bits are - * left-justified in this part. At most 16 bits can be passed to emit_bits - * in one call, and we never retain more than 7 bits in put_buffer - * between calls, so 24 bits are sufficient. - */ - -INLINE -LOCAL(void) -emit_bits (phuff_entropy_ptr entropy, unsigned int code, int size) -/* Emit some bits, unless we are in gather mode */ -{ - /* This routine is heavily used, so it's worth coding tightly. */ - register INT32 put_buffer = (INT32) code; - register int put_bits = entropy->put_bits; - - /* if size is 0, caller used an invalid Huffman table entry */ - if (size == 0) - ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE); - - if (entropy->gather_statistics) - return; /* do nothing if we're only getting stats */ - - put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */ - - put_bits += size; /* new number of bits in buffer */ - - put_buffer <<= 24 - put_bits; /* align incoming bits */ - - put_buffer |= entropy->put_buffer; /* and merge with old buffer contents */ - - while (put_bits >= 8) { - int c = (int) ((put_buffer >> 16) & 0xFF); - - emit_byte(entropy, c); - if (c == 0xFF) { /* need to stuff a zero byte? */ - emit_byte(entropy, 0); - } - put_buffer <<= 8; - put_bits -= 8; - } - - entropy->put_buffer = put_buffer; /* update variables */ - entropy->put_bits = put_bits; -} - - -LOCAL(void) -flush_bits (phuff_entropy_ptr entropy) -{ - emit_bits(entropy, 0x7F, 7); /* fill any partial byte with ones */ - entropy->put_buffer = 0; /* and reset bit-buffer to empty */ - entropy->put_bits = 0; -} - - -/* - * Emit (or just count) a Huffman symbol. - */ - -INLINE -LOCAL(void) -emit_symbol (phuff_entropy_ptr entropy, int tbl_no, int symbol) -{ - if (entropy->gather_statistics) - entropy->count_ptrs[tbl_no][symbol]++; - else { - c_derived_tbl * tbl = entropy->derived_tbls[tbl_no]; - emit_bits(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]); - } -} - - -/* - * Emit bits from a correction bit buffer. - */ - -LOCAL(void) -emit_buffered_bits (phuff_entropy_ptr entropy, char * bufstart, - unsigned int nbits) -{ - if (entropy->gather_statistics) - return; /* no real work */ - - while (nbits > 0) { - emit_bits(entropy, (unsigned int) (*bufstart), 1); - bufstart++; - nbits--; - } -} - - -/* - * Emit any pending EOBRUN symbol. - */ - -LOCAL(void) -emit_eobrun (phuff_entropy_ptr entropy) -{ - register int temp, nbits; - - if (entropy->EOBRUN > 0) { /* if there is any pending EOBRUN */ - temp = entropy->EOBRUN; - nbits = 0; - while ((temp >>= 1)) - nbits++; - /* safety check: shouldn't happen given limited correction-bit buffer */ - if (nbits > 14) - ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE); - - emit_symbol(entropy, entropy->ac_tbl_no, nbits << 4); - if (nbits) - emit_bits(entropy, entropy->EOBRUN, nbits); - - entropy->EOBRUN = 0; - - /* Emit any buffered correction bits */ - emit_buffered_bits(entropy, entropy->bit_buffer, entropy->BE); - entropy->BE = 0; - } -} - - -/* - * Emit a restart marker & resynchronize predictions. - */ - -LOCAL(void) -emit_restart (phuff_entropy_ptr entropy, int restart_num) -{ - int ci; - - emit_eobrun(entropy); - - if (! entropy->gather_statistics) { - flush_bits(entropy); - emit_byte(entropy, 0xFF); - emit_byte(entropy, JPEG_RST0 + restart_num); - } - - if (entropy->cinfo->Ss == 0) { - /* Re-initialize DC predictions to 0 */ - for (ci = 0; ci < entropy->cinfo->comps_in_scan; ci++) - entropy->last_dc_val[ci] = 0; - } else { - /* Re-initialize all AC-related fields to 0 */ - entropy->EOBRUN = 0; - entropy->BE = 0; - } -} - - -/* - * MCU encoding for DC initial scan (either spectral selection, - * or first pass of successive approximation). - */ - -METHODDEF(boolean) -encode_mcu_DC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - register int temp, temp2; - register int nbits; - int blkn, ci; - int Al = cinfo->Al; - JBLOCKROW block; - jpeg_component_info * compptr; - ISHIFT_TEMPS - - entropy->next_output_byte = cinfo->dest->next_output_byte; - entropy->free_in_buffer = cinfo->dest->free_in_buffer; - - /* Emit restart marker if needed */ - if (cinfo->restart_interval) - if (entropy->restarts_to_go == 0) - emit_restart(entropy, entropy->next_restart_num); - - /* Encode the MCU data blocks */ - for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { - block = MCU_data[blkn]; - ci = cinfo->MCU_membership[blkn]; - compptr = cinfo->cur_comp_info[ci]; - - /* Compute the DC value after the required point transform by Al. - * This is simply an arithmetic right shift. - */ - temp2 = IRIGHT_SHIFT((int) ((*block)[0]), Al); - - /* DC differences are figured on the point-transformed values. */ - temp = temp2 - entropy->last_dc_val[ci]; - entropy->last_dc_val[ci] = temp2; - - /* Encode the DC coefficient difference per section G.1.2.1 */ - temp2 = temp; - if (temp < 0) { - temp = -temp; /* temp is abs value of input */ - /* For a negative input, want temp2 = bitwise complement of abs(input) */ - /* This code assumes we are on a two's complement machine */ - temp2--; - } - - /* Find the number of bits needed for the magnitude of the coefficient */ - nbits = 0; - while (temp) { - nbits++; - temp >>= 1; - } - /* Check for out-of-range coefficient values. - * Since we're encoding a difference, the range limit is twice as much. - */ - if (nbits > MAX_COEF_BITS+1) - ERREXIT(cinfo, JERR_BAD_DCT_COEF); - - /* Count/emit the Huffman-coded symbol for the number of bits */ - emit_symbol(entropy, compptr->dc_tbl_no, nbits); - - /* Emit that number of bits of the value, if positive, */ - /* or the complement of its magnitude, if negative. */ - if (nbits) /* emit_bits rejects calls with size 0 */ - emit_bits(entropy, (unsigned int) temp2, nbits); - } - - cinfo->dest->next_output_byte = entropy->next_output_byte; - cinfo->dest->free_in_buffer = entropy->free_in_buffer; - - /* Update restart-interval state too */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) { - entropy->restarts_to_go = cinfo->restart_interval; - entropy->next_restart_num++; - entropy->next_restart_num &= 7; - } - entropy->restarts_to_go--; - } - - return TRUE; -} - - -/* - * MCU encoding for AC initial scan (either spectral selection, - * or first pass of successive approximation). - */ - -METHODDEF(boolean) -encode_mcu_AC_first (j_compress_ptr cinfo, JBLOCKROW *MCU_data) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - register int temp, temp2; - register int nbits; - register int r, k; - int Se = cinfo->Se; - int Al = cinfo->Al; - JBLOCKROW block; - - entropy->next_output_byte = cinfo->dest->next_output_byte; - entropy->free_in_buffer = cinfo->dest->free_in_buffer; - - /* Emit restart marker if needed */ - if (cinfo->restart_interval) - if (entropy->restarts_to_go == 0) - emit_restart(entropy, entropy->next_restart_num); - - /* Encode the MCU data block */ - block = MCU_data[0]; - - /* Encode the AC coefficients per section G.1.2.2, fig. G.3 */ - - r = 0; /* r = run length of zeros */ - - for (k = cinfo->Ss; k <= Se; k++) { - if ((temp = (*block)[jpeg_natural_order[k]]) == 0) { - r++; - continue; - } - /* We must apply the point transform by Al. For AC coefficients this - * is an integer division with rounding towards 0. To do this portably - * in C, we shift after obtaining the absolute value; so the code is - * interwoven with finding the abs value (temp) and output bits (temp2). - */ - if (temp < 0) { - temp = -temp; /* temp is abs value of input */ - temp >>= Al; /* apply the point transform */ - /* For a negative coef, want temp2 = bitwise complement of abs(coef) */ - temp2 = ~temp; - } else { - temp >>= Al; /* apply the point transform */ - temp2 = temp; - } - /* Watch out for case that nonzero coef is zero after point transform */ - if (temp == 0) { - r++; - continue; - } - - /* Emit any pending EOBRUN */ - if (entropy->EOBRUN > 0) - emit_eobrun(entropy); - /* if run length > 15, must emit special run-length-16 codes (0xF0) */ - while (r > 15) { - emit_symbol(entropy, entropy->ac_tbl_no, 0xF0); - r -= 16; - } - - /* Find the number of bits needed for the magnitude of the coefficient */ - nbits = 1; /* there must be at least one 1 bit */ - while ((temp >>= 1)) - nbits++; - /* Check for out-of-range coefficient values */ - if (nbits > MAX_COEF_BITS) - ERREXIT(cinfo, JERR_BAD_DCT_COEF); - - /* Count/emit Huffman symbol for run length / number of bits */ - emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + nbits); - - /* Emit that number of bits of the value, if positive, */ - /* or the complement of its magnitude, if negative. */ - emit_bits(entropy, (unsigned int) temp2, nbits); - - r = 0; /* reset zero run length */ - } - - if (r > 0) { /* If there are trailing zeroes, */ - entropy->EOBRUN++; /* count an EOB */ - if (entropy->EOBRUN == 0x7FFF) - emit_eobrun(entropy); /* force it out to avoid overflow */ - } - - cinfo->dest->next_output_byte = entropy->next_output_byte; - cinfo->dest->free_in_buffer = entropy->free_in_buffer; - - /* Update restart-interval state too */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) { - entropy->restarts_to_go = cinfo->restart_interval; - entropy->next_restart_num++; - entropy->next_restart_num &= 7; - } - entropy->restarts_to_go--; - } - - return TRUE; -} - - -/* - * MCU encoding for DC successive approximation refinement scan. - * Note: we assume such scans can be multi-component, although the spec - * is not very clear on the point. - */ - -METHODDEF(boolean) -encode_mcu_DC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - register int temp; - int blkn; - int Al = cinfo->Al; - JBLOCKROW block; - - entropy->next_output_byte = cinfo->dest->next_output_byte; - entropy->free_in_buffer = cinfo->dest->free_in_buffer; - - /* Emit restart marker if needed */ - if (cinfo->restart_interval) - if (entropy->restarts_to_go == 0) - emit_restart(entropy, entropy->next_restart_num); - - /* Encode the MCU data blocks */ - for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { - block = MCU_data[blkn]; - - /* We simply emit the Al'th bit of the DC coefficient value. */ - temp = (*block)[0]; - emit_bits(entropy, (unsigned int) (temp >> Al), 1); - } - - cinfo->dest->next_output_byte = entropy->next_output_byte; - cinfo->dest->free_in_buffer = entropy->free_in_buffer; - - /* Update restart-interval state too */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) { - entropy->restarts_to_go = cinfo->restart_interval; - entropy->next_restart_num++; - entropy->next_restart_num &= 7; - } - entropy->restarts_to_go--; - } - - return TRUE; -} - - -/* - * MCU encoding for AC successive approximation refinement scan. - */ - -METHODDEF(boolean) -encode_mcu_AC_refine (j_compress_ptr cinfo, JBLOCKROW *MCU_data) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - register int temp; - register int r, k; - int EOB; - char *BR_buffer; - unsigned int BR; - int Se = cinfo->Se; - int Al = cinfo->Al; - JBLOCKROW block; - int absvalues[DCTSIZE2]; - - entropy->next_output_byte = cinfo->dest->next_output_byte; - entropy->free_in_buffer = cinfo->dest->free_in_buffer; - - /* Emit restart marker if needed */ - if (cinfo->restart_interval) - if (entropy->restarts_to_go == 0) - emit_restart(entropy, entropy->next_restart_num); - - /* Encode the MCU data block */ - block = MCU_data[0]; - - /* It is convenient to make a pre-pass to determine the transformed - * coefficients' absolute values and the EOB position. - */ - EOB = 0; - for (k = cinfo->Ss; k <= Se; k++) { - temp = (*block)[jpeg_natural_order[k]]; - /* We must apply the point transform by Al. For AC coefficients this - * is an integer division with rounding towards 0. To do this portably - * in C, we shift after obtaining the absolute value. - */ - if (temp < 0) - temp = -temp; /* temp is abs value of input */ - temp >>= Al; /* apply the point transform */ - absvalues[k] = temp; /* save abs value for main pass */ - if (temp == 1) - EOB = k; /* EOB = index of last newly-nonzero coef */ - } - - /* Encode the AC coefficients per section G.1.2.3, fig. G.7 */ - - r = 0; /* r = run length of zeros */ - BR = 0; /* BR = count of buffered bits added now */ - BR_buffer = entropy->bit_buffer + entropy->BE; /* Append bits to buffer */ - - for (k = cinfo->Ss; k <= Se; k++) { - if ((temp = absvalues[k]) == 0) { - r++; - continue; - } - - /* Emit any required ZRLs, but not if they can be folded into EOB */ - while (r > 15 && k <= EOB) { - /* emit any pending EOBRUN and the BE correction bits */ - emit_eobrun(entropy); - /* Emit ZRL */ - emit_symbol(entropy, entropy->ac_tbl_no, 0xF0); - r -= 16; - /* Emit buffered correction bits that must be associated with ZRL */ - emit_buffered_bits(entropy, BR_buffer, BR); - BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ - BR = 0; - } - - /* If the coef was previously nonzero, it only needs a correction bit. - * NOTE: a straight translation of the spec's figure G.7 would suggest - * that we also need to test r > 15. But if r > 15, we can only get here - * if k > EOB, which implies that this coefficient is not 1. - */ - if (temp > 1) { - /* The correction bit is the next bit of the absolute value. */ - BR_buffer[BR++] = (char) (temp & 1); - continue; - } - - /* Emit any pending EOBRUN and the BE correction bits */ - emit_eobrun(entropy); - - /* Count/emit Huffman symbol for run length / number of bits */ - emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + 1); - - /* Emit output bit for newly-nonzero coef */ - temp = ((*block)[jpeg_natural_order[k]] < 0) ? 0 : 1; - emit_bits(entropy, (unsigned int) temp, 1); - - /* Emit buffered correction bits that must be associated with this code */ - emit_buffered_bits(entropy, BR_buffer, BR); - BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ - BR = 0; - r = 0; /* reset zero run length */ - } - - if (r > 0 || BR > 0) { /* If there are trailing zeroes, */ - entropy->EOBRUN++; /* count an EOB */ - entropy->BE += BR; /* concat my correction bits to older ones */ - /* We force out the EOB if we risk either: - * 1. overflow of the EOB counter; - * 2. overflow of the correction bit buffer during the next MCU. - */ - if (entropy->EOBRUN == 0x7FFF || entropy->BE > (MAX_CORR_BITS-DCTSIZE2+1)) - emit_eobrun(entropy); - } - - cinfo->dest->next_output_byte = entropy->next_output_byte; - cinfo->dest->free_in_buffer = entropy->free_in_buffer; - - /* Update restart-interval state too */ - if (cinfo->restart_interval) { - if (entropy->restarts_to_go == 0) { - entropy->restarts_to_go = cinfo->restart_interval; - entropy->next_restart_num++; - entropy->next_restart_num &= 7; - } - entropy->restarts_to_go--; - } - - return TRUE; -} - - -/* - * Finish up at the end of a Huffman-compressed progressive scan. - */ - -METHODDEF(void) -finish_pass_phuff (j_compress_ptr cinfo) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - - entropy->next_output_byte = cinfo->dest->next_output_byte; - entropy->free_in_buffer = cinfo->dest->free_in_buffer; - - /* Flush out any buffered data */ - emit_eobrun(entropy); - flush_bits(entropy); - - cinfo->dest->next_output_byte = entropy->next_output_byte; - cinfo->dest->free_in_buffer = entropy->free_in_buffer; -} - - -/* - * Finish up a statistics-gathering pass and create the new Huffman tables. - */ - -METHODDEF(void) -finish_pass_gather_phuff (j_compress_ptr cinfo) -{ - phuff_entropy_ptr entropy = (phuff_entropy_ptr) cinfo->entropy; - boolean is_DC_band; - int ci, tbl; - jpeg_component_info * compptr; - JHUFF_TBL **htblptr; - boolean did[NUM_HUFF_TBLS]; - - /* Flush out buffered data (all we care about is counting the EOB symbol) */ - emit_eobrun(entropy); - - is_DC_band = (cinfo->Ss == 0); - - /* It's important not to apply jpeg_gen_optimal_table more than once - * per table, because it clobbers the input frequency counts! - */ - MEMZERO(did, SIZEOF(did)); - - for (ci = 0; ci < cinfo->comps_in_scan; ci++) { - compptr = cinfo->cur_comp_info[ci]; - if (is_DC_band) { - if (cinfo->Ah != 0) /* DC refinement needs no table */ - continue; - tbl = compptr->dc_tbl_no; - } else { - tbl = compptr->ac_tbl_no; - } - if (! did[tbl]) { - if (is_DC_band) - htblptr = & cinfo->dc_huff_tbl_ptrs[tbl]; - else - htblptr = & cinfo->ac_huff_tbl_ptrs[tbl]; - if (*htblptr == NULL) - *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo); - jpeg_gen_optimal_table(cinfo, *htblptr, entropy->count_ptrs[tbl]); - did[tbl] = TRUE; - } - } -} - - -/* - * Module initialization routine for progressive Huffman entropy encoding. - */ - -GLOBAL(void) -jinit_phuff_encoder (j_compress_ptr cinfo) -{ - phuff_entropy_ptr entropy; - int i; - - entropy = (phuff_entropy_ptr) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - SIZEOF(phuff_entropy_encoder)); - cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; - entropy->pub.start_pass = start_pass_phuff; - - /* Mark tables unallocated */ - for (i = 0; i < NUM_HUFF_TBLS; i++) { - entropy->derived_tbls[i] = NULL; - entropy->count_ptrs[i] = NULL; - } - entropy->bit_buffer = NULL; /* needed only in AC refinement scan */ -} - -#endif /* C_PROGRESSIVE_SUPPORTED */ diff --git a/src/libjpeg/jdarith.c b/src/libjpeg/jdarith.c new file mode 100644 index 0000000..702950f --- /dev/null +++ b/src/libjpeg/jdarith.c @@ -0,0 +1,762 @@ +/* + * jdarith.c + * + * Developed 1997 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]; +} 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. + * Note that we use one additional AC bin for codings with fixed + * probability (0.5), thus the minimum number for AC is 246. + * + * 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) +{ + extern const INT32 jaritab[]; + 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.2: + * Qe values and probability estimation state machine + */ + sv = *st; + qe = jaritab[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); + + for (ci = 0; ci < cinfo->comps_in_scan; ci++) { + compptr = cinfo->cur_comp_info[ci]; + /* Re-initialize statistics areas */ + if (cinfo->progressive_mode == 0 || (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 == 0 || 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) (((INT32) 1 << cinfo->arith_dc_L[tbl]) >> 1)) + entropy->dc_context[ci] = 0; /* zero diff category */ + else if (m > (int) (((INT32) 1 << 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; + + /* 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 */ + + /* 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 */ + entropy->ac_stats[tbl][245] = 0; + sign = arith_decode(cinfo, entropy->ac_stats[tbl] + 245); + 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)[jpeg_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[4]; + 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--; + } + + 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++) { + st[0] = 0; /* use fixed probability estimation */ + /* 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; + + /* 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 */ + + /* 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 + 1; kex > 1; kex--) + if ((*block)[jpeg_natural_order[kex - 1]]) 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 + jpeg_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 */ + entropy->ac_stats[tbl][245] = 0; + if (arith_decode(cinfo, entropy->ac_stats[tbl] + 245)) + *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; + + /* 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]; + 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) (((INT32) 1 << cinfo->arith_dc_L[tbl]) >> 1)) + entropy->dc_context[ci] = 0; /* zero diff category */ + else if (m > (int) (((INT32) 1 << 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 */ + + tbl = compptr->ac_tbl_no; + + /* Figure F.20: Decode_AC_coefficients */ + for (k = 1; k < DCTSIZE2; 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 >= DCTSIZE2) { + 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 */ + entropy->ac_stats[tbl][245] = 0; + sign = arith_decode(cinfo, entropy->ac_stats[tbl] + 245); + 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)[jpeg_natural_order[k]] = (JCOEF) v; + } + } + + 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 >= DCTSIZE2) + 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 because + * there are some baseline files out there with all zeroes in these bytes. + */ + if (cinfo->Ss != 0 || cinfo->Se != DCTSIZE2-1 || + cinfo->Ah != 0 || cinfo->Al != 0) + WARNMS(cinfo, JWRN_NOT_SEQUENTIAL); + /* Select MCU decoding routine */ + entropy->pub.decode_mcu = decode_mcu; + } + + for (ci = 0; ci < cinfo->comps_in_scan; ci++) { + compptr = cinfo->cur_comp_info[ci]; + /* Allocate & initialize requested statistics areas */ + if (cinfo->progressive_mode == 0 || (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 == 0 || 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; + } + + 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; + } +} diff --git a/src/libjpeg/jdhuff.h b/src/libjpeg/jdhuff.h deleted file mode 100644 index ae19b6c..0000000 --- a/src/libjpeg/jdhuff.h +++ /dev/null @@ -1,201 +0,0 @@ -/* - * jdhuff.h - * - * Copyright (C) 1991-1997, 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 declarations for Huffman entropy decoding routines - * that are shared between the sequential decoder (jdhuff.c) and the - * progressive decoder (jdphuff.c). No other modules need to see these. - */ - -/* Short forms of external names for systems with brain-damaged linkers. */ - -#ifdef NEED_SHORT_EXTERNAL_NAMES -#define jpeg_make_d_derived_tbl jMkDDerived -#define jpeg_fill_bit_buffer jFilBitBuf -#define jpeg_huff_decode jHufDecode -#endif /* NEED_SHORT_EXTERNAL_NAMES */ - - -/* Derived data constructed for each Huffman table */ - -#define HUFF_LOOKAHEAD 8 /* # of bits of lookahead */ - -typedef struct { - /* Basic tables: (element [0] of each array is unused) */ - INT32 maxcode[18]; /* largest code of length k (-1 if none) */ - /* (maxcode[17] is a sentinel to ensure jpeg_huff_decode terminates) */ - INT32 valoffset[17]; /* huffval[] offset for codes of length k */ - /* valoffset[k] = huffval[] index of 1st symbol of code length k, less - * the smallest code of length k; so given a code of length k, the - * corresponding symbol is huffval[code + valoffset[k]] - */ - - /* Link to public Huffman table (needed only in jpeg_huff_decode) */ - JHUFF_TBL *pub; - - /* Lookahead tables: indexed by the next HUFF_LOOKAHEAD bits of - * the input data stream. If the next Huffman code is no more - * than HUFF_LOOKAHEAD bits long, we can obtain its length and - * the corresponding symbol directly from these tables. - */ - int look_nbits[1<<HUFF_LOOKAHEAD]; /* # bits, or 0 if too long */ - UINT8 look_sym[1<<HUFF_LOOKAHEAD]; /* symbol, or unused */ -} d_derived_tbl; - -/* Expand a Huffman table definition into the derived format */ -EXTERN(void) jpeg_make_d_derived_tbl - JPP((j_decompress_ptr cinfo, boolean isDC, int tblno, - d_derived_tbl ** pdtbl)); - - -/* - * Fetching the next N bits from the input stream is a time-critical operation - * for the Huffman decoders. We implement it with a combination of inline - * macros and out-of-line subroutines. Note that N (the number of bits - * demanded at one time) never exceeds 15 for JPEG use. - * - * We read source bytes into get_buffer and dole out bits as needed. - * If get_buffer already contains enough bits, they are fetched in-line - * by the macros CHECK_BIT_BUFFER and GET_BITS. When there aren't enough - * bits, jpeg_fill_bit_buffer is called; it will attempt to fill get_buffer - * as full as possible (not just to the number of bits needed; this - * prefetching reduces the overhead cost of calling jpeg_fill_bit_buffer). - * Note that jpeg_fill_bit_buffer may return FALSE to indicate suspension. - * On TRUE return, jpeg_fill_bit_buffer guarantees that get_buffer contains - * at least the requested number of bits --- dummy zeroes are inserted if - * necessary. - */ - -typedef INT32 bit_buf_type; /* type of bit-extraction buffer */ -#define BIT_BUF_SIZE 32 /* size of buffer in bits */ - -/* If long is > 32 bits on your machine, and shifting/masking longs is - * reasonably fast, making bit_buf_type be long and setting BIT_BUF_SIZE - * appropriately should be a win. Unfortunately we can't define the size - * with something like #define BIT_BUF_SIZE (sizeof(bit_buf_type)*8) - * because not all machines measure sizeof in 8-bit bytes. - */ - -typedef struct { /* Bitreading state saved across MCUs */ - bit_buf_type get_buffer; /* current bit-extraction buffer */ - int bits_left; /* # of unused bits in it */ -} bitread_perm_state; - -typedef struct { /* Bitreading working state within an MCU */ - /* Current data source location */ - /* We need a copy, rather than munging the original, in case of suspension */ - const JOCTET * next_input_byte; /* => next byte to read from source */ - size_t bytes_in_buffer; /* # of bytes remaining in source buffer */ - /* Bit input buffer --- note these values are kept in register variables, - * not in this struct, inside the inner loops. - */ - bit_buf_type get_buffer; /* current bit-extraction buffer */ - int bits_left; /* # of unused bits in it */ - /* Pointer needed by jpeg_fill_bit_buffer. */ - j_decompress_ptr cinfo; /* back link to decompress master record */ -} bitread_working_state; - -/* Macros to declare and load/save bitread local variables. */ -#define BITREAD_STATE_VARS \ - register bit_buf_type get_buffer; \ - register int bits_left; \ - bitread_working_state br_state - -#define BITREAD_LOAD_STATE(cinfop,permstate) \ - br_state.cinfo = cinfop; \ - br_state.next_input_byte = cinfop->src->next_input_byte; \ - br_state.bytes_in_buffer = cinfop->src->bytes_in_buffer; \ - get_buffer = permstate.get_buffer; \ - bits_left = permstate.bits_left; - -#define BITREAD_SAVE_STATE(cinfop,permstate) \ - cinfop->src->next_input_byte = br_state.next_input_byte; \ - cinfop->src->bytes_in_buffer = br_state.bytes_in_buffer; \ - permstate.get_buffer = get_buffer; \ - permstate.bits_left = bits_left - -/* - * These macros provide the in-line portion of bit fetching. - * Use CHECK_BIT_BUFFER to ensure there are N bits in get_buffer - * before using GET_BITS, PEEK_BITS, or DROP_BITS. - * The variables get_buffer and bits_left are assumed to be locals, - * but the state struct might not be (jpeg_huff_decode needs this). - * CHECK_BIT_BUFFER(state,n,action); - * Ensure there are N bits in get_buffer; if suspend, take action. - * val = GET_BITS(n); - * Fetch next N bits. - * val = PEEK_BITS(n); - * Fetch next N bits without removing them from the buffer. - * DROP_BITS(n); - * Discard next N bits. - * The value N should be a simple variable, not an expression, because it - * is evaluated multiple times. - */ - -#define CHECK_BIT_BUFFER(state,nbits,action) \ - { if (bits_left < (nbits)) { \ - if (! jpeg_fill_bit_buffer(&(state),get_buffer,bits_left,nbits)) \ - { action; } \ - get_buffer = (state).get_buffer; bits_left = (state).bits_left; } } - -#define GET_BITS(nbits) \ - (((int) (get_buffer >> (bits_left -= (nbits)))) & ((1<<(nbits))-1)) - -#define PEEK_BITS(nbits) \ - (((int) (get_buffer >> (bits_left - (nbits)))) & ((1<<(nbits))-1)) - -#define DROP_BITS(nbits) \ - (bits_left -= (nbits)) - -/* Load up the bit buffer to a depth of at least nbits */ -EXTERN(boolean) jpeg_fill_bit_buffer - JPP((bitread_working_state * state, register bit_buf_type get_buffer, - register int bits_left, int nbits)); - - -/* - * Code for extracting next Huffman-coded symbol from input bit stream. - * Again, this is time-critical and we make the main paths be macros. - * - * We use a lookahead table to process codes of up to HUFF_LOOKAHEAD bits - * without looping. Usually, more than 95% of the Huffman codes will be 8 - * or fewer bits long. The few overlength codes are handled with a loop, - * which need not be inline code. - * - * Notes about the HUFF_DECODE macro: - * 1. Near the end of the data segment, we may fail to get enough bits - * for a lookahead. In that case, we do it the hard way. - * 2. If the lookahead table contains no entry, the next code must be - * more than HUFF_LOOKAHEAD bits long. - * 3. jpeg_huff_decode returns -1 if forced to suspend. - */ - -#define HUFF_DECODE(result,state,htbl,failaction,slowlabel) \ -{ register int nb, look; \ - if (bits_left < HUFF_LOOKAHEAD) { \ - if (! jpeg_fill_bit_buffer(&state,get_buffer,bits_left, 0)) {failaction;} \ - get_buffer = state.get_buffer; bits_left = state.bits_left; \ - if (bits_left < HUFF_LOOKAHEAD) { \ - nb = 1; goto slowlabel; \ - } \ - } \ - look = PEEK_BITS(HUFF_LOOKAHEAD); \ - if ((nb = htbl->look_nbits[look]) != 0) { \ - DROP_BITS(nb); \ - result = htbl->look_sym[look]; \ - } else { \ - nb = HUFF_LOOKAHEAD+1; \ -slowlabel: \ - if ((result=jpeg_huff_decode(&state,get_buffer,bits_left,htbl,nb)) < 0) \ - { failaction; } \ - get_buffer = state.get_buffer; bits_left = state.bits_left; \ - } \ -} - -/* Out-of-line case for Huffman code fetching */ -EXTERN(int) jpeg_huff_decode - JPP((bitread_working_state * state, register bit_buf_type get_buffer, - register int bits_left, d_derived_tbl * htbl, int min_bits)); diff --git a/src/libjpeg/jdphuff.c b/src/libjpeg/jdphuff.c deleted file mode 100644 index 2267809..0000000 --- a/src/libjpeg/jdphuff.c +++ /dev/null @@ -1,668 +0,0 @@ -/* - * 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 */ diff --git a/src/libjpeg/jidctred.c b/src/libjpeg/jidctred.c deleted file mode 100644 index 421f3c7..0000000 --- a/src/libjpeg/jidctred.c +++ /dev/null @@ -1,398 +0,0 @@ -/* - * jidctred.c - * - * Copyright (C) 1994-1998, 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 inverse-DCT routines that produce reduced-size output: - * either 4x4, 2x2, or 1x1 pixels from an 8x8 DCT block. - * - * The implementation is based on the Loeffler, Ligtenberg and Moschytz (LL&M) - * algorithm used in jidctint.c. We simply replace each 8-to-8 1-D IDCT step - * with an 8-to-4 step that produces the four averages of two adjacent outputs - * (or an 8-to-2 step producing two averages of four outputs, for 2x2 output). - * These steps were derived by computing the corresponding values at the end - * of the normal LL&M code, then simplifying as much as possible. - * - * 1x1 is trivial: just take the DC coefficient divided by 8. - * - * See jidctint.c for additional comments. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" -#include "jdct.h" /* Private declarations for DCT subsystem */ - -#ifdef IDCT_SCALING_SUPPORTED - - -/* - * This module is specialized to the case DCTSIZE = 8. - */ - -#if DCTSIZE != 8 - Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */ -#endif - - -/* Scaling is the same as in jidctint.c. */ - -#if BITS_IN_JSAMPLE == 8 -#define CONST_BITS 13 -#define PASS1_BITS 2 -#else -#define CONST_BITS 13 -#define PASS1_BITS 1 /* lose a little precision to avoid overflow */ -#endif - -/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus - * causing a lot of useless floating-point operations at run time. - * To get around this we use the following pre-calculated constants. - * If you change CONST_BITS you may want to add appropriate values. - * (With a reasonable C compiler, you can just rely on the FIX() macro...) - */ - -#if CONST_BITS == 13 -#define FIX_0_211164243 ((INT32) 1730) /* FIX(0.211164243) */ -#define FIX_0_509795579 ((INT32) 4176) /* FIX(0.509795579) */ -#define FIX_0_601344887 ((INT32) 4926) /* FIX(0.601344887) */ -#define FIX_0_720959822 ((INT32) 5906) /* FIX(0.720959822) */ -#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */ -#define FIX_0_850430095 ((INT32) 6967) /* FIX(0.850430095) */ -#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */ -#define FIX_1_061594337 ((INT32) 8697) /* FIX(1.061594337) */ -#define FIX_1_272758580 ((INT32) 10426) /* FIX(1.272758580) */ -#define FIX_1_451774981 ((INT32) 11893) /* FIX(1.451774981) */ -#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */ -#define FIX_2_172734803 ((INT32) 17799) /* FIX(2.172734803) */ -#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */ -#define FIX_3_624509785 ((INT32) 29692) /* FIX(3.624509785) */ -#else -#define FIX_0_211164243 FIX(0.211164243) -#define FIX_0_509795579 FIX(0.509795579) -#define FIX_0_601344887 FIX(0.601344887) -#define FIX_0_720959822 FIX(0.720959822) -#define FIX_0_765366865 FIX(0.765366865) -#define FIX_0_850430095 FIX(0.850430095) -#define FIX_0_899976223 FIX(0.899976223) -#define FIX_1_061594337 FIX(1.061594337) -#define FIX_1_272758580 FIX(1.272758580) -#define FIX_1_451774981 FIX(1.451774981) -#define FIX_1_847759065 FIX(1.847759065) -#define FIX_2_172734803 FIX(2.172734803) -#define FIX_2_562915447 FIX(2.562915447) -#define FIX_3_624509785 FIX(3.624509785) -#endif - - -/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result. - * For 8-bit samples with the recommended scaling, all the variable - * and constant values involved are no more than 16 bits wide, so a - * 16x16->32 bit multiply can be used instead of a full 32x32 multiply. - * For 12-bit samples, a full 32-bit multiplication will be needed. - */ - -#if BITS_IN_JSAMPLE == 8 -#define MULTIPLY(var,const) MULTIPLY16C16(var,const) -#else -#define MULTIPLY(var,const) ((var) * (const)) -#endif - - -/* Dequantize a coefficient by multiplying it by the multiplier-table - * entry; produce an int result. In this module, both inputs and result - * are 16 bits or less, so either int or short multiply will work. - */ - -#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval)) - - -/* - * Perform dequantization and inverse DCT on one block of coefficients, - * producing a reduced-size 4x4 output block. - */ - -GLOBAL(void) -jpeg_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JCOEFPTR coef_block, - JSAMPARRAY output_buf, JDIMENSION output_col) -{ - INT32 tmp0, tmp2, tmp10, tmp12; - INT32 z1, z2, z3, z4; - JCOEFPTR inptr; - ISLOW_MULT_TYPE * quantptr; - int * wsptr; - JSAMPROW outptr; - JSAMPLE *range_limit = IDCT_range_limit(cinfo); - int ctr; - int workspace[DCTSIZE*4]; /* buffers data between passes */ - SHIFT_TEMPS - - /* Pass 1: process columns from input, store into work array. */ - - inptr = coef_block; - quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; - wsptr = workspace; - for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) { - /* Don't bother to process column 4, because second pass won't use it */ - if (ctr == DCTSIZE-4) - continue; - if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && - inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*5] == 0 && - inptr[DCTSIZE*6] == 0 && inptr[DCTSIZE*7] == 0) { - /* AC terms all zero; we need not examine term 4 for 4x4 output */ - int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; - - wsptr[DCTSIZE*0] = dcval; - wsptr[DCTSIZE*1] = dcval; - wsptr[DCTSIZE*2] = dcval; - wsptr[DCTSIZE*3] = dcval; - - continue; - } - - /* Even part */ - - tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); - tmp0 <<= (CONST_BITS+1); - - z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); - z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); - - tmp2 = MULTIPLY(z2, FIX_1_847759065) + MULTIPLY(z3, - FIX_0_765366865); - - tmp10 = tmp0 + tmp2; - tmp12 = tmp0 - tmp2; - - /* Odd part */ - - z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); - z2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); - z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); - z4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); - - tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */ - + MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */ - + MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */ - + MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */ - - tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */ - + MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */ - + MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */ - + MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */ - - /* Final output stage */ - - wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp2, CONST_BITS-PASS1_BITS+1); - wsptr[DCTSIZE*3] = (int) DESCALE(tmp10 - tmp2, CONST_BITS-PASS1_BITS+1); - wsptr[DCTSIZE*1] = (int) DESCALE(tmp12 + tmp0, CONST_BITS-PASS1_BITS+1); - wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 - tmp0, CONST_BITS-PASS1_BITS+1); - } - - /* Pass 2: process 4 rows from work array, store into output array. */ - - wsptr = workspace; - for (ctr = 0; ctr < 4; ctr++) { - outptr = output_buf[ctr] + output_col; - /* It's not clear whether a zero row test is worthwhile here ... */ - -#ifndef NO_ZERO_ROW_TEST - if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && - wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) { - /* AC terms all zero */ - JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3) - & RANGE_MASK]; - - outptr[0] = dcval; - outptr[1] = dcval; - outptr[2] = dcval; - outptr[3] = dcval; - - wsptr += DCTSIZE; /* advance pointer to next row */ - continue; - } -#endif - - /* Even part */ - - tmp0 = ((INT32) wsptr[0]) << (CONST_BITS+1); - - tmp2 = MULTIPLY((INT32) wsptr[2], FIX_1_847759065) - + MULTIPLY((INT32) wsptr[6], - FIX_0_765366865); - - tmp10 = tmp0 + tmp2; - tmp12 = tmp0 - tmp2; - - /* Odd part */ - - z1 = (INT32) wsptr[7]; - z2 = (INT32) wsptr[5]; - z3 = (INT32) wsptr[3]; - z4 = (INT32) wsptr[1]; - - tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */ - + MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */ - + MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */ - + MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */ - - tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */ - + MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */ - + MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */ - + MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */ - - /* Final output stage */ - - outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp2, - CONST_BITS+PASS1_BITS+3+1) - & RANGE_MASK]; - outptr[3] = range_limit[(int) DESCALE(tmp10 - tmp2, - CONST_BITS+PASS1_BITS+3+1) - & RANGE_MASK]; - outptr[1] = range_limit[(int) DESCALE(tmp12 + tmp0, - CONST_BITS+PASS1_BITS+3+1) - & RANGE_MASK]; - outptr[2] = range_limit[(int) DESCALE(tmp12 - tmp0, - CONST_BITS+PASS1_BITS+3+1) - & RANGE_MASK]; - - wsptr += DCTSIZE; /* advance pointer to next row */ - } -} - - -/* - * Perform dequantization and inverse DCT on one block of coefficients, - * producing a reduced-size 2x2 output block. - */ - -GLOBAL(void) -jpeg_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JCOEFPTR coef_block, - JSAMPARRAY output_buf, JDIMENSION output_col) -{ - INT32 tmp0, tmp10, z1; - JCOEFPTR inptr; - ISLOW_MULT_TYPE * quantptr; - int * wsptr; - JSAMPROW outptr; - JSAMPLE *range_limit = IDCT_range_limit(cinfo); - int ctr; - int workspace[DCTSIZE*2]; /* buffers data between passes */ - SHIFT_TEMPS - - /* Pass 1: process columns from input, store into work array. */ - - inptr = coef_block; - quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; - wsptr = workspace; - for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) { - /* Don't bother to process columns 2,4,6 */ - if (ctr == DCTSIZE-2 || ctr == DCTSIZE-4 || ctr == DCTSIZE-6) - continue; - if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*3] == 0 && - inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*7] == 0) { - /* AC terms all zero; we need not examine terms 2,4,6 for 2x2 output */ - int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; - - wsptr[DCTSIZE*0] = dcval; - wsptr[DCTSIZE*1] = dcval; - - continue; - } - - /* Even part */ - - z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); - tmp10 = z1 << (CONST_BITS+2); - - /* Odd part */ - - z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); - tmp0 = MULTIPLY(z1, - FIX_0_720959822); /* sqrt(2) * (c7-c5+c3-c1) */ - z1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); - tmp0 += MULTIPLY(z1, FIX_0_850430095); /* sqrt(2) * (-c1+c3+c5+c7) */ - z1 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); - tmp0 += MULTIPLY(z1, - FIX_1_272758580); /* sqrt(2) * (-c1+c3-c5-c7) */ - z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); - tmp0 += MULTIPLY(z1, FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */ - - /* Final output stage */ - - wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp0, CONST_BITS-PASS1_BITS+2); - wsptr[DCTSIZE*1] = (int) DESCALE(tmp10 - tmp0, CONST_BITS-PASS1_BITS+2); - } - - /* Pass 2: process 2 rows from work array, store into output array. */ - - wsptr = workspace; - for (ctr = 0; ctr < 2; ctr++) { - outptr = output_buf[ctr] + output_col; - /* It's not clear whether a zero row test is worthwhile here ... */ - -#ifndef NO_ZERO_ROW_TEST - if (wsptr[1] == 0 && wsptr[3] == 0 && wsptr[5] == 0 && wsptr[7] == 0) { - /* AC terms all zero */ - JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3) - & RANGE_MASK]; - - outptr[0] = dcval; - outptr[1] = dcval; - - wsptr += DCTSIZE; /* advance pointer to next row */ - continue; - } -#endif - - /* Even part */ - - tmp10 = ((INT32) wsptr[0]) << (CONST_BITS+2); - - /* Odd part */ - - tmp0 = MULTIPLY((INT32) wsptr[7], - FIX_0_720959822) /* sqrt(2) * (c7-c5+c3-c1) */ - + MULTIPLY((INT32) wsptr[5], FIX_0_850430095) /* sqrt(2) * (-c1+c3+c5+c7) */ - + MULTIPLY((INT32) wsptr[3], - FIX_1_272758580) /* sqrt(2) * (-c1+c3-c5-c7) */ - + MULTIPLY((INT32) wsptr[1], FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */ - - /* Final output stage */ - - outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp0, - CONST_BITS+PASS1_BITS+3+2) - & RANGE_MASK]; - outptr[1] = range_limit[(int) DESCALE(tmp10 - tmp0, - CONST_BITS+PASS1_BITS+3+2) - & RANGE_MASK]; - - wsptr += DCTSIZE; /* advance pointer to next row */ - } -} - - -/* - * Perform dequantization and inverse DCT on one block of coefficients, - * producing a reduced-size 1x1 output block. - */ - -GLOBAL(void) -jpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, - JCOEFPTR coef_block, - JSAMPARRAY output_buf, JDIMENSION output_col) -{ - int dcval; - ISLOW_MULT_TYPE * quantptr; - JSAMPLE *range_limit = IDCT_range_limit(cinfo); - SHIFT_TEMPS - - /* We hardly need an inverse DCT routine for this: just take the - * average pixel value, which is one-eighth of the DC coefficient. - */ - quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; - dcval = DEQUANTIZE(coef_block[0], quantptr[0]); - dcval = (int) DESCALE((INT32) dcval, 3); - - output_buf[0][output_col] = range_limit[dcval & RANGE_MASK]; -} - -#endif /* IDCT_SCALING_SUPPORTED */ |