Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * jchuff.c |
| 3 | * |
DRC | a73e870 | 2012-12-31 02:52:30 +0000 | [diff] [blame] | 4 | * This file was part of the Independent JPEG Group's software: |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 5 | * Copyright (C) 1991-1997, Thomas G. Lane. |
DRC | a6ef282 | 2013-09-28 03:23:49 +0000 | [diff] [blame] | 6 | * libjpeg-turbo Modifications: |
DRC | 6399d0a | 2019-04-23 14:10:04 -0500 | [diff] [blame] | 7 | * Copyright (C) 2009-2011, 2014-2016, 2018-2019, D. R. Commander. |
DRC | 123f725 | 2016-05-24 10:23:56 -0500 | [diff] [blame] | 8 | * Copyright (C) 2015, Matthieu Darbois. |
DRC | 7e3acc0 | 2015-10-10 10:25:46 -0500 | [diff] [blame] | 9 | * For conditions of distribution and use, see the accompanying README.ijg |
| 10 | * file. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 11 | * |
| 12 | * This file contains Huffman entropy encoding routines. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 13 | * |
| 14 | * Much of the complexity here has to do with supporting output suspension. |
| 15 | * If the data destination module demands suspension, we want to be able to |
| 16 | * back up to the start of the current MCU. To do this, we copy state |
| 17 | * variables into local working storage, and update them back to the |
| 18 | * permanent JPEG objects only upon successful completion of an MCU. |
DRC | a628952 | 2018-07-24 18:36:51 -0500 | [diff] [blame] | 19 | * |
| 20 | * NOTE: All referenced figures are from |
| 21 | * Recommendation ITU-T T.81 (1992) | ISO/IEC 10918-1:1994. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 22 | */ |
| 23 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 24 | #define JPEG_INTERNALS |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 25 | #include "jinclude.h" |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 26 | #include "jpeglib.h" |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 27 | #include "jsimd.h" |
DRC | 5a3b4fe | 2016-01-06 19:17:54 -0600 | [diff] [blame] | 28 | #include "jconfigint.h" |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 29 | #include <limits.h> |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 30 | |
DRC | 0cfc4c1 | 2014-03-28 18:33:25 +0000 | [diff] [blame] | 31 | /* |
| 32 | * NOTE: If USE_CLZ_INTRINSIC is defined, then clz/bsr instructions will be |
| 33 | * used for bit counting rather than the lookup table. This will reduce the |
| 34 | * memory footprint by 64k, which is important for some mobile applications |
| 35 | * that create many isolated instances of libjpeg-turbo (web browsers, for |
| 36 | * instance.) This may improve performance on some mobile platforms as well. |
| 37 | * This feature is enabled by default only on ARM processors, because some x86 |
| 38 | * chips have a slow implementation of bsr, and the use of clz/bsr cannot be |
| 39 | * shown to have a significant performance impact even on the x86 chips that |
| 40 | * have a fast implementation of it. When building for ARMv6, you can |
| 41 | * explicitly disable the use of clz/bsr by adding -mthumb to the compiler |
| 42 | * flags (this defines __thumb__). |
| 43 | */ |
| 44 | |
| 45 | /* NOTE: Both GCC and Clang define __GNUC__ */ |
DRC | 803b5d2 | 2014-11-18 15:56:43 +0000 | [diff] [blame] | 46 | #if defined __GNUC__ && (defined __arm__ || defined __aarch64__) |
DRC | 0cfc4c1 | 2014-03-28 18:33:25 +0000 | [diff] [blame] | 47 | #if !defined __thumb__ || defined __thumb2__ |
| 48 | #define USE_CLZ_INTRINSIC |
| 49 | #endif |
| 50 | #endif |
| 51 | |
| 52 | #ifdef USE_CLZ_INTRINSIC |
DRC | 293263c | 2018-03-17 15:14:35 -0500 | [diff] [blame] | 53 | #define JPEG_NBITS_NONZERO(x) (32 - __builtin_clz(x)) |
| 54 | #define JPEG_NBITS(x) (x ? JPEG_NBITS_NONZERO(x) : 0) |
DRC | 0cfc4c1 | 2014-03-28 18:33:25 +0000 | [diff] [blame] | 55 | #else |
DRC | ef9a4e0 | 2014-03-28 18:50:30 +0000 | [diff] [blame] | 56 | #include "jpeg_nbits_table.h" |
DRC | 293263c | 2018-03-17 15:14:35 -0500 | [diff] [blame] | 57 | #define JPEG_NBITS(x) (jpeg_nbits_table[x]) |
| 58 | #define JPEG_NBITS_NONZERO(x) JPEG_NBITS(x) |
DRC | 0cfc4c1 | 2014-03-28 18:33:25 +0000 | [diff] [blame] | 59 | #endif |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 60 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 61 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 62 | /* Expanded entropy encoder object for Huffman encoding. |
| 63 | * |
| 64 | * The savable_state subrecord contains fields that change within an MCU, |
| 65 | * but must not be updated permanently until we complete the MCU. |
| 66 | */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 67 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 68 | typedef struct { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 69 | size_t put_buffer; /* current bit-accumulation buffer */ |
| 70 | int put_bits; /* # of bits now in it */ |
| 71 | int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 72 | } savable_state; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 73 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 74 | /* This macro is to work around compilers with missing or broken |
| 75 | * structure assignment. You'll need to fix this code if you have |
| 76 | * such a compiler and you change MAX_COMPS_IN_SCAN. |
| 77 | */ |
| 78 | |
| 79 | #ifndef NO_STRUCT_ASSIGN |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 80 | #define ASSIGN_STATE(dest, src) ((dest) = (src)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 81 | #else |
| 82 | #if MAX_COMPS_IN_SCAN == 4 |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 83 | #define ASSIGN_STATE(dest, src) \ |
| 84 | ((dest).put_buffer = (src).put_buffer, \ |
| 85 | (dest).put_bits = (src).put_bits, \ |
| 86 | (dest).last_dc_val[0] = (src).last_dc_val[0], \ |
| 87 | (dest).last_dc_val[1] = (src).last_dc_val[1], \ |
| 88 | (dest).last_dc_val[2] = (src).last_dc_val[2], \ |
| 89 | (dest).last_dc_val[3] = (src).last_dc_val[3]) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 90 | #endif |
| 91 | #endif |
| 92 | |
| 93 | |
| 94 | typedef struct { |
| 95 | struct jpeg_entropy_encoder pub; /* public fields */ |
| 96 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 97 | savable_state saved; /* Bit buffer & DC state at start of MCU */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 98 | |
| 99 | /* These fields are NOT loaded into local working state. */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 100 | unsigned int restarts_to_go; /* MCUs left in this restart interval */ |
| 101 | int next_restart_num; /* next restart number to write (0-7) */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 102 | |
| 103 | /* Pointers to derived tables (these workspaces have image lifespan) */ |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 104 | c_derived_tbl *dc_derived_tbls[NUM_HUFF_TBLS]; |
| 105 | c_derived_tbl *ac_derived_tbls[NUM_HUFF_TBLS]; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 106 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 107 | #ifdef ENTROPY_OPT_SUPPORTED /* Statistics tables for optimization */ |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 108 | long *dc_count_ptrs[NUM_HUFF_TBLS]; |
| 109 | long *ac_count_ptrs[NUM_HUFF_TBLS]; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 110 | #endif |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 111 | |
| 112 | int simd; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 113 | } huff_entropy_encoder; |
| 114 | |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 115 | typedef huff_entropy_encoder *huff_entropy_ptr; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 116 | |
| 117 | /* Working state while writing an MCU. |
| 118 | * This struct contains all the fields that are needed by subroutines. |
| 119 | */ |
| 120 | |
| 121 | typedef struct { |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 122 | JOCTET *next_output_byte; /* => next byte to write in buffer */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 123 | size_t free_in_buffer; /* # of byte spaces remaining in buffer */ |
| 124 | savable_state cur; /* Current bit buffer & DC state */ |
| 125 | j_compress_ptr cinfo; /* dump_buffer needs access to this */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 126 | } working_state; |
| 127 | |
| 128 | |
| 129 | /* Forward declarations */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 130 | METHODDEF(boolean) encode_mcu_huff(j_compress_ptr cinfo, JBLOCKROW *MCU_data); |
| 131 | METHODDEF(void) finish_pass_huff(j_compress_ptr cinfo); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 132 | #ifdef ENTROPY_OPT_SUPPORTED |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 133 | METHODDEF(boolean) encode_mcu_gather(j_compress_ptr cinfo, |
| 134 | JBLOCKROW *MCU_data); |
| 135 | METHODDEF(void) finish_pass_gather(j_compress_ptr cinfo); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 136 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 137 | |
| 138 | |
| 139 | /* |
| 140 | * Initialize for a Huffman-compressed scan. |
| 141 | * If gather_statistics is TRUE, we do not output anything during the scan, |
| 142 | * just count the Huffman symbols used and generate Huffman code tables. |
| 143 | */ |
| 144 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 145 | METHODDEF(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 146 | start_pass_huff(j_compress_ptr cinfo, boolean gather_statistics) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 147 | { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 148 | huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 149 | int ci, dctbl, actbl; |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 150 | jpeg_component_info *compptr; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 151 | |
| 152 | if (gather_statistics) { |
| 153 | #ifdef ENTROPY_OPT_SUPPORTED |
| 154 | entropy->pub.encode_mcu = encode_mcu_gather; |
| 155 | entropy->pub.finish_pass = finish_pass_gather; |
| 156 | #else |
| 157 | ERREXIT(cinfo, JERR_NOT_COMPILED); |
| 158 | #endif |
| 159 | } else { |
| 160 | entropy->pub.encode_mcu = encode_mcu_huff; |
| 161 | entropy->pub.finish_pass = finish_pass_huff; |
| 162 | } |
| 163 | |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 164 | entropy->simd = jsimd_can_huff_encode_one_block(); |
| 165 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 166 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| 167 | compptr = cinfo->cur_comp_info[ci]; |
| 168 | dctbl = compptr->dc_tbl_no; |
| 169 | actbl = compptr->ac_tbl_no; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 170 | if (gather_statistics) { |
| 171 | #ifdef ENTROPY_OPT_SUPPORTED |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 172 | /* Check for invalid table indexes */ |
| 173 | /* (make_c_derived_tbl does this in the other path) */ |
| 174 | if (dctbl < 0 || dctbl >= NUM_HUFF_TBLS) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 175 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, dctbl); |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 176 | if (actbl < 0 || actbl >= NUM_HUFF_TBLS) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 177 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, actbl); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 178 | /* Allocate and zero the statistics tables */ |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 179 | /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 180 | if (entropy->dc_count_ptrs[dctbl] == NULL) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 181 | entropy->dc_count_ptrs[dctbl] = (long *) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 182 | (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 183 | 257 * sizeof(long)); |
| 184 | MEMZERO(entropy->dc_count_ptrs[dctbl], 257 * sizeof(long)); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 185 | if (entropy->ac_count_ptrs[actbl] == NULL) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 186 | entropy->ac_count_ptrs[actbl] = (long *) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 187 | (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 188 | 257 * sizeof(long)); |
| 189 | MEMZERO(entropy->ac_count_ptrs[actbl], 257 * sizeof(long)); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 190 | #endif |
| 191 | } else { |
| 192 | /* Compute derived values for Huffman tables */ |
| 193 | /* We may do this more than once for a table, but it's not expensive */ |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 194 | jpeg_make_c_derived_tbl(cinfo, TRUE, dctbl, |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 195 | &entropy->dc_derived_tbls[dctbl]); |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 196 | jpeg_make_c_derived_tbl(cinfo, FALSE, actbl, |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 197 | &entropy->ac_derived_tbls[actbl]); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 198 | } |
| 199 | /* Initialize DC predictions to 0 */ |
| 200 | entropy->saved.last_dc_val[ci] = 0; |
| 201 | } |
| 202 | |
| 203 | /* Initialize bit buffer to empty */ |
| 204 | entropy->saved.put_buffer = 0; |
| 205 | entropy->saved.put_bits = 0; |
| 206 | |
| 207 | /* Initialize restart stuff */ |
| 208 | entropy->restarts_to_go = cinfo->restart_interval; |
| 209 | entropy->next_restart_num = 0; |
| 210 | } |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 211 | |
| 212 | |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 213 | /* |
| 214 | * Compute the derived values for a Huffman table. |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 215 | * This routine also performs some validation checks on the table. |
| 216 | * |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 217 | * Note this is also used by jcphuff.c. |
| 218 | */ |
| 219 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 220 | GLOBAL(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 221 | jpeg_make_c_derived_tbl(j_compress_ptr cinfo, boolean isDC, int tblno, |
| 222 | c_derived_tbl **pdtbl) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 223 | { |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 224 | JHUFF_TBL *htbl; |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 225 | c_derived_tbl *dtbl; |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 226 | int p, i, l, lastp, si, maxsymbol; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 227 | char huffsize[257]; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 228 | unsigned int huffcode[257]; |
| 229 | unsigned int code; |
| 230 | |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 231 | /* Note that huffsize[] and huffcode[] are filled in code-length order, |
| 232 | * paralleling the order of the symbols themselves in htbl->huffval[]. |
| 233 | */ |
| 234 | |
| 235 | /* Find the input Huffman table */ |
| 236 | if (tblno < 0 || tblno >= NUM_HUFF_TBLS) |
| 237 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); |
| 238 | htbl = |
| 239 | isDC ? cinfo->dc_huff_tbl_ptrs[tblno] : cinfo->ac_huff_tbl_ptrs[tblno]; |
| 240 | if (htbl == NULL) |
| 241 | ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tblno); |
| 242 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 243 | /* Allocate a workspace if we haven't already done so. */ |
| 244 | if (*pdtbl == NULL) |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 245 | *pdtbl = (c_derived_tbl *) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 246 | (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 247 | sizeof(c_derived_tbl)); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 248 | dtbl = *pdtbl; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 249 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 250 | /* Figure C.1: make table of Huffman code length for each symbol */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 251 | |
| 252 | p = 0; |
| 253 | for (l = 1; l <= 16; l++) { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 254 | i = (int)htbl->bits[l]; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 255 | if (i < 0 || p + i > 256) /* protect against table overrun */ |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 256 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
| 257 | while (i--) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 258 | huffsize[p++] = (char)l; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 259 | } |
| 260 | huffsize[p] = 0; |
| 261 | lastp = p; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 262 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 263 | /* Figure C.2: generate the codes themselves */ |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 264 | /* We also validate that the counts represent a legal Huffman code tree. */ |
| 265 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 266 | code = 0; |
| 267 | si = huffsize[0]; |
| 268 | p = 0; |
| 269 | while (huffsize[p]) { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 270 | while (((int)huffsize[p]) == si) { |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 271 | huffcode[p++] = code; |
| 272 | code++; |
| 273 | } |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 274 | /* code is now 1 more than the last code used for codelength si; but |
| 275 | * it must still fit in si bits, since no code is allowed to be all ones. |
| 276 | */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 277 | if (((JLONG)code) >= (((JLONG)1) << si)) |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 278 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 279 | code <<= 1; |
| 280 | si++; |
| 281 | } |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 282 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 283 | /* Figure C.3: generate encoding tables */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 284 | /* These are code and size indexed by symbol value */ |
| 285 | |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 286 | /* Set all codeless symbols to have code length 0; |
| 287 | * this lets us detect duplicate VAL entries here, and later |
| 288 | * allows emit_bits to detect any attempt to emit such symbols. |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 289 | */ |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 290 | MEMZERO(dtbl->ehufsi, sizeof(dtbl->ehufsi)); |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 291 | |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 292 | /* This is also a convenient place to check for out-of-range |
| 293 | * and duplicated VAL entries. We allow 0..255 for AC symbols |
| 294 | * but only 0..15 for DC. (We could constrain them further |
| 295 | * based on data depth and mode, but this seems enough.) |
| 296 | */ |
| 297 | maxsymbol = isDC ? 15 : 255; |
| 298 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 299 | for (p = 0; p < lastp; p++) { |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 300 | i = htbl->huffval[p]; |
| 301 | if (i < 0 || i > maxsymbol || dtbl->ehufsi[i]) |
| 302 | ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
| 303 | dtbl->ehufco[i] = huffcode[p]; |
| 304 | dtbl->ehufsi[i] = huffsize[p]; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 305 | } |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 306 | } |
| 307 | |
| 308 | |
| 309 | /* Outputting bytes to the file */ |
| 310 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 311 | /* Emit a byte, taking 'action' if must suspend. */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 312 | #define emit_byte(state, val, action) { \ |
| 313 | *(state)->next_output_byte++ = (JOCTET)(val); \ |
| 314 | if (--(state)->free_in_buffer == 0) \ |
| 315 | if (!dump_buffer(state)) \ |
| 316 | { action; } \ |
| 317 | } |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 318 | |
| 319 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 320 | LOCAL(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 321 | dump_buffer(working_state *state) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 322 | /* Empty the output buffer; return TRUE if successful, FALSE if must suspend */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 323 | { |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 324 | struct jpeg_destination_mgr *dest = state->cinfo->dest; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 325 | |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 326 | if (!(*dest->empty_output_buffer) (state->cinfo)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 327 | return FALSE; |
| 328 | /* After a successful buffer dump, must reset buffer pointers */ |
| 329 | state->next_output_byte = dest->next_output_byte; |
| 330 | state->free_in_buffer = dest->free_in_buffer; |
| 331 | return TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 332 | } |
| 333 | |
| 334 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 335 | /* Outputting bits to the file */ |
| 336 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 337 | /* These macros perform the same task as the emit_bits() function in the |
| 338 | * original libjpeg code. In addition to reducing overhead by explicitly |
| 339 | * inlining the code, additional performance is achieved by taking into |
| 340 | * account the size of the bit buffer and waiting until it is almost full |
| 341 | * before emptying it. This mostly benefits 64-bit platforms, since 6 |
| 342 | * bytes can be stored in a 64-bit bit buffer before it has to be emptied. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 343 | */ |
| 344 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 345 | #define EMIT_BYTE() { \ |
| 346 | JOCTET c; \ |
| 347 | put_bits -= 8; \ |
| 348 | c = (JOCTET)GETJOCTET(put_buffer >> put_bits); \ |
| 349 | *buffer++ = c; \ |
| 350 | if (c == 0xFF) /* need to stuff a zero byte? */ \ |
| 351 | *buffer++ = 0; \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 352 | } |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 353 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 354 | #define PUT_BITS(code, size) { \ |
| 355 | put_bits += size; \ |
| 356 | put_buffer = (put_buffer << size) | code; \ |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 357 | } |
| 358 | |
DRC | 6399d0a | 2019-04-23 14:10:04 -0500 | [diff] [blame] | 359 | #if SIZEOF_SIZE_T != 8 && !defined(_WIN64) |
| 360 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 361 | #define CHECKBUF15() { \ |
| 362 | if (put_bits > 15) { \ |
| 363 | EMIT_BYTE() \ |
| 364 | EMIT_BYTE() \ |
| 365 | } \ |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 366 | } |
| 367 | |
DRC | 6399d0a | 2019-04-23 14:10:04 -0500 | [diff] [blame] | 368 | #endif |
| 369 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 370 | #define CHECKBUF31() { \ |
| 371 | if (put_bits > 31) { \ |
| 372 | EMIT_BYTE() \ |
| 373 | EMIT_BYTE() \ |
| 374 | EMIT_BYTE() \ |
| 375 | EMIT_BYTE() \ |
| 376 | } \ |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 377 | } |
| 378 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 379 | #define CHECKBUF47() { \ |
| 380 | if (put_bits > 47) { \ |
| 381 | EMIT_BYTE() \ |
| 382 | EMIT_BYTE() \ |
| 383 | EMIT_BYTE() \ |
| 384 | EMIT_BYTE() \ |
| 385 | EMIT_BYTE() \ |
| 386 | EMIT_BYTE() \ |
| 387 | } \ |
| 388 | } |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 389 | |
DRC | 3ebcc32 | 2015-05-15 19:09:44 +0000 | [diff] [blame] | 390 | #if !defined(_WIN32) && !defined(SIZEOF_SIZE_T) |
| 391 | #error Cannot determine word size |
DRC | f64b36f | 2015-04-22 08:43:04 +0000 | [diff] [blame] | 392 | #endif |
| 393 | |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 394 | #if SIZEOF_SIZE_T == 8 || defined(_WIN64) |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 395 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 396 | #define EMIT_BITS(code, size) { \ |
| 397 | CHECKBUF47() \ |
| 398 | PUT_BITS(code, size) \ |
| 399 | } |
| 400 | |
| 401 | #define EMIT_CODE(code, size) { \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 402 | temp2 &= (((JLONG)1) << nbits) - 1; \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 403 | CHECKBUF31() \ |
| 404 | PUT_BITS(code, size) \ |
| 405 | PUT_BITS(temp2, nbits) \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 406 | } |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 407 | |
| 408 | #else |
| 409 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 410 | #define EMIT_BITS(code, size) { \ |
| 411 | PUT_BITS(code, size) \ |
| 412 | CHECKBUF15() \ |
| 413 | } |
| 414 | |
| 415 | #define EMIT_CODE(code, size) { \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 416 | temp2 &= (((JLONG)1) << nbits) - 1; \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 417 | PUT_BITS(code, size) \ |
| 418 | CHECKBUF15() \ |
| 419 | PUT_BITS(temp2, nbits) \ |
| 420 | CHECKBUF15() \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 421 | } |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 422 | |
DRC | 8443e52 | 2009-07-30 08:35:06 +0000 | [diff] [blame] | 423 | #endif |
| 424 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 425 | |
DRC | 402a715 | 2014-11-22 22:09:30 +0000 | [diff] [blame] | 426 | /* Although it is exceedingly rare, it is possible for a Huffman-encoded |
| 427 | * coefficient block to be larger than the 128-byte unencoded block. For each |
| 428 | * of the 64 coefficients, PUT_BITS is invoked twice, and each invocation can |
| 429 | * theoretically store 16 bits (for a maximum of 2048 bits or 256 bytes per |
| 430 | * encoded block.) If, for instance, one artificially sets the AC |
| 431 | * coefficients to alternating values of 32767 and -32768 (using the JPEG |
| 432 | * scanning order-- 1, 8, 16, etc.), then this will produce an encoded block |
| 433 | * larger than 200 bytes. |
| 434 | */ |
DRC | 293263c | 2018-03-17 15:14:35 -0500 | [diff] [blame] | 435 | #define BUFSIZE (DCTSIZE2 * 4) |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 436 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 437 | #define LOAD_BUFFER() { \ |
| 438 | if (state->free_in_buffer < BUFSIZE) { \ |
| 439 | localbuf = 1; \ |
| 440 | buffer = _buffer; \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 441 | } else \ |
| 442 | buffer = state->next_output_byte; \ |
| 443 | } |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 444 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 445 | #define STORE_BUFFER() { \ |
| 446 | if (localbuf) { \ |
| 447 | bytes = buffer - _buffer; \ |
| 448 | buffer = _buffer; \ |
| 449 | while (bytes > 0) { \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 450 | bytestocopy = MIN(bytes, state->free_in_buffer); \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 451 | MEMCOPY(state->next_output_byte, buffer, bytestocopy); \ |
| 452 | state->next_output_byte += bytestocopy; \ |
| 453 | buffer += bytestocopy; \ |
| 454 | state->free_in_buffer -= bytestocopy; \ |
| 455 | if (state->free_in_buffer == 0) \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 456 | if (!dump_buffer(state)) return FALSE; \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 457 | bytes -= bytestocopy; \ |
| 458 | } \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 459 | } else { \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 460 | state->free_in_buffer -= (buffer - state->next_output_byte); \ |
| 461 | state->next_output_byte = buffer; \ |
| 462 | } \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 463 | } |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 464 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 465 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 466 | LOCAL(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 467 | flush_bits(working_state *state) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 468 | { |
DRC | eddc355 | 2014-08-21 03:38:14 +0000 | [diff] [blame] | 469 | JOCTET _buffer[BUFSIZE], *buffer; |
DRC | 0489909 | 2010-02-26 23:01:19 +0000 | [diff] [blame] | 470 | size_t put_buffer; int put_bits; |
| 471 | size_t bytes, bytestocopy; int localbuf = 0; |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 472 | |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 473 | put_buffer = state->cur.put_buffer; |
| 474 | put_bits = state->cur.put_bits; |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 475 | LOAD_BUFFER() |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 476 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 477 | /* fill any partial byte with ones */ |
| 478 | PUT_BITS(0x7F, 7) |
| 479 | while (put_bits >= 8) EMIT_BYTE() |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 480 | |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 481 | state->cur.put_buffer = 0; /* and reset bit-buffer to empty */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 482 | state->cur.put_bits = 0; |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 483 | STORE_BUFFER() |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 484 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 485 | return TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 486 | } |
| 487 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 488 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 489 | /* Encode a single block's worth of coefficients */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 490 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 491 | LOCAL(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 492 | encode_one_block_simd(working_state *state, JCOEFPTR block, int last_dc_val, |
| 493 | c_derived_tbl *dctbl, c_derived_tbl *actbl) |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 494 | { |
| 495 | JOCTET _buffer[BUFSIZE], *buffer; |
| 496 | size_t bytes, bytestocopy; int localbuf = 0; |
| 497 | |
| 498 | LOAD_BUFFER() |
| 499 | |
| 500 | buffer = jsimd_huff_encode_one_block(state, buffer, block, last_dc_val, |
| 501 | dctbl, actbl); |
| 502 | |
| 503 | STORE_BUFFER() |
| 504 | |
| 505 | return TRUE; |
| 506 | } |
| 507 | |
| 508 | LOCAL(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 509 | encode_one_block(working_state *state, JCOEFPTR block, int last_dc_val, |
| 510 | c_derived_tbl *dctbl, c_derived_tbl *actbl) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 511 | { |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 512 | int temp, temp2, temp3; |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 513 | int nbits; |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 514 | int r, code, size; |
DRC | eddc355 | 2014-08-21 03:38:14 +0000 | [diff] [blame] | 515 | JOCTET _buffer[BUFSIZE], *buffer; |
DRC | 0489909 | 2010-02-26 23:01:19 +0000 | [diff] [blame] | 516 | size_t put_buffer; int put_bits; |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 517 | int code_0xf0 = actbl->ehufco[0xf0], size_0xf0 = actbl->ehufsi[0xf0]; |
DRC | 0489909 | 2010-02-26 23:01:19 +0000 | [diff] [blame] | 518 | size_t bytes, bytestocopy; int localbuf = 0; |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 519 | |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 520 | put_buffer = state->cur.put_buffer; |
| 521 | put_bits = state->cur.put_bits; |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 522 | LOAD_BUFFER() |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 523 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 524 | /* Encode the DC coefficient difference per section F.1.2.1 */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 525 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 526 | temp = temp2 = block[0] - last_dc_val; |
Thomas G. Lane | bd543f0 | 1991-12-13 00:00:00 +0000 | [diff] [blame] | 527 | |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 528 | /* This is a well-known technique for obtaining the absolute value without a |
| 529 | * branch. It is derived from an assembly language technique presented in |
| 530 | * "How to Optimize for the Pentium Processors", Copyright (c) 1996, 1997 by |
| 531 | * Agner Fog. |
| 532 | */ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 533 | temp3 = temp >> (CHAR_BIT * sizeof(int) - 1); |
| 534 | temp ^= temp3; |
| 535 | temp -= temp3; |
| 536 | |
| 537 | /* For a negative input, want temp2 = bitwise complement of abs(input) */ |
| 538 | /* This code assumes we are on a two's complement machine */ |
| 539 | temp2 += temp3; |
| 540 | |
| 541 | /* Find the number of bits needed for the magnitude of the coefficient */ |
DRC | 0cfc4c1 | 2014-03-28 18:33:25 +0000 | [diff] [blame] | 542 | nbits = JPEG_NBITS(temp); |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 543 | |
| 544 | /* Emit the Huffman-coded symbol for the number of bits */ |
| 545 | code = dctbl->ehufco[nbits]; |
| 546 | size = dctbl->ehufsi[nbits]; |
DRC | a8b6ea2 | 2015-05-06 22:41:12 +0000 | [diff] [blame] | 547 | EMIT_BITS(code, size) |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 548 | |
| 549 | /* Mask off any extra bits in code */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 550 | temp2 &= (((JLONG)1) << nbits) - 1; |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 551 | |
| 552 | /* Emit that number of bits of the value, if positive, */ |
| 553 | /* or the complement of its magnitude, if negative. */ |
DRC | a8b6ea2 | 2015-05-06 22:41:12 +0000 | [diff] [blame] | 554 | EMIT_BITS(temp2, nbits) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 555 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 556 | /* Encode the AC coefficients per section F.1.2.2 */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 557 | |
| 558 | r = 0; /* r = run length of zeros */ |
Thomas G. Lane | bd543f0 | 1991-12-13 00:00:00 +0000 | [diff] [blame] | 559 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 560 | /* Manually unroll the k loop to eliminate the counter variable. This |
| 561 | * improves performance greatly on systems with a limited number of |
| 562 | * registers (such as x86.) |
| 563 | */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 564 | #define kloop(jpeg_natural_order_of_k) { \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 565 | if ((temp = block[jpeg_natural_order_of_k]) == 0) { \ |
| 566 | r++; \ |
| 567 | } else { \ |
| 568 | temp2 = temp; \ |
| 569 | /* Branch-less absolute value, bitwise complement, etc., same as above */ \ |
| 570 | temp3 = temp >> (CHAR_BIT * sizeof(int) - 1); \ |
| 571 | temp ^= temp3; \ |
| 572 | temp -= temp3; \ |
| 573 | temp2 += temp3; \ |
DRC | 0cfc4c1 | 2014-03-28 18:33:25 +0000 | [diff] [blame] | 574 | nbits = JPEG_NBITS_NONZERO(temp); \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 575 | /* if run length > 15, must emit special run-length-16 codes (0xF0) */ \ |
| 576 | while (r > 15) { \ |
| 577 | EMIT_BITS(code_0xf0, size_0xf0) \ |
| 578 | r -= 16; \ |
| 579 | } \ |
| 580 | /* Emit Huffman symbol for run length / number of bits */ \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 581 | temp3 = (r << 4) + nbits; \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 582 | code = actbl->ehufco[temp3]; \ |
| 583 | size = actbl->ehufsi[temp3]; \ |
| 584 | EMIT_CODE(code, size) \ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 585 | r = 0; \ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 586 | } \ |
| 587 | } |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 588 | |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 589 | /* One iteration for each value in jpeg_natural_order[] */ |
| 590 | kloop(1); kloop(8); kloop(16); kloop(9); kloop(2); kloop(3); |
| 591 | kloop(10); kloop(17); kloop(24); kloop(32); kloop(25); kloop(18); |
| 592 | kloop(11); kloop(4); kloop(5); kloop(12); kloop(19); kloop(26); |
| 593 | kloop(33); kloop(40); kloop(48); kloop(41); kloop(34); kloop(27); |
| 594 | kloop(20); kloop(13); kloop(6); kloop(7); kloop(14); kloop(21); |
| 595 | kloop(28); kloop(35); kloop(42); kloop(49); kloop(56); kloop(57); |
| 596 | kloop(50); kloop(43); kloop(36); kloop(29); kloop(22); kloop(15); |
| 597 | kloop(23); kloop(30); kloop(37); kloop(44); kloop(51); kloop(58); |
| 598 | kloop(59); kloop(52); kloop(45); kloop(38); kloop(31); kloop(39); |
| 599 | kloop(46); kloop(53); kloop(60); kloop(61); kloop(54); kloop(47); |
| 600 | kloop(55); kloop(62); kloop(63); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 601 | |
| 602 | /* If the last coef(s) were zero, emit an end-of-block code */ |
DRC | 6bb57b7 | 2011-04-26 22:08:31 +0000 | [diff] [blame] | 603 | if (r > 0) { |
| 604 | code = actbl->ehufco[0]; |
| 605 | size = actbl->ehufsi[0]; |
| 606 | EMIT_BITS(code, size) |
| 607 | } |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 608 | |
| 609 | state->cur.put_buffer = put_buffer; |
| 610 | state->cur.put_bits = put_bits; |
DRC | 3cba8db | 2009-03-16 23:58:30 +0000 | [diff] [blame] | 611 | STORE_BUFFER() |
DRC | 9931338 | 2009-03-12 17:24:27 +0000 | [diff] [blame] | 612 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 613 | return TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 614 | } |
| 615 | |
| 616 | |
| 617 | /* |
| 618 | * Emit a restart marker & resynchronize predictions. |
| 619 | */ |
| 620 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 621 | LOCAL(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 622 | emit_restart(working_state *state, int restart_num) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 623 | { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 624 | int ci; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 625 | |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 626 | if (!flush_bits(state)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 627 | return FALSE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 628 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 629 | emit_byte(state, 0xFF, return FALSE); |
| 630 | emit_byte(state, JPEG_RST0 + restart_num, return FALSE); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 631 | |
| 632 | /* Re-initialize DC predictions to 0 */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 633 | for (ci = 0; ci < state->cinfo->comps_in_scan; ci++) |
| 634 | state->cur.last_dc_val[ci] = 0; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 635 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 636 | /* The restart counter is not updated until we successfully write the MCU. */ |
| 637 | |
| 638 | return TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 639 | } |
| 640 | |
| 641 | |
| 642 | /* |
| 643 | * Encode and output one MCU's worth of Huffman-compressed coefficients. |
| 644 | */ |
| 645 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 646 | METHODDEF(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 647 | encode_mcu_huff(j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 648 | { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 649 | huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 650 | working_state state; |
| 651 | int blkn, ci; |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 652 | jpeg_component_info *compptr; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 653 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 654 | /* Load up working state */ |
| 655 | state.next_output_byte = cinfo->dest->next_output_byte; |
| 656 | state.free_in_buffer = cinfo->dest->free_in_buffer; |
| 657 | ASSIGN_STATE(state.cur, entropy->saved); |
| 658 | state.cinfo = cinfo; |
| 659 | |
| 660 | /* Emit restart marker if needed */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 661 | if (cinfo->restart_interval) { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 662 | if (entropy->restarts_to_go == 0) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 663 | if (!emit_restart(&state, entropy->next_restart_num)) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 664 | return FALSE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 665 | } |
| 666 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 667 | /* Encode the MCU data blocks */ |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 668 | if (entropy->simd) { |
| 669 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
| 670 | ci = cinfo->MCU_membership[blkn]; |
| 671 | compptr = cinfo->cur_comp_info[ci]; |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 672 | if (!encode_one_block_simd(&state, |
| 673 | MCU_data[blkn][0], state.cur.last_dc_val[ci], |
| 674 | entropy->dc_derived_tbls[compptr->dc_tbl_no], |
| 675 | entropy->ac_derived_tbls[compptr->ac_tbl_no])) |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 676 | return FALSE; |
| 677 | /* Update last_dc_val */ |
| 678 | state.cur.last_dc_val[ci] = MCU_data[blkn][0][0]; |
| 679 | } |
| 680 | } else { |
| 681 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
| 682 | ci = cinfo->MCU_membership[blkn]; |
| 683 | compptr = cinfo->cur_comp_info[ci]; |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 684 | if (!encode_one_block(&state, |
| 685 | MCU_data[blkn][0], state.cur.last_dc_val[ci], |
| 686 | entropy->dc_derived_tbls[compptr->dc_tbl_no], |
| 687 | entropy->ac_derived_tbls[compptr->ac_tbl_no])) |
DRC | f3a8684 | 2016-01-07 00:19:43 -0600 | [diff] [blame] | 688 | return FALSE; |
| 689 | /* Update last_dc_val */ |
| 690 | state.cur.last_dc_val[ci] = MCU_data[blkn][0][0]; |
| 691 | } |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 692 | } |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 693 | |
| 694 | /* Completed MCU, so update state */ |
| 695 | cinfo->dest->next_output_byte = state.next_output_byte; |
| 696 | cinfo->dest->free_in_buffer = state.free_in_buffer; |
| 697 | ASSIGN_STATE(entropy->saved, state.cur); |
| 698 | |
| 699 | /* Update restart-interval state too */ |
| 700 | if (cinfo->restart_interval) { |
| 701 | if (entropy->restarts_to_go == 0) { |
| 702 | entropy->restarts_to_go = cinfo->restart_interval; |
| 703 | entropy->next_restart_num++; |
| 704 | entropy->next_restart_num &= 7; |
| 705 | } |
| 706 | entropy->restarts_to_go--; |
| 707 | } |
| 708 | |
| 709 | return TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 710 | } |
| 711 | |
| 712 | |
| 713 | /* |
| 714 | * Finish up at the end of a Huffman-compressed scan. |
| 715 | */ |
| 716 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 717 | METHODDEF(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 718 | finish_pass_huff(j_compress_ptr cinfo) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 719 | { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 720 | huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 721 | working_state state; |
| 722 | |
| 723 | /* Load up working state ... flush_bits needs it */ |
| 724 | state.next_output_byte = cinfo->dest->next_output_byte; |
| 725 | state.free_in_buffer = cinfo->dest->free_in_buffer; |
| 726 | ASSIGN_STATE(state.cur, entropy->saved); |
| 727 | state.cinfo = cinfo; |
| 728 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 729 | /* Flush out the last data */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 730 | if (!flush_bits(&state)) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 731 | ERREXIT(cinfo, JERR_CANT_SUSPEND); |
| 732 | |
| 733 | /* Update state */ |
| 734 | cinfo->dest->next_output_byte = state.next_output_byte; |
| 735 | cinfo->dest->free_in_buffer = state.free_in_buffer; |
| 736 | ASSIGN_STATE(entropy->saved, state.cur); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 737 | } |
| 738 | |
| 739 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 740 | /* |
| 741 | * Huffman coding optimization. |
| 742 | * |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 743 | * We first scan the supplied data and count the number of uses of each symbol |
| 744 | * that is to be Huffman-coded. (This process MUST agree with the code above.) |
| 745 | * Then we build a Huffman coding tree for the observed counts. |
| 746 | * Symbols which are not needed at all for the particular image are not |
| 747 | * assigned any code, which saves space in the DHT marker as well as in |
| 748 | * the compressed data. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 749 | */ |
| 750 | |
| 751 | #ifdef ENTROPY_OPT_SUPPORTED |
| 752 | |
| 753 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 754 | /* Process a single block's worth of coefficients */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 755 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 756 | LOCAL(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 757 | htest_one_block(j_compress_ptr cinfo, JCOEFPTR block, int last_dc_val, |
| 758 | long dc_counts[], long ac_counts[]) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 759 | { |
| 760 | register int temp; |
| 761 | register int nbits; |
| 762 | register int k, r; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 763 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 764 | /* Encode the DC coefficient difference per section F.1.2.1 */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 765 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 766 | temp = block[0] - last_dc_val; |
| 767 | if (temp < 0) |
| 768 | temp = -temp; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 769 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 770 | /* Find the number of bits needed for the magnitude of the coefficient */ |
| 771 | nbits = 0; |
| 772 | while (temp) { |
| 773 | nbits++; |
| 774 | temp >>= 1; |
| 775 | } |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 776 | /* Check for out-of-range coefficient values. |
| 777 | * Since we're encoding a difference, the range limit is twice as much. |
| 778 | */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 779 | if (nbits > MAX_COEF_BITS + 1) |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 780 | ERREXIT(cinfo, JERR_BAD_DCT_COEF); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 781 | |
| 782 | /* Count the Huffman symbol for the number of bits */ |
| 783 | dc_counts[nbits]++; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 784 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 785 | /* Encode the AC coefficients per section F.1.2.2 */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 786 | |
| 787 | r = 0; /* r = run length of zeros */ |
| 788 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 789 | for (k = 1; k < DCTSIZE2; k++) { |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 790 | if ((temp = block[jpeg_natural_order[k]]) == 0) { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 791 | r++; |
| 792 | } else { |
| 793 | /* if run length > 15, must emit special run-length-16 codes (0xF0) */ |
| 794 | while (r > 15) { |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 795 | ac_counts[0xF0]++; |
| 796 | r -= 16; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 797 | } |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 798 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 799 | /* Find the number of bits needed for the magnitude of the coefficient */ |
| 800 | if (temp < 0) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 801 | temp = -temp; |
| 802 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 803 | /* Find the number of bits needed for the magnitude of the coefficient */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 804 | nbits = 1; /* there must be at least one 1 bit */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 805 | while ((temp >>= 1)) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 806 | nbits++; |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 807 | /* Check for out-of-range coefficient values */ |
| 808 | if (nbits > MAX_COEF_BITS) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 809 | ERREXIT(cinfo, JERR_BAD_DCT_COEF); |
| 810 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 811 | /* Count Huffman symbol for run length / number of bits */ |
| 812 | ac_counts[(r << 4) + nbits]++; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 813 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 814 | r = 0; |
| 815 | } |
| 816 | } |
| 817 | |
| 818 | /* If the last coef(s) were zero, emit an end-of-block code */ |
| 819 | if (r > 0) |
| 820 | ac_counts[0]++; |
| 821 | } |
| 822 | |
| 823 | |
| 824 | /* |
| 825 | * Trial-encode one MCU's worth of Huffman-compressed coefficients. |
| 826 | * No data is actually output, so no suspension return is possible. |
| 827 | */ |
| 828 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 829 | METHODDEF(boolean) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 830 | encode_mcu_gather(j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 831 | { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 832 | huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 833 | int blkn, ci; |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 834 | jpeg_component_info *compptr; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 835 | |
| 836 | /* Take care of restart intervals if needed */ |
| 837 | if (cinfo->restart_interval) { |
| 838 | if (entropy->restarts_to_go == 0) { |
| 839 | /* Re-initialize DC predictions to 0 */ |
| 840 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 841 | entropy->saved.last_dc_val[ci] = 0; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 842 | /* Update restart state */ |
| 843 | entropy->restarts_to_go = cinfo->restart_interval; |
| 844 | } |
| 845 | entropy->restarts_to_go--; |
| 846 | } |
| 847 | |
| 848 | for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
| 849 | ci = cinfo->MCU_membership[blkn]; |
| 850 | compptr = cinfo->cur_comp_info[ci]; |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 851 | htest_one_block(cinfo, MCU_data[blkn][0], entropy->saved.last_dc_val[ci], |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 852 | entropy->dc_count_ptrs[compptr->dc_tbl_no], |
| 853 | entropy->ac_count_ptrs[compptr->ac_tbl_no]); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 854 | entropy->saved.last_dc_val[ci] = MCU_data[blkn][0][0]; |
| 855 | } |
| 856 | |
| 857 | return TRUE; |
| 858 | } |
| 859 | |
| 860 | |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 861 | /* |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 862 | * Generate the best Huffman code table for the given counts, fill htbl. |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 863 | * Note this is also used by jcphuff.c. |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 864 | * |
| 865 | * The JPEG standard requires that no symbol be assigned a codeword of all |
| 866 | * one bits (so that padding bits added at the end of a compressed segment |
| 867 | * can't look like a valid code). Because of the canonical ordering of |
| 868 | * codewords, this just means that there must be an unused slot in the |
DRC | a628952 | 2018-07-24 18:36:51 -0500 | [diff] [blame] | 869 | * longest codeword length category. Annex K (Clause K.2) of |
| 870 | * Rec. ITU-T T.81 (1992) | ISO/IEC 10918-1:1994 suggests reserving such a slot |
| 871 | * by pretending that symbol 256 is a valid symbol with count 1. In theory |
| 872 | * that's not optimal; giving it count zero but including it in the symbol set |
| 873 | * anyway should give a better Huffman code. But the theoretically better code |
| 874 | * actually seems to come out worse in practice, because it produces more |
| 875 | * all-ones bytes (which incur stuffed zero bytes in the final file). In any |
| 876 | * case the difference is tiny. |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 877 | * |
| 878 | * The JPEG standard requires Huffman codes to be no more than 16 bits long. |
| 879 | * If some symbols have a very small but nonzero probability, the Huffman tree |
| 880 | * must be adjusted to meet the code length restriction. We currently use |
| 881 | * the adjustment method suggested in JPEG section K.2. This method is *not* |
| 882 | * optimal; it may not choose the best possible limited-length code. But |
| 883 | * typically only very-low-frequency symbols will be given less-than-optimal |
| 884 | * lengths, so the code is almost optimal. Experimental comparisons against |
| 885 | * an optimal limited-length-code algorithm indicate that the difference is |
| 886 | * microscopic --- usually less than a hundredth of a percent of total size. |
| 887 | * So the extra complexity of an optimal algorithm doesn't seem worthwhile. |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 888 | */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 889 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 890 | GLOBAL(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 891 | jpeg_gen_optimal_table(j_compress_ptr cinfo, JHUFF_TBL *htbl, long freq[]) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 892 | { |
DRC | 293263c | 2018-03-17 15:14:35 -0500 | [diff] [blame] | 893 | #define MAX_CLEN 32 /* assumed maximum initial code length */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 894 | UINT8 bits[MAX_CLEN + 1]; /* bits[k] = # of symbols with code length k */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 895 | int codesize[257]; /* codesize[k] = code length of symbol k */ |
| 896 | int others[257]; /* next symbol in current branch of tree */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 897 | int c1, c2; |
| 898 | int p, i, j; |
| 899 | long v; |
| 900 | |
Thomas G. Lane | 4a6b730 | 1992-03-17 00:00:00 +0000 | [diff] [blame] | 901 | /* This algorithm is explained in section K.2 of the JPEG standard */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 902 | |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 903 | MEMZERO(bits, sizeof(bits)); |
| 904 | MEMZERO(codesize, sizeof(codesize)); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 905 | for (i = 0; i < 257; i++) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 906 | others[i] = -1; /* init links to empty */ |
| 907 | |
| 908 | freq[256] = 1; /* make sure 256 has a nonzero count */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 909 | /* Including the pseudo-symbol 256 in the Huffman procedure guarantees |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 910 | * that no real symbol is given code-value of all ones, because 256 |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 911 | * will be placed last in the largest codeword category. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 912 | */ |
| 913 | |
| 914 | /* Huffman's basic algorithm to assign optimal code lengths to symbols */ |
| 915 | |
| 916 | for (;;) { |
| 917 | /* Find the smallest nonzero frequency, set c1 = its symbol */ |
| 918 | /* In case of ties, take the larger symbol number */ |
| 919 | c1 = -1; |
| 920 | v = 1000000000L; |
| 921 | for (i = 0; i <= 256; i++) { |
| 922 | if (freq[i] && freq[i] <= v) { |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 923 | v = freq[i]; |
| 924 | c1 = i; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 925 | } |
| 926 | } |
| 927 | |
| 928 | /* Find the next smallest nonzero frequency, set c2 = its symbol */ |
| 929 | /* In case of ties, take the larger symbol number */ |
| 930 | c2 = -1; |
| 931 | v = 1000000000L; |
| 932 | for (i = 0; i <= 256; i++) { |
| 933 | if (freq[i] && freq[i] <= v && i != c1) { |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 934 | v = freq[i]; |
| 935 | c2 = i; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 936 | } |
| 937 | } |
| 938 | |
| 939 | /* Done if we've merged everything into one frequency */ |
| 940 | if (c2 < 0) |
| 941 | break; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 942 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 943 | /* Else merge the two counts/trees */ |
| 944 | freq[c1] += freq[c2]; |
| 945 | freq[c2] = 0; |
| 946 | |
| 947 | /* Increment the codesize of everything in c1's tree branch */ |
| 948 | codesize[c1]++; |
| 949 | while (others[c1] >= 0) { |
| 950 | c1 = others[c1]; |
| 951 | codesize[c1]++; |
| 952 | } |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 953 | |
| 954 | others[c1] = c2; /* chain c2 onto c1's tree branch */ |
| 955 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 956 | /* Increment the codesize of everything in c2's tree branch */ |
| 957 | codesize[c2]++; |
| 958 | while (others[c2] >= 0) { |
| 959 | c2 = others[c2]; |
| 960 | codesize[c2]++; |
| 961 | } |
| 962 | } |
| 963 | |
| 964 | /* Now count the number of symbols of each code length */ |
| 965 | for (i = 0; i <= 256; i++) { |
| 966 | if (codesize[i]) { |
| 967 | /* The JPEG standard seems to think that this can't happen, */ |
| 968 | /* but I'm paranoid... */ |
| 969 | if (codesize[i] > MAX_CLEN) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 970 | ERREXIT(cinfo, JERR_HUFF_CLEN_OVERFLOW); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 971 | |
| 972 | bits[codesize[i]]++; |
| 973 | } |
| 974 | } |
| 975 | |
| 976 | /* JPEG doesn't allow symbols with code lengths over 16 bits, so if the pure |
| 977 | * Huffman procedure assigned any such lengths, we must adjust the coding. |
DRC | a628952 | 2018-07-24 18:36:51 -0500 | [diff] [blame] | 978 | * Here is what Rec. ITU-T T.81 | ISO/IEC 10918-1 says about how this next |
| 979 | * bit works: Since symbols are paired for the longest Huffman code, the |
| 980 | * symbols are removed from this length category two at a time. The prefix |
| 981 | * for the pair (which is one bit shorter) is allocated to one of the pair; |
| 982 | * then, skipping the BITS entry for that prefix length, a code word from the |
| 983 | * next shortest nonzero BITS entry is converted into a prefix for two code |
| 984 | * words one bit longer. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 985 | */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 986 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 987 | for (i = MAX_CLEN; i > 16; i--) { |
| 988 | while (bits[i] > 0) { |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 989 | j = i - 2; /* find length of new prefix to be used */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 990 | while (bits[j] == 0) |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 991 | j--; |
| 992 | |
| 993 | bits[i] -= 2; /* remove two symbols */ |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 994 | bits[i - 1]++; /* one goes in this length */ |
| 995 | bits[j + 1] += 2; /* two new symbols in this length */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 996 | bits[j]--; /* symbol of this length is now a prefix */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 997 | } |
| 998 | } |
| 999 | |
| 1000 | /* Remove the count for the pseudo-symbol 256 from the largest codelength */ |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 1001 | while (bits[i] == 0) /* find largest codelength still in use */ |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1002 | i--; |
| 1003 | bits[i]--; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 1004 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1005 | /* Return final symbol counts (only for lengths 0..16) */ |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 1006 | MEMCOPY(htbl->bits, bits, sizeof(htbl->bits)); |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 1007 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1008 | /* Return a list of the symbols sorted by code length */ |
| 1009 | /* It's not real clear to me why we don't need to consider the codelength |
DRC | a628952 | 2018-07-24 18:36:51 -0500 | [diff] [blame] | 1010 | * changes made above, but Rec. ITU-T T.81 | ISO/IEC 10918-1 seems to think |
| 1011 | * this works. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1012 | */ |
| 1013 | p = 0; |
| 1014 | for (i = 1; i <= MAX_CLEN; i++) { |
| 1015 | for (j = 0; j <= 255; j++) { |
| 1016 | if (codesize[j] == i) { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1017 | htbl->huffval[p] = (UINT8)j; |
DRC | e5eaf37 | 2014-05-09 18:00:32 +0000 | [diff] [blame] | 1018 | p++; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1019 | } |
| 1020 | } |
| 1021 | } |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1022 | |
| 1023 | /* Set sent_table FALSE so updated table will be written to JPEG file. */ |
| 1024 | htbl->sent_table = FALSE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1025 | } |
| 1026 | |
| 1027 | |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1028 | /* |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1029 | * Finish up a statistics-gathering pass and create the new Huffman tables. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1030 | */ |
| 1031 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 1032 | METHODDEF(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1033 | finish_pass_gather(j_compress_ptr cinfo) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1034 | { |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1035 | huff_entropy_ptr entropy = (huff_entropy_ptr)cinfo->entropy; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1036 | int ci, dctbl, actbl; |
DRC | bd49803 | 2016-02-19 08:53:33 -0600 | [diff] [blame] | 1037 | jpeg_component_info *compptr; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1038 | JHUFF_TBL **htblptr; |
| 1039 | boolean did_dc[NUM_HUFF_TBLS]; |
| 1040 | boolean did_ac[NUM_HUFF_TBLS]; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1041 | |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 1042 | /* It's important not to apply jpeg_gen_optimal_table more than once |
| 1043 | * per table, because it clobbers the input frequency counts! |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1044 | */ |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 1045 | MEMZERO(did_dc, sizeof(did_dc)); |
| 1046 | MEMZERO(did_ac, sizeof(did_ac)); |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1047 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1048 | for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| 1049 | compptr = cinfo->cur_comp_info[ci]; |
| 1050 | dctbl = compptr->dc_tbl_no; |
| 1051 | actbl = compptr->ac_tbl_no; |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1052 | if (!did_dc[dctbl]) { |
| 1053 | htblptr = &cinfo->dc_huff_tbl_ptrs[dctbl]; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1054 | if (*htblptr == NULL) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1055 | *htblptr = jpeg_alloc_huff_table((j_common_ptr)cinfo); |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 1056 | jpeg_gen_optimal_table(cinfo, *htblptr, entropy->dc_count_ptrs[dctbl]); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1057 | did_dc[dctbl] = TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1058 | } |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1059 | if (!did_ac[actbl]) { |
| 1060 | htblptr = &cinfo->ac_huff_tbl_ptrs[actbl]; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1061 | if (*htblptr == NULL) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1062 | *htblptr = jpeg_alloc_huff_table((j_common_ptr)cinfo); |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 1063 | jpeg_gen_optimal_table(cinfo, *htblptr, entropy->ac_count_ptrs[actbl]); |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1064 | did_ac[actbl] = TRUE; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1065 | } |
| 1066 | } |
| 1067 | } |
| 1068 | |
| 1069 | |
| 1070 | #endif /* ENTROPY_OPT_SUPPORTED */ |
| 1071 | |
| 1072 | |
| 1073 | /* |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1074 | * Module initialization routine for Huffman entropy encoding. |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1075 | */ |
| 1076 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 1077 | GLOBAL(void) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1078 | jinit_huff_encoder(j_compress_ptr cinfo) |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1079 | { |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1080 | huff_entropy_ptr entropy; |
| 1081 | int i; |
| 1082 | |
| 1083 | entropy = (huff_entropy_ptr) |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1084 | (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE, |
DRC | 5de454b | 2014-05-18 19:04:03 +0000 | [diff] [blame] | 1085 | sizeof(huff_entropy_encoder)); |
DRC | 19c791c | 2018-03-08 10:55:20 -0600 | [diff] [blame] | 1086 | cinfo->entropy = (struct jpeg_entropy_encoder *)entropy; |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1087 | entropy->pub.start_pass = start_pass_huff; |
| 1088 | |
| 1089 | /* Mark tables unallocated */ |
| 1090 | for (i = 0; i < NUM_HUFF_TBLS; i++) { |
| 1091 | entropy->dc_derived_tbls[i] = entropy->ac_derived_tbls[i] = NULL; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1092 | #ifdef ENTROPY_OPT_SUPPORTED |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1093 | entropy->dc_count_ptrs[i] = entropy->ac_count_ptrs[i] = NULL; |
Thomas G. Lane | 2cbeb8a | 1991-10-07 00:00:00 +0000 | [diff] [blame] | 1094 | #endif |
| 1095 | } |
| 1096 | } |