| OLD | NEW |
| 1 /* | 1 /* |
| 2 * jcarith.c | 2 * jcarith.c |
| 3 * | 3 * |
| 4 * This file was part of the Independent JPEG Group's software: |
| 4 * Developed 1997-2009 by Guido Vollbeding. | 5 * Developed 1997-2009 by Guido Vollbeding. |
| 5 * This file is part of the Independent JPEG Group's software. | 6 * libjpeg-turbo Modifications: |
| 6 * For conditions of distribution and use, see the accompanying README file. | 7 * Copyright (C) 2015, D. R. Commander. |
| 8 * For conditions of distribution and use, see the accompanying README.ijg |
| 9 * file. |
| 7 * | 10 * |
| 8 * This file contains portable arithmetic entropy encoding routines for JPEG | 11 * This file contains portable arithmetic entropy encoding routines for JPEG |
| 9 * (implementing the ISO/IEC IS 10918-1 and CCITT Recommendation ITU-T T.81). | 12 * (implementing the ISO/IEC IS 10918-1 and CCITT Recommendation ITU-T T.81). |
| 10 * | 13 * |
| 11 * Both sequential and progressive modes are supported in this single module. | 14 * Both sequential and progressive modes are supported in this single module. |
| 12 * | 15 * |
| 13 * Suspension is not currently supported in this module. | 16 * Suspension is not currently supported in this module. |
| 14 */ | 17 */ |
| 15 | 18 |
| 16 #define JPEG_INTERNALS | 19 #define JPEG_INTERNALS |
| 17 #include "jinclude.h" | 20 #include "jinclude.h" |
| 18 #include "jpeglib.h" | 21 #include "jpeglib.h" |
| 19 | 22 |
| 20 | 23 |
| 21 /* Expanded entropy encoder object for arithmetic encoding. */ | 24 /* Expanded entropy encoder object for arithmetic encoding. */ |
| 22 | 25 |
| 23 typedef struct { | 26 typedef struct { |
| 24 struct jpeg_entropy_encoder pub; /* public fields */ | 27 struct jpeg_entropy_encoder pub; /* public fields */ |
| 25 | 28 |
| 26 INT32 c; /* C register, base of coding interval, layout as in sec. D.1.3 */ | 29 JLONG c; /* C register, base of coding interval, layout as in sec. D.1.3 */ |
| 27 INT32 a; /* A register, normalized size of coding interval */ | 30 JLONG a; /* A register, normalized size of coding interval */ |
| 28 INT32 sc; /* counter for stacked 0xFF values which might overflow */ | 31 JLONG sc; /* counter for stacked 0xFF values which might overflow */ |
| 29 INT32 zc; /* counter for pending 0x00 output values which might * | 32 JLONG zc; /* counter for pending 0x00 output values which might * |
| 30 * be discarded at the end ("Pacman" termination) */ | 33 * be discarded at the end ("Pacman" termination) */ |
| 31 int ct; /* bit shift counter, determines when next byte will be written */ | 34 int ct; /* bit shift counter, determines when next byte will be written */ |
| 32 int buffer; /* buffer for most recent output byte != 0xFF */ | 35 int buffer; /* buffer for most recent output byte != 0xFF */ |
| 33 | 36 |
| 34 int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ | 37 int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */ |
| 35 int dc_context[MAX_COMPS_IN_SCAN]; /* context index for DC conditioning */ | 38 int dc_context[MAX_COMPS_IN_SCAN]; /* context index for DC conditioning */ |
| 36 | 39 |
| 37 unsigned int restarts_to_go;» /* MCUs left in this restart interval */ | 40 unsigned int restarts_to_go; /* MCUs left in this restart interval */ |
| 38 int next_restart_num;»» /* next restart number to write (0-7) */ | 41 int next_restart_num; /* next restart number to write (0-7) */ |
| 39 | 42 |
| 40 /* Pointers to statistics areas (these workspaces have image lifespan) */ | 43 /* Pointers to statistics areas (these workspaces have image lifespan) */ |
| 41 unsigned char * dc_stats[NUM_ARITH_TBLS]; | 44 unsigned char *dc_stats[NUM_ARITH_TBLS]; |
| 42 unsigned char * ac_stats[NUM_ARITH_TBLS]; | 45 unsigned char *ac_stats[NUM_ARITH_TBLS]; |
| 43 | 46 |
| 44 /* Statistics bin for coding with fixed probability 0.5 */ | 47 /* Statistics bin for coding with fixed probability 0.5 */ |
| 45 unsigned char fixed_bin[4]; | 48 unsigned char fixed_bin[4]; |
| 46 } arith_entropy_encoder; | 49 } arith_entropy_encoder; |
| 47 | 50 |
| 48 typedef arith_entropy_encoder * arith_entropy_ptr; | 51 typedef arith_entropy_encoder *arith_entropy_ptr; |
| 49 | 52 |
| 50 /* The following two definitions specify the allocation chunk size | 53 /* The following two definitions specify the allocation chunk size |
| 51 * for the statistics area. | 54 * for the statistics area. |
| 52 * According to sections F.1.4.4.1.3 and F.1.4.4.2, we need at least | 55 * According to sections F.1.4.4.1.3 and F.1.4.4.2, we need at least |
| 53 * 49 statistics bins for DC, and 245 statistics bins for AC coding. | 56 * 49 statistics bins for DC, and 245 statistics bins for AC coding. |
| 54 * | 57 * |
| 55 * We use a compact representation with 1 byte per statistics bin, | 58 * We use a compact representation with 1 byte per statistics bin, |
| 56 * thus the numbers directly represent byte sizes. | 59 * thus the numbers directly represent byte sizes. |
| 57 * This 1 byte per statistics bin contains the meaning of the MPS | 60 * This 1 byte per statistics bin contains the meaning of the MPS |
| 58 * (more probable symbol) in the highest bit (mask 0x80), and the | 61 * (more probable symbol) in the highest bit (mask 0x80), and the |
| (...skipping 29 matching lines...) Expand all Loading... |
| 88 * that the conditioning has no significant influence on the | 91 * that the conditioning has no significant influence on the |
| 89 * compression performance. This means that the basic | 92 * compression performance. This means that the basic |
| 90 * statistical model is already rather stable. | 93 * statistical model is already rather stable. |
| 91 * | 94 * |
| 92 * Thus, at the moment, we use the default conditioning values | 95 * Thus, at the moment, we use the default conditioning values |
| 93 * anyway, and do not use the custom formula. | 96 * anyway, and do not use the custom formula. |
| 94 * | 97 * |
| 95 #define CALCULATE_SPECTRAL_CONDITIONING | 98 #define CALCULATE_SPECTRAL_CONDITIONING |
| 96 */ | 99 */ |
| 97 | 100 |
| 98 /* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than INT32. | 101 /* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than JLONG. |
| 99 * We assume that int right shift is unsigned if INT32 right shift is, | 102 * We assume that int right shift is unsigned if JLONG right shift is, |
| 100 * which should be safe. | 103 * which should be safe. |
| 101 */ | 104 */ |
| 102 | 105 |
| 103 #ifdef RIGHT_SHIFT_IS_UNSIGNED | 106 #ifdef RIGHT_SHIFT_IS_UNSIGNED |
| 104 #define ISHIFT_TEMPS» int ishift_temp; | 107 #define ISHIFT_TEMPS int ishift_temp; |
| 105 #define IRIGHT_SHIFT(x,shft) \ | 108 #define IRIGHT_SHIFT(x,shft) \ |
| 106 » ((ishift_temp = (x)) < 0 ? \ | 109 ((ishift_temp = (x)) < 0 ? \ |
| 107 » (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ | 110 (ishift_temp >> (shft)) | ((~0) << (16-(shft))) : \ |
| 108 » (ishift_temp >> (shft))) | 111 (ishift_temp >> (shft))) |
| 109 #else | 112 #else |
| 110 #define ISHIFT_TEMPS | 113 #define ISHIFT_TEMPS |
| 111 #define IRIGHT_SHIFT(x,shft)» ((x) >> (shft)) | 114 #define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) |
| 112 #endif | 115 #endif |
| 113 | 116 |
| 114 | 117 |
| 115 LOCAL(void) | 118 LOCAL(void) |
| 116 emit_byte (int val, j_compress_ptr cinfo) | 119 emit_byte (int val, j_compress_ptr cinfo) |
| 117 /* Write next output byte; we do not support suspension in this module. */ | 120 /* Write next output byte; we do not support suspension in this module. */ |
| 118 { | 121 { |
| 119 struct jpeg_destination_mgr * dest = cinfo->dest; | 122 struct jpeg_destination_mgr *dest = cinfo->dest; |
| 120 | 123 |
| 121 *dest->next_output_byte++ = (JOCTET) val; | 124 *dest->next_output_byte++ = (JOCTET) val; |
| 122 if (--dest->free_in_buffer == 0) | 125 if (--dest->free_in_buffer == 0) |
| 123 if (! (*dest->empty_output_buffer) (cinfo)) | 126 if (! (*dest->empty_output_buffer) (cinfo)) |
| 124 ERREXIT(cinfo, JERR_CANT_SUSPEND); | 127 ERREXIT(cinfo, JERR_CANT_SUSPEND); |
| 125 } | 128 } |
| 126 | 129 |
| 127 | 130 |
| 128 /* | 131 /* |
| 129 * Finish up at the end of an arithmetic-compressed scan. | 132 * Finish up at the end of an arithmetic-compressed scan. |
| 130 */ | 133 */ |
| 131 | 134 |
| 132 METHODDEF(void) | 135 METHODDEF(void) |
| 133 finish_pass (j_compress_ptr cinfo) | 136 finish_pass (j_compress_ptr cinfo) |
| 134 { | 137 { |
| 135 arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; | 138 arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; |
| 136 INT32 temp; | 139 JLONG temp; |
| 137 | 140 |
| 138 /* Section D.1.8: Termination of encoding */ | 141 /* Section D.1.8: Termination of encoding */ |
| 139 | 142 |
| 140 /* Find the e->c in the coding interval with the largest | 143 /* Find the e->c in the coding interval with the largest |
| 141 * number of trailing zero bits */ | 144 * number of trailing zero bits */ |
| 142 if ((temp = (e->a - 1 + e->c) & 0xFFFF0000L) < e->c) | 145 if ((temp = (e->a - 1 + e->c) & 0xFFFF0000L) < e->c) |
| 143 e->c = temp + 0x8000L; | 146 e->c = temp + 0x8000L; |
| 144 else | 147 else |
| 145 e->c = temp; | 148 e->c = temp; |
| 146 /* Send remaining bytes to output */ | 149 /* Send remaining bytes to output */ |
| 147 e->c <<= e->ct; | 150 e->c <<= e->ct; |
| 148 if (e->c & 0xF8000000L) { | 151 if (e->c & 0xF8000000L) { |
| 149 /* One final overflow has to be handled */ | 152 /* One final overflow has to be handled */ |
| 150 if (e->buffer >= 0) { | 153 if (e->buffer >= 0) { |
| 151 if (e->zc) | 154 if (e->zc) |
| 152 » do emit_byte(0x00, cinfo); | 155 do emit_byte(0x00, cinfo); |
| 153 » while (--e->zc); | 156 while (--e->zc); |
| 154 emit_byte(e->buffer + 1, cinfo); | 157 emit_byte(e->buffer + 1, cinfo); |
| 155 if (e->buffer + 1 == 0xFF) | 158 if (e->buffer + 1 == 0xFF) |
| 156 » emit_byte(0x00, cinfo); | 159 emit_byte(0x00, cinfo); |
| 157 } | 160 } |
| 158 e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ | 161 e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ |
| 159 e->sc = 0; | 162 e->sc = 0; |
| 160 } else { | 163 } else { |
| 161 if (e->buffer == 0) | 164 if (e->buffer == 0) |
| 162 ++e->zc; | 165 ++e->zc; |
| 163 else if (e->buffer >= 0) { | 166 else if (e->buffer >= 0) { |
| 164 if (e->zc) | 167 if (e->zc) |
| 165 » do emit_byte(0x00, cinfo); | 168 do emit_byte(0x00, cinfo); |
| 166 » while (--e->zc); | 169 while (--e->zc); |
| 167 emit_byte(e->buffer, cinfo); | 170 emit_byte(e->buffer, cinfo); |
| 168 } | 171 } |
| 169 if (e->sc) { | 172 if (e->sc) { |
| 170 if (e->zc) | 173 if (e->zc) |
| 171 » do emit_byte(0x00, cinfo); | 174 do emit_byte(0x00, cinfo); |
| 172 » while (--e->zc); | 175 while (--e->zc); |
| 173 do { | 176 do { |
| 174 » emit_byte(0xFF, cinfo); | 177 emit_byte(0xFF, cinfo); |
| 175 » emit_byte(0x00, cinfo); | 178 emit_byte(0x00, cinfo); |
| 176 } while (--e->sc); | 179 } while (--e->sc); |
| 177 } | 180 } |
| 178 } | 181 } |
| 179 /* Output final bytes only if they are not 0x00 */ | 182 /* Output final bytes only if they are not 0x00 */ |
| 180 if (e->c & 0x7FFF800L) { | 183 if (e->c & 0x7FFF800L) { |
| 181 if (e->zc) /* output final pending zero bytes */ | 184 if (e->zc) /* output final pending zero bytes */ |
| 182 do emit_byte(0x00, cinfo); | 185 do emit_byte(0x00, cinfo); |
| 183 while (--e->zc); | 186 while (--e->zc); |
| 184 emit_byte((e->c >> 19) & 0xFF, cinfo); | 187 emit_byte((e->c >> 19) & 0xFF, cinfo); |
| 185 if (((e->c >> 19) & 0xFF) == 0xFF) | 188 if (((e->c >> 19) & 0xFF) == 0xFF) |
| 186 emit_byte(0x00, cinfo); | 189 emit_byte(0x00, cinfo); |
| 187 if (e->c & 0x7F800L) { | 190 if (e->c & 0x7F800L) { |
| 188 emit_byte((e->c >> 11) & 0xFF, cinfo); | 191 emit_byte((e->c >> 11) & 0xFF, cinfo); |
| 189 if (((e->c >> 11) & 0xFF) == 0xFF) | 192 if (((e->c >> 11) & 0xFF) == 0xFF) |
| 190 » emit_byte(0x00, cinfo); | 193 emit_byte(0x00, cinfo); |
| 191 } | 194 } |
| 192 } | 195 } |
| 193 } | 196 } |
| 194 | 197 |
| 195 | 198 |
| 196 /* | 199 /* |
| 197 * The core arithmetic encoding routine (common in JPEG and JBIG). | 200 * The core arithmetic encoding routine (common in JPEG and JBIG). |
| 198 * This needs to go as fast as possible. | 201 * This needs to go as fast as possible. |
| 199 * Machine-dependent optimization facilities | 202 * Machine-dependent optimization facilities |
| 200 * are not utilized in this portable implementation. | 203 * are not utilized in this portable implementation. |
| 201 * However, this code should be fairly efficient and | 204 * However, this code should be fairly efficient and |
| 202 * may be a good base for further optimizations anyway. | 205 * may be a good base for further optimizations anyway. |
| 203 * | 206 * |
| 204 * Parameter 'val' to be encoded may be 0 or 1 (binary decision). | 207 * Parameter 'val' to be encoded may be 0 or 1 (binary decision). |
| 205 * | 208 * |
| 206 * Note: I've added full "Pacman" termination support to the | 209 * Note: I've added full "Pacman" termination support to the |
| 207 * byte output routines, which is equivalent to the optional | 210 * byte output routines, which is equivalent to the optional |
| 208 * Discard_final_zeros procedure (Figure D.15) in the spec. | 211 * Discard_final_zeros procedure (Figure D.15) in the spec. |
| 209 * Thus, we always produce the shortest possible output | 212 * Thus, we always produce the shortest possible output |
| 210 * stream compliant to the spec (no trailing zero bytes, | 213 * stream compliant to the spec (no trailing zero bytes, |
| 211 * except for FF stuffing). | 214 * except for FF stuffing). |
| 212 * | 215 * |
| 213 * I've also introduced a new scheme for accessing | 216 * I've also introduced a new scheme for accessing |
| 214 * the probability estimation state machine table, | 217 * the probability estimation state machine table, |
| 215 * derived from Markus Kuhn's JBIG implementation. | 218 * derived from Markus Kuhn's JBIG implementation. |
| 216 */ | 219 */ |
| 217 | 220 |
| 218 LOCAL(void) | 221 LOCAL(void) |
| 219 arith_encode (j_compress_ptr cinfo, unsigned char *st, int val) | 222 arith_encode (j_compress_ptr cinfo, unsigned char *st, int val) |
| 220 { | 223 { |
| 221 register arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; | 224 register arith_entropy_ptr e = (arith_entropy_ptr) cinfo->entropy; |
| 222 register unsigned char nl, nm; | 225 register unsigned char nl, nm; |
| 223 register INT32 qe, temp; | 226 register JLONG qe, temp; |
| 224 register int sv; | 227 register int sv; |
| 225 | 228 |
| 226 /* Fetch values from our compact representation of Table D.2: | 229 /* Fetch values from our compact representation of Table D.2: |
| 227 * Qe values and probability estimation state machine | 230 * Qe values and probability estimation state machine |
| 228 */ | 231 */ |
| 229 sv = *st; | 232 sv = *st; |
| 230 qe = jpeg_aritab[sv & 0x7F];» /* => Qe_Value */ | 233 qe = jpeg_aritab[sv & 0x7F]; /* => Qe_Value */ |
| 231 nl = qe & 0xFF; qe >>= 8;» /* Next_Index_LPS + Switch_MPS */ | 234 nl = qe & 0xFF; qe >>= 8; /* Next_Index_LPS + Switch_MPS */ |
| 232 nm = qe & 0xFF; qe >>= 8;» /* Next_Index_MPS */ | 235 nm = qe & 0xFF; qe >>= 8; /* Next_Index_MPS */ |
| 233 | 236 |
| 234 /* Encode & estimation procedures per sections D.1.4 & D.1.5 */ | 237 /* Encode & estimation procedures per sections D.1.4 & D.1.5 */ |
| 235 e->a -= qe; | 238 e->a -= qe; |
| 236 if (val != (sv >> 7)) { | 239 if (val != (sv >> 7)) { |
| 237 /* Encode the less probable symbol */ | 240 /* Encode the less probable symbol */ |
| 238 if (e->a >= qe) { | 241 if (e->a >= qe) { |
| 239 /* If the interval size (qe) for the less probable symbol (LPS) | 242 /* If the interval size (qe) for the less probable symbol (LPS) |
| 240 * is larger than the interval size for the MPS, then exchange | 243 * is larger than the interval size for the MPS, then exchange |
| 241 * the two symbols for coding efficiency, otherwise code the LPS | 244 * the two symbols for coding efficiency, otherwise code the LPS |
| 242 * as usual: */ | 245 * as usual: */ |
| 243 e->c += e->a; | 246 e->c += e->a; |
| 244 e->a = qe; | 247 e->a = qe; |
| 245 } | 248 } |
| 246 *st = (sv & 0x80) ^ nl;» /* Estimate_after_LPS */ | 249 *st = (sv & 0x80) ^ nl; /* Estimate_after_LPS */ |
| 247 } else { | 250 } else { |
| 248 /* Encode the more probable symbol */ | 251 /* Encode the more probable symbol */ |
| 249 if (e->a >= 0x8000L) | 252 if (e->a >= 0x8000L) |
| 250 return; /* A >= 0x8000 -> ready, no renormalization required */ | 253 return; /* A >= 0x8000 -> ready, no renormalization required */ |
| 251 if (e->a < qe) { | 254 if (e->a < qe) { |
| 252 /* If the interval size (qe) for the less probable symbol (LPS) | 255 /* If the interval size (qe) for the less probable symbol (LPS) |
| 253 * is larger than the interval size for the MPS, then exchange | 256 * is larger than the interval size for the MPS, then exchange |
| 254 * the two symbols for coding efficiency: */ | 257 * the two symbols for coding efficiency: */ |
| 255 e->c += e->a; | 258 e->c += e->a; |
| 256 e->a = qe; | 259 e->a = qe; |
| 257 } | 260 } |
| 258 *st = (sv & 0x80) ^ nm;» /* Estimate_after_MPS */ | 261 *st = (sv & 0x80) ^ nm; /* Estimate_after_MPS */ |
| 259 } | 262 } |
| 260 | 263 |
| 261 /* Renormalization & data output per section D.1.6 */ | 264 /* Renormalization & data output per section D.1.6 */ |
| 262 do { | 265 do { |
| 263 e->a <<= 1; | 266 e->a <<= 1; |
| 264 e->c <<= 1; | 267 e->c <<= 1; |
| 265 if (--e->ct == 0) { | 268 if (--e->ct == 0) { |
| 266 /* Another byte is ready for output */ | 269 /* Another byte is ready for output */ |
| 267 temp = e->c >> 19; | 270 temp = e->c >> 19; |
| 268 if (temp > 0xFF) { | 271 if (temp > 0xFF) { |
| 269 » /* Handle overflow over all stacked 0xFF bytes */ | 272 /* Handle overflow over all stacked 0xFF bytes */ |
| 270 » if (e->buffer >= 0) { | 273 if (e->buffer >= 0) { |
| 271 » if (e->zc) | 274 if (e->zc) |
| 272 » do emit_byte(0x00, cinfo); | 275 do emit_byte(0x00, cinfo); |
| 273 » while (--e->zc); | 276 while (--e->zc); |
| 274 » emit_byte(e->buffer + 1, cinfo); | 277 emit_byte(e->buffer + 1, cinfo); |
| 275 » if (e->buffer + 1 == 0xFF) | 278 if (e->buffer + 1 == 0xFF) |
| 276 » emit_byte(0x00, cinfo); | 279 emit_byte(0x00, cinfo); |
| 277 » } | 280 } |
| 278 » e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ | 281 e->zc += e->sc; /* carry-over converts stacked 0xFF bytes to 0x00 */ |
| 279 » e->sc = 0; | 282 e->sc = 0; |
| 280 » /* Note: The 3 spacer bits in the C register guarantee | 283 /* Note: The 3 spacer bits in the C register guarantee |
| 281 » * that the new buffer byte can't be 0xFF here | 284 * that the new buffer byte can't be 0xFF here |
| 282 » * (see page 160 in the P&M JPEG book). */ | 285 * (see page 160 in the P&M JPEG book). */ |
| 283 » e->buffer = temp & 0xFF; /* new output byte, might overflow later */ | 286 e->buffer = temp & 0xFF; /* new output byte, might overflow later */ |
| 284 } else if (temp == 0xFF) { | 287 } else if (temp == 0xFF) { |
| 285 » ++e->sc; /* stack 0xFF byte (which might overflow later) */ | 288 ++e->sc; /* stack 0xFF byte (which might overflow later) */ |
| 286 } else { | 289 } else { |
| 287 » /* Output all stacked 0xFF bytes, they will not overflow any more */ | 290 /* Output all stacked 0xFF bytes, they will not overflow any more */ |
| 288 » if (e->buffer == 0) | 291 if (e->buffer == 0) |
| 289 » ++e->zc; | 292 ++e->zc; |
| 290 » else if (e->buffer >= 0) { | 293 else if (e->buffer >= 0) { |
| 291 » if (e->zc) | 294 if (e->zc) |
| 292 » do emit_byte(0x00, cinfo); | 295 do emit_byte(0x00, cinfo); |
| 293 » while (--e->zc); | 296 while (--e->zc); |
| 294 » emit_byte(e->buffer, cinfo); | 297 emit_byte(e->buffer, cinfo); |
| 295 » } | 298 } |
| 296 » if (e->sc) { | 299 if (e->sc) { |
| 297 » if (e->zc) | 300 if (e->zc) |
| 298 » do emit_byte(0x00, cinfo); | 301 do emit_byte(0x00, cinfo); |
| 299 » while (--e->zc); | 302 while (--e->zc); |
| 300 » do { | 303 do { |
| 301 » emit_byte(0xFF, cinfo); | 304 emit_byte(0xFF, cinfo); |
| 302 » emit_byte(0x00, cinfo); | 305 emit_byte(0x00, cinfo); |
| 303 » } while (--e->sc); | 306 } while (--e->sc); |
| 304 » } | 307 } |
| 305 » e->buffer = temp & 0xFF; /* new output byte (can still overflow) */ | 308 e->buffer = temp & 0xFF; /* new output byte (can still overflow) */ |
| 306 } | 309 } |
| 307 e->c &= 0x7FFFFL; | 310 e->c &= 0x7FFFFL; |
| 308 e->ct += 8; | 311 e->ct += 8; |
| 309 } | 312 } |
| 310 } while (e->a < 0x8000L); | 313 } while (e->a < 0x8000L); |
| 311 } | 314 } |
| 312 | 315 |
| 313 | 316 |
| 314 /* | 317 /* |
| 315 * Emit a restart marker & resynchronize predictions. | 318 * Emit a restart marker & resynchronize predictions. |
| 316 */ | 319 */ |
| 317 | 320 |
| 318 LOCAL(void) | 321 LOCAL(void) |
| 319 emit_restart (j_compress_ptr cinfo, int restart_num) | 322 emit_restart (j_compress_ptr cinfo, int restart_num) |
| 320 { | 323 { |
| 321 arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; | 324 arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
| 322 int ci; | 325 int ci; |
| 323 jpeg_component_info * compptr; | 326 jpeg_component_info *compptr; |
| 324 | 327 |
| 325 finish_pass(cinfo); | 328 finish_pass(cinfo); |
| 326 | 329 |
| 327 emit_byte(0xFF, cinfo); | 330 emit_byte(0xFF, cinfo); |
| 328 emit_byte(JPEG_RST0 + restart_num, cinfo); | 331 emit_byte(JPEG_RST0 + restart_num, cinfo); |
| 329 | 332 |
| 330 /* Re-initialize statistics areas */ | 333 /* Re-initialize statistics areas */ |
| 331 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | 334 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| 332 compptr = cinfo->cur_comp_info[ci]; | 335 compptr = cinfo->cur_comp_info[ci]; |
| 333 /* DC needs no table for refinement scan */ | 336 /* DC needs no table for refinement scan */ |
| (...skipping 57 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
| 391 m = IRIGHT_SHIFT((int) ((*block)[0]), cinfo->Al); | 394 m = IRIGHT_SHIFT((int) ((*block)[0]), cinfo->Al); |
| 392 | 395 |
| 393 /* Sections F.1.4.1 & F.1.4.4.1: Encoding of DC coefficients */ | 396 /* Sections F.1.4.1 & F.1.4.4.1: Encoding of DC coefficients */ |
| 394 | 397 |
| 395 /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ | 398 /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ |
| 396 st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; | 399 st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; |
| 397 | 400 |
| 398 /* Figure F.4: Encode_DC_DIFF */ | 401 /* Figure F.4: Encode_DC_DIFF */ |
| 399 if ((v = m - entropy->last_dc_val[ci]) == 0) { | 402 if ((v = m - entropy->last_dc_val[ci]) == 0) { |
| 400 arith_encode(cinfo, st, 0); | 403 arith_encode(cinfo, st, 0); |
| 401 entropy->dc_context[ci] = 0;» /* zero diff category */ | 404 entropy->dc_context[ci] = 0; /* zero diff category */ |
| 402 } else { | 405 } else { |
| 403 entropy->last_dc_val[ci] = m; | 406 entropy->last_dc_val[ci] = m; |
| 404 arith_encode(cinfo, st, 1); | 407 arith_encode(cinfo, st, 1); |
| 405 /* Figure F.6: Encoding nonzero value v */ | 408 /* Figure F.6: Encoding nonzero value v */ |
| 406 /* Figure F.7: Encoding the sign of v */ | 409 /* Figure F.7: Encoding the sign of v */ |
| 407 if (v > 0) { | 410 if (v > 0) { |
| 408 » arith_encode(cinfo, st + 1, 0);»/* Table F.4: SS = S0 + 1 */ | 411 arith_encode(cinfo, st + 1, 0); /* Table F.4: SS = S0 + 1 */ |
| 409 » st += 2;» » » /* Table F.4: SP = S0 + 2 */ | 412 st += 2; /* Table F.4: SP = S0 + 2 */ |
| 410 » entropy->dc_context[ci] = 4;» /* small positive diff category */ | 413 entropy->dc_context[ci] = 4; /* small positive diff category */ |
| 411 } else { | 414 } else { |
| 412 » v = -v; | 415 v = -v; |
| 413 » arith_encode(cinfo, st + 1, 1);»/* Table F.4: SS = S0 + 1 */ | 416 arith_encode(cinfo, st + 1, 1); /* Table F.4: SS = S0 + 1 */ |
| 414 » st += 3;» » » /* Table F.4: SN = S0 + 3 */ | 417 st += 3; /* Table F.4: SN = S0 + 3 */ |
| 415 » entropy->dc_context[ci] = 8;» /* small negative diff category */ | 418 entropy->dc_context[ci] = 8; /* small negative diff category */ |
| 416 } | 419 } |
| 417 /* Figure F.8: Encoding the magnitude category of v */ | 420 /* Figure F.8: Encoding the magnitude category of v */ |
| 418 m = 0; | 421 m = 0; |
| 419 if (v -= 1) { | 422 if (v -= 1) { |
| 420 » arith_encode(cinfo, st, 1); | 423 arith_encode(cinfo, st, 1); |
| 421 » m = 1; | 424 m = 1; |
| 422 » v2 = v; | 425 v2 = v; |
| 423 » st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ | 426 st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ |
| 424 » while (v2 >>= 1) { | 427 while (v2 >>= 1) { |
| 425 » arith_encode(cinfo, st, 1); | 428 arith_encode(cinfo, st, 1); |
| 426 » m <<= 1; | 429 m <<= 1; |
| 427 » st += 1; | 430 st += 1; |
| 428 » } | 431 } |
| 429 } | 432 } |
| 430 arith_encode(cinfo, st, 0); | 433 arith_encode(cinfo, st, 0); |
| 431 /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ | 434 /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ |
| 432 if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) | 435 if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) |
| 433 » entropy->dc_context[ci] = 0;» /* zero diff category */ | 436 entropy->dc_context[ci] = 0; /* zero diff category */ |
| 434 else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) | 437 else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) |
| 435 » entropy->dc_context[ci] += 8;» /* large diff category */ | 438 entropy->dc_context[ci] += 8; /* large diff category */ |
| 436 /* Figure F.9: Encoding the magnitude bit pattern of v */ | 439 /* Figure F.9: Encoding the magnitude bit pattern of v */ |
| 437 st += 14; | 440 st += 14; |
| 438 while (m >>= 1) | 441 while (m >>= 1) |
| 439 » arith_encode(cinfo, st, (m & v) ? 1 : 0); | 442 arith_encode(cinfo, st, (m & v) ? 1 : 0); |
| 440 } | 443 } |
| 441 } | 444 } |
| 442 | 445 |
| 443 return TRUE; | 446 return TRUE; |
| 444 } | 447 } |
| 445 | 448 |
| 446 | 449 |
| 447 /* | 450 /* |
| 448 * MCU encoding for AC initial scan (either spectral selection, | 451 * MCU encoding for AC initial scan (either spectral selection, |
| 449 * or first pass of successive approximation). | 452 * or first pass of successive approximation). |
| (...skipping 34 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
| 484 if ((v = (*block)[jpeg_natural_order[ke]]) >= 0) { | 487 if ((v = (*block)[jpeg_natural_order[ke]]) >= 0) { |
| 485 if (v >>= cinfo->Al) break; | 488 if (v >>= cinfo->Al) break; |
| 486 } else { | 489 } else { |
| 487 v = -v; | 490 v = -v; |
| 488 if (v >>= cinfo->Al) break; | 491 if (v >>= cinfo->Al) break; |
| 489 } | 492 } |
| 490 | 493 |
| 491 /* Figure F.5: Encode_AC_Coefficients */ | 494 /* Figure F.5: Encode_AC_Coefficients */ |
| 492 for (k = cinfo->Ss; k <= ke; k++) { | 495 for (k = cinfo->Ss; k <= ke; k++) { |
| 493 st = entropy->ac_stats[tbl] + 3 * (k - 1); | 496 st = entropy->ac_stats[tbl] + 3 * (k - 1); |
| 494 arith_encode(cinfo, st, 0);»» /* EOB decision */ | 497 arith_encode(cinfo, st, 0); /* EOB decision */ |
| 495 for (;;) { | 498 for (;;) { |
| 496 if ((v = (*block)[jpeg_natural_order[k]]) >= 0) { | 499 if ((v = (*block)[jpeg_natural_order[k]]) >= 0) { |
| 497 » if (v >>= cinfo->Al) { | 500 if (v >>= cinfo->Al) { |
| 498 » arith_encode(cinfo, st + 1, 1); | 501 arith_encode(cinfo, st + 1, 1); |
| 499 » arith_encode(cinfo, entropy->fixed_bin, 0); | 502 arith_encode(cinfo, entropy->fixed_bin, 0); |
| 500 » break; | 503 break; |
| 501 » } | 504 } |
| 502 } else { | 505 } else { |
| 503 » v = -v; | 506 v = -v; |
| 504 » if (v >>= cinfo->Al) { | 507 if (v >>= cinfo->Al) { |
| 505 » arith_encode(cinfo, st + 1, 1); | 508 arith_encode(cinfo, st + 1, 1); |
| 506 » arith_encode(cinfo, entropy->fixed_bin, 1); | 509 arith_encode(cinfo, entropy->fixed_bin, 1); |
| 507 » break; | 510 break; |
| 508 » } | 511 } |
| 509 } | 512 } |
| 510 arith_encode(cinfo, st + 1, 0); st += 3; k++; | 513 arith_encode(cinfo, st + 1, 0); st += 3; k++; |
| 511 } | 514 } |
| 512 st += 2; | 515 st += 2; |
| 513 /* Figure F.8: Encoding the magnitude category of v */ | 516 /* Figure F.8: Encoding the magnitude category of v */ |
| 514 m = 0; | 517 m = 0; |
| 515 if (v -= 1) { | 518 if (v -= 1) { |
| 516 arith_encode(cinfo, st, 1); | 519 arith_encode(cinfo, st, 1); |
| 517 m = 1; | 520 m = 1; |
| 518 v2 = v; | 521 v2 = v; |
| 519 if (v2 >>= 1) { | 522 if (v2 >>= 1) { |
| 520 » arith_encode(cinfo, st, 1); | 523 arith_encode(cinfo, st, 1); |
| 521 » m <<= 1; | 524 m <<= 1; |
| 522 » st = entropy->ac_stats[tbl] + | 525 st = entropy->ac_stats[tbl] + |
| 523 » (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); | 526 (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); |
| 524 » while (v2 >>= 1) { | 527 while (v2 >>= 1) { |
| 525 » arith_encode(cinfo, st, 1); | 528 arith_encode(cinfo, st, 1); |
| 526 » m <<= 1; | 529 m <<= 1; |
| 527 » st += 1; | 530 st += 1; |
| 528 » } | 531 } |
| 529 } | 532 } |
| 530 } | 533 } |
| 531 arith_encode(cinfo, st, 0); | 534 arith_encode(cinfo, st, 0); |
| 532 /* Figure F.9: Encoding the magnitude bit pattern of v */ | 535 /* Figure F.9: Encoding the magnitude bit pattern of v */ |
| 533 st += 14; | 536 st += 14; |
| 534 while (m >>= 1) | 537 while (m >>= 1) |
| 535 arith_encode(cinfo, st, (m & v) ? 1 : 0); | 538 arith_encode(cinfo, st, (m & v) ? 1 : 0); |
| 536 } | 539 } |
| 537 /* Encode EOB decision only if k <= cinfo->Se */ | 540 /* Encode EOB decision only if k <= cinfo->Se */ |
| 538 if (k <= cinfo->Se) { | 541 if (k <= cinfo->Se) { |
| (...skipping 20 matching lines...) Expand all Loading... |
| 559 if (cinfo->restart_interval) { | 562 if (cinfo->restart_interval) { |
| 560 if (entropy->restarts_to_go == 0) { | 563 if (entropy->restarts_to_go == 0) { |
| 561 emit_restart(cinfo, entropy->next_restart_num); | 564 emit_restart(cinfo, entropy->next_restart_num); |
| 562 entropy->restarts_to_go = cinfo->restart_interval; | 565 entropy->restarts_to_go = cinfo->restart_interval; |
| 563 entropy->next_restart_num++; | 566 entropy->next_restart_num++; |
| 564 entropy->next_restart_num &= 7; | 567 entropy->next_restart_num &= 7; |
| 565 } | 568 } |
| 566 entropy->restarts_to_go--; | 569 entropy->restarts_to_go--; |
| 567 } | 570 } |
| 568 | 571 |
| 569 st = entropy->fixed_bin;» /* use fixed probability estimation */ | 572 st = entropy->fixed_bin; /* use fixed probability estimation */ |
| 570 Al = cinfo->Al; | 573 Al = cinfo->Al; |
| 571 | 574 |
| 572 /* Encode the MCU data blocks */ | 575 /* Encode the MCU data blocks */ |
| 573 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { | 576 for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) { |
| 574 /* We simply emit the Al'th bit of the DC coefficient value. */ | 577 /* We simply emit the Al'th bit of the DC coefficient value. */ |
| 575 arith_encode(cinfo, st, (MCU_data[blkn][0][0] >> Al) & 1); | 578 arith_encode(cinfo, st, (MCU_data[blkn][0][0] >> Al) & 1); |
| 576 } | 579 } |
| 577 | 580 |
| 578 return TRUE; | 581 return TRUE; |
| 579 } | 582 } |
| (...skipping 48 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
| 628 if (v >>= cinfo->Ah) break; | 631 if (v >>= cinfo->Ah) break; |
| 629 } else { | 632 } else { |
| 630 v = -v; | 633 v = -v; |
| 631 if (v >>= cinfo->Ah) break; | 634 if (v >>= cinfo->Ah) break; |
| 632 } | 635 } |
| 633 | 636 |
| 634 /* Figure G.10: Encode_AC_Coefficients_SA */ | 637 /* Figure G.10: Encode_AC_Coefficients_SA */ |
| 635 for (k = cinfo->Ss; k <= ke; k++) { | 638 for (k = cinfo->Ss; k <= ke; k++) { |
| 636 st = entropy->ac_stats[tbl] + 3 * (k - 1); | 639 st = entropy->ac_stats[tbl] + 3 * (k - 1); |
| 637 if (k > kex) | 640 if (k > kex) |
| 638 arith_encode(cinfo, st, 0);» /* EOB decision */ | 641 arith_encode(cinfo, st, 0); /* EOB decision */ |
| 639 for (;;) { | 642 for (;;) { |
| 640 if ((v = (*block)[jpeg_natural_order[k]]) >= 0) { | 643 if ((v = (*block)[jpeg_natural_order[k]]) >= 0) { |
| 641 » if (v >>= cinfo->Al) { | 644 if (v >>= cinfo->Al) { |
| 642 » if (v >> 1)» » » /* previously nonzero coef */ | 645 if (v >> 1) /* previously nonzero coef */ |
| 643 » arith_encode(cinfo, st + 2, (v & 1)); | 646 arith_encode(cinfo, st + 2, (v & 1)); |
| 644 » else {» » » /* newly nonzero coef */ | 647 else { /* newly nonzero coef */ |
| 645 » arith_encode(cinfo, st + 1, 1); | 648 arith_encode(cinfo, st + 1, 1); |
| 646 » arith_encode(cinfo, entropy->fixed_bin, 0); | 649 arith_encode(cinfo, entropy->fixed_bin, 0); |
| 647 » } | 650 } |
| 648 » break; | 651 break; |
| 649 » } | 652 } |
| 650 } else { | 653 } else { |
| 651 » v = -v; | 654 v = -v; |
| 652 » if (v >>= cinfo->Al) { | 655 if (v >>= cinfo->Al) { |
| 653 » if (v >> 1)» » » /* previously nonzero coef */ | 656 if (v >> 1) /* previously nonzero coef */ |
| 654 » arith_encode(cinfo, st + 2, (v & 1)); | 657 arith_encode(cinfo, st + 2, (v & 1)); |
| 655 » else {» » » /* newly nonzero coef */ | 658 else { /* newly nonzero coef */ |
| 656 » arith_encode(cinfo, st + 1, 1); | 659 arith_encode(cinfo, st + 1, 1); |
| 657 » arith_encode(cinfo, entropy->fixed_bin, 1); | 660 arith_encode(cinfo, entropy->fixed_bin, 1); |
| 658 » } | 661 } |
| 659 » break; | 662 break; |
| 660 » } | 663 } |
| 661 } | 664 } |
| 662 arith_encode(cinfo, st + 1, 0); st += 3; k++; | 665 arith_encode(cinfo, st + 1, 0); st += 3; k++; |
| 663 } | 666 } |
| 664 } | 667 } |
| 665 /* Encode EOB decision only if k <= cinfo->Se */ | 668 /* Encode EOB decision only if k <= cinfo->Se */ |
| 666 if (k <= cinfo->Se) { | 669 if (k <= cinfo->Se) { |
| 667 st = entropy->ac_stats[tbl] + 3 * (k - 1); | 670 st = entropy->ac_stats[tbl] + 3 * (k - 1); |
| 668 arith_encode(cinfo, st, 1); | 671 arith_encode(cinfo, st, 1); |
| 669 } | 672 } |
| 670 | 673 |
| 671 return TRUE; | 674 return TRUE; |
| 672 } | 675 } |
| 673 | 676 |
| 674 | 677 |
| 675 /* | 678 /* |
| 676 * Encode and output one MCU's worth of arithmetic-compressed coefficients. | 679 * Encode and output one MCU's worth of arithmetic-compressed coefficients. |
| 677 */ | 680 */ |
| 678 | 681 |
| 679 METHODDEF(boolean) | 682 METHODDEF(boolean) |
| 680 encode_mcu (j_compress_ptr cinfo, JBLOCKROW *MCU_data) | 683 encode_mcu (j_compress_ptr cinfo, JBLOCKROW *MCU_data) |
| 681 { | 684 { |
| 682 arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; | 685 arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
| 683 jpeg_component_info * compptr; | 686 jpeg_component_info *compptr; |
| 684 JBLOCKROW block; | 687 JBLOCKROW block; |
| 685 unsigned char *st; | 688 unsigned char *st; |
| 686 int blkn, ci, tbl, k, ke; | 689 int blkn, ci, tbl, k, ke; |
| 687 int v, v2, m; | 690 int v, v2, m; |
| 688 | 691 |
| 689 /* Emit restart marker if needed */ | 692 /* Emit restart marker if needed */ |
| 690 if (cinfo->restart_interval) { | 693 if (cinfo->restart_interval) { |
| 691 if (entropy->restarts_to_go == 0) { | 694 if (entropy->restarts_to_go == 0) { |
| 692 emit_restart(cinfo, entropy->next_restart_num); | 695 emit_restart(cinfo, entropy->next_restart_num); |
| 693 entropy->restarts_to_go = cinfo->restart_interval; | 696 entropy->restarts_to_go = cinfo->restart_interval; |
| (...skipping 12 matching lines...) Expand all Loading... |
| 706 /* Sections F.1.4.1 & F.1.4.4.1: Encoding of DC coefficients */ | 709 /* Sections F.1.4.1 & F.1.4.4.1: Encoding of DC coefficients */ |
| 707 | 710 |
| 708 tbl = compptr->dc_tbl_no; | 711 tbl = compptr->dc_tbl_no; |
| 709 | 712 |
| 710 /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ | 713 /* Table F.4: Point to statistics bin S0 for DC coefficient coding */ |
| 711 st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; | 714 st = entropy->dc_stats[tbl] + entropy->dc_context[ci]; |
| 712 | 715 |
| 713 /* Figure F.4: Encode_DC_DIFF */ | 716 /* Figure F.4: Encode_DC_DIFF */ |
| 714 if ((v = (*block)[0] - entropy->last_dc_val[ci]) == 0) { | 717 if ((v = (*block)[0] - entropy->last_dc_val[ci]) == 0) { |
| 715 arith_encode(cinfo, st, 0); | 718 arith_encode(cinfo, st, 0); |
| 716 entropy->dc_context[ci] = 0;» /* zero diff category */ | 719 entropy->dc_context[ci] = 0; /* zero diff category */ |
| 717 } else { | 720 } else { |
| 718 entropy->last_dc_val[ci] = (*block)[0]; | 721 entropy->last_dc_val[ci] = (*block)[0]; |
| 719 arith_encode(cinfo, st, 1); | 722 arith_encode(cinfo, st, 1); |
| 720 /* Figure F.6: Encoding nonzero value v */ | 723 /* Figure F.6: Encoding nonzero value v */ |
| 721 /* Figure F.7: Encoding the sign of v */ | 724 /* Figure F.7: Encoding the sign of v */ |
| 722 if (v > 0) { | 725 if (v > 0) { |
| 723 » arith_encode(cinfo, st + 1, 0);»/* Table F.4: SS = S0 + 1 */ | 726 arith_encode(cinfo, st + 1, 0); /* Table F.4: SS = S0 + 1 */ |
| 724 » st += 2;» » » /* Table F.4: SP = S0 + 2 */ | 727 st += 2; /* Table F.4: SP = S0 + 2 */ |
| 725 » entropy->dc_context[ci] = 4;» /* small positive diff category */ | 728 entropy->dc_context[ci] = 4; /* small positive diff category */ |
| 726 } else { | 729 } else { |
| 727 » v = -v; | 730 v = -v; |
| 728 » arith_encode(cinfo, st + 1, 1);»/* Table F.4: SS = S0 + 1 */ | 731 arith_encode(cinfo, st + 1, 1); /* Table F.4: SS = S0 + 1 */ |
| 729 » st += 3;» » » /* Table F.4: SN = S0 + 3 */ | 732 st += 3; /* Table F.4: SN = S0 + 3 */ |
| 730 » entropy->dc_context[ci] = 8;» /* small negative diff category */ | 733 entropy->dc_context[ci] = 8; /* small negative diff category */ |
| 731 } | 734 } |
| 732 /* Figure F.8: Encoding the magnitude category of v */ | 735 /* Figure F.8: Encoding the magnitude category of v */ |
| 733 m = 0; | 736 m = 0; |
| 734 if (v -= 1) { | 737 if (v -= 1) { |
| 735 » arith_encode(cinfo, st, 1); | 738 arith_encode(cinfo, st, 1); |
| 736 » m = 1; | 739 m = 1; |
| 737 » v2 = v; | 740 v2 = v; |
| 738 » st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ | 741 st = entropy->dc_stats[tbl] + 20; /* Table F.4: X1 = 20 */ |
| 739 » while (v2 >>= 1) { | 742 while (v2 >>= 1) { |
| 740 » arith_encode(cinfo, st, 1); | 743 arith_encode(cinfo, st, 1); |
| 741 » m <<= 1; | 744 m <<= 1; |
| 742 » st += 1; | 745 st += 1; |
| 743 » } | 746 } |
| 744 } | 747 } |
| 745 arith_encode(cinfo, st, 0); | 748 arith_encode(cinfo, st, 0); |
| 746 /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ | 749 /* Section F.1.4.4.1.2: Establish dc_context conditioning category */ |
| 747 if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) | 750 if (m < (int) ((1L << cinfo->arith_dc_L[tbl]) >> 1)) |
| 748 » entropy->dc_context[ci] = 0;» /* zero diff category */ | 751 entropy->dc_context[ci] = 0; /* zero diff category */ |
| 749 else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) | 752 else if (m > (int) ((1L << cinfo->arith_dc_U[tbl]) >> 1)) |
| 750 » entropy->dc_context[ci] += 8;» /* large diff category */ | 753 entropy->dc_context[ci] += 8; /* large diff category */ |
| 751 /* Figure F.9: Encoding the magnitude bit pattern of v */ | 754 /* Figure F.9: Encoding the magnitude bit pattern of v */ |
| 752 st += 14; | 755 st += 14; |
| 753 while (m >>= 1) | 756 while (m >>= 1) |
| 754 » arith_encode(cinfo, st, (m & v) ? 1 : 0); | 757 arith_encode(cinfo, st, (m & v) ? 1 : 0); |
| 755 } | 758 } |
| 756 | 759 |
| 757 /* Sections F.1.4.2 & F.1.4.4.2: Encoding of AC coefficients */ | 760 /* Sections F.1.4.2 & F.1.4.4.2: Encoding of AC coefficients */ |
| 758 | 761 |
| 759 tbl = compptr->ac_tbl_no; | 762 tbl = compptr->ac_tbl_no; |
| 760 | 763 |
| 761 /* Establish EOB (end-of-block) index */ | 764 /* Establish EOB (end-of-block) index */ |
| 762 for (ke = DCTSIZE2 - 1; ke > 0; ke--) | 765 for (ke = DCTSIZE2 - 1; ke > 0; ke--) |
| 763 if ((*block)[jpeg_natural_order[ke]]) break; | 766 if ((*block)[jpeg_natural_order[ke]]) break; |
| 764 | 767 |
| 765 /* Figure F.5: Encode_AC_Coefficients */ | 768 /* Figure F.5: Encode_AC_Coefficients */ |
| 766 for (k = 1; k <= ke; k++) { | 769 for (k = 1; k <= ke; k++) { |
| 767 st = entropy->ac_stats[tbl] + 3 * (k - 1); | 770 st = entropy->ac_stats[tbl] + 3 * (k - 1); |
| 768 arith_encode(cinfo, st, 0);» /* EOB decision */ | 771 arith_encode(cinfo, st, 0); /* EOB decision */ |
| 769 while ((v = (*block)[jpeg_natural_order[k]]) == 0) { | 772 while ((v = (*block)[jpeg_natural_order[k]]) == 0) { |
| 770 » arith_encode(cinfo, st + 1, 0); st += 3; k++; | 773 arith_encode(cinfo, st + 1, 0); st += 3; k++; |
| 771 } | 774 } |
| 772 arith_encode(cinfo, st + 1, 1); | 775 arith_encode(cinfo, st + 1, 1); |
| 773 /* Figure F.6: Encoding nonzero value v */ | 776 /* Figure F.6: Encoding nonzero value v */ |
| 774 /* Figure F.7: Encoding the sign of v */ | 777 /* Figure F.7: Encoding the sign of v */ |
| 775 if (v > 0) { | 778 if (v > 0) { |
| 776 » arith_encode(cinfo, entropy->fixed_bin, 0); | 779 arith_encode(cinfo, entropy->fixed_bin, 0); |
| 777 } else { | 780 } else { |
| 778 » v = -v; | 781 v = -v; |
| 779 » arith_encode(cinfo, entropy->fixed_bin, 1); | 782 arith_encode(cinfo, entropy->fixed_bin, 1); |
| 780 } | 783 } |
| 781 st += 2; | 784 st += 2; |
| 782 /* Figure F.8: Encoding the magnitude category of v */ | 785 /* Figure F.8: Encoding the magnitude category of v */ |
| 783 m = 0; | 786 m = 0; |
| 784 if (v -= 1) { | 787 if (v -= 1) { |
| 785 » arith_encode(cinfo, st, 1); | 788 arith_encode(cinfo, st, 1); |
| 786 » m = 1; | 789 m = 1; |
| 787 » v2 = v; | 790 v2 = v; |
| 788 » if (v2 >>= 1) { | 791 if (v2 >>= 1) { |
| 789 » arith_encode(cinfo, st, 1); | 792 arith_encode(cinfo, st, 1); |
| 790 » m <<= 1; | 793 m <<= 1; |
| 791 » st = entropy->ac_stats[tbl] + | 794 st = entropy->ac_stats[tbl] + |
| 792 » (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); | 795 (k <= cinfo->arith_ac_K[tbl] ? 189 : 217); |
| 793 » while (v2 >>= 1) { | 796 while (v2 >>= 1) { |
| 794 » arith_encode(cinfo, st, 1); | 797 arith_encode(cinfo, st, 1); |
| 795 » m <<= 1; | 798 m <<= 1; |
| 796 » st += 1; | 799 st += 1; |
| 797 » } | 800 } |
| 798 » } | 801 } |
| 799 } | 802 } |
| 800 arith_encode(cinfo, st, 0); | 803 arith_encode(cinfo, st, 0); |
| 801 /* Figure F.9: Encoding the magnitude bit pattern of v */ | 804 /* Figure F.9: Encoding the magnitude bit pattern of v */ |
| 802 st += 14; | 805 st += 14; |
| 803 while (m >>= 1) | 806 while (m >>= 1) |
| 804 » arith_encode(cinfo, st, (m & v) ? 1 : 0); | 807 arith_encode(cinfo, st, (m & v) ? 1 : 0); |
| 805 } | 808 } |
| 806 /* Encode EOB decision only if k <= DCTSIZE2 - 1 */ | 809 /* Encode EOB decision only if k <= DCTSIZE2 - 1 */ |
| 807 if (k <= DCTSIZE2 - 1) { | 810 if (k <= DCTSIZE2 - 1) { |
| 808 st = entropy->ac_stats[tbl] + 3 * (k - 1); | 811 st = entropy->ac_stats[tbl] + 3 * (k - 1); |
| 809 arith_encode(cinfo, st, 1); | 812 arith_encode(cinfo, st, 1); |
| 810 } | 813 } |
| 811 } | 814 } |
| 812 | 815 |
| 813 return TRUE; | 816 return TRUE; |
| 814 } | 817 } |
| 815 | 818 |
| 816 | 819 |
| 817 /* | 820 /* |
| 818 * Initialize for an arithmetic-compressed scan. | 821 * Initialize for an arithmetic-compressed scan. |
| 819 */ | 822 */ |
| 820 | 823 |
| 821 METHODDEF(void) | 824 METHODDEF(void) |
| 822 start_pass (j_compress_ptr cinfo, boolean gather_statistics) | 825 start_pass (j_compress_ptr cinfo, boolean gather_statistics) |
| 823 { | 826 { |
| 824 arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; | 827 arith_entropy_ptr entropy = (arith_entropy_ptr) cinfo->entropy; |
| 825 int ci, tbl; | 828 int ci, tbl; |
| 826 jpeg_component_info * compptr; | 829 jpeg_component_info *compptr; |
| 827 | 830 |
| 828 if (gather_statistics) | 831 if (gather_statistics) |
| 829 /* Make sure to avoid that in the master control logic! | 832 /* Make sure to avoid that in the master control logic! |
| 830 * We are fully adaptive here and need no extra | 833 * We are fully adaptive here and need no extra |
| 831 * statistics gathering pass! | 834 * statistics gathering pass! |
| 832 */ | 835 */ |
| 833 ERREXIT(cinfo, JERR_NOT_COMPILED); | 836 ERREXIT(cinfo, JERR_NOT_COMPILED); |
| 834 | 837 |
| 835 /* We assume jcmaster.c already validated the progressive scan parameters. */ | 838 /* We assume jcmaster.c already validated the progressive scan parameters. */ |
| 836 | 839 |
| 837 /* Select execution routines */ | 840 /* Select execution routines */ |
| 838 if (cinfo->progressive_mode) { | 841 if (cinfo->progressive_mode) { |
| 839 if (cinfo->Ah == 0) { | 842 if (cinfo->Ah == 0) { |
| 840 if (cinfo->Ss == 0) | 843 if (cinfo->Ss == 0) |
| 841 » entropy->pub.encode_mcu = encode_mcu_DC_first; | 844 entropy->pub.encode_mcu = encode_mcu_DC_first; |
| 842 else | 845 else |
| 843 » entropy->pub.encode_mcu = encode_mcu_AC_first; | 846 entropy->pub.encode_mcu = encode_mcu_AC_first; |
| 844 } else { | 847 } else { |
| 845 if (cinfo->Ss == 0) | 848 if (cinfo->Ss == 0) |
| 846 » entropy->pub.encode_mcu = encode_mcu_DC_refine; | 849 entropy->pub.encode_mcu = encode_mcu_DC_refine; |
| 847 else | 850 else |
| 848 » entropy->pub.encode_mcu = encode_mcu_AC_refine; | 851 entropy->pub.encode_mcu = encode_mcu_AC_refine; |
| 849 } | 852 } |
| 850 } else | 853 } else |
| 851 entropy->pub.encode_mcu = encode_mcu; | 854 entropy->pub.encode_mcu = encode_mcu; |
| 852 | 855 |
| 853 /* Allocate & initialize requested statistics areas */ | 856 /* Allocate & initialize requested statistics areas */ |
| 854 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { | 857 for (ci = 0; ci < cinfo->comps_in_scan; ci++) { |
| 855 compptr = cinfo->cur_comp_info[ci]; | 858 compptr = cinfo->cur_comp_info[ci]; |
| 856 /* DC needs no table for refinement scan */ | 859 /* DC needs no table for refinement scan */ |
| 857 if (cinfo->progressive_mode == 0 || (cinfo->Ss == 0 && cinfo->Ah == 0)) { | 860 if (cinfo->progressive_mode == 0 || (cinfo->Ss == 0 && cinfo->Ah == 0)) { |
| 858 tbl = compptr->dc_tbl_no; | 861 tbl = compptr->dc_tbl_no; |
| 859 if (tbl < 0 || tbl >= NUM_ARITH_TBLS) | 862 if (tbl < 0 || tbl >= NUM_ARITH_TBLS) |
| 860 » ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); | 863 ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); |
| 861 if (entropy->dc_stats[tbl] == NULL) | 864 if (entropy->dc_stats[tbl] == NULL) |
| 862 » entropy->dc_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) | 865 entropy->dc_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) |
| 863 » ((j_common_ptr) cinfo, JPOOL_IMAGE, DC_STAT_BINS); | 866 ((j_common_ptr) cinfo, JPOOL_IMAGE, DC_STAT_BINS); |
| 864 MEMZERO(entropy->dc_stats[tbl], DC_STAT_BINS); | 867 MEMZERO(entropy->dc_stats[tbl], DC_STAT_BINS); |
| 865 /* Initialize DC predictions to 0 */ | 868 /* Initialize DC predictions to 0 */ |
| 866 entropy->last_dc_val[ci] = 0; | 869 entropy->last_dc_val[ci] = 0; |
| 867 entropy->dc_context[ci] = 0; | 870 entropy->dc_context[ci] = 0; |
| 868 } | 871 } |
| 869 /* AC needs no table when not present */ | 872 /* AC needs no table when not present */ |
| 870 if (cinfo->progressive_mode == 0 || cinfo->Se) { | 873 if (cinfo->progressive_mode == 0 || cinfo->Se) { |
| 871 tbl = compptr->ac_tbl_no; | 874 tbl = compptr->ac_tbl_no; |
| 872 if (tbl < 0 || tbl >= NUM_ARITH_TBLS) | 875 if (tbl < 0 || tbl >= NUM_ARITH_TBLS) |
| 873 » ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); | 876 ERREXIT1(cinfo, JERR_NO_ARITH_TABLE, tbl); |
| 874 if (entropy->ac_stats[tbl] == NULL) | 877 if (entropy->ac_stats[tbl] == NULL) |
| 875 » entropy->ac_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) | 878 entropy->ac_stats[tbl] = (unsigned char *) (*cinfo->mem->alloc_small) |
| 876 » ((j_common_ptr) cinfo, JPOOL_IMAGE, AC_STAT_BINS); | 879 ((j_common_ptr) cinfo, JPOOL_IMAGE, AC_STAT_BINS); |
| 877 MEMZERO(entropy->ac_stats[tbl], AC_STAT_BINS); | 880 MEMZERO(entropy->ac_stats[tbl], AC_STAT_BINS); |
| 878 #ifdef CALCULATE_SPECTRAL_CONDITIONING | 881 #ifdef CALCULATE_SPECTRAL_CONDITIONING |
| 879 if (cinfo->progressive_mode) | 882 if (cinfo->progressive_mode) |
| 880 » /* Section G.1.3.2: Set appropriate arithmetic conditioning value Kx */ | 883 /* Section G.1.3.2: Set appropriate arithmetic conditioning value Kx */ |
| 881 » cinfo->arith_ac_K[tbl] = cinfo->Ss + ((8 + cinfo->Se - cinfo->Ss) >> 4); | 884 cinfo->arith_ac_K[tbl] = cinfo->Ss + ((8 + cinfo->Se - cinfo->Ss) >> 4); |
| 882 #endif | 885 #endif |
| 883 } | 886 } |
| 884 } | 887 } |
| 885 | 888 |
| 886 /* Initialize arithmetic encoding variables */ | 889 /* Initialize arithmetic encoding variables */ |
| 887 entropy->c = 0; | 890 entropy->c = 0; |
| 888 entropy->a = 0x10000L; | 891 entropy->a = 0x10000L; |
| 889 entropy->sc = 0; | 892 entropy->sc = 0; |
| 890 entropy->zc = 0; | 893 entropy->zc = 0; |
| 891 entropy->ct = 11; | 894 entropy->ct = 11; |
| (...skipping 10 matching lines...) Expand all Loading... |
| 902 */ | 905 */ |
| 903 | 906 |
| 904 GLOBAL(void) | 907 GLOBAL(void) |
| 905 jinit_arith_encoder (j_compress_ptr cinfo) | 908 jinit_arith_encoder (j_compress_ptr cinfo) |
| 906 { | 909 { |
| 907 arith_entropy_ptr entropy; | 910 arith_entropy_ptr entropy; |
| 908 int i; | 911 int i; |
| 909 | 912 |
| 910 entropy = (arith_entropy_ptr) | 913 entropy = (arith_entropy_ptr) |
| 911 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | 914 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
| 912 » » » » SIZEOF(arith_entropy_encoder)); | 915 sizeof(arith_entropy_encoder)); |
| 913 cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; | 916 cinfo->entropy = (struct jpeg_entropy_encoder *) entropy; |
| 914 entropy->pub.start_pass = start_pass; | 917 entropy->pub.start_pass = start_pass; |
| 915 entropy->pub.finish_pass = finish_pass; | 918 entropy->pub.finish_pass = finish_pass; |
| 916 | 919 |
| 917 /* Mark tables unallocated */ | 920 /* Mark tables unallocated */ |
| 918 for (i = 0; i < NUM_ARITH_TBLS; i++) { | 921 for (i = 0; i < NUM_ARITH_TBLS; i++) { |
| 919 entropy->dc_stats[i] = NULL; | 922 entropy->dc_stats[i] = NULL; |
| 920 entropy->ac_stats[i] = NULL; | 923 entropy->ac_stats[i] = NULL; |
| 921 } | 924 } |
| 922 | 925 |
| 923 /* Initialize index for fixed probability estimation */ | 926 /* Initialize index for fixed probability estimation */ |
| 924 entropy->fixed_bin[0] = 113; | 927 entropy->fixed_bin[0] = 113; |
| 925 } | 928 } |
| OLD | NEW |