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). |
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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) { |
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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 } |
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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; |
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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 } |
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