59b4f9eca072b65f95cf463738d69ec76b49d9f8
[libav.git] / libavcodec / golomb.h
1 /*
2 * exp golomb vlc stuff
3 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Alex Beregszaszi
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file libavcodec/golomb.h
25 * @brief
26 * exp golomb vlc stuff
27 * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
28 */
29
30 #ifndef AVCODEC_GOLOMB_H
31 #define AVCODEC_GOLOMB_H
32
33 #include <stdint.h>
34 #include "bitstream.h"
35
36 #define INVALID_VLC 0x80000000
37
38 extern const uint8_t ff_golomb_vlc_len[512];
39 extern const uint8_t ff_ue_golomb_vlc_code[512];
40 extern const int8_t ff_se_golomb_vlc_code[512];
41 extern const uint8_t ff_ue_golomb_len[256];
42
43 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
44 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
45 extern const int8_t ff_interleaved_se_golomb_vlc_code[256];
46 extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
47
48
49 /**
50 * read unsigned exp golomb code.
51 */
52 static inline int get_ue_golomb(GetBitContext *gb){
53 unsigned int buf;
54 int log;
55
56 OPEN_READER(re, gb);
57 UPDATE_CACHE(re, gb);
58 buf=GET_CACHE(re, gb);
59
60 if(buf >= (1<<27)){
61 buf >>= 32 - 9;
62 LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
63 CLOSE_READER(re, gb);
64
65 return ff_ue_golomb_vlc_code[buf];
66 }else{
67 log= 2*av_log2(buf) - 31;
68 buf>>= log;
69 buf--;
70 LAST_SKIP_BITS(re, gb, 32 - log);
71 CLOSE_READER(re, gb);
72
73 return buf;
74 }
75 }
76
77 /**
78 * read unsigned exp golomb code, constraint to a max of 31.
79 * the return value is undefined if the stored value exceeds 31.
80 */
81 static inline int get_ue_golomb_31(GetBitContext *gb){
82 unsigned int buf;
83
84 OPEN_READER(re, gb);
85 UPDATE_CACHE(re, gb);
86 buf=GET_CACHE(re, gb);
87
88 buf >>= 32 - 9;
89 LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
90 CLOSE_READER(re, gb);
91
92 return ff_ue_golomb_vlc_code[buf];
93 }
94
95 static inline int svq3_get_ue_golomb(GetBitContext *gb){
96 uint32_t buf;
97
98 OPEN_READER(re, gb);
99 UPDATE_CACHE(re, gb);
100 buf=GET_CACHE(re, gb);
101
102 if(buf&0xAA800000){
103 buf >>= 32 - 8;
104 LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
105 CLOSE_READER(re, gb);
106
107 return ff_interleaved_ue_golomb_vlc_code[buf];
108 }else{
109 int ret = 1;
110
111 while (1) {
112 buf >>= 32 - 8;
113 LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
114
115 if (ff_interleaved_golomb_vlc_len[buf] != 9){
116 ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
117 ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
118 break;
119 }
120 ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
121 UPDATE_CACHE(re, gb);
122 buf = GET_CACHE(re, gb);
123 }
124
125 CLOSE_READER(re, gb);
126 return ret - 1;
127 }
128 }
129
130 /**
131 * read unsigned truncated exp golomb code.
132 */
133 static inline int get_te0_golomb(GetBitContext *gb, int range){
134 assert(range >= 1);
135
136 if(range==1) return 0;
137 else if(range==2) return get_bits1(gb)^1;
138 else return get_ue_golomb(gb);
139 }
140
141 /**
142 * read unsigned truncated exp golomb code.
143 */
144 static inline int get_te_golomb(GetBitContext *gb, int range){
145 assert(range >= 1);
146
147 if(range==2) return get_bits1(gb)^1;
148 else return get_ue_golomb(gb);
149 }
150
151
152 /**
153 * read signed exp golomb code.
154 */
155 static inline int get_se_golomb(GetBitContext *gb){
156 unsigned int buf;
157 int log;
158
159 OPEN_READER(re, gb);
160 UPDATE_CACHE(re, gb);
161 buf=GET_CACHE(re, gb);
162
163 if(buf >= (1<<27)){
164 buf >>= 32 - 9;
165 LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
166 CLOSE_READER(re, gb);
167
168 return ff_se_golomb_vlc_code[buf];
169 }else{
170 log= 2*av_log2(buf) - 31;
171 buf>>= log;
172
173 LAST_SKIP_BITS(re, gb, 32 - log);
174 CLOSE_READER(re, gb);
175
176 if(buf&1) buf= -(buf>>1);
177 else buf= (buf>>1);
178
179 return buf;
180 }
181 }
182
183 static inline int svq3_get_se_golomb(GetBitContext *gb){
184 unsigned int buf;
185 int log;
186
187 OPEN_READER(re, gb);
188 UPDATE_CACHE(re, gb);
189 buf=GET_CACHE(re, gb);
190
191 if(buf&0xAA800000){
192 buf >>= 32 - 8;
193 LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
194 CLOSE_READER(re, gb);
195
196 return ff_interleaved_se_golomb_vlc_code[buf];
197 }else{
198 LAST_SKIP_BITS(re, gb, 8);
199 UPDATE_CACHE(re, gb);
200 buf |= 1 | (GET_CACHE(re, gb) >> 8);
201
202 if((buf & 0xAAAAAAAA) == 0)
203 return INVALID_VLC;
204
205 for(log=31; (buf & 0x80000000) == 0; log--){
206 buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
207 }
208
209 LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
210 CLOSE_READER(re, gb);
211
212 return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
213 }
214 }
215
216 static inline int dirac_get_se_golomb(GetBitContext *gb){
217 uint32_t buf;
218 uint32_t ret;
219
220 ret = svq3_get_ue_golomb(gb);
221
222 if (ret) {
223 OPEN_READER(re, gb);
224 UPDATE_CACHE(re, gb);
225 buf = SHOW_SBITS(re, gb, 1);
226 LAST_SKIP_BITS(re, gb, 1);
227 ret = (ret ^ buf) - buf;
228 CLOSE_READER(re, gb);
229 }
230
231 return ret;
232 }
233
234 /**
235 * read unsigned golomb rice code (ffv1).
236 */
237 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
238 unsigned int buf;
239 int log;
240
241 OPEN_READER(re, gb);
242 UPDATE_CACHE(re, gb);
243 buf=GET_CACHE(re, gb);
244
245 log= av_log2(buf);
246
247 if(log > 31-limit){
248 buf >>= log - k;
249 buf += (30-log)<<k;
250 LAST_SKIP_BITS(re, gb, 32 + k - log);
251 CLOSE_READER(re, gb);
252
253 return buf;
254 }else{
255 buf >>= 32 - limit - esc_len;
256 LAST_SKIP_BITS(re, gb, esc_len + limit);
257 CLOSE_READER(re, gb);
258
259 return buf + limit - 1;
260 }
261 }
262
263 /**
264 * read unsigned golomb rice code (jpegls).
265 */
266 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
267 unsigned int buf;
268 int log;
269
270 OPEN_READER(re, gb);
271 UPDATE_CACHE(re, gb);
272 buf=GET_CACHE(re, gb);
273
274 log= av_log2(buf);
275
276 if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
277 buf >>= log - k;
278 buf += (30-log)<<k;
279 LAST_SKIP_BITS(re, gb, 32 + k - log);
280 CLOSE_READER(re, gb);
281
282 return buf;
283 }else{
284 int i;
285 for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
286 LAST_SKIP_BITS(re, gb, 1);
287 UPDATE_CACHE(re, gb);
288 }
289 SKIP_BITS(re, gb, 1);
290
291 if(i < limit - 1){
292 if(k){
293 buf = SHOW_UBITS(re, gb, k);
294 LAST_SKIP_BITS(re, gb, k);
295 }else{
296 buf=0;
297 }
298
299 CLOSE_READER(re, gb);
300 return buf + (i<<k);
301 }else if(i == limit - 1){
302 buf = SHOW_UBITS(re, gb, esc_len);
303 LAST_SKIP_BITS(re, gb, esc_len);
304 CLOSE_READER(re, gb);
305
306 return buf + 1;
307 }else
308 return -1;
309 }
310 }
311
312 /**
313 * read signed golomb rice code (ffv1).
314 */
315 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
316 int v= get_ur_golomb(gb, k, limit, esc_len);
317
318 v++;
319 if (v&1) return v>>1;
320 else return -(v>>1);
321
322 // return (v>>1) ^ -(v&1);
323 }
324
325 /**
326 * read signed golomb rice code (flac).
327 */
328 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
329 int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
330 return (v>>1) ^ -(v&1);
331 }
332
333 /**
334 * read unsigned golomb rice code (shorten).
335 */
336 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
337 return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
338 }
339
340 /**
341 * read signed golomb rice code (shorten).
342 */
343 static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
344 {
345 int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
346 if (uvar & 1)
347 return ~(uvar >> 1);
348 else
349 return uvar >> 1;
350 }
351
352
353
354 #ifdef TRACE
355
356 static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){
357 int show= show_bits(s, 24);
358 int pos= get_bits_count(s);
359 int i= get_ue_golomb(s);
360 int len= get_bits_count(s) - pos;
361 int bits= show>>(24-len);
362
363 print_bin(bits, len);
364
365 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
366
367 return i;
368 }
369
370 static inline int get_se(GetBitContext *s, char *file, const char *func, int line){
371 int show= show_bits(s, 24);
372 int pos= get_bits_count(s);
373 int i= get_se_golomb(s);
374 int len= get_bits_count(s) - pos;
375 int bits= show>>(24-len);
376
377 print_bin(bits, len);
378
379 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
380
381 return i;
382 }
383
384 static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){
385 int show= show_bits(s, 24);
386 int pos= get_bits_count(s);
387 int i= get_te0_golomb(s, r);
388 int len= get_bits_count(s) - pos;
389 int bits= show>>(24-len);
390
391 print_bin(bits, len);
392
393 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
394
395 return i;
396 }
397
398 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
399 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
400 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
401 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
402
403 #endif
404
405 /**
406 * write unsigned exp golomb code.
407 */
408 static inline void set_ue_golomb(PutBitContext *pb, int i){
409 int e;
410
411 assert(i>=0);
412
413 #if 0
414 if(i=0){
415 put_bits(pb, 1, 1);
416 return;
417 }
418 #endif
419 if(i<256)
420 put_bits(pb, ff_ue_golomb_len[i], i+1);
421 else{
422 e= av_log2(i+1);
423
424 put_bits(pb, 2*e+1, i+1);
425 }
426 }
427
428 /**
429 * write truncated unsigned exp golomb code.
430 */
431 static inline void set_te_golomb(PutBitContext *pb, int i, int range){
432 assert(range >= 1);
433 assert(i<=range);
434
435 if(range==2) put_bits(pb, 1, i^1);
436 else set_ue_golomb(pb, i);
437 }
438
439 /**
440 * write signed exp golomb code. 16 bits at most.
441 */
442 static inline void set_se_golomb(PutBitContext *pb, int i){
443 // if (i>32767 || i<-32767)
444 // av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
445 #if 0
446 if(i<=0) i= -2*i;
447 else i= 2*i-1;
448 #elif 1
449 i= 2*i-1;
450 if(i<0) i^= -1; //FIXME check if gcc does the right thing
451 #else
452 i= 2*i-1;
453 i^= (i>>31);
454 #endif
455 set_ue_golomb(pb, i);
456 }
457
458 /**
459 * write unsigned golomb rice code (ffv1).
460 */
461 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
462 int e;
463
464 assert(i>=0);
465
466 e= i>>k;
467 if(e<limit){
468 put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
469 }else{
470 put_bits(pb, limit + esc_len, i - limit + 1);
471 }
472 }
473
474 /**
475 * write unsigned golomb rice code (jpegls).
476 */
477 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
478 int e;
479
480 assert(i>=0);
481
482 e= (i>>k) + 1;
483 if(e<limit){
484 while(e > 31) {
485 put_bits(pb, 31, 0);
486 e -= 31;
487 }
488 put_bits(pb, e, 1);
489 if(k)
490 put_sbits(pb, k, i);
491 }else{
492 while(limit > 31) {
493 put_bits(pb, 31, 0);
494 limit -= 31;
495 }
496 put_bits(pb, limit , 1);
497 put_bits(pb, esc_len, i - 1);
498 }
499 }
500
501 /**
502 * write signed golomb rice code (ffv1).
503 */
504 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
505 int v;
506
507 v = -2*i-1;
508 v ^= (v>>31);
509
510 set_ur_golomb(pb, v, k, limit, esc_len);
511 }
512
513 /**
514 * write signed golomb rice code (flac).
515 */
516 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
517 int v;
518
519 v = -2*i-1;
520 v ^= (v>>31);
521
522 set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
523 }
524
525 #endif /* AVCODEC_GOLOMB_H */