bb40ff4f38db1d1c44be4e0261a69571f4ad07c4
[libav.git] / libavcodec / get_bits.h
1 /*
2 * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file libavcodec/get_bits.h
23 * bitstream reader API header.
24 */
25
26 #ifndef AVCODEC_GET_BITS_H
27 #define AVCODEC_GET_BITS_H
28
29 #include <stdint.h>
30 #include <stdlib.h>
31 #include <assert.h>
32 #include "libavutil/bswap.h"
33 #include "libavutil/common.h"
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/log.h"
36 #include "mathops.h"
37
38 #if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
39 # define ALT_BITSTREAM_READER
40 #endif
41
42 #if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER)
43 # if ARCH_ARM && !HAVE_FAST_UNALIGNED
44 # define A32_BITSTREAM_READER
45 # else
46 # define ALT_BITSTREAM_READER
47 //#define LIBMPEG2_BITSTREAM_READER
48 //#define A32_BITSTREAM_READER
49 # endif
50 #endif
51
52 /* bit input */
53 /* buffer, buffer_end and size_in_bits must be present and used by every reader */
54 typedef struct GetBitContext {
55 const uint8_t *buffer, *buffer_end;
56 #ifdef ALT_BITSTREAM_READER
57 int index;
58 #elif defined LIBMPEG2_BITSTREAM_READER
59 uint8_t *buffer_ptr;
60 uint32_t cache;
61 int bit_count;
62 #elif defined A32_BITSTREAM_READER
63 uint32_t *buffer_ptr;
64 uint32_t cache0;
65 uint32_t cache1;
66 int bit_count;
67 #endif
68 int size_in_bits;
69 } GetBitContext;
70
71 #define VLC_TYPE int16_t
72
73 typedef struct VLC {
74 int bits;
75 VLC_TYPE (*table)[2]; ///< code, bits
76 int table_size, table_allocated;
77 } VLC;
78
79 typedef struct RL_VLC_ELEM {
80 int16_t level;
81 int8_t len;
82 uint8_t run;
83 } RL_VLC_ELEM;
84
85 /* Bitstream reader API docs:
86 name
87 arbitrary name which is used as prefix for the internal variables
88
89 gb
90 getbitcontext
91
92 OPEN_READER(name, gb)
93 loads gb into local variables
94
95 CLOSE_READER(name, gb)
96 stores local vars in gb
97
98 UPDATE_CACHE(name, gb)
99 refills the internal cache from the bitstream
100 after this call at least MIN_CACHE_BITS will be available,
101
102 GET_CACHE(name, gb)
103 will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
104
105 SHOW_UBITS(name, gb, num)
106 will return the next num bits
107
108 SHOW_SBITS(name, gb, num)
109 will return the next num bits and do sign extension
110
111 SKIP_BITS(name, gb, num)
112 will skip over the next num bits
113 note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
114
115 SKIP_CACHE(name, gb, num)
116 will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
117
118 SKIP_COUNTER(name, gb, num)
119 will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
120
121 LAST_SKIP_CACHE(name, gb, num)
122 will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
123
124 LAST_SKIP_BITS(name, gb, num)
125 is equivalent to LAST_SKIP_CACHE; SKIP_COUNTER
126
127 for examples see get_bits, show_bits, skip_bits, get_vlc
128 */
129
130 #ifdef ALT_BITSTREAM_READER
131 # define MIN_CACHE_BITS 25
132
133 # define OPEN_READER(name, gb)\
134 unsigned int name##_index= (gb)->index;\
135 int name##_cache= 0;\
136
137 # define CLOSE_READER(name, gb)\
138 (gb)->index= name##_index;\
139
140 # ifdef ALT_BITSTREAM_READER_LE
141 # define UPDATE_CACHE(name, gb)\
142 name##_cache= AV_RL32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
143
144 # define SKIP_CACHE(name, gb, num)\
145 name##_cache >>= (num);
146 # else
147 # define UPDATE_CACHE(name, gb)\
148 name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
149
150 # define SKIP_CACHE(name, gb, num)\
151 name##_cache <<= (num);
152 # endif
153
154 // FIXME name?
155 # define SKIP_COUNTER(name, gb, num)\
156 name##_index += (num);\
157
158 # define SKIP_BITS(name, gb, num)\
159 {\
160 SKIP_CACHE(name, gb, num)\
161 SKIP_COUNTER(name, gb, num)\
162 }\
163
164 # define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
165 # define LAST_SKIP_CACHE(name, gb, num) ;
166
167 # ifdef ALT_BITSTREAM_READER_LE
168 # define SHOW_UBITS(name, gb, num)\
169 ((name##_cache) & (NEG_USR32(0xffffffff,num)))
170
171 # define SHOW_SBITS(name, gb, num)\
172 NEG_SSR32((name##_cache)<<(32-(num)), num)
173 # else
174 # define SHOW_UBITS(name, gb, num)\
175 NEG_USR32(name##_cache, num)
176
177 # define SHOW_SBITS(name, gb, num)\
178 NEG_SSR32(name##_cache, num)
179 # endif
180
181 # define GET_CACHE(name, gb)\
182 ((uint32_t)name##_cache)
183
184 static inline int get_bits_count(const GetBitContext *s){
185 return s->index;
186 }
187
188 static inline void skip_bits_long(GetBitContext *s, int n){
189 s->index += n;
190 }
191
192 #elif defined LIBMPEG2_BITSTREAM_READER
193 //libmpeg2 like reader
194
195 # define MIN_CACHE_BITS 17
196
197 # define OPEN_READER(name, gb)\
198 int name##_bit_count=(gb)->bit_count;\
199 int name##_cache= (gb)->cache;\
200 uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
201
202 # define CLOSE_READER(name, gb)\
203 (gb)->bit_count= name##_bit_count;\
204 (gb)->cache= name##_cache;\
205 (gb)->buffer_ptr= name##_buffer_ptr;\
206
207 # define UPDATE_CACHE(name, gb)\
208 if(name##_bit_count >= 0){\
209 name##_cache+= AV_RB16(name##_buffer_ptr) << name##_bit_count; \
210 name##_buffer_ptr+=2;\
211 name##_bit_count-= 16;\
212 }\
213
214 # define SKIP_CACHE(name, gb, num)\
215 name##_cache <<= (num);\
216
217 # define SKIP_COUNTER(name, gb, num)\
218 name##_bit_count += (num);\
219
220 # define SKIP_BITS(name, gb, num)\
221 {\
222 SKIP_CACHE(name, gb, num)\
223 SKIP_COUNTER(name, gb, num)\
224 }\
225
226 # define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
227 # define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
228
229 # define SHOW_UBITS(name, gb, num)\
230 NEG_USR32(name##_cache, num)
231
232 # define SHOW_SBITS(name, gb, num)\
233 NEG_SSR32(name##_cache, num)
234
235 # define GET_CACHE(name, gb)\
236 ((uint32_t)name##_cache)
237
238 static inline int get_bits_count(const GetBitContext *s){
239 return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
240 }
241
242 static inline void skip_bits_long(GetBitContext *s, int n){
243 OPEN_READER(re, s)
244 re_bit_count += n;
245 re_buffer_ptr += 2*(re_bit_count>>4);
246 re_bit_count &= 15;
247 re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count);
248 UPDATE_CACHE(re, s)
249 CLOSE_READER(re, s)
250 }
251
252 #elif defined A32_BITSTREAM_READER
253
254 # define MIN_CACHE_BITS 32
255
256 # define OPEN_READER(name, gb)\
257 int name##_bit_count=(gb)->bit_count;\
258 uint32_t name##_cache0= (gb)->cache0;\
259 uint32_t name##_cache1= (gb)->cache1;\
260 uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
261
262 # define CLOSE_READER(name, gb)\
263 (gb)->bit_count= name##_bit_count;\
264 (gb)->cache0= name##_cache0;\
265 (gb)->cache1= name##_cache1;\
266 (gb)->buffer_ptr= name##_buffer_ptr;\
267
268 # define UPDATE_CACHE(name, gb)\
269 if(name##_bit_count > 0){\
270 const uint32_t next= be2me_32( *name##_buffer_ptr );\
271 name##_cache0 |= NEG_USR32(next,name##_bit_count);\
272 name##_cache1 |= next<<name##_bit_count;\
273 name##_buffer_ptr++;\
274 name##_bit_count-= 32;\
275 }\
276
277 #if ARCH_X86
278 # define SKIP_CACHE(name, gb, num)\
279 __asm__(\
280 "shldl %2, %1, %0 \n\t"\
281 "shll %2, %1 \n\t"\
282 : "+r" (name##_cache0), "+r" (name##_cache1)\
283 : "Ic" ((uint8_t)(num))\
284 );
285 #else
286 # define SKIP_CACHE(name, gb, num)\
287 name##_cache0 <<= (num);\
288 name##_cache0 |= NEG_USR32(name##_cache1,num);\
289 name##_cache1 <<= (num);
290 #endif
291
292 # define SKIP_COUNTER(name, gb, num)\
293 name##_bit_count += (num);\
294
295 # define SKIP_BITS(name, gb, num)\
296 {\
297 SKIP_CACHE(name, gb, num)\
298 SKIP_COUNTER(name, gb, num)\
299 }\
300
301 # define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
302 # define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
303
304 # define SHOW_UBITS(name, gb, num)\
305 NEG_USR32(name##_cache0, num)
306
307 # define SHOW_SBITS(name, gb, num)\
308 NEG_SSR32(name##_cache0, num)
309
310 # define GET_CACHE(name, gb)\
311 (name##_cache0)
312
313 static inline int get_bits_count(const GetBitContext *s){
314 return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
315 }
316
317 static inline void skip_bits_long(GetBitContext *s, int n){
318 OPEN_READER(re, s)
319 re_bit_count += n;
320 re_buffer_ptr += re_bit_count>>5;
321 re_bit_count &= 31;
322 re_cache0 = be2me_32( re_buffer_ptr[-1] ) << re_bit_count;
323 re_cache1 = 0;
324 UPDATE_CACHE(re, s)
325 CLOSE_READER(re, s)
326 }
327
328 #endif
329
330 /**
331 * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
332 * if MSB not set it is negative
333 * @param n length in bits
334 * @author BERO
335 */
336 static inline int get_xbits(GetBitContext *s, int n){
337 register int sign;
338 register int32_t cache;
339 OPEN_READER(re, s)
340 UPDATE_CACHE(re, s)
341 cache = GET_CACHE(re,s);
342 sign=(~cache)>>31;
343 LAST_SKIP_BITS(re, s, n)
344 CLOSE_READER(re, s)
345 return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
346 }
347
348 static inline int get_sbits(GetBitContext *s, int n){
349 register int tmp;
350 OPEN_READER(re, s)
351 UPDATE_CACHE(re, s)
352 tmp= SHOW_SBITS(re, s, n);
353 LAST_SKIP_BITS(re, s, n)
354 CLOSE_READER(re, s)
355 return tmp;
356 }
357
358 /**
359 * reads 1-17 bits.
360 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
361 */
362 static inline unsigned int get_bits(GetBitContext *s, int n){
363 register int tmp;
364 OPEN_READER(re, s)
365 UPDATE_CACHE(re, s)
366 tmp= SHOW_UBITS(re, s, n);
367 LAST_SKIP_BITS(re, s, n)
368 CLOSE_READER(re, s)
369 return tmp;
370 }
371
372 /**
373 * shows 1-17 bits.
374 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
375 */
376 static inline unsigned int show_bits(GetBitContext *s, int n){
377 register int tmp;
378 OPEN_READER(re, s)
379 UPDATE_CACHE(re, s)
380 tmp= SHOW_UBITS(re, s, n);
381 // CLOSE_READER(re, s)
382 return tmp;
383 }
384
385 static inline void skip_bits(GetBitContext *s, int n){
386 //Note gcc seems to optimize this to s->index+=n for the ALT_READER :))
387 OPEN_READER(re, s)
388 UPDATE_CACHE(re, s)
389 LAST_SKIP_BITS(re, s, n)
390 CLOSE_READER(re, s)
391 }
392
393 static inline unsigned int get_bits1(GetBitContext *s){
394 #ifdef ALT_BITSTREAM_READER
395 unsigned int index= s->index;
396 uint8_t result= s->buffer[ index>>3 ];
397 #ifdef ALT_BITSTREAM_READER_LE
398 result>>= (index&0x07);
399 result&= 1;
400 #else
401 result<<= (index&0x07);
402 result>>= 8 - 1;
403 #endif
404 index++;
405 s->index= index;
406
407 return result;
408 #else
409 return get_bits(s, 1);
410 #endif
411 }
412
413 static inline unsigned int show_bits1(GetBitContext *s){
414 return show_bits(s, 1);
415 }
416
417 static inline void skip_bits1(GetBitContext *s){
418 skip_bits(s, 1);
419 }
420
421 /**
422 * reads 0-32 bits.
423 */
424 static inline unsigned int get_bits_long(GetBitContext *s, int n){
425 if(n<=17) return get_bits(s, n);
426 else{
427 #ifdef ALT_BITSTREAM_READER_LE
428 int ret= get_bits(s, 16);
429 return ret | (get_bits(s, n-16) << 16);
430 #else
431 int ret= get_bits(s, 16) << (n-16);
432 return ret | get_bits(s, n-16);
433 #endif
434 }
435 }
436
437 /**
438 * reads 0-32 bits as a signed integer.
439 */
440 static inline int get_sbits_long(GetBitContext *s, int n) {
441 return sign_extend(get_bits_long(s, n), n);
442 }
443
444 /**
445 * shows 0-32 bits.
446 */
447 static inline unsigned int show_bits_long(GetBitContext *s, int n){
448 if(n<=17) return show_bits(s, n);
449 else{
450 GetBitContext gb= *s;
451 return get_bits_long(&gb, n);
452 }
453 }
454
455 static inline int check_marker(GetBitContext *s, const char *msg)
456 {
457 int bit= get_bits1(s);
458 if(!bit)
459 av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
460
461 return bit;
462 }
463
464 /**
465 * init GetBitContext.
466 * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
467 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
468 * @param bit_size the size of the buffer in bits
469 *
470 * While GetBitContext stores the buffer size, for performance reasons you are
471 * responsible for checking for the buffer end yourself (take advantage of the padding)!
472 */
473 static inline void init_get_bits(GetBitContext *s,
474 const uint8_t *buffer, int bit_size)
475 {
476 int buffer_size= (bit_size+7)>>3;
477 if(buffer_size < 0 || bit_size < 0) {
478 buffer_size = bit_size = 0;
479 buffer = NULL;
480 }
481
482 s->buffer= buffer;
483 s->size_in_bits= bit_size;
484 s->buffer_end= buffer + buffer_size;
485 #ifdef ALT_BITSTREAM_READER
486 s->index=0;
487 #elif defined LIBMPEG2_BITSTREAM_READER
488 s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));
489 s->bit_count = 16 + 8*((intptr_t)buffer&1);
490 skip_bits_long(s, 0);
491 #elif defined A32_BITSTREAM_READER
492 s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));
493 s->bit_count = 32 + 8*((intptr_t)buffer&3);
494 skip_bits_long(s, 0);
495 #endif
496 }
497
498 static inline void align_get_bits(GetBitContext *s)
499 {
500 int n= (-get_bits_count(s)) & 7;
501 if(n) skip_bits(s, n);
502 }
503
504 #define init_vlc(vlc, nb_bits, nb_codes,\
505 bits, bits_wrap, bits_size,\
506 codes, codes_wrap, codes_size,\
507 flags)\
508 init_vlc_sparse(vlc, nb_bits, nb_codes,\
509 bits, bits_wrap, bits_size,\
510 codes, codes_wrap, codes_size,\
511 NULL, 0, 0, flags)
512
513 int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
514 const void *bits, int bits_wrap, int bits_size,
515 const void *codes, int codes_wrap, int codes_size,
516 const void *symbols, int symbols_wrap, int symbols_size,
517 int flags);
518 #define INIT_VLC_LE 2
519 #define INIT_VLC_USE_NEW_STATIC 4
520 void free_vlc(VLC *vlc);
521
522 #define INIT_VLC_STATIC(vlc, bits, a,b,c,d,e,f,g, static_size)\
523 {\
524 static VLC_TYPE table[static_size][2];\
525 (vlc)->table= table;\
526 (vlc)->table_allocated= static_size;\
527 init_vlc(vlc, bits, a,b,c,d,e,f,g, INIT_VLC_USE_NEW_STATIC);\
528 }
529
530
531 /**
532 *
533 * If the vlc code is invalid and max_depth=1, then no bits will be removed.
534 * If the vlc code is invalid and max_depth>1, then the number of bits removed
535 * is undefined.
536 */
537 #define GET_VLC(code, name, gb, table, bits, max_depth)\
538 {\
539 int n, nb_bits;\
540 unsigned int index;\
541 \
542 index= SHOW_UBITS(name, gb, bits);\
543 code = table[index][0];\
544 n = table[index][1];\
545 \
546 if(max_depth > 1 && n < 0){\
547 LAST_SKIP_BITS(name, gb, bits)\
548 UPDATE_CACHE(name, gb)\
549 \
550 nb_bits = -n;\
551 \
552 index= SHOW_UBITS(name, gb, nb_bits) + code;\
553 code = table[index][0];\
554 n = table[index][1];\
555 if(max_depth > 2 && n < 0){\
556 LAST_SKIP_BITS(name, gb, nb_bits)\
557 UPDATE_CACHE(name, gb)\
558 \
559 nb_bits = -n;\
560 \
561 index= SHOW_UBITS(name, gb, nb_bits) + code;\
562 code = table[index][0];\
563 n = table[index][1];\
564 }\
565 }\
566 SKIP_BITS(name, gb, n)\
567 }
568
569 #define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
570 {\
571 int n, nb_bits;\
572 unsigned int index;\
573 \
574 index= SHOW_UBITS(name, gb, bits);\
575 level = table[index].level;\
576 n = table[index].len;\
577 \
578 if(max_depth > 1 && n < 0){\
579 SKIP_BITS(name, gb, bits)\
580 if(need_update){\
581 UPDATE_CACHE(name, gb)\
582 }\
583 \
584 nb_bits = -n;\
585 \
586 index= SHOW_UBITS(name, gb, nb_bits) + level;\
587 level = table[index].level;\
588 n = table[index].len;\
589 }\
590 run= table[index].run;\
591 SKIP_BITS(name, gb, n)\
592 }
593
594
595 /**
596 * parses a vlc code, faster then get_vlc()
597 * @param bits is the number of bits which will be read at once, must be
598 * identical to nb_bits in init_vlc()
599 * @param max_depth is the number of times bits bits must be read to completely
600 * read the longest vlc code
601 * = (max_vlc_length + bits - 1) / bits
602 */
603 static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
604 int bits, int max_depth)
605 {
606 int code;
607
608 OPEN_READER(re, s)
609 UPDATE_CACHE(re, s)
610
611 GET_VLC(code, re, s, table, bits, max_depth)
612
613 CLOSE_READER(re, s)
614 return code;
615 }
616
617 //#define TRACE
618
619 #ifdef TRACE
620 static inline void print_bin(int bits, int n){
621 int i;
622
623 for(i=n-1; i>=0; i--){
624 av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
625 }
626 for(i=n; i<24; i++)
627 av_log(NULL, AV_LOG_DEBUG, " ");
628 }
629
630 static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
631 int r= get_bits(s, n);
632
633 print_bin(r, n);
634 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d bit @%5d in %s %s:%d\n", r, n, r, get_bits_count(s)-n, file, func, line);
635 return r;
636 }
637 static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){
638 int show= show_bits(s, 24);
639 int pos= get_bits_count(s);
640 int r= get_vlc2(s, table, bits, max_depth);
641 int len= get_bits_count(s) - pos;
642 int bits2= show>>(24-len);
643
644 print_bin(bits2, len);
645
646 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line);
647 return r;
648 }
649 static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
650 int show= show_bits(s, n);
651 int r= get_xbits(s, n);
652
653 print_bin(show, n);
654 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d xbt @%5d in %s %s:%d\n", show, n, r, get_bits_count(s)-n, file, func, line);
655 return r;
656 }
657
658 #define get_bits(s, n) get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
659 #define get_bits1(s) get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
660 #define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
661 #define get_vlc(s, vlc) get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
662 #define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
663
664 #define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
665
666 #else //TRACE
667 #define tprintf(p, ...) {}
668 #endif
669
670 static inline int decode012(GetBitContext *gb){
671 int n;
672 n = get_bits1(gb);
673 if (n == 0)
674 return 0;
675 else
676 return get_bits1(gb) + 1;
677 }
678
679 static inline int decode210(GetBitContext *gb){
680 if (get_bits1(gb))
681 return 0;
682 else
683 return 2 - get_bits1(gb);
684 }
685
686 static inline int get_bits_left(GetBitContext *gb)
687 {
688 return gb->size_in_bits - get_bits_count(gb);
689 }
690
691 #endif /* AVCODEC_GET_BITS_H */