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get_bits.h
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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
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 
31 #include "libavutil/common.h"
32 #include "libavutil/intreadwrite.h"
33 #include "libavutil/log.h"
34 #include "libavutil/avassert.h"
35 #include "avcodec.h"
36 #include "mathops.h"
37 #include "vlc.h"
38 
39 /*
40  * Safe bitstream reading:
41  * optionally, the get_bits API can check to ensure that we
42  * don't read past input buffer boundaries. This is protected
43  * with CONFIG_SAFE_BITSTREAM_READER at the global level, and
44  * then below that with UNCHECKED_BITSTREAM_READER at the per-
45  * decoder level. This means that decoders that check internally
46  * can "#define UNCHECKED_BITSTREAM_READER 1" to disable
47  * overread checks.
48  * Boundary checking causes a minor performance penalty so for
49  * applications that won't want/need this, it can be disabled
50  * globally using "#define CONFIG_SAFE_BITSTREAM_READER 0".
51  */
52 #ifndef UNCHECKED_BITSTREAM_READER
53 #define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER
54 #endif
55 
56 typedef struct GetBitContext {
58  int index;
62 
63 /* Bitstream reader API docs:
64  * name
65  * arbitrary name which is used as prefix for the internal variables
66  *
67  * gb
68  * getbitcontext
69  *
70  * OPEN_READER(name, gb)
71  * load gb into local variables
72  *
73  * CLOSE_READER(name, gb)
74  * store local vars in gb
75  *
76  * UPDATE_CACHE(name, gb)
77  * Refill the internal cache from the bitstream.
78  * After this call at least MIN_CACHE_BITS will be available.
79  *
80  * GET_CACHE(name, gb)
81  * Will output the contents of the internal cache,
82  * next bit is MSB of 32 or 64 bits (FIXME 64 bits).
83  *
84  * SHOW_UBITS(name, gb, num)
85  * Will return the next num bits.
86  *
87  * SHOW_SBITS(name, gb, num)
88  * Will return the next num bits and do sign extension.
89  *
90  * SKIP_BITS(name, gb, num)
91  * Will skip over the next num bits.
92  * Note, this is equivalent to SKIP_CACHE; SKIP_COUNTER.
93  *
94  * SKIP_CACHE(name, gb, num)
95  * Will remove the next num bits from the cache (note SKIP_COUNTER
96  * MUST be called before UPDATE_CACHE / CLOSE_READER).
97  *
98  * SKIP_COUNTER(name, gb, num)
99  * Will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS).
100  *
101  * LAST_SKIP_BITS(name, gb, num)
102  * Like SKIP_BITS, to be used if next call is UPDATE_CACHE or CLOSE_READER.
103  *
104  * BITS_LEFT(name, gb)
105  * Return the number of bits left
106  *
107  * For examples see get_bits, show_bits, skip_bits, get_vlc.
108  */
109 
110 #ifdef LONG_BITSTREAM_READER
111 # define MIN_CACHE_BITS 32
112 #else
113 # define MIN_CACHE_BITS 25
114 #endif
115 
116 #define OPEN_READER_NOSIZE(name, gb) \
117  unsigned int name ## _index = (gb)->index; \
118  unsigned int av_unused name ## _cache
119 
120 #if UNCHECKED_BITSTREAM_READER
121 #define OPEN_READER(name, gb) OPEN_READER_NOSIZE(name, gb)
122 
123 #define BITS_AVAILABLE(name, gb) 1
124 #else
125 #define OPEN_READER(name, gb) \
126  OPEN_READER_NOSIZE(name, gb); \
127  unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8
128 
129 #define BITS_AVAILABLE(name, gb) name ## _index < name ## _size_plus8
130 #endif
131 
132 #define CLOSE_READER(name, gb) (gb)->index = name ## _index
133 
134 # ifdef LONG_BITSTREAM_READER
135 
136 # define UPDATE_CACHE_LE(name, gb) name ## _cache = \
137  AV_RL64((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7)
138 
139 # define UPDATE_CACHE_BE(name, gb) name ## _cache = \
140  AV_RB64((gb)->buffer + (name ## _index >> 3)) >> (32 - (name ## _index & 7))
141 
142 #else
143 
144 # define UPDATE_CACHE_LE(name, gb) name ## _cache = \
145  AV_RL32((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7)
146 
147 # define UPDATE_CACHE_BE(name, gb) name ## _cache = \
148  AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7)
149 
150 #endif
151 
152 
153 #ifdef BITSTREAM_READER_LE
154 
155 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb)
156 
157 # define SKIP_CACHE(name, gb, num) name ## _cache >>= (num)
158 
159 #else
160 
161 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb)
162 
163 # define SKIP_CACHE(name, gb, num) name ## _cache <<= (num)
164 
165 #endif
166 
167 #if UNCHECKED_BITSTREAM_READER
168 # define SKIP_COUNTER(name, gb, num) name ## _index += (num)
169 #else
170 # define SKIP_COUNTER(name, gb, num) \
171  name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num))
172 #endif
173 
174 #define BITS_LEFT(name, gb) ((int)((gb)->size_in_bits - name ## _index))
175 
176 #define SKIP_BITS(name, gb, num) \
177  do { \
178  SKIP_CACHE(name, gb, num); \
179  SKIP_COUNTER(name, gb, num); \
180  } while (0)
181 
182 #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
183 
184 #define SHOW_UBITS_LE(name, gb, num) zero_extend(name ## _cache, num)
185 #define SHOW_SBITS_LE(name, gb, num) sign_extend(name ## _cache, num)
186 
187 #define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num)
188 #define SHOW_SBITS_BE(name, gb, num) NEG_SSR32(name ## _cache, num)
189 
190 #ifdef BITSTREAM_READER_LE
191 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num)
192 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num)
193 #else
194 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num)
195 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num)
196 #endif
197 
198 #define GET_CACHE(name, gb) ((uint32_t) name ## _cache)
199 
200 static inline int get_bits_count(const GetBitContext *s)
201 {
202  return s->index;
203 }
204 
205 /**
206  * Skips the specified number of bits.
207  * @param n the number of bits to skip,
208  * For the UNCHECKED_BITSTREAM_READER this must not cause the distance
209  * from the start to overflow int32_t. Staying within the bitstream + padding
210  * is sufficient, too.
211  */
212 static inline void skip_bits_long(GetBitContext *s, int n)
213 {
214 #if UNCHECKED_BITSTREAM_READER
215  s->index += n;
216 #else
217  s->index += av_clip(n, -s->index, s->size_in_bits_plus8 - s->index);
218 #endif
219 }
220 
221 /**
222  * Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
223  * if MSB not set it is negative
224  * @param n length in bits
225  */
226 static inline int get_xbits(GetBitContext *s, int n)
227 {
228  register int sign;
229  register int32_t cache;
230  OPEN_READER(re, s);
231  av_assert2(n>0 && n<=25);
232  UPDATE_CACHE(re, s);
233  cache = GET_CACHE(re, s);
234  sign = ~cache >> 31;
235  LAST_SKIP_BITS(re, s, n);
236  CLOSE_READER(re, s);
237  return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
238 }
239 
240 static inline int get_xbits_le(GetBitContext *s, int n)
241 {
242  register int sign;
243  register int32_t cache;
244  OPEN_READER(re, s);
245  av_assert2(n>0 && n<=25);
246  UPDATE_CACHE_LE(re, s);
247  cache = GET_CACHE(re, s);
248  sign = sign_extend(~cache, n) >> 31;
249  LAST_SKIP_BITS(re, s, n);
250  CLOSE_READER(re, s);
251  return (zero_extend(sign ^ cache, n) ^ sign) - sign;
252 }
253 
254 static inline int get_sbits(GetBitContext *s, int n)
255 {
256  register int tmp;
257  OPEN_READER(re, s);
258  av_assert2(n>0 && n<=25);
259  UPDATE_CACHE(re, s);
260  tmp = SHOW_SBITS(re, s, n);
261  LAST_SKIP_BITS(re, s, n);
262  CLOSE_READER(re, s);
263  return tmp;
264 }
265 
266 /**
267  * Read 1-25 bits.
268  */
269 static inline unsigned int get_bits(GetBitContext *s, int n)
270 {
271  register int tmp;
272  OPEN_READER(re, s);
273  av_assert2(n>0 && n<=25);
274  UPDATE_CACHE(re, s);
275  tmp = SHOW_UBITS(re, s, n);
276  LAST_SKIP_BITS(re, s, n);
277  CLOSE_READER(re, s);
278  return tmp;
279 }
280 
281 /**
282  * Read 0-25 bits.
283  */
285 {
286  return n ? get_bits(s, n) : 0;
287 }
288 
289 static inline unsigned int get_bits_le(GetBitContext *s, int n)
290 {
291  register int tmp;
292  OPEN_READER(re, s);
293  av_assert2(n>0 && n<=25);
294  UPDATE_CACHE_LE(re, s);
295  tmp = SHOW_UBITS_LE(re, s, n);
296  LAST_SKIP_BITS(re, s, n);
297  CLOSE_READER(re, s);
298  return tmp;
299 }
300 
301 /**
302  * Show 1-25 bits.
303  */
304 static inline unsigned int show_bits(GetBitContext *s, int n)
305 {
306  register int tmp;
308  av_assert2(n>0 && n<=25);
309  UPDATE_CACHE(re, s);
310  tmp = SHOW_UBITS(re, s, n);
311  return tmp;
312 }
313 
314 static inline void skip_bits(GetBitContext *s, int n)
315 {
316  OPEN_READER(re, s);
317  LAST_SKIP_BITS(re, s, n);
318  CLOSE_READER(re, s);
319 }
320 
321 static inline unsigned int get_bits1(GetBitContext *s)
322 {
323  unsigned int index = s->index;
324  uint8_t result = s->buffer[index >> 3];
325 #ifdef BITSTREAM_READER_LE
326  result >>= index & 7;
327  result &= 1;
328 #else
329  result <<= index & 7;
330  result >>= 8 - 1;
331 #endif
332 #if !UNCHECKED_BITSTREAM_READER
333  if (s->index < s->size_in_bits_plus8)
334 #endif
335  index++;
336  s->index = index;
337 
338  return result;
339 }
340 
341 static inline unsigned int show_bits1(GetBitContext *s)
342 {
343  return show_bits(s, 1);
344 }
345 
346 static inline void skip_bits1(GetBitContext *s)
347 {
348  skip_bits(s, 1);
349 }
350 
351 /**
352  * Read 0-32 bits.
353  */
354 static inline unsigned int get_bits_long(GetBitContext *s, int n)
355 {
356  av_assert2(n>=0 && n<=32);
357  if (!n) {
358  return 0;
359  } else if (n <= MIN_CACHE_BITS) {
360  return get_bits(s, n);
361  } else {
362 #ifdef BITSTREAM_READER_LE
363  unsigned ret = get_bits(s, 16);
364  return ret | (get_bits(s, n - 16) << 16);
365 #else
366  unsigned ret = get_bits(s, 16) << (n - 16);
367  return ret | get_bits(s, n - 16);
368 #endif
369  }
370 }
371 
372 /**
373  * Read 0-64 bits.
374  */
375 static inline uint64_t get_bits64(GetBitContext *s, int n)
376 {
377  if (n <= 32) {
378  return get_bits_long(s, n);
379  } else {
380 #ifdef BITSTREAM_READER_LE
381  uint64_t ret = get_bits_long(s, 32);
382  return ret | (uint64_t) get_bits_long(s, n - 32) << 32;
383 #else
384  uint64_t ret = (uint64_t) get_bits_long(s, n - 32) << 32;
385  return ret | get_bits_long(s, 32);
386 #endif
387  }
388 }
389 
390 /**
391  * Read 0-32 bits as a signed integer.
392  */
393 static inline int get_sbits_long(GetBitContext *s, int n)
394 {
395  // sign_extend(x, 0) is undefined
396  if (!n)
397  return 0;
398 
399  return sign_extend(get_bits_long(s, n), n);
400 }
401 
402 /**
403  * Show 0-32 bits.
404  */
405 static inline unsigned int show_bits_long(GetBitContext *s, int n)
406 {
407  if (n <= MIN_CACHE_BITS) {
408  return show_bits(s, n);
409  } else {
410  GetBitContext gb = *s;
411  return get_bits_long(&gb, n);
412  }
413 }
414 
415 static inline int check_marker(void *logctx, GetBitContext *s, const char *msg)
416 {
417  int bit = get_bits1(s);
418  if (!bit)
419  av_log(logctx, AV_LOG_INFO, "Marker bit missing at %d of %d %s\n",
420  get_bits_count(s) - 1, s->size_in_bits, msg);
421 
422  return bit;
423 }
424 
425 /**
426  * Initialize GetBitContext.
427  * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
428  * larger than the actual read bits because some optimized bitstream
429  * readers read 32 or 64 bit at once and could read over the end
430  * @param bit_size the size of the buffer in bits
431  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
432  */
433 static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
434  int bit_size)
435 {
436  int buffer_size;
437  int ret = 0;
438 
439  if (bit_size >= INT_MAX - FFMAX(7, AV_INPUT_BUFFER_PADDING_SIZE*8) || bit_size < 0 || !buffer) {
440  bit_size = 0;
441  buffer = NULL;
442  ret = AVERROR_INVALIDDATA;
443  }
444 
445  buffer_size = (bit_size + 7) >> 3;
446 
447  s->buffer = buffer;
448  s->size_in_bits = bit_size;
449  s->size_in_bits_plus8 = bit_size + 8;
450  s->buffer_end = buffer + buffer_size;
451  s->index = 0;
452 
453  return ret;
454 }
455 
456 /**
457  * Initialize GetBitContext.
458  * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
459  * larger than the actual read bits because some optimized bitstream
460  * readers read 32 or 64 bit at once and could read over the end
461  * @param byte_size the size of the buffer in bytes
462  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
463  */
464 static inline int init_get_bits8(GetBitContext *s, const uint8_t *buffer,
465  int byte_size)
466 {
467  if (byte_size > INT_MAX / 8 || byte_size < 0)
468  byte_size = -1;
469  return init_get_bits(s, buffer, byte_size * 8);
470 }
471 
472 static inline const uint8_t *align_get_bits(GetBitContext *s)
473 {
474  int n = -get_bits_count(s) & 7;
475  if (n)
476  skip_bits(s, n);
477  return s->buffer + (s->index >> 3);
478 }
479 
480 /**
481  * If the vlc code is invalid and max_depth=1, then no bits will be removed.
482  * If the vlc code is invalid and max_depth>1, then the number of bits removed
483  * is undefined.
484  */
485 #define GET_VLC(code, name, gb, table, bits, max_depth) \
486  do { \
487  int n, nb_bits; \
488  unsigned int index; \
489  \
490  index = SHOW_UBITS(name, gb, bits); \
491  code = table[index][0]; \
492  n = table[index][1]; \
493  \
494  if (max_depth > 1 && n < 0) { \
495  LAST_SKIP_BITS(name, gb, bits); \
496  UPDATE_CACHE(name, gb); \
497  \
498  nb_bits = -n; \
499  \
500  index = SHOW_UBITS(name, gb, nb_bits) + code; \
501  code = table[index][0]; \
502  n = table[index][1]; \
503  if (max_depth > 2 && n < 0) { \
504  LAST_SKIP_BITS(name, gb, nb_bits); \
505  UPDATE_CACHE(name, gb); \
506  \
507  nb_bits = -n; \
508  \
509  index = SHOW_UBITS(name, gb, nb_bits) + code; \
510  code = table[index][0]; \
511  n = table[index][1]; \
512  } \
513  } \
514  SKIP_BITS(name, gb, n); \
515  } while (0)
516 
517 #define GET_RL_VLC(level, run, name, gb, table, bits, \
518  max_depth, need_update) \
519  do { \
520  int n, nb_bits; \
521  unsigned int index; \
522  \
523  index = SHOW_UBITS(name, gb, bits); \
524  level = table[index].level; \
525  n = table[index].len; \
526  \
527  if (max_depth > 1 && n < 0) { \
528  SKIP_BITS(name, gb, bits); \
529  if (need_update) { \
530  UPDATE_CACHE(name, gb); \
531  } \
532  \
533  nb_bits = -n; \
534  \
535  index = SHOW_UBITS(name, gb, nb_bits) + level; \
536  level = table[index].level; \
537  n = table[index].len; \
538  if (max_depth > 2 && n < 0) { \
539  LAST_SKIP_BITS(name, gb, nb_bits); \
540  if (need_update) { \
541  UPDATE_CACHE(name, gb); \
542  } \
543  nb_bits = -n; \
544  \
545  index = SHOW_UBITS(name, gb, nb_bits) + level; \
546  level = table[index].level; \
547  n = table[index].len; \
548  } \
549  } \
550  run = table[index].run; \
551  SKIP_BITS(name, gb, n); \
552  } while (0)
553 
554 /**
555  * Parse a vlc code.
556  * @param bits is the number of bits which will be read at once, must be
557  * identical to nb_bits in init_vlc()
558  * @param max_depth is the number of times bits bits must be read to completely
559  * read the longest vlc code
560  * = (max_vlc_length + bits - 1) / bits
561  * @returns the code parsed or -1 if no vlc matches
562  */
564  int bits, int max_depth)
565 {
566  int code;
567 
568  OPEN_READER(re, s);
569  UPDATE_CACHE(re, s);
570 
571  GET_VLC(code, re, s, table, bits, max_depth);
572 
573  CLOSE_READER(re, s);
574 
575  return code;
576 }
577 
578 static inline int decode012(GetBitContext *gb)
579 {
580  int n;
581  n = get_bits1(gb);
582  if (n == 0)
583  return 0;
584  else
585  return get_bits1(gb) + 1;
586 }
587 
588 static inline int decode210(GetBitContext *gb)
589 {
590  if (get_bits1(gb))
591  return 0;
592  else
593  return 2 - get_bits1(gb);
594 }
595 
596 static inline int get_bits_left(GetBitContext *gb)
597 {
598  return gb->size_in_bits - get_bits_count(gb);
599 }
600 
601 static inline int skip_1stop_8data_bits(GetBitContext *gb)
602 {
603  if (get_bits_left(gb) <= 0)
604  return AVERROR_INVALIDDATA;
605 
606  while (get_bits1(gb)) {
607  skip_bits(gb, 8);
608  if (get_bits_left(gb) <= 0)
609  return AVERROR_INVALIDDATA;
610  }
611 
612  return 0;
613 }
614 
615 #endif /* AVCODEC_GET_BITS_H */
static int get_xbits_le(GetBitContext *s, int n)
Definition: get_bits.h:240
static unsigned int show_bits_long(GetBitContext *s, int n)
Show 0-32 bits.
Definition: get_bits.h:405
static unsigned int show_bits1(GetBitContext *s)
Definition: get_bits.h:341
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
float re
Definition: fft.c:82
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:269
static void skip_bits_long(GetBitContext *s, int n)
Skips the specified number of bits.
Definition: get_bits.h:212
static int check_marker(void *logctx, GetBitContext *s, const char *msg)
Definition: get_bits.h:415
const uint8_t * buffer
Definition: get_bits.h:57
static av_const unsigned zero_extend(unsigned val, unsigned bits)
Definition: mathops.h:139
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:254
static int get_sbits_long(GetBitContext *s, int n)
Read 0-32 bits as a signed integer.
Definition: get_bits.h:393
uint8_t
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition: avassert.h:64
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:200
#define SHOW_UBITS_LE(name, gb, num)
Definition: get_bits.h:184
#define av_log(a,...)
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:596
static uint64_t get_bits64(GetBitContext *s, int n)
Read 0-64 bits.
Definition: get_bits.h:375
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:161
static const struct endianess table[]
simple assert() macros that are a bit more flexible than ISO C assert().
#define CLOSE_READER(name, gb)
Definition: get_bits.h:132
#define FFMAX(a, b)
Definition: common.h:94
#define NEG_USR32(a, s)
Definition: mathops.h:166
int size_in_bits
Definition: get_bits.h:59
int32_t
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition: get_bits.h:304
#define s(width, name)
Definition: cbs_vp9.c:257
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:182
static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE(*table)[2], int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:563
int n
Definition: avisynth_c.h:684
#define GET_VLC(code, name, gb, table, bits, max_depth)
If the vlc code is invalid and max_depth=1, then no bits will be removed.
Definition: get_bits.h:485
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:194
static int decode210(GetBitContext *gb)
Definition: get_bits.h:588
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
Libavcodec external API header.
int size_in_bits_plus8
Definition: get_bits.h:60
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:464
static int get_xbits(GetBitContext *s, int n)
Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
Definition: get_bits.h:226
#define OPEN_READER(name, gb)
Definition: get_bits.h:121
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:321
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:346
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:314
int index
Definition: gxfenc.c:89
#define UPDATE_CACHE_LE(name, gb)
Definition: get_bits.h:144
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:433
#define GET_CACHE(name, gb)
Definition: get_bits.h:198
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:354
#define MIN_CACHE_BITS
Definition: get_bits.h:113
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:130
static unsigned int get_bits_le(GetBitContext *s, int n)
Definition: get_bits.h:289
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:195
#define OPEN_READER_NOSIZE(name, gb)
Definition: get_bits.h:116
common internal and external API header
const uint8_t * buffer_end
Definition: get_bits.h:57
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:774
static int decode012(GetBitContext *gb)
Definition: get_bits.h:578
static const uint8_t * align_get_bits(GetBitContext *s)
Definition: get_bits.h:472
static int skip_1stop_8data_bits(GetBitContext *gb)
Definition: get_bits.h:601
#define av_always_inline
Definition: attributes.h:39
#define VLC_TYPE
Definition: vlc.h:24
static av_always_inline int get_bitsz(GetBitContext *s, int n)
Read 0-25 bits.
Definition: get_bits.h:284
GLuint buffer
Definition: opengl_enc.c:102
static uint8_t tmp[11]
Definition: aes_ctr.c:26