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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 "mathops.h"
36 #include "vlc.h"
37 
38 /*
39  * Safe bitstream reading:
40  * optionally, the get_bits API can check to ensure that we
41  * don't read past input buffer boundaries. This is protected
42  * with CONFIG_SAFE_BITSTREAM_READER at the global level, and
43  * then below that with UNCHECKED_BITSTREAM_READER at the per-
44  * decoder level. This means that decoders that check internally
45  * can "#define UNCHECKED_BITSTREAM_READER 1" to disable
46  * overread checks.
47  * Boundary checking causes a minor performance penalty so for
48  * applications that won't want/need this, it can be disabled
49  * globally using "#define CONFIG_SAFE_BITSTREAM_READER 0".
50  */
51 #ifndef UNCHECKED_BITSTREAM_READER
52 #define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER
53 #endif
54 
55 typedef struct GetBitContext {
57  int index;
61 
62 /* Bitstream reader API docs:
63  * name
64  * arbitrary name which is used as prefix for the internal variables
65  *
66  * gb
67  * getbitcontext
68  *
69  * OPEN_READER(name, gb)
70  * load gb into local variables
71  *
72  * CLOSE_READER(name, gb)
73  * store local vars in gb
74  *
75  * UPDATE_CACHE(name, gb)
76  * Refill the internal cache from the bitstream.
77  * After this call at least MIN_CACHE_BITS will be available.
78  *
79  * GET_CACHE(name, gb)
80  * Will output the contents of the internal cache,
81  * next bit is MSB of 32 or 64 bits (FIXME 64 bits).
82  *
83  * SHOW_UBITS(name, gb, num)
84  * Will return the next num bits.
85  *
86  * SHOW_SBITS(name, gb, num)
87  * Will return the next num bits and do sign extension.
88  *
89  * SKIP_BITS(name, gb, num)
90  * Will skip over the next num bits.
91  * Note, this is equivalent to SKIP_CACHE; SKIP_COUNTER.
92  *
93  * SKIP_CACHE(name, gb, num)
94  * Will remove the next num bits from the cache (note SKIP_COUNTER
95  * MUST be called before UPDATE_CACHE / CLOSE_READER).
96  *
97  * SKIP_COUNTER(name, gb, num)
98  * Will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS).
99  *
100  * LAST_SKIP_BITS(name, gb, num)
101  * Like SKIP_BITS, to be used if next call is UPDATE_CACHE or CLOSE_READER.
102  *
103  * BITS_LEFT(name, gb)
104  * Return the number of bits left
105  *
106  * For examples see get_bits, show_bits, skip_bits, get_vlc.
107  */
108 
109 #ifdef LONG_BITSTREAM_READER
110 # define MIN_CACHE_BITS 32
111 #else
112 # define MIN_CACHE_BITS 25
113 #endif
114 
115 #define OPEN_READER_NOSIZE(name, gb) \
116  unsigned int name ## _index = (gb)->index; \
117  unsigned int av_unused name ## _cache
118 
119 #if UNCHECKED_BITSTREAM_READER
120 #define OPEN_READER(name, gb) OPEN_READER_NOSIZE(name, gb)
121 
122 #define BITS_AVAILABLE(name, gb) 1
123 #else
124 #define OPEN_READER(name, gb) \
125  OPEN_READER_NOSIZE(name, gb); \
126  unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8
127 
128 #define BITS_AVAILABLE(name, gb) name ## _index < name ## _size_plus8
129 #endif
130 
131 #define CLOSE_READER(name, gb) (gb)->index = name ## _index
132 
133 # ifdef LONG_BITSTREAM_READER
134 
135 # define UPDATE_CACHE_LE(name, gb) name ## _cache = \
136  AV_RL64((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7)
137 
138 # define UPDATE_CACHE_BE(name, gb) name ## _cache = \
139  AV_RB64((gb)->buffer + (name ## _index >> 3)) >> (32 - (name ## _index & 7))
140 
141 #else
142 
143 # define UPDATE_CACHE_LE(name, gb) name ## _cache = \
144  AV_RL32((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7)
145 
146 # define UPDATE_CACHE_BE(name, gb) name ## _cache = \
147  AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7)
148 
149 #endif
150 
151 
152 #ifdef BITSTREAM_READER_LE
153 
154 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb)
155 
156 # define SKIP_CACHE(name, gb, num) name ## _cache >>= (num)
157 
158 #else
159 
160 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb)
161 
162 # define SKIP_CACHE(name, gb, num) name ## _cache <<= (num)
163 
164 #endif
165 
166 #if UNCHECKED_BITSTREAM_READER
167 # define SKIP_COUNTER(name, gb, num) name ## _index += (num)
168 #else
169 # define SKIP_COUNTER(name, gb, num) \
170  name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num))
171 #endif
172 
173 #define BITS_LEFT(name, gb) ((int)((gb)->size_in_bits - name ## _index))
174 
175 #define SKIP_BITS(name, gb, num) \
176  do { \
177  SKIP_CACHE(name, gb, num); \
178  SKIP_COUNTER(name, gb, num); \
179  } while (0)
180 
181 #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
182 
183 #define SHOW_UBITS_LE(name, gb, num) zero_extend(name ## _cache, num)
184 #define SHOW_SBITS_LE(name, gb, num) sign_extend(name ## _cache, num)
185 
186 #define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num)
187 #define SHOW_SBITS_BE(name, gb, num) NEG_SSR32(name ## _cache, num)
188 
189 #ifdef BITSTREAM_READER_LE
190 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num)
191 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num)
192 #else
193 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num)
194 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num)
195 #endif
196 
197 #define GET_CACHE(name, gb) ((uint32_t) name ## _cache)
198 
199 static inline int get_bits_count(const GetBitContext *s)
200 {
201  return s->index;
202 }
203 
204 static inline void skip_bits_long(GetBitContext *s, int n)
205 {
206 #if UNCHECKED_BITSTREAM_READER
207  s->index += n;
208 #else
209  s->index += av_clip(n, -s->index, s->size_in_bits_plus8 - s->index);
210 #endif
211 }
212 
213 /**
214  * Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
215  * if MSB not set it is negative
216  * @param n length in bits
217  */
218 static inline int get_xbits(GetBitContext *s, int n)
219 {
220  register int sign;
221  register int32_t cache;
222  OPEN_READER(re, s);
223  av_assert2(n>0 && n<=25);
224  UPDATE_CACHE(re, s);
225  cache = GET_CACHE(re, s);
226  sign = ~cache >> 31;
227  LAST_SKIP_BITS(re, s, n);
228  CLOSE_READER(re, s);
229  return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
230 }
231 
232 static inline int get_xbits_le(GetBitContext *s, int n)
233 {
234  register int sign;
235  register int32_t cache;
236  OPEN_READER(re, s);
237  av_assert2(n>0 && n<=25);
238  UPDATE_CACHE_LE(re, s);
239  cache = GET_CACHE(re, s);
240  sign = sign_extend(~cache, n) >> 31;
241  LAST_SKIP_BITS(re, s, n);
242  CLOSE_READER(re, s);
243  return (zero_extend(sign ^ cache, n) ^ sign) - sign;
244 }
245 
246 static inline int get_sbits(GetBitContext *s, int n)
247 {
248  register int tmp;
249  OPEN_READER(re, s);
250  av_assert2(n>0 && n<=25);
251  UPDATE_CACHE(re, s);
252  tmp = SHOW_SBITS(re, s, n);
253  LAST_SKIP_BITS(re, s, n);
254  CLOSE_READER(re, s);
255  return tmp;
256 }
257 
258 /**
259  * Read 1-25 bits.
260  */
261 static inline unsigned int get_bits(GetBitContext *s, int n)
262 {
263  register int tmp;
264  OPEN_READER(re, s);
265  av_assert2(n>0 && n<=25);
266  UPDATE_CACHE(re, s);
267  tmp = SHOW_UBITS(re, s, n);
268  LAST_SKIP_BITS(re, s, n);
269  CLOSE_READER(re, s);
270  return tmp;
271 }
272 
273 /**
274  * Read 0-25 bits.
275  */
277 {
278  return n ? get_bits(s, n) : 0;
279 }
280 
281 static inline unsigned int get_bits_le(GetBitContext *s, int n)
282 {
283  register int tmp;
284  OPEN_READER(re, s);
285  av_assert2(n>0 && n<=25);
286  UPDATE_CACHE_LE(re, s);
287  tmp = SHOW_UBITS_LE(re, s, n);
288  LAST_SKIP_BITS(re, s, n);
289  CLOSE_READER(re, s);
290  return tmp;
291 }
292 
293 /**
294  * Show 1-25 bits.
295  */
296 static inline unsigned int show_bits(GetBitContext *s, int n)
297 {
298  register int tmp;
300  av_assert2(n>0 && n<=25);
301  UPDATE_CACHE(re, s);
302  tmp = SHOW_UBITS(re, s, n);
303  return tmp;
304 }
305 
306 static inline void skip_bits(GetBitContext *s, int n)
307 {
308  OPEN_READER(re, s);
309  LAST_SKIP_BITS(re, s, n);
310  CLOSE_READER(re, s);
311 }
312 
313 static inline unsigned int get_bits1(GetBitContext *s)
314 {
315  unsigned int index = s->index;
316  uint8_t result = s->buffer[index >> 3];
317 #ifdef BITSTREAM_READER_LE
318  result >>= index & 7;
319  result &= 1;
320 #else
321  result <<= index & 7;
322  result >>= 8 - 1;
323 #endif
324 #if !UNCHECKED_BITSTREAM_READER
325  if (s->index < s->size_in_bits_plus8)
326 #endif
327  index++;
328  s->index = index;
329 
330  return result;
331 }
332 
333 static inline unsigned int show_bits1(GetBitContext *s)
334 {
335  return show_bits(s, 1);
336 }
337 
338 static inline void skip_bits1(GetBitContext *s)
339 {
340  skip_bits(s, 1);
341 }
342 
343 /**
344  * Read 0-32 bits.
345  */
346 static inline unsigned int get_bits_long(GetBitContext *s, int n)
347 {
348  av_assert2(n>=0 && n<=32);
349  if (!n) {
350  return 0;
351  } else if (n <= MIN_CACHE_BITS) {
352  return get_bits(s, n);
353  } else {
354 #ifdef BITSTREAM_READER_LE
355  unsigned ret = get_bits(s, 16);
356  return ret | (get_bits(s, n - 16) << 16);
357 #else
358  unsigned ret = get_bits(s, 16) << (n - 16);
359  return ret | get_bits(s, n - 16);
360 #endif
361  }
362 }
363 
364 /**
365  * Read 0-64 bits.
366  */
367 static inline uint64_t get_bits64(GetBitContext *s, int n)
368 {
369  if (n <= 32) {
370  return get_bits_long(s, n);
371  } else {
372 #ifdef BITSTREAM_READER_LE
373  uint64_t ret = get_bits_long(s, 32);
374  return ret | (uint64_t) get_bits_long(s, n - 32) << 32;
375 #else
376  uint64_t ret = (uint64_t) get_bits_long(s, n - 32) << 32;
377  return ret | get_bits_long(s, 32);
378 #endif
379  }
380 }
381 
382 /**
383  * Read 0-32 bits as a signed integer.
384  */
385 static inline int get_sbits_long(GetBitContext *s, int n)
386 {
387  // sign_extend(x, 0) is undefined
388  if (!n)
389  return 0;
390 
391  return sign_extend(get_bits_long(s, n), n);
392 }
393 
394 /**
395  * Show 0-32 bits.
396  */
397 static inline unsigned int show_bits_long(GetBitContext *s, int n)
398 {
399  if (n <= MIN_CACHE_BITS) {
400  return show_bits(s, n);
401  } else {
402  GetBitContext gb = *s;
403  return get_bits_long(&gb, n);
404  }
405 }
406 
407 static inline int check_marker(void *logctx, GetBitContext *s, const char *msg)
408 {
409  int bit = get_bits1(s);
410  if (!bit)
411  av_log(logctx, AV_LOG_INFO, "Marker bit missing at %d of %d %s\n",
412  get_bits_count(s) - 1, s->size_in_bits, msg);
413 
414  return bit;
415 }
416 
417 /**
418  * Initialize GetBitContext.
419  * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
420  * larger than the actual read bits because some optimized bitstream
421  * readers read 32 or 64 bit at once and could read over the end
422  * @param bit_size the size of the buffer in bits
423  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
424  */
425 static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
426  int bit_size)
427 {
428  int buffer_size;
429  int ret = 0;
430 
431  if (bit_size >= INT_MAX - 7 || bit_size < 0 || !buffer) {
432  bit_size = 0;
433  buffer = NULL;
434  ret = AVERROR_INVALIDDATA;
435  }
436 
437  buffer_size = (bit_size + 7) >> 3;
438 
439  s->buffer = buffer;
440  s->size_in_bits = bit_size;
441  s->size_in_bits_plus8 = bit_size + 8;
442  s->buffer_end = buffer + buffer_size;
443  s->index = 0;
444 
445  return ret;
446 }
447 
448 /**
449  * Initialize GetBitContext.
450  * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
451  * larger than the actual read bits because some optimized bitstream
452  * readers read 32 or 64 bit at once and could read over the end
453  * @param byte_size the size of the buffer in bytes
454  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
455  */
456 static inline int init_get_bits8(GetBitContext *s, const uint8_t *buffer,
457  int byte_size)
458 {
459  if (byte_size > INT_MAX / 8 || byte_size < 0)
460  byte_size = -1;
461  return init_get_bits(s, buffer, byte_size * 8);
462 }
463 
464 static inline const uint8_t *align_get_bits(GetBitContext *s)
465 {
466  int n = -get_bits_count(s) & 7;
467  if (n)
468  skip_bits(s, n);
469  return s->buffer + (s->index >> 3);
470 }
471 
472 /**
473  * If the vlc code is invalid and max_depth=1, then no bits will be removed.
474  * If the vlc code is invalid and max_depth>1, then the number of bits removed
475  * is undefined.
476  */
477 #define GET_VLC(code, name, gb, table, bits, max_depth) \
478  do { \
479  int n, nb_bits; \
480  unsigned int index; \
481  \
482  index = SHOW_UBITS(name, gb, bits); \
483  code = table[index][0]; \
484  n = table[index][1]; \
485  \
486  if (max_depth > 1 && n < 0) { \
487  LAST_SKIP_BITS(name, gb, bits); \
488  UPDATE_CACHE(name, gb); \
489  \
490  nb_bits = -n; \
491  \
492  index = SHOW_UBITS(name, gb, nb_bits) + code; \
493  code = table[index][0]; \
494  n = table[index][1]; \
495  if (max_depth > 2 && n < 0) { \
496  LAST_SKIP_BITS(name, gb, nb_bits); \
497  UPDATE_CACHE(name, gb); \
498  \
499  nb_bits = -n; \
500  \
501  index = SHOW_UBITS(name, gb, nb_bits) + code; \
502  code = table[index][0]; \
503  n = table[index][1]; \
504  } \
505  } \
506  SKIP_BITS(name, gb, n); \
507  } while (0)
508 
509 #define GET_RL_VLC(level, run, name, gb, table, bits, \
510  max_depth, need_update) \
511  do { \
512  int n, nb_bits; \
513  unsigned int index; \
514  \
515  index = SHOW_UBITS(name, gb, bits); \
516  level = table[index].level; \
517  n = table[index].len; \
518  \
519  if (max_depth > 1 && n < 0) { \
520  SKIP_BITS(name, gb, bits); \
521  if (need_update) { \
522  UPDATE_CACHE(name, gb); \
523  } \
524  \
525  nb_bits = -n; \
526  \
527  index = SHOW_UBITS(name, gb, nb_bits) + level; \
528  level = table[index].level; \
529  n = table[index].len; \
530  if (max_depth > 2 && n < 0) { \
531  LAST_SKIP_BITS(name, gb, nb_bits); \
532  if (need_update) { \
533  UPDATE_CACHE(name, gb); \
534  } \
535  nb_bits = -n; \
536  \
537  index = SHOW_UBITS(name, gb, nb_bits) + level; \
538  level = table[index].level; \
539  n = table[index].len; \
540  } \
541  } \
542  run = table[index].run; \
543  SKIP_BITS(name, gb, n); \
544  } while (0)
545 
546 /**
547  * Parse a vlc code.
548  * @param bits is the number of bits which will be read at once, must be
549  * identical to nb_bits in init_vlc()
550  * @param max_depth is the number of times bits bits must be read to completely
551  * read the longest vlc code
552  * = (max_vlc_length + bits - 1) / bits
553  */
555  int bits, int max_depth)
556 {
557  int code;
558 
559  OPEN_READER(re, s);
560  UPDATE_CACHE(re, s);
561 
562  GET_VLC(code, re, s, table, bits, max_depth);
563 
564  CLOSE_READER(re, s);
565 
566  return code;
567 }
568 
569 static inline int decode012(GetBitContext *gb)
570 {
571  int n;
572  n = get_bits1(gb);
573  if (n == 0)
574  return 0;
575  else
576  return get_bits1(gb) + 1;
577 }
578 
579 static inline int decode210(GetBitContext *gb)
580 {
581  if (get_bits1(gb))
582  return 0;
583  else
584  return 2 - get_bits1(gb);
585 }
586 
587 static inline int get_bits_left(GetBitContext *gb)
588 {
589  return gb->size_in_bits - get_bits_count(gb);
590 }
591 
592 static inline int skip_1stop_8data_bits(GetBitContext *gb)
593 {
594  if (get_bits_left(gb) <= 0)
595  return AVERROR_INVALIDDATA;
596 
597  while (get_bits1(gb)) {
598  skip_bits(gb, 8);
599  if (get_bits_left(gb) <= 0)
600  return AVERROR_INVALIDDATA;
601  }
602 
603  return 0;
604 }
605 
606 #endif /* AVCODEC_GET_BITS_H */
static int get_xbits_le(GetBitContext *s, int n)
Definition: get_bits.h:232
static unsigned int show_bits_long(GetBitContext *s, int n)
Show 0-32 bits.
Definition: get_bits.h:397
static unsigned int show_bits1(GetBitContext *s)
Definition: get_bits.h:333
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
#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:261
static void skip_bits_long(GetBitContext *s, int n)
Definition: get_bits.h:204
static int check_marker(void *logctx, GetBitContext *s, const char *msg)
Definition: get_bits.h:407
const uint8_t * buffer
Definition: get_bits.h:56
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:246
static int get_sbits_long(GetBitContext *s, int n)
Read 0-32 bits as a signed integer.
Definition: get_bits.h:385
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:199
#define SHOW_UBITS_LE(name, gb, num)
Definition: get_bits.h:183
#define av_log(a,...)
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:587
static uint64_t get_bits64(GetBitContext *s, int n)
Read 0-64 bits.
Definition: get_bits.h:367
#define UPDATE_CACHE(name, gb)
Definition: get_bits.h:160
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:131
#define NEG_USR32(a, s)
Definition: mathops.h:166
int size_in_bits
Definition: get_bits.h:58
int32_t
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition: get_bits.h:296
#define LAST_SKIP_BITS(name, gb, num)
Definition: get_bits.h:181
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:554
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:477
#define SHOW_UBITS(name, gb, num)
Definition: get_bits.h:193
static int decode210(GetBitContext *gb)
Definition: get_bits.h:579
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
int size_in_bits_plus8
Definition: get_bits.h:59
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:456
static int get_xbits(GetBitContext *s, int n)
Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
Definition: get_bits.h:218
#define OPEN_READER(name, gb)
Definition: get_bits.h:120
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:313
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:338
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:306
int index
Definition: gxfenc.c:89
#define UPDATE_CACHE_LE(name, gb)
Definition: get_bits.h:143
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:425
#define GET_CACHE(name, gb)
Definition: get_bits.h:197
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:346
#define MIN_CACHE_BITS
Definition: get_bits.h:112
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:281
#define SHOW_SBITS(name, gb, num)
Definition: get_bits.h:194
#define OPEN_READER_NOSIZE(name, gb)
Definition: get_bits.h:115
common internal and external API header
const uint8_t * buffer_end
Definition: get_bits.h:56
static int decode012(GetBitContext *gb)
Definition: get_bits.h:569
static const uint8_t * align_get_bits(GetBitContext *s)
Definition: get_bits.h:464
static int skip_1stop_8data_bits(GetBitContext *gb)
Definition: get_bits.h:592
#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:276
GLuint buffer
Definition: opengl_enc.c:102
static uint8_t tmp[11]
Definition: aes_ctr.c:26