FFmpeg: libavcodec/get_bits.h Source File

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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/avassert.h"
34
35#include "defs.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#ifndef CACHED_BITSTREAM_READER
57 #define CACHED_BITSTREAM_READER 0
58#endif
59
60#if CACHED_BITSTREAM_READER
61
62// we always want the LE implementation, to provide get_bits_le()
63#define BITSTREAM_LE
64
65#ifndef BITSTREAM_READER_LE
66# define BITSTREAM_BE
67# define BITSTREAM_DEFAULT_BE
68#endif
69
70#include "bitstream.h"
71
72#undef BITSTREAM_LE
73#undef BITSTREAM_BE
74#undef BITSTREAM_DEFAULT_BE
75
76typedef BitstreamContext GetBitContext;
77
78#define get_bits_count bits_tell
79#define get_bits_bytesize bits_bytesize
80#define get_bits_left bits_left
81#define skip_bits_long bits_skip
82#define skip_bits bits_skip
83#define get_bits bits_read_nz
84#define get_bitsz bits_read
85#define get_bits_long bits_read
86#define get_bits1 bits_read_bit
87#define get_bits64 bits_read_64
88#define get_xbits bits_read_xbits
89#define get_sbits bits_read_signed_nz
90#define get_sbits_long bits_read_signed
91#define show_bits bits_peek
92#define show_bits_long bits_peek
93#define init_get_bits bits_init
94#define init_get_bits8 bits_init8
95#define align_get_bits bits_align
96#define get_vlc2 bits_read_vlc
97#define get_vlc_multi bits_read_vlc_multi
98
99#define init_get_bits8_le(s, buffer, byte_size) bits_init8_le((BitstreamContextLE*)s, buffer, byte_size)
100#define get_bits_le(s, n) bits_read_le((BitstreamContextLE*)s, n)
101
102#define show_bits1(s) bits_peek(s, 1)
103#define skip_bits1(s) bits_skip(s, 1)
104
105#define skip_1stop_8data_bits bits_skip_1stop_8data
106
107#else // CACHED_BITSTREAM_READER
108
109 typedef struct GetBitContext {
110 const uint8_t *buffer;
111 int index;
115
116static inline unsigned int get_bits(GetBitContext *s, int n);
117static inline void skip_bits(GetBitContext *s, int n);
118static inline unsigned int show_bits(GetBitContext *s, int n);
119
120/* Bitstream reader API docs:
121 * name
122 * arbitrary name which is used as prefix for the internal variables
123 *
124 * gb
125 * getbitcontext
126 *
127 * OPEN_READER(name, gb)
128 * load gb into local variables
129 *
130 * CLOSE_READER(name, gb)
131 * store local vars in gb
132 *
133 * UPDATE_CACHE(name, gb)
134 * Refill the internal cache from the bitstream.
135 * After this call at least MIN_CACHE_BITS will be available.
136 *
137 * GET_CACHE(name, gb)
138 * Will output the contents of the internal cache,
139 * next bit is MSB of 32 or 64 bits (FIXME 64 bits).
140 *
141 * SHOW_UBITS(name, gb, num)
142 * Will return the next num bits.
143 *
144 * SHOW_SBITS(name, gb, num)
145 * Will return the next num bits and do sign extension.
146 *
147 * SKIP_BITS(name, gb, num)
148 * Will skip over the next num bits.
149 * Note, this is equivalent to SKIP_CACHE; SKIP_COUNTER.
150 *
151 * SKIP_CACHE(name, gb, num)
152 * Will remove the next num bits from the cache (note SKIP_COUNTER
153 * MUST be called before UPDATE_CACHE / CLOSE_READER).
154 *
155 * SKIP_COUNTER(name, gb, num)
156 * Will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS).
157 *
158 * LAST_SKIP_BITS(name, gb, num)
159 * Like SKIP_BITS, to be used if next call is UPDATE_CACHE or CLOSE_READER.
160 *
161 * BITS_LEFT(name, gb)
162 * Return the number of bits left
163 *
164 * For examples see get_bits, show_bits, skip_bits, get_vlc.
165 */
166
167 #define MIN_CACHE_BITS 25
168
169 #define OPEN_READER_NOSIZE_NOCACHE(name, gb) \
170 unsigned int name ## _index = (gb)->index
171
172 #define OPEN_READER_NOSIZE(name, gb) \
173 OPEN_READER_NOSIZE_NOCACHE(name, gb); \
174 unsigned int name ## _cache
175
176#if UNCHECKED_BITSTREAM_READER
177#define OPEN_READER(name, gb) OPEN_READER_NOSIZE(name, gb)
178#define OPEN_READER_SIZE(name, gb) ((void)0)
179#define BITS_AVAILABLE(name, gb) 1
180#else
181 #define OPEN_READER_SIZE(name, gb) unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8
182 #define OPEN_READER(name, gb) \
183 OPEN_READER_NOSIZE(name, gb); \
184 OPEN_READER_SIZE(name, gb)
185
186 #define BITS_AVAILABLE(name, gb) name ## _index < name ## _size_plus8
187#endif
188
189 #define CLOSE_READER(name, gb) (gb)->index = name ## _index
190
191 #define UPDATE_CACHE_BE_EXT(name, gb, bits, dst_bits) name ## _cache = \
192 AV_RB ## bits((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7) >> (bits - dst_bits)
193
194 #define UPDATE_CACHE_LE_EXT(name, gb, bits, dst_bits) name ## _cache = \
195 (uint ## dst_bits ## _t)(AV_RL ## bits((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7))
196
197/* Using these two macros ensures that 32 bits are available. */
198 # define UPDATE_CACHE_LE_32(name, gb) UPDATE_CACHE_LE_EXT(name, (gb), 64, 32)
199 # define UPDATE_CACHE_BE_32(name, gb) UPDATE_CACHE_BE_EXT(name, (gb), 64, 32)
200
201 # define UPDATE_CACHE_LE(name, gb) UPDATE_CACHE_LE_EXT(name, (gb), 32, 32)
202 # define UPDATE_CACHE_BE(name, gb) UPDATE_CACHE_BE_EXT(name, (gb), 32, 32)
203
204#ifdef BITSTREAM_READER_LE
205
206# define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb)
207# define UPDATE_CACHE_32(name, gb) UPDATE_CACHE_LE_32(name, (gb))
208
209# define SKIP_CACHE(name, gb, num) name ## _cache >>= (num)
210
211#else
212
213 # define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb)
214 # define UPDATE_CACHE_32(name, gb) UPDATE_CACHE_BE_32(name, (gb))
215
216 # define SKIP_CACHE(name, gb, num) name ## _cache <<= (num)
217
218#endif
219
220#if UNCHECKED_BITSTREAM_READER
221# define SKIP_COUNTER(name, gb, num) name ## _index += (num)
222#else
223 # define SKIP_COUNTER(name, gb, num) \
224 name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num))
225#endif
226
227 #define BITS_LEFT(name, gb) ((int)((gb)->size_in_bits - name ## _index))
228
229 #define SKIP_BITS(name, gb, num) \
230 do { \
231 SKIP_CACHE(name, gb, num); \
232 SKIP_COUNTER(name, gb, num); \
233 } while (0)
234
235 #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
236
237 #define SHOW_UBITS_LE(name, gb, num) zero_extend(name ## _cache, num)
238 #define SHOW_SBITS_LE(name, gb, num) sign_extend(name ## _cache, num)
239
240 #define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num)
241 #define SHOW_SBITS_BE(name, gb, num) NEG_SSR32(name ## _cache, num)
242
243#ifdef BITSTREAM_READER_LE
244# define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num)
245# define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num)
246#else
247 # define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num)
248 # define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num)
249#endif
250
251 #define GET_CACHE(name, gb) ((uint32_t) name ## _cache)
252
253
254 static inline int get_bits_count(const GetBitContext *s)
255{
256 return s->index;
257}
258
259/**
260 * Get the size of the GetBitContext's buffer in bytes.
261 *
262 * @param s the GetBitContext
263 * @param round_up If set, the number of bits will be rounded up to full bytes;
264 * this does not matter if the number of bits is known to be
265 * a multiple of eight, e.g. if the GetBitContext has been
266 * initialized with init_get_bits8.
267 */
268 static inline int get_bits_bytesize(const GetBitContext *s, int round_up)
269{
270 return (s->size_in_bits + (round_up ? 7 : 0)) >> 3;
271}
272
273/**
274 * Skips the specified number of bits.
275 * @param n the number of bits to skip,
276 * For the UNCHECKED_BITSTREAM_READER this must not cause the distance
277 * from the start to overflow int32_t. Staying within the bitstream + padding
278 * is sufficient, too.
279 */
280 static inline void skip_bits_long(GetBitContext *s, int n)
281{
282#if UNCHECKED_BITSTREAM_READER
283 s->index += n;
284#else
285 s->index += av_clip(n, -s->index, s->size_in_bits_plus8 - s->index);
286#endif
287}
288
289/**
290 * Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
291 * if MSB not set it is negative
292 * @param n length in bits
293 */
294 static inline int get_xbits(GetBitContext *s, int n)
295{
296 register int sign;
297 register int32_t cache;
298 OPEN_READER(re, s);
299 av_assert2(n>0 && n<=25);
300 UPDATE_CACHE(re, s);
301 cache = GET_CACHE(re, s);
302 sign = ~cache >> 31;
303 LAST_SKIP_BITS(re, s, n);
304 CLOSE_READER(re, s);
305 return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
306}
307
308 static inline int get_xbits_le(GetBitContext *s, int n)
309{
310 register int sign;
311 register int32_t cache;
312 OPEN_READER(re, s);
313 av_assert2(n>0 && n<=25);
314 UPDATE_CACHE_LE(re, s);
315 cache = GET_CACHE(re, s);
316 sign = sign_extend(~cache, n) >> 31;
317 LAST_SKIP_BITS(re, s, n);
318 CLOSE_READER(re, s);
319 return (zero_extend(sign ^ cache, n) ^ sign) - sign;
320}
321
322 static inline int get_sbits(GetBitContext *s, int n)
323{
324 register int tmp;
325 OPEN_READER(re, s);
326 av_assert2(n>0 && n<=25);
327 UPDATE_CACHE(re, s);
328 tmp = SHOW_SBITS(re, s, n);
329 LAST_SKIP_BITS(re, s, n);
330 CLOSE_READER(re, s);
331 return tmp;
332}
333
334/**
335 * Read 1-25 bits.
336 */
337 static inline unsigned int get_bits(GetBitContext *s, int n)
338{
339 register unsigned int tmp;
340 OPEN_READER(re, s);
341 av_assert2(n>0 && n<=25);
342 UPDATE_CACHE(re, s);
343 tmp = SHOW_UBITS(re, s, n);
344 LAST_SKIP_BITS(re, s, n);
345 CLOSE_READER(re, s);
346 av_assert2(tmp < UINT64_C(1) << n);
347 return tmp;
348}
349
350/**
351 * Read 0-25 bits.
352 */
354{
355 return n ? get_bits(s, n) : 0;
356}
357
358 static inline unsigned int get_bits_le(GetBitContext *s, int n)
359{
360 register int tmp;
361 OPEN_READER(re, s);
362 av_assert2(n>0 && n<=25);
363 UPDATE_CACHE_LE(re, s);
364 tmp = SHOW_UBITS_LE(re, s, n);
365 LAST_SKIP_BITS(re, s, n);
366 CLOSE_READER(re, s);
367 return tmp;
368}
369
370/**
371 * Show 1-25 bits.
372 */
373 static inline unsigned int show_bits(GetBitContext *s, int n)
374{
375 register unsigned int tmp;
377 av_assert2(n>0 && n<=25);
378 UPDATE_CACHE(re, s);
379 tmp = SHOW_UBITS(re, s, n);
380 return tmp;
381}
382
383 static inline void skip_bits(GetBitContext *s, int n)
384{
386 OPEN_READER_SIZE(re, s);
387 LAST_SKIP_BITS(re, s, n);
388 CLOSE_READER(re, s);
389}
390
391 static inline unsigned int get_bits1(GetBitContext *s)
392{
393 unsigned int index = s->index;
394 uint8_t result = s->buffer[index >> 3];
395#ifdef BITSTREAM_READER_LE
396 result >>= index & 7;
397 result &= 1;
398#else
399 result <<= index & 7;
400 result >>= 8 - 1;
401#endif
402#if !UNCHECKED_BITSTREAM_READER
403 if (s->index < s->size_in_bits_plus8)
404#endif
405 index++;
406 s->index = index;
407
408 return result;
409}
410
411 static inline unsigned int show_bits1(GetBitContext *s)
412{
413 return show_bits(s, 1);
414}
415
416 static inline void skip_bits1(GetBitContext *s)
417{
418 skip_bits(s, 1);
419}
420
421/**
422 * Read 0-32 bits.
423 */
424 static inline unsigned int get_bits_long(GetBitContext *s, int n)
425{
426 av_assert2(n>=0 && n<=32);
427 if (!n) {
428 return 0;
429 } else if ((!HAVE_FAST_64BIT || av_builtin_constant_p(n <= MIN_CACHE_BITS))
430 && n <= MIN_CACHE_BITS) {
431 return get_bits(s, n);
432 } else {
433#if HAVE_FAST_64BIT
434 unsigned tmp;
435 OPEN_READER(re, s);
436 UPDATE_CACHE_32(re, s);
437 tmp = SHOW_UBITS(re, s, n);
438 LAST_SKIP_BITS(re, s, n);
439 CLOSE_READER(re, s);
440 return tmp;
441#else
442#ifdef BITSTREAM_READER_LE
443 unsigned ret = get_bits(s, 16);
444 return ret | (get_bits(s, n - 16) << 16);
445#else
446 unsigned ret = get_bits(s, 16) << (n - 16);
447 return ret | get_bits(s, n - 16);
448#endif
449#endif
450 }
451}
452
453/**
454 * Read 0-64 bits.
455 */
456 static inline uint64_t get_bits64(GetBitContext *s, int n)
457{
458 if (n <= 32) {
459 return get_bits_long(s, n);
460 } else {
461#ifdef BITSTREAM_READER_LE
462 uint64_t ret = get_bits_long(s, 32);
463 return ret | (uint64_t) get_bits_long(s, n - 32) << 32;
464#else
465 uint64_t ret = (uint64_t) get_bits_long(s, n - 32) << 32;
466 return ret | get_bits_long(s, 32);
467#endif
468 }
469}
470
471/**
472 * Read 0-32 bits as a signed integer.
473 */
474 static inline int get_sbits_long(GetBitContext *s, int n)
475{
476 // sign_extend(x, 0) is undefined
477 if (!n)
478 return 0;
479
480 return sign_extend(get_bits_long(s, n), n);
481}
482
483/**
484 * Read 0-64 bits as a signed integer.
485 */
486 static inline int64_t get_sbits64(GetBitContext *s, int n)
487{
488 // sign_extend(x, 0) is undefined
489 if (!n)
490 return 0;
491
492 return sign_extend64(get_bits64(s, n), n);
493}
494
495/**
496 * Show 0-32 bits.
497 */
498 static inline unsigned int show_bits_long(GetBitContext *s, int n)
499{
500 if (n <= MIN_CACHE_BITS) {
501 return show_bits(s, n);
502 } else {
503 GetBitContext gb = *s;
504 return get_bits_long(&gb, n);
505 }
506}
507
508
509/**
510 * Initialize GetBitContext.
511 * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
512 * larger than the actual read bits because some optimized bitstream
513 * readers read 32 or 64 bit at once and could read over the end
514 * @param bit_size the size of the buffer in bits
515 * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
516 */
517 static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
518 int bit_size)
519{
520 int ret = 0;
521
522 if (bit_size >= INT_MAX - FFMAX(7, AV_INPUT_BUFFER_PADDING_SIZE*8) || bit_size < 0 || !buffer) {
523 bit_size = 0;
524 buffer = NULL;
526 }
527
528 s->buffer = buffer;
529 s->size_in_bits = bit_size;
530 s->size_in_bits_plus8 = bit_size + 8;
531 s->index = 0;
532
533 return ret;
534}
535
536/**
537 * Initialize GetBitContext.
538 * @param buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes
539 * larger than the actual read bits because some optimized bitstream
540 * readers read 32 or 64 bit at once and could read over the end
541 * @param byte_size the size of the buffer in bytes
542 * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
543 */
544 static inline int init_get_bits8(GetBitContext *s, const uint8_t *buffer,
545 int byte_size)
546{
547 if (byte_size > INT_MAX / 8 || byte_size < 0)
548 byte_size = -1;
549 return init_get_bits(s, buffer, byte_size * 8);
550}
551
552 static inline int init_get_bits8_le(GetBitContext *s, const uint8_t *buffer,
553 int byte_size)
554{
555 if (byte_size > INT_MAX / 8 || byte_size < 0)
556 byte_size = -1;
557 return init_get_bits(s, buffer, byte_size * 8);
558}
559
560 static inline const uint8_t *align_get_bits(GetBitContext *s)
561{
562 int n = -get_bits_count(s) & 7;
563 if (n)
564 skip_bits(s, n);
565 return s->buffer + (s->index >> 3);
566}
567
568/**
569 * If the vlc code is invalid and max_depth=1, then no bits will be removed.
570 * If the vlc code is invalid and max_depth>1, then the number of bits removed
571 * is undefined.
572 */
573 #define GET_VLC(code, name, gb, table, bits, max_depth) \
574 do { \
575 unsigned idx_ = SHOW_UBITS(name, gb, bits); \
576 code = table[idx_].sym; \
577 int n_ = table[idx_].len; \
578 \
579 if (max_depth > 1 && n_ < 0) { \
580 LAST_SKIP_BITS(name, gb, bits); \
581 UPDATE_CACHE(name, gb); \
582 \
583 int nb__bits = -n_; \
584 \
585 idx_ = SHOW_UBITS(name, gb, nb__bits) + code; \
586 code = table[idx_].sym; \
587 n_ = table[idx_].len; \
588 if (max_depth > 2 && n_ < 0) { \
589 LAST_SKIP_BITS(name, gb, nb__bits); \
590 UPDATE_CACHE(name, gb); \
591 \
592 nb__bits = -n_; \
593 \
594 idx_ = SHOW_UBITS(name, gb, nb__bits) + code; \
595 code = table[idx_].sym; \
596 n_ = table[idx_].len; \
597 } \
598 } \
599 SKIP_BITS(name, gb, n_); \
600 } while (0)
601
602 #define GET_RL_VLC(level, run, name, gb, table, bits, \
603 max_depth, need_update) \
604 do { \
605 unsigned idx_ = SHOW_UBITS(name, gb, bits); \
606 level = table[idx_].level; \
607 int n_ = table[idx_].len8; \
608 \
609 if (max_depth > 1 && n_ < 0) { \
610 SKIP_BITS(name, gb, bits); \
611 if (need_update) { \
612 UPDATE_CACHE(name, gb); \
613 } \
614 \
615 int nb__bits = -n_; \
616 \
617 idx_ = SHOW_UBITS(name, gb, nb__bits) + level; \
618 level = table[idx_].level; \
619 n_ = table[idx_].len8; \
620 if (max_depth > 2 && n_ < 0) { \
621 LAST_SKIP_BITS(name, gb, nb__bits); \
622 if (need_update) { \
623 UPDATE_CACHE(name, gb); \
624 } \
625 nb__bits = -n_; \
626 \
627 idx_ = SHOW_UBITS(name, gb, nb__bits) + level; \
628 level = table[idx_].level; \
629 n_ = table[idx_].len8; \
630 } \
631 } \
632 run = table[idx_].run; \
633 SKIP_BITS(name, gb, n_); \
634 } while (0)
635
636/**
637 * Parse a vlc code.
638 * @param bits is the number of bits which will be read at once, must be
639 * identical to nb_bits in vlc_init()
640 * @param max_depth is the number of times bits bits must be read to completely
641 * read the longest vlc code
642 * = (max_vlc_length + bits - 1) / bits
643 * @returns the code parsed or -1 if no vlc matches
644 */
646 int bits, int max_depth)
647{
648 int code;
649
650 OPEN_READER(re, s);
651 UPDATE_CACHE(re, s);
652
653 GET_VLC(code, re, s, table, bits, max_depth);
654
655 CLOSE_READER(re, s);
656
657 return code;
658}
659
660 static inline int get_vlc_multi(GetBitContext *s, uint8_t *dst,
661 av_unused const VLC_MULTI_ELEM *const Jtable,
662 const VLCElem *const table,
663 const int bits, const int max_depth,
664 av_unused const int symbols_size)
665{
666 dst[0] = get_vlc2(s, table, bits, max_depth);
667 return 1;
668}
669
670 static inline int decode012(GetBitContext *gb)
671{
672 int n;
673 n = get_bits1(gb);
674 if (n == 0)
675 return 0;
676 else
677 return get_bits1(gb) + 1;
678}
679
680 static inline int decode210(GetBitContext *gb)
681{
682 if (get_bits1(gb))
683 return 0;
684 else
685 return 2 - get_bits1(gb);
686}
687
688 static inline int get_bits_left(GetBitContext *gb)
689{
690 return gb->size_in_bits - get_bits_count(gb);
691}
692
694{
695 if (get_bits_left(gb) <= 0)
696 return AVERROR_INVALIDDATA;
697
698 while (get_bits1(gb)) {
699 skip_bits(gb, 8);
700 if (get_bits_left(gb) <= 0)
701 return AVERROR_INVALIDDATA;
702 }
703
704 return 0;
705}
706
707#endif // CACHED_BITSTREAM_READER
708
709#endif /* AVCODEC_GET_BITS_H */
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst
Definition dsp.h:87
int32_t
Definition audioconvert.c:56
simple assert() macros that are a bit more flexible than ISO C assert().
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition avassert.h:68
bitstream reader API header.
#define BitstreamContext
Definition bitstream.h:110
s
#define s(width, name)
Definition cbs_vp9.c:198
common internal and external API header
#define av_clip
Definition common.h:100
#define NULL
Definition coverity.c:32
long long int64_t
Definition coverity.c:34
Misc types and constants that do not belong anywhere else.
static const uint8_t bits[8]
Definition fastaudio.c:100
static unsigned int get_bits_le(GetBitContext *s, int n)
Definition get_bits.h:358
static int get_sbits_long(GetBitContext *s, int n)
Read 0-32 bits as a signed integer.
Definition get_bits.h:474
#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:573
static unsigned int show_bits_long(GetBitContext *s, int n)
Show 0-32 bits.
Definition get_bits.h:498
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition get_bits.h:424
static int init_get_bits8_le(GetBitContext *s, const uint8_t *buffer, int byte_size)
Definition get_bits.h:552
static int decode012(GetBitContext *gb)
Definition get_bits.h:670
#define GET_CACHE(name, gb)
Definition get_bits.h:251
static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table, int bits, int max_depth)
Parse a vlc code.
Definition get_bits.h:645
static int get_sbits(GetBitContext *s, int n)
Definition get_bits.h:322
#define CLOSE_READER(name, gb)
Definition get_bits.h:189
static int get_bits_left(GetBitContext *gb)
Definition get_bits.h:688
static int get_vlc_multi(GetBitContext *s, uint8_t *dst, av_unused const VLC_MULTI_ELEM *const Jtable, const VLCElem *const table, const int bits, const int max_depth, av_unused const int symbols_size)
Definition get_bits.h:660
static void skip_bits_long(GetBitContext *s, int n)
Skips the specified number of bits.
Definition get_bits.h:280
static int get_xbits_le(GetBitContext *s, int n)
Definition get_bits.h:308
#define SHOW_UBITS(name, gb, num)
Definition get_bits.h:247
static unsigned int get_bits1(GetBitContext *s)
Definition get_bits.h:391
#define SHOW_SBITS(name, gb, num)
Definition get_bits.h:248
static int decode210(GetBitContext *gb)
Definition get_bits.h:680
#define OPEN_READER_NOSIZE(name, gb)
Definition get_bits.h:172
#define OPEN_READER(name, gb)
Definition get_bits.h:182
static void skip_bits(GetBitContext *s, int n)
Definition get_bits.h:383
static int skip_1stop_8data_bits(GetBitContext *gb)
Definition get_bits.h:693
#define UPDATE_CACHE(name, gb)
Definition get_bits.h:213
static uint64_t get_bits64(GetBitContext *s, int n)
Read 0-64 bits.
Definition get_bits.h:456
#define OPEN_READER_SIZE(name, gb)
Definition get_bits.h:181
#define MIN_CACHE_BITS
Definition get_bits.h:167
#define SHOW_UBITS_LE(name, gb, num)
Definition get_bits.h:237
#define OPEN_READER_NOSIZE_NOCACHE(name, gb)
Definition get_bits.h:169
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition get_bits.h:544
#define LAST_SKIP_BITS(name, gb, num)
Definition get_bits.h:235
static const uint8_t * align_get_bits(GetBitContext *s)
Definition get_bits.h:560
static int get_bits_count(const GetBitContext *s)
Definition get_bits.h:254
static int64_t get_sbits64(GetBitContext *s, int n)
Read 0-64 bits as a signed integer.
Definition get_bits.h:486
static void skip_bits1(GetBitContext *s)
Definition get_bits.h:416
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition get_bits.h:337
#define UPDATE_CACHE_LE(name, gb)
Definition get_bits.h:201
static unsigned int show_bits(GetBitContext *s, int n)
Show 1-25 bits.
Definition get_bits.h:373
#define UPDATE_CACHE_32(name, gb)
Definition get_bits.h:214
static av_always_inline int get_bitsz(GetBitContext *s, int n)
Read 0-25 bits.
Definition get_bits.h:353
static int get_bits_bytesize(const GetBitContext *s, int round_up)
Get the size of the GetBitContext's buffer in bytes.
Definition get_bits.h:268
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition get_bits.h:517
static unsigned int show_bits1(GetBitContext *s)
Definition get_bits.h:411
static int get_xbits(GetBitContext *s, int n)
Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
Definition get_bits.h:294
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
Definition defs.h:40
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition error.h:61
int index
Definition gxfenc.c:90
#define av_always_inline
Definition attributes.h:72
#define av_builtin_constant_p
Definition attributes.h:193
#define av_unused
Definition attributes.h:164
#define FFMAX(a, b)
Definition macros.h:47
static av_const unsigned zero_extend(unsigned val, unsigned bits)
Definition mathops.h:153
static av_const int sign_extend(int val, unsigned bits)
Definition mathops.h:135
static av_const int64_t sign_extend64(int64_t val, unsigned bits)
Definition mathops.h:144
#define NEG_USR32(a, s)
Definition mathops.h:180
static const uint16_t table[]
Definition prosumer.c:203
const uint8_t * code
Definition spdifenc.c:433
int size_in_bits_plus8
Definition get_bits.h:113
const uint8_t * buffer
Definition get_bits.h:110
int size_in_bits
Definition get_bits.h:112
Definition vlc.h:32
Definition vlc.h:56
static uint8_t tmp[40]
Definition aes_ctr.c:52
static char buffer[20]
Definition seek.c:32
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