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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 | ||
37 | /* | |
38 | * Safe bitstream reading: | |
39 | * optionally, the get_bits API can check to ensure that we | |
40 | * don't read past input buffer boundaries. This is protected | |
41 | * with CONFIG_SAFE_BITSTREAM_READER at the global level, and | |
42 | * then below that with UNCHECKED_BITSTREAM_READER at the per- | |
43 | * decoder level. This means that decoders that check internally | |
44 | * can "#define UNCHECKED_BITSTREAM_READER 1" to disable | |
45 | * overread checks. | |
46 | * Boundary checking causes a minor performance penalty so for | |
47 | * applications that won't want/need this, it can be disabled | |
48 | * globally using "#define CONFIG_SAFE_BITSTREAM_READER 0". | |
49 | */ | |
50 | #ifndef UNCHECKED_BITSTREAM_READER | |
51 | #define UNCHECKED_BITSTREAM_READER !CONFIG_SAFE_BITSTREAM_READER | |
52 | #endif | |
53 | ||
54 | typedef struct GetBitContext { | |
55 | const uint8_t *buffer, *buffer_end; | |
56 | int index; | |
57 | int size_in_bits; | |
58 | int size_in_bits_plus8; | |
59 | } GetBitContext; | |
60 | ||
61 | #define VLC_TYPE int16_t | |
62 | ||
63 | typedef struct VLC { | |
64 | int bits; | |
65 | VLC_TYPE (*table)[2]; ///< code, bits | |
66 | int table_size, table_allocated; | |
67 | } VLC; | |
68 | ||
69 | typedef struct RL_VLC_ELEM { | |
70 | int16_t level; | |
71 | int8_t len; | |
72 | uint8_t run; | |
73 | } RL_VLC_ELEM; | |
74 | ||
75 | /* Bitstream reader API docs: | |
76 | * name | |
77 | * arbitrary name which is used as prefix for the internal variables | |
78 | * | |
79 | * gb | |
80 | * getbitcontext | |
81 | * | |
82 | * OPEN_READER(name, gb) | |
83 | * load gb into local variables | |
84 | * | |
85 | * CLOSE_READER(name, gb) | |
86 | * store local vars in gb | |
87 | * | |
88 | * UPDATE_CACHE(name, gb) | |
89 | * Refill the internal cache from the bitstream. | |
90 | * After this call at least MIN_CACHE_BITS will be available. | |
91 | * | |
92 | * GET_CACHE(name, gb) | |
93 | * Will output the contents of the internal cache, | |
94 | * next bit is MSB of 32 or 64 bit (FIXME 64bit). | |
95 | * | |
96 | * SHOW_UBITS(name, gb, num) | |
97 | * Will return the next num bits. | |
98 | * | |
99 | * SHOW_SBITS(name, gb, num) | |
100 | * Will return the next num bits and do sign extension. | |
101 | * | |
102 | * SKIP_BITS(name, gb, num) | |
103 | * Will skip over the next num bits. | |
104 | * Note, this is equivalent to SKIP_CACHE; SKIP_COUNTER. | |
105 | * | |
106 | * SKIP_CACHE(name, gb, num) | |
107 | * Will remove the next num bits from the cache (note SKIP_COUNTER | |
108 | * MUST be called before UPDATE_CACHE / CLOSE_READER). | |
109 | * | |
110 | * SKIP_COUNTER(name, gb, num) | |
111 | * Will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS). | |
112 | * | |
113 | * LAST_SKIP_BITS(name, gb, num) | |
114 | * Like SKIP_BITS, to be used if next call is UPDATE_CACHE or CLOSE_READER. | |
115 | * | |
116 | * BITS_LEFT(name, gb) | |
117 | * Return the number of bits left | |
118 | * | |
119 | * For examples see get_bits, show_bits, skip_bits, get_vlc. | |
120 | */ | |
121 | ||
122 | #ifdef LONG_BITSTREAM_READER | |
123 | # define MIN_CACHE_BITS 32 | |
124 | #else | |
125 | # define MIN_CACHE_BITS 25 | |
126 | #endif | |
127 | ||
128 | #define OPEN_READER_NOSIZE(name, gb) \ | |
129 | unsigned int name ## _index = (gb)->index; \ | |
130 | unsigned int av_unused name ## _cache | |
131 | ||
132 | #if UNCHECKED_BITSTREAM_READER | |
133 | #define OPEN_READER(name, gb) OPEN_READER_NOSIZE(name, gb) | |
134 | ||
135 | #define BITS_AVAILABLE(name, gb) 1 | |
136 | #else | |
137 | #define OPEN_READER(name, gb) \ | |
138 | OPEN_READER_NOSIZE(name, gb); \ | |
139 | unsigned int name ## _size_plus8 = (gb)->size_in_bits_plus8 | |
140 | ||
141 | #define BITS_AVAILABLE(name, gb) name ## _index < name ## _size_plus8 | |
142 | #endif | |
143 | ||
144 | #define CLOSE_READER(name, gb) (gb)->index = name ## _index | |
145 | ||
146 | # ifdef LONG_BITSTREAM_READER | |
147 | ||
148 | # define UPDATE_CACHE_LE(name, gb) name ## _cache = \ | |
149 | AV_RL64((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) | |
150 | ||
151 | # define UPDATE_CACHE_BE(name, gb) name ## _cache = \ | |
152 | AV_RB64((gb)->buffer + (name ## _index >> 3)) >> (32 - (name ## _index & 7)) | |
153 | ||
154 | #else | |
155 | ||
156 | # define UPDATE_CACHE_LE(name, gb) name ## _cache = \ | |
157 | AV_RL32((gb)->buffer + (name ## _index >> 3)) >> (name ## _index & 7) | |
158 | ||
159 | # define UPDATE_CACHE_BE(name, gb) name ## _cache = \ | |
160 | AV_RB32((gb)->buffer + (name ## _index >> 3)) << (name ## _index & 7) | |
161 | ||
162 | #endif | |
163 | ||
164 | ||
165 | #ifdef BITSTREAM_READER_LE | |
166 | ||
167 | # define UPDATE_CACHE(name, gb) UPDATE_CACHE_LE(name, gb) | |
168 | ||
169 | # define SKIP_CACHE(name, gb, num) name ## _cache >>= (num) | |
170 | ||
171 | #else | |
172 | ||
173 | # define UPDATE_CACHE(name, gb) UPDATE_CACHE_BE(name, gb) | |
174 | ||
175 | # define SKIP_CACHE(name, gb, num) name ## _cache <<= (num) | |
176 | ||
177 | #endif | |
178 | ||
179 | #if UNCHECKED_BITSTREAM_READER | |
180 | # define SKIP_COUNTER(name, gb, num) name ## _index += (num) | |
181 | #else | |
182 | # define SKIP_COUNTER(name, gb, num) \ | |
183 | name ## _index = FFMIN(name ## _size_plus8, name ## _index + (num)) | |
184 | #endif | |
185 | ||
186 | #define BITS_LEFT(name, gb) ((int)((gb)->size_in_bits - name ## _index)) | |
187 | ||
188 | #define SKIP_BITS(name, gb, num) \ | |
189 | do { \ | |
190 | SKIP_CACHE(name, gb, num); \ | |
191 | SKIP_COUNTER(name, gb, num); \ | |
192 | } while (0) | |
193 | ||
194 | #define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num) | |
195 | ||
196 | #define SHOW_UBITS_LE(name, gb, num) zero_extend(name ## _cache, num) | |
197 | #define SHOW_SBITS_LE(name, gb, num) sign_extend(name ## _cache, num) | |
198 | ||
199 | #define SHOW_UBITS_BE(name, gb, num) NEG_USR32(name ## _cache, num) | |
200 | #define SHOW_SBITS_BE(name, gb, num) NEG_SSR32(name ## _cache, num) | |
201 | ||
202 | #ifdef BITSTREAM_READER_LE | |
203 | # define SHOW_UBITS(name, gb, num) SHOW_UBITS_LE(name, gb, num) | |
204 | # define SHOW_SBITS(name, gb, num) SHOW_SBITS_LE(name, gb, num) | |
205 | #else | |
206 | # define SHOW_UBITS(name, gb, num) SHOW_UBITS_BE(name, gb, num) | |
207 | # define SHOW_SBITS(name, gb, num) SHOW_SBITS_BE(name, gb, num) | |
208 | #endif | |
209 | ||
210 | #define GET_CACHE(name, gb) ((uint32_t) name ## _cache) | |
211 | ||
212 | static inline int get_bits_count(const GetBitContext *s) | |
213 | { | |
214 | return s->index; | |
215 | } | |
216 | ||
217 | static inline void skip_bits_long(GetBitContext *s, int n) | |
218 | { | |
219 | #if UNCHECKED_BITSTREAM_READER | |
220 | s->index += n; | |
221 | #else | |
222 | s->index += av_clip(n, -s->index, s->size_in_bits_plus8 - s->index); | |
223 | #endif | |
224 | } | |
225 | ||
226 | /** | |
227 | * read mpeg1 dc style vlc (sign bit + mantissa with no MSB). | |
228 | * if MSB not set it is negative | |
229 | * @param n length in bits | |
230 | */ | |
231 | static inline int get_xbits(GetBitContext *s, int n) | |
232 | { | |
233 | register int sign; | |
234 | register int32_t cache; | |
235 | OPEN_READER(re, s); | |
236 | av_assert2(n>0 && n<=25); | |
237 | UPDATE_CACHE(re, s); | |
238 | cache = GET_CACHE(re, s); | |
239 | sign = ~cache >> 31; | |
240 | LAST_SKIP_BITS(re, s, n); | |
241 | CLOSE_READER(re, s); | |
242 | return (NEG_USR32(sign ^ cache, n) ^ sign) - sign; | |
243 | } | |
244 | ||
245 | static inline int get_sbits(GetBitContext *s, int n) | |
246 | { | |
247 | register int tmp; | |
248 | OPEN_READER(re, s); | |
249 | av_assert2(n>0 && n<=25); | |
250 | UPDATE_CACHE(re, s); | |
251 | tmp = SHOW_SBITS(re, s, n); | |
252 | LAST_SKIP_BITS(re, s, n); | |
253 | CLOSE_READER(re, s); | |
254 | return tmp; | |
255 | } | |
256 | ||
257 | /** | |
258 | * Read 1-25 bits. | |
259 | */ | |
260 | static inline unsigned int get_bits(GetBitContext *s, int n) | |
261 | { | |
262 | register int tmp; | |
263 | OPEN_READER(re, s); | |
264 | av_assert2(n>0 && n<=25); | |
265 | UPDATE_CACHE(re, s); | |
266 | tmp = SHOW_UBITS(re, s, n); | |
267 | LAST_SKIP_BITS(re, s, n); | |
268 | CLOSE_READER(re, s); | |
269 | return tmp; | |
270 | } | |
271 | ||
272 | static inline unsigned int get_bits_le(GetBitContext *s, int n) | |
273 | { | |
274 | register int tmp; | |
275 | OPEN_READER(re, s); | |
276 | av_assert2(n>0 && n<=25); | |
277 | UPDATE_CACHE_LE(re, s); | |
278 | tmp = SHOW_UBITS_LE(re, s, n); | |
279 | LAST_SKIP_BITS(re, s, n); | |
280 | CLOSE_READER(re, s); | |
281 | return tmp; | |
282 | } | |
283 | ||
284 | /** | |
285 | * Show 1-25 bits. | |
286 | */ | |
287 | static inline unsigned int show_bits(GetBitContext *s, int n) | |
288 | { | |
289 | register int tmp; | |
290 | OPEN_READER_NOSIZE(re, s); | |
291 | av_assert2(n>0 && n<=25); | |
292 | UPDATE_CACHE(re, s); | |
293 | tmp = SHOW_UBITS(re, s, n); | |
294 | return tmp; | |
295 | } | |
296 | ||
297 | static inline void skip_bits(GetBitContext *s, int n) | |
298 | { | |
299 | OPEN_READER(re, s); | |
300 | LAST_SKIP_BITS(re, s, n); | |
301 | CLOSE_READER(re, s); | |
302 | } | |
303 | ||
304 | static inline unsigned int get_bits1(GetBitContext *s) | |
305 | { | |
306 | unsigned int index = s->index; | |
307 | uint8_t result = s->buffer[index >> 3]; | |
308 | #ifdef BITSTREAM_READER_LE | |
309 | result >>= index & 7; | |
310 | result &= 1; | |
311 | #else | |
312 | result <<= index & 7; | |
313 | result >>= 8 - 1; | |
314 | #endif | |
315 | #if !UNCHECKED_BITSTREAM_READER | |
316 | if (s->index < s->size_in_bits_plus8) | |
317 | #endif | |
318 | index++; | |
319 | s->index = index; | |
320 | ||
321 | return result; | |
322 | } | |
323 | ||
324 | static inline unsigned int show_bits1(GetBitContext *s) | |
325 | { | |
326 | return show_bits(s, 1); | |
327 | } | |
328 | ||
329 | static inline void skip_bits1(GetBitContext *s) | |
330 | { | |
331 | skip_bits(s, 1); | |
332 | } | |
333 | ||
334 | /** | |
335 | * Read 0-32 bits. | |
336 | */ | |
337 | static inline unsigned int get_bits_long(GetBitContext *s, int n) | |
338 | { | |
339 | if (!n) { | |
340 | return 0; | |
341 | } else if (n <= MIN_CACHE_BITS) { | |
342 | return get_bits(s, n); | |
343 | } else { | |
344 | #ifdef BITSTREAM_READER_LE | |
345 | unsigned ret = get_bits(s, 16); | |
346 | return ret | (get_bits(s, n - 16) << 16); | |
347 | #else | |
348 | unsigned ret = get_bits(s, 16) << (n - 16); | |
349 | return ret | get_bits(s, n - 16); | |
350 | #endif | |
351 | } | |
352 | } | |
353 | ||
354 | /** | |
355 | * Read 0-64 bits. | |
356 | */ | |
357 | static inline uint64_t get_bits64(GetBitContext *s, int n) | |
358 | { | |
359 | if (n <= 32) { | |
360 | return get_bits_long(s, n); | |
361 | } else { | |
362 | #ifdef BITSTREAM_READER_LE | |
363 | uint64_t ret = get_bits_long(s, 32); | |
364 | return ret | (uint64_t) get_bits_long(s, n - 32) << 32; | |
365 | #else | |
366 | uint64_t ret = (uint64_t) get_bits_long(s, n - 32) << 32; | |
367 | return ret | get_bits_long(s, 32); | |
368 | #endif | |
369 | } | |
370 | } | |
371 | ||
372 | /** | |
373 | * Read 0-32 bits as a signed integer. | |
374 | */ | |
375 | static inline int get_sbits_long(GetBitContext *s, int n) | |
376 | { | |
377 | return sign_extend(get_bits_long(s, n), n); | |
378 | } | |
379 | ||
380 | /** | |
381 | * Show 0-32 bits. | |
382 | */ | |
383 | static inline unsigned int show_bits_long(GetBitContext *s, int n) | |
384 | { | |
385 | if (n <= MIN_CACHE_BITS) { | |
386 | return show_bits(s, n); | |
387 | } else { | |
388 | GetBitContext gb = *s; | |
389 | return get_bits_long(&gb, n); | |
390 | } | |
391 | } | |
392 | ||
393 | static inline int check_marker(GetBitContext *s, const char *msg) | |
394 | { | |
395 | int bit = get_bits1(s); | |
396 | if (!bit) | |
397 | av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg); | |
398 | ||
399 | return bit; | |
400 | } | |
401 | ||
402 | /** | |
403 | * Initialize GetBitContext. | |
404 | * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes | |
405 | * larger than the actual read bits because some optimized bitstream | |
406 | * readers read 32 or 64 bit at once and could read over the end | |
407 | * @param bit_size the size of the buffer in bits | |
408 | * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow. | |
409 | */ | |
410 | static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer, | |
411 | int bit_size) | |
412 | { | |
413 | int buffer_size; | |
414 | int ret = 0; | |
415 | ||
416 | if (bit_size >= INT_MAX - 7 || bit_size < 0 || !buffer) { | |
417 | bit_size = 0; | |
418 | buffer = NULL; | |
419 | ret = AVERROR_INVALIDDATA; | |
420 | } | |
421 | ||
422 | buffer_size = (bit_size + 7) >> 3; | |
423 | ||
424 | s->buffer = buffer; | |
425 | s->size_in_bits = bit_size; | |
426 | s->size_in_bits_plus8 = bit_size + 8; | |
427 | s->buffer_end = buffer + buffer_size; | |
428 | s->index = 0; | |
429 | ||
430 | return ret; | |
431 | } | |
432 | ||
433 | /** | |
434 | * Initialize GetBitContext. | |
435 | * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes | |
436 | * larger than the actual read bits because some optimized bitstream | |
437 | * readers read 32 or 64 bit at once and could read over the end | |
438 | * @param byte_size the size of the buffer in bytes | |
439 | * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow. | |
440 | */ | |
441 | static inline int init_get_bits8(GetBitContext *s, const uint8_t *buffer, | |
442 | int byte_size) | |
443 | { | |
444 | if (byte_size > INT_MAX / 8 || byte_size < 0) | |
445 | byte_size = -1; | |
446 | return init_get_bits(s, buffer, byte_size * 8); | |
447 | } | |
448 | ||
449 | static inline const uint8_t *align_get_bits(GetBitContext *s) | |
450 | { | |
451 | int n = -get_bits_count(s) & 7; | |
452 | if (n) | |
453 | skip_bits(s, n); | |
454 | return s->buffer + (s->index >> 3); | |
455 | } | |
456 | ||
457 | #define init_vlc(vlc, nb_bits, nb_codes, \ | |
458 | bits, bits_wrap, bits_size, \ | |
459 | codes, codes_wrap, codes_size, \ | |
460 | flags) \ | |
461 | ff_init_vlc_sparse(vlc, nb_bits, nb_codes, \ | |
462 | bits, bits_wrap, bits_size, \ | |
463 | codes, codes_wrap, codes_size, \ | |
464 | NULL, 0, 0, flags) | |
465 | ||
466 | int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, | |
467 | const void *bits, int bits_wrap, int bits_size, | |
468 | const void *codes, int codes_wrap, int codes_size, | |
469 | const void *symbols, int symbols_wrap, int symbols_size, | |
470 | int flags); | |
471 | void ff_free_vlc(VLC *vlc); | |
472 | ||
473 | #define INIT_VLC_LE 2 | |
474 | #define INIT_VLC_USE_NEW_STATIC 4 | |
475 | ||
476 | #define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \ | |
477 | do { \ | |
478 | static VLC_TYPE table[static_size][2]; \ | |
479 | (vlc)->table = table; \ | |
480 | (vlc)->table_allocated = static_size; \ | |
481 | init_vlc(vlc, bits, a, b, c, d, e, f, g, INIT_VLC_USE_NEW_STATIC); \ | |
482 | } while (0) | |
483 | ||
484 | /** | |
485 | * If the vlc code is invalid and max_depth=1, then no bits will be removed. | |
486 | * If the vlc code is invalid and max_depth>1, then the number of bits removed | |
487 | * is undefined. | |
488 | */ | |
489 | #define GET_VLC(code, name, gb, table, bits, max_depth) \ | |
490 | do { \ | |
491 | int n, nb_bits; \ | |
492 | unsigned int index; \ | |
493 | \ | |
494 | index = SHOW_UBITS(name, gb, bits); \ | |
495 | code = table[index][0]; \ | |
496 | n = table[index][1]; \ | |
497 | \ | |
498 | if (max_depth > 1 && n < 0) { \ | |
499 | LAST_SKIP_BITS(name, gb, bits); \ | |
500 | UPDATE_CACHE(name, gb); \ | |
501 | \ | |
502 | nb_bits = -n; \ | |
503 | \ | |
504 | index = SHOW_UBITS(name, gb, nb_bits) + code; \ | |
505 | code = table[index][0]; \ | |
506 | n = table[index][1]; \ | |
507 | if (max_depth > 2 && n < 0) { \ | |
508 | LAST_SKIP_BITS(name, gb, nb_bits); \ | |
509 | UPDATE_CACHE(name, gb); \ | |
510 | \ | |
511 | nb_bits = -n; \ | |
512 | \ | |
513 | index = SHOW_UBITS(name, gb, nb_bits) + code; \ | |
514 | code = table[index][0]; \ | |
515 | n = table[index][1]; \ | |
516 | } \ | |
517 | } \ | |
518 | SKIP_BITS(name, gb, n); \ | |
519 | } while (0) | |
520 | ||
521 | #define GET_RL_VLC_INTERNAL(level, run, name, gb, table, bits, \ | |
522 | max_depth, need_update) \ | |
523 | do { \ | |
524 | int n, nb_bits; \ | |
525 | unsigned int index; \ | |
526 | \ | |
527 | index = SHOW_UBITS(name, gb, bits); \ | |
528 | level = table[index].level; \ | |
529 | n = table[index].len; \ | |
530 | \ | |
531 | if (max_depth > 1 && n < 0) { \ | |
532 | SKIP_BITS(name, gb, bits); \ | |
533 | if (need_update) { \ | |
534 | UPDATE_CACHE(name, gb); \ | |
535 | } \ | |
536 | \ | |
537 | nb_bits = -n; \ | |
538 | \ | |
539 | index = SHOW_UBITS(name, gb, nb_bits) + level; \ | |
540 | level = table[index].level; \ | |
541 | n = table[index].len; \ | |
542 | } \ | |
543 | run = table[index].run; \ | |
544 | SKIP_BITS(name, gb, n); \ | |
545 | } while (0) | |
546 | ||
547 | /** | |
548 | * Parse a vlc code. | |
549 | * @param bits is the number of bits which will be read at once, must be | |
550 | * identical to nb_bits in init_vlc() | |
551 | * @param max_depth is the number of times bits bits must be read to completely | |
552 | * read the longest vlc code | |
553 | * = (max_vlc_length + bits - 1) / bits | |
554 | */ | |
555 | static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2], | |
556 | int bits, int max_depth) | |
557 | { | |
558 | int code; | |
559 | ||
560 | OPEN_READER(re, s); | |
561 | UPDATE_CACHE(re, s); | |
562 | ||
563 | GET_VLC(code, re, s, table, bits, max_depth); | |
564 | ||
565 | CLOSE_READER(re, s); | |
566 | ||
567 | return code; | |
568 | } | |
569 | ||
570 | static inline int decode012(GetBitContext *gb) | |
571 | { | |
572 | int n; | |
573 | n = get_bits1(gb); | |
574 | if (n == 0) | |
575 | return 0; | |
576 | else | |
577 | return get_bits1(gb) + 1; | |
578 | } | |
579 | ||
580 | static inline int decode210(GetBitContext *gb) | |
581 | { | |
582 | if (get_bits1(gb)) | |
583 | return 0; | |
584 | else | |
585 | return 2 - get_bits1(gb); | |
586 | } | |
587 | ||
588 | static inline int get_bits_left(GetBitContext *gb) | |
589 | { | |
590 | return gb->size_in_bits - get_bits_count(gb); | |
591 | } | |
592 | ||
593 | static inline int skip_1stop_8data_bits(GetBitContext *gb) | |
594 | { | |
595 | if (get_bits_left(gb) <= 0) | |
596 | return AVERROR_INVALIDDATA; | |
597 | ||
598 | while (get_bits1(gb)) { | |
599 | skip_bits(gb, 8); | |
600 | if (get_bits_left(gb) <= 0) | |
601 | return AVERROR_INVALIDDATA; | |
602 | } | |
603 | ||
604 | return 0; | |
605 | } | |
606 | ||
607 | //#define TRACE | |
608 | ||
609 | #ifdef TRACE | |
610 | static inline void print_bin(int bits, int n) | |
611 | { | |
612 | int i; | |
613 | ||
614 | for (i = n - 1; i >= 0; i--) | |
615 | av_log(NULL, AV_LOG_DEBUG, "%d", (bits >> i) & 1); | |
616 | for (i = n; i < 24; i++) | |
617 | av_log(NULL, AV_LOG_DEBUG, " "); | |
618 | } | |
619 | ||
620 | static inline int get_bits_trace(GetBitContext *s, int n, const char *file, | |
621 | const char *func, int line) | |
622 | { | |
623 | int r = get_bits(s, n); | |
624 | ||
625 | print_bin(r, n); | |
626 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d bit @%5d in %s %s:%d\n", | |
627 | r, n, r, get_bits_count(s) - n, file, func, line); | |
628 | ||
629 | return r; | |
630 | } | |
631 | ||
632 | static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], | |
633 | int bits, int max_depth, const char *file, | |
634 | const char *func, int line) | |
635 | { | |
636 | int show = show_bits(s, 24); | |
637 | int pos = get_bits_count(s); | |
638 | int r = get_vlc2(s, table, bits, max_depth); | |
639 | int len = get_bits_count(s) - pos; | |
640 | int bits2 = show >> (24 - len); | |
641 | ||
642 | print_bin(bits2, len); | |
643 | ||
644 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", | |
645 | bits2, len, r, pos, file, func, line); | |
646 | ||
647 | return r; | |
648 | } | |
649 | ||
650 | #define GET_RL_VLC(level, run, name, gb, table, bits, \ | |
651 | max_depth, need_update) \ | |
652 | do { \ | |
653 | int show = SHOW_UBITS(name, gb, 24); \ | |
654 | int len; \ | |
655 | int pos = name ## _index; \ | |
656 | \ | |
657 | GET_RL_VLC_INTERNAL(level, run, name, gb, table, bits,max_depth, need_update); \ | |
658 | \ | |
659 | len = name ## _index - pos + 1; \ | |
660 | show = show >> (24 - len); \ | |
661 | \ | |
662 | print_bin(show, len); \ | |
663 | \ | |
664 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d/%-3d rlv @%5d in %s %s:%d\n",\ | |
665 | show, len, run-1, level, pos, __FILE__, __PRETTY_FUNCTION__, __LINE__);\ | |
666 | } while (0) \ | |
667 | ||
668 | ||
669 | static inline int get_xbits_trace(GetBitContext *s, int n, const char *file, | |
670 | const char *func, int line) | |
671 | { | |
672 | int show = show_bits(s, n); | |
673 | int r = get_xbits(s, n); | |
674 | ||
675 | print_bin(show, n); | |
676 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d xbt @%5d in %s %s:%d\n", | |
677 | show, n, r, get_bits_count(s) - n, file, func, line); | |
678 | ||
679 | return r; | |
680 | } | |
681 | ||
682 | #define get_bits(s, n) get_bits_trace(s , n, __FILE__, __PRETTY_FUNCTION__, __LINE__) | |
683 | #define get_bits1(s) get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__) | |
684 | #define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__) | |
685 | ||
686 | #define get_vlc(s, vlc) get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__) | |
687 | #define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__) | |
688 | ||
689 | #define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__) | |
690 | ||
691 | #else //TRACE | |
692 | #define tprintf(p, ...) { } | |
693 | #define GET_RL_VLC GET_RL_VLC_INTERNAL | |
694 | #endif | |
695 | ||
696 | #endif /* AVCODEC_GET_BITS_H */ |