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Diffstat (limited to 'apps/codecs/lib/ffmpeg_get_bits.h')
-rw-r--r-- | apps/codecs/lib/ffmpeg_get_bits.h | 750 |
1 files changed, 750 insertions, 0 deletions
diff --git a/apps/codecs/lib/ffmpeg_get_bits.h b/apps/codecs/lib/ffmpeg_get_bits.h new file mode 100644 index 0000000000..1a461e9e25 --- /dev/null +++ b/apps/codecs/lib/ffmpeg_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 | #include <stdlib.h> | ||
31 | //#include <assert.h> | ||
32 | //#include "libavutil/bswap.h" | ||
33 | //#include "libavutil/common.h" | ||
34 | //#include "libavutil/intreadwrite.h" | ||
35 | //#include "libavutil/log.h" | ||
36 | //#include "mathops.h" | ||
37 | |||
38 | #include "codecs.h" | ||
39 | |||
40 | /* rockbox' optimised inline functions */ | ||
41 | #define bswap_16(x) swap16(x) | ||
42 | #define bswap_32(x) swap32(x) | ||
43 | |||
44 | #ifdef ROCKBOX_BIG_ENDIAN | ||
45 | #define be2me_16(x) (x) | ||
46 | #define be2me_32(x) (x) | ||
47 | #define le2me_16(x) bswap_16(x) | ||
48 | #define le2me_32(x) bswap_32(x) | ||
49 | #else | ||
50 | #define be2me_16(x) bswap_16(x) | ||
51 | #define be2me_32(x) bswap_32(x) | ||
52 | #define le2me_16(x) (x) | ||
53 | #define le2me_32(x) (x) | ||
54 | #endif | ||
55 | |||
56 | #define av_const __attribute__((const)) | ||
57 | #define av_always_inline inline __attribute__((always_inline)) | ||
58 | |||
59 | /* Coldfire cpu's support unaligned long reads */ | ||
60 | #ifdef CPU_COLDFIRE | ||
61 | #define AV_RB32(x) (*(const uint32_t*)(x)) | ||
62 | #else | ||
63 | /* The following define is taken from libavutil/intreadwrite.h */ | ||
64 | #define AV_RB32(x) ((((const uint8_t*)(x))[0] << 24) | \ | ||
65 | (((const uint8_t*)(x))[1] << 16) | \ | ||
66 | (((const uint8_t*)(x))[2] << 8) | \ | ||
67 | ((const uint8_t*)(x))[3]) | ||
68 | #endif | ||
69 | /* The following is taken from mathops.h */ | ||
70 | |||
71 | #ifndef sign_extend | ||
72 | static inline av_const int sign_extend(int val, unsigned bits) | ||
73 | { | ||
74 | return (val << ((8 * sizeof(int)) - bits)) >> ((8 * sizeof(int)) - bits); | ||
75 | } | ||
76 | #endif | ||
77 | |||
78 | #ifndef NEG_SSR32 | ||
79 | # define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s))) | ||
80 | #endif | ||
81 | |||
82 | #ifndef NEG_USR32 | ||
83 | # define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s))) | ||
84 | #endif | ||
85 | |||
86 | /* these 2 are from libavutil/common.h */ | ||
87 | |||
88 | #define FFMAX(a,b) ((a) > (b) ? (a) : (b)) | ||
89 | #define FFMIN(a,b) ((a) > (b) ? (b) : (a)) | ||
90 | |||
91 | #if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER) | ||
92 | # define ALT_BITSTREAM_READER | ||
93 | #endif | ||
94 | |||
95 | /* | ||
96 | #if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER) | ||
97 | # if ARCH_ARM && !HAVE_FAST_UNALIGNED | ||
98 | # define A32_BITSTREAM_READER | ||
99 | # else | ||
100 | */ | ||
101 | # define ALT_BITSTREAM_READER | ||
102 | /* | ||
103 | //#define LIBMPEG2_BITSTREAM_READER | ||
104 | //#define A32_BITSTREAM_READER | ||
105 | # endif | ||
106 | #endif | ||
107 | */ | ||
108 | |||
109 | /* bit input */ | ||
110 | /* buffer, buffer_end and size_in_bits must be present and used by every reader */ | ||
111 | typedef struct GetBitContext { | ||
112 | const uint8_t *buffer, *buffer_end; | ||
113 | #ifdef ALT_BITSTREAM_READER | ||
114 | int index; | ||
115 | #elif defined LIBMPEG2_BITSTREAM_READER | ||
116 | uint8_t *buffer_ptr; | ||
117 | uint32_t cache; | ||
118 | int bit_count; | ||
119 | #elif defined A32_BITSTREAM_READER | ||
120 | uint32_t *buffer_ptr; | ||
121 | uint32_t cache0; | ||
122 | uint32_t cache1; | ||
123 | int bit_count; | ||
124 | #endif | ||
125 | int size_in_bits; | ||
126 | } GetBitContext; | ||
127 | |||
128 | #define VLC_TYPE int16_t | ||
129 | |||
130 | typedef struct VLC { | ||
131 | int bits; | ||
132 | VLC_TYPE (*table)[2]; ///< code, bits | ||
133 | int table_size, table_allocated; | ||
134 | } VLC; | ||
135 | |||
136 | typedef struct RL_VLC_ELEM { | ||
137 | int16_t level; | ||
138 | int8_t len; | ||
139 | uint8_t run; | ||
140 | } RL_VLC_ELEM; | ||
141 | |||
142 | /* Bitstream reader API docs: | ||
143 | name | ||
144 | arbitrary name which is used as prefix for the internal variables | ||
145 | |||
146 | gb | ||
147 | getbitcontext | ||
148 | |||
149 | OPEN_READER(name, gb) | ||
150 | loads gb into local variables | ||
151 | |||
152 | CLOSE_READER(name, gb) | ||
153 | stores local vars in gb | ||
154 | |||
155 | UPDATE_CACHE(name, gb) | ||
156 | refills the internal cache from the bitstream | ||
157 | after this call at least MIN_CACHE_BITS will be available, | ||
158 | |||
159 | GET_CACHE(name, gb) | ||
160 | will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit) | ||
161 | |||
162 | SHOW_UBITS(name, gb, num) | ||
163 | will return the next num bits | ||
164 | |||
165 | SHOW_SBITS(name, gb, num) | ||
166 | will return the next num bits and do sign extension | ||
167 | |||
168 | SKIP_BITS(name, gb, num) | ||
169 | will skip over the next num bits | ||
170 | note, this is equivalent to SKIP_CACHE; SKIP_COUNTER | ||
171 | |||
172 | SKIP_CACHE(name, gb, num) | ||
173 | will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER) | ||
174 | |||
175 | SKIP_COUNTER(name, gb, num) | ||
176 | will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS) | ||
177 | |||
178 | LAST_SKIP_CACHE(name, gb, num) | ||
179 | will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing | ||
180 | |||
181 | LAST_SKIP_BITS(name, gb, num) | ||
182 | is equivalent to LAST_SKIP_CACHE; SKIP_COUNTER | ||
183 | |||
184 | for examples see get_bits, show_bits, skip_bits, get_vlc | ||
185 | */ | ||
186 | |||
187 | #ifdef ALT_BITSTREAM_READER | ||
188 | # define MIN_CACHE_BITS 25 | ||
189 | |||
190 | # define OPEN_READER(name, gb)\ | ||
191 | unsigned int name##_index= (gb)->index;\ | ||
192 | int name##_cache= 0;\ | ||
193 | |||
194 | # define CLOSE_READER(name, gb)\ | ||
195 | (gb)->index= name##_index;\ | ||
196 | |||
197 | # ifdef ALT_BITSTREAM_READER_LE | ||
198 | # define UPDATE_CACHE(name, gb)\ | ||
199 | name##_cache= AV_RL32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\ | ||
200 | |||
201 | # define SKIP_CACHE(name, gb, num)\ | ||
202 | name##_cache >>= (num); | ||
203 | # else | ||
204 | # define UPDATE_CACHE(name, gb)\ | ||
205 | name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\ | ||
206 | |||
207 | # define SKIP_CACHE(name, gb, num)\ | ||
208 | name##_cache <<= (num); | ||
209 | # endif | ||
210 | |||
211 | // FIXME name? | ||
212 | # define SKIP_COUNTER(name, gb, num)\ | ||
213 | name##_index += (num);\ | ||
214 | |||
215 | # define SKIP_BITS(name, gb, num)\ | ||
216 | {\ | ||
217 | SKIP_CACHE(name, gb, num)\ | ||
218 | SKIP_COUNTER(name, gb, num)\ | ||
219 | }\ | ||
220 | |||
221 | # define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num) | ||
222 | # define LAST_SKIP_CACHE(name, gb, num) ; | ||
223 | |||
224 | # ifdef ALT_BITSTREAM_READER_LE | ||
225 | # define SHOW_UBITS(name, gb, num)\ | ||
226 | zero_extend(name##_cache, num) | ||
227 | |||
228 | # define SHOW_SBITS(name, gb, num)\ | ||
229 | sign_extend(name##_cache, num) | ||
230 | # else | ||
231 | # define SHOW_UBITS(name, gb, num)\ | ||
232 | NEG_USR32(name##_cache, num) | ||
233 | |||
234 | # define SHOW_SBITS(name, gb, num)\ | ||
235 | NEG_SSR32(name##_cache, num) | ||
236 | # endif | ||
237 | |||
238 | # define GET_CACHE(name, gb)\ | ||
239 | ((uint32_t)name##_cache) | ||
240 | |||
241 | static inline int get_bits_count(const GetBitContext *s){ | ||
242 | return s->index; | ||
243 | } | ||
244 | |||
245 | static inline void skip_bits_long(GetBitContext *s, int n){ | ||
246 | s->index += n; | ||
247 | } | ||
248 | |||
249 | #elif defined LIBMPEG2_BITSTREAM_READER | ||
250 | //libmpeg2 like reader | ||
251 | |||
252 | # define MIN_CACHE_BITS 17 | ||
253 | |||
254 | # define OPEN_READER(name, gb)\ | ||
255 | int name##_bit_count=(gb)->bit_count;\ | ||
256 | int name##_cache= (gb)->cache;\ | ||
257 | uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\ | ||
258 | |||
259 | # define CLOSE_READER(name, gb)\ | ||
260 | (gb)->bit_count= name##_bit_count;\ | ||
261 | (gb)->cache= name##_cache;\ | ||
262 | (gb)->buffer_ptr= name##_buffer_ptr;\ | ||
263 | |||
264 | # define UPDATE_CACHE(name, gb)\ | ||
265 | if(name##_bit_count >= 0){\ | ||
266 | name##_cache+= AV_RB16(name##_buffer_ptr) << name##_bit_count; \ | ||
267 | name##_buffer_ptr+=2;\ | ||
268 | name##_bit_count-= 16;\ | ||
269 | }\ | ||
270 | |||
271 | # define SKIP_CACHE(name, gb, num)\ | ||
272 | name##_cache <<= (num);\ | ||
273 | |||
274 | # define SKIP_COUNTER(name, gb, num)\ | ||
275 | name##_bit_count += (num);\ | ||
276 | |||
277 | # define SKIP_BITS(name, gb, num)\ | ||
278 | {\ | ||
279 | SKIP_CACHE(name, gb, num)\ | ||
280 | SKIP_COUNTER(name, gb, num)\ | ||
281 | }\ | ||
282 | |||
283 | # define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num) | ||
284 | # define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num) | ||
285 | |||
286 | # define SHOW_UBITS(name, gb, num)\ | ||
287 | NEG_USR32(name##_cache, num) | ||
288 | |||
289 | # define SHOW_SBITS(name, gb, num)\ | ||
290 | NEG_SSR32(name##_cache, num) | ||
291 | |||
292 | # define GET_CACHE(name, gb)\ | ||
293 | ((uint32_t)name##_cache) | ||
294 | |||
295 | static inline int get_bits_count(const GetBitContext *s){ | ||
296 | return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count; | ||
297 | } | ||
298 | |||
299 | static inline void skip_bits_long(GetBitContext *s, int n){ | ||
300 | OPEN_READER(re, s) | ||
301 | re_bit_count += n; | ||
302 | re_buffer_ptr += 2*(re_bit_count>>4); | ||
303 | re_bit_count &= 15; | ||
304 | re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count); | ||
305 | UPDATE_CACHE(re, s) | ||
306 | CLOSE_READER(re, s) | ||
307 | } | ||
308 | |||
309 | #elif defined A32_BITSTREAM_READER | ||
310 | |||
311 | # define MIN_CACHE_BITS 32 | ||
312 | |||
313 | # define OPEN_READER(name, gb)\ | ||
314 | int name##_bit_count=(gb)->bit_count;\ | ||
315 | uint32_t name##_cache0= (gb)->cache0;\ | ||
316 | uint32_t name##_cache1= (gb)->cache1;\ | ||
317 | uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\ | ||
318 | |||
319 | # define CLOSE_READER(name, gb)\ | ||
320 | (gb)->bit_count= name##_bit_count;\ | ||
321 | (gb)->cache0= name##_cache0;\ | ||
322 | (gb)->cache1= name##_cache1;\ | ||
323 | (gb)->buffer_ptr= name##_buffer_ptr;\ | ||
324 | |||
325 | # define UPDATE_CACHE(name, gb)\ | ||
326 | if(name##_bit_count > 0){\ | ||
327 | const uint32_t next= av_be2ne32( *name##_buffer_ptr );\ | ||
328 | name##_cache0 |= NEG_USR32(next,name##_bit_count);\ | ||
329 | name##_cache1 |= next<<name##_bit_count;\ | ||
330 | name##_buffer_ptr++;\ | ||
331 | name##_bit_count-= 32;\ | ||
332 | }\ | ||
333 | |||
334 | #if ARCH_X86 | ||
335 | # define SKIP_CACHE(name, gb, num)\ | ||
336 | __asm__(\ | ||
337 | "shldl %2, %1, %0 \n\t"\ | ||
338 | "shll %2, %1 \n\t"\ | ||
339 | : "+r" (name##_cache0), "+r" (name##_cache1)\ | ||
340 | : "Ic" ((uint8_t)(num))\ | ||
341 | ); | ||
342 | #else | ||
343 | # define SKIP_CACHE(name, gb, num)\ | ||
344 | name##_cache0 <<= (num);\ | ||
345 | name##_cache0 |= NEG_USR32(name##_cache1,num);\ | ||
346 | name##_cache1 <<= (num); | ||
347 | #endif | ||
348 | |||
349 | # define SKIP_COUNTER(name, gb, num)\ | ||
350 | name##_bit_count += (num);\ | ||
351 | |||
352 | # define SKIP_BITS(name, gb, num)\ | ||
353 | {\ | ||
354 | SKIP_CACHE(name, gb, num)\ | ||
355 | SKIP_COUNTER(name, gb, num)\ | ||
356 | }\ | ||
357 | |||
358 | # define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num) | ||
359 | # define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num) | ||
360 | |||
361 | # define SHOW_UBITS(name, gb, num)\ | ||
362 | NEG_USR32(name##_cache0, num) | ||
363 | |||
364 | # define SHOW_SBITS(name, gb, num)\ | ||
365 | NEG_SSR32(name##_cache0, num) | ||
366 | |||
367 | # define GET_CACHE(name, gb)\ | ||
368 | (name##_cache0) | ||
369 | |||
370 | static inline int get_bits_count(const GetBitContext *s){ | ||
371 | return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count; | ||
372 | } | ||
373 | |||
374 | static inline void skip_bits_long(GetBitContext *s, int n){ | ||
375 | OPEN_READER(re, s) | ||
376 | re_bit_count += n; | ||
377 | re_buffer_ptr += re_bit_count>>5; | ||
378 | re_bit_count &= 31; | ||
379 | re_cache0 = av_be2ne32( re_buffer_ptr[-1] ) << re_bit_count; | ||
380 | re_cache1 = 0; | ||
381 | UPDATE_CACHE(re, s) | ||
382 | CLOSE_READER(re, s) | ||
383 | } | ||
384 | |||
385 | #endif | ||
386 | |||
387 | /** | ||
388 | * read mpeg1 dc style vlc (sign bit + mantisse with no MSB). | ||
389 | * if MSB not set it is negative | ||
390 | * @param n length in bits | ||
391 | * @author BERO | ||
392 | */ | ||
393 | static inline int get_xbits(GetBitContext *s, int n){ | ||
394 | register int sign; | ||
395 | register int32_t cache; | ||
396 | OPEN_READER(re, s) | ||
397 | UPDATE_CACHE(re, s) | ||
398 | cache = GET_CACHE(re,s); | ||
399 | sign=(~cache)>>31; | ||
400 | LAST_SKIP_BITS(re, s, n) | ||
401 | CLOSE_READER(re, s) | ||
402 | return (NEG_USR32(sign ^ cache, n) ^ sign) - sign; | ||
403 | } | ||
404 | |||
405 | static inline int get_sbits(GetBitContext *s, int n){ | ||
406 | register int tmp; | ||
407 | OPEN_READER(re, s) | ||
408 | UPDATE_CACHE(re, s) | ||
409 | tmp= SHOW_SBITS(re, s, n); | ||
410 | LAST_SKIP_BITS(re, s, n) | ||
411 | CLOSE_READER(re, s) | ||
412 | return tmp; | ||
413 | } | ||
414 | |||
415 | /** | ||
416 | * reads 1-17 bits. | ||
417 | * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't | ||
418 | */ | ||
419 | static inline unsigned int get_bits(GetBitContext *s, int n){ | ||
420 | register int tmp; | ||
421 | OPEN_READER(re, s) | ||
422 | UPDATE_CACHE(re, s) | ||
423 | tmp= SHOW_UBITS(re, s, n); | ||
424 | LAST_SKIP_BITS(re, s, n) | ||
425 | CLOSE_READER(re, s) | ||
426 | return tmp; | ||
427 | } | ||
428 | |||
429 | /** | ||
430 | * shows 1-17 bits. | ||
431 | * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't | ||
432 | */ | ||
433 | static inline unsigned int show_bits(GetBitContext *s, int n){ | ||
434 | register int tmp; | ||
435 | OPEN_READER(re, s) | ||
436 | UPDATE_CACHE(re, s) | ||
437 | tmp= SHOW_UBITS(re, s, n); | ||
438 | // CLOSE_READER(re, s) | ||
439 | return tmp; | ||
440 | } | ||
441 | |||
442 | static inline void skip_bits(GetBitContext *s, int n){ | ||
443 | //Note gcc seems to optimize this to s->index+=n for the ALT_READER :)) | ||
444 | OPEN_READER(re, s) | ||
445 | UPDATE_CACHE(re, s) | ||
446 | LAST_SKIP_BITS(re, s, n) | ||
447 | CLOSE_READER(re, s) | ||
448 | } | ||
449 | |||
450 | static inline unsigned int get_bits1(GetBitContext *s){ | ||
451 | #ifdef ALT_BITSTREAM_READER | ||
452 | unsigned int index= s->index; | ||
453 | uint8_t result= s->buffer[ index>>3 ]; | ||
454 | #ifdef ALT_BITSTREAM_READER_LE | ||
455 | result>>= (index&0x07); | ||
456 | result&= 1; | ||
457 | #else | ||
458 | result<<= (index&0x07); | ||
459 | result>>= 8 - 1; | ||
460 | #endif | ||
461 | index++; | ||
462 | s->index= index; | ||
463 | |||
464 | return result; | ||
465 | #else | ||
466 | return get_bits(s, 1); | ||
467 | #endif | ||
468 | } | ||
469 | |||
470 | static inline unsigned int show_bits1(GetBitContext *s){ | ||
471 | return show_bits(s, 1); | ||
472 | } | ||
473 | |||
474 | static inline void skip_bits1(GetBitContext *s){ | ||
475 | skip_bits(s, 1); | ||
476 | } | ||
477 | |||
478 | /** | ||
479 | * reads 0-32 bits. | ||
480 | */ | ||
481 | static inline unsigned int get_bits_long(GetBitContext *s, int n){ | ||
482 | if(n<=MIN_CACHE_BITS) return get_bits(s, n); | ||
483 | else{ | ||
484 | #ifdef ALT_BITSTREAM_READER_LE | ||
485 | int ret= get_bits(s, 16); | ||
486 | return ret | (get_bits(s, n-16) << 16); | ||
487 | #else | ||
488 | int ret= get_bits(s, 16) << (n-16); | ||
489 | return ret | get_bits(s, n-16); | ||
490 | #endif | ||
491 | } | ||
492 | } | ||
493 | |||
494 | /** | ||
495 | * reads 0-32 bits as a signed integer. | ||
496 | */ | ||
497 | static inline int get_sbits_long(GetBitContext *s, int n) { | ||
498 | return sign_extend(get_bits_long(s, n), n); | ||
499 | } | ||
500 | |||
501 | /** | ||
502 | * shows 0-32 bits. | ||
503 | */ | ||
504 | static inline unsigned int show_bits_long(GetBitContext *s, int n){ | ||
505 | if(n<=MIN_CACHE_BITS) return show_bits(s, n); | ||
506 | else{ | ||
507 | GetBitContext gb= *s; | ||
508 | return get_bits_long(&gb, n); | ||
509 | } | ||
510 | } | ||
511 | |||
512 | /* not used | ||
513 | static inline int check_marker(GetBitContext *s, const char *msg) | ||
514 | { | ||
515 | int bit= get_bits1(s); | ||
516 | if(!bit) | ||
517 | av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg); | ||
518 | |||
519 | return bit; | ||
520 | } | ||
521 | */ | ||
522 | |||
523 | /** | ||
524 | * init GetBitContext. | ||
525 | * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits | ||
526 | * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end | ||
527 | * @param bit_size the size of the buffer in bits | ||
528 | * | ||
529 | * While GetBitContext stores the buffer size, for performance reasons you are | ||
530 | * responsible for checking for the buffer end yourself (take advantage of the padding)! | ||
531 | */ | ||
532 | static inline void init_get_bits(GetBitContext *s, | ||
533 | const uint8_t *buffer, int bit_size) | ||
534 | { | ||
535 | int buffer_size= (bit_size+7)>>3; | ||
536 | if(buffer_size < 0 || bit_size < 0) { | ||
537 | buffer_size = bit_size = 0; | ||
538 | buffer = NULL; | ||
539 | } | ||
540 | |||
541 | s->buffer= buffer; | ||
542 | s->size_in_bits= bit_size; | ||
543 | s->buffer_end= buffer + buffer_size; | ||
544 | #ifdef ALT_BITSTREAM_READER | ||
545 | s->index=0; | ||
546 | #elif defined LIBMPEG2_BITSTREAM_READER | ||
547 | s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1)); | ||
548 | s->bit_count = 16 + 8*((intptr_t)buffer&1); | ||
549 | skip_bits_long(s, 0); | ||
550 | #elif defined A32_BITSTREAM_READER | ||
551 | s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3)); | ||
552 | s->bit_count = 32 + 8*((intptr_t)buffer&3); | ||
553 | skip_bits_long(s, 0); | ||
554 | #endif | ||
555 | } | ||
556 | |||
557 | static inline void align_get_bits(GetBitContext *s) | ||
558 | { | ||
559 | int n= (-get_bits_count(s)) & 7; | ||
560 | if(n) skip_bits(s, n); | ||
561 | } | ||
562 | |||
563 | #define init_vlc(vlc, nb_bits, nb_codes,\ | ||
564 | bits, bits_wrap, bits_size,\ | ||
565 | codes, codes_wrap, codes_size,\ | ||
566 | flags)\ | ||
567 | init_vlc_sparse(vlc, nb_bits, nb_codes,\ | ||
568 | bits, bits_wrap, bits_size,\ | ||
569 | codes, codes_wrap, codes_size,\ | ||
570 | NULL, 0, 0, flags) | ||
571 | |||
572 | int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, | ||
573 | const void *bits, int bits_wrap, int bits_size, | ||
574 | const void *codes, int codes_wrap, int codes_size, | ||
575 | const void *symbols, int symbols_wrap, int symbols_size, | ||
576 | int flags); | ||
577 | #define INIT_VLC_LE 2 | ||
578 | #define INIT_VLC_USE_NEW_STATIC 4 | ||
579 | void free_vlc(VLC *vlc); | ||
580 | |||
581 | #define INIT_VLC_STATIC(vlc, bits, a,b,c,d,e,f,g, static_size)\ | ||
582 | {\ | ||
583 | static VLC_TYPE table[static_size][2];\ | ||
584 | (vlc)->table= table;\ | ||
585 | (vlc)->table_allocated= static_size;\ | ||
586 | init_vlc(vlc, bits, a,b,c,d,e,f,g, INIT_VLC_USE_NEW_STATIC);\ | ||
587 | } | ||
588 | |||
589 | |||
590 | /** | ||
591 | * | ||
592 | * If the vlc code is invalid and max_depth=1, then no bits will be removed. | ||
593 | * If the vlc code is invalid and max_depth>1, then the number of bits removed | ||
594 | * is undefined. | ||
595 | */ | ||
596 | #define GET_VLC(code, name, gb, table, bits, max_depth)\ | ||
597 | {\ | ||
598 | int n, nb_bits;\ | ||
599 | unsigned int index;\ | ||
600 | \ | ||
601 | index= SHOW_UBITS(name, gb, bits);\ | ||
602 | code = table[index][0];\ | ||
603 | n = table[index][1];\ | ||
604 | \ | ||
605 | if(max_depth > 1 && n < 0){\ | ||
606 | LAST_SKIP_BITS(name, gb, bits)\ | ||
607 | UPDATE_CACHE(name, gb)\ | ||
608 | \ | ||
609 | nb_bits = -n;\ | ||
610 | \ | ||
611 | index= SHOW_UBITS(name, gb, nb_bits) + code;\ | ||
612 | code = table[index][0];\ | ||
613 | n = table[index][1];\ | ||
614 | if(max_depth > 2 && n < 0){\ | ||
615 | LAST_SKIP_BITS(name, gb, nb_bits)\ | ||
616 | UPDATE_CACHE(name, gb)\ | ||
617 | \ | ||
618 | nb_bits = -n;\ | ||
619 | \ | ||
620 | index= SHOW_UBITS(name, gb, nb_bits) + code;\ | ||
621 | code = table[index][0];\ | ||
622 | n = table[index][1];\ | ||
623 | }\ | ||
624 | }\ | ||
625 | SKIP_BITS(name, gb, n)\ | ||
626 | } | ||
627 | |||
628 | #define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\ | ||
629 | {\ | ||
630 | int n, nb_bits;\ | ||
631 | unsigned int index;\ | ||
632 | \ | ||
633 | index= SHOW_UBITS(name, gb, bits);\ | ||
634 | level = table[index].level;\ | ||
635 | n = table[index].len;\ | ||
636 | \ | ||
637 | if(max_depth > 1 && n < 0){\ | ||
638 | SKIP_BITS(name, gb, bits)\ | ||
639 | if(need_update){\ | ||
640 | UPDATE_CACHE(name, gb)\ | ||
641 | }\ | ||
642 | \ | ||
643 | nb_bits = -n;\ | ||
644 | \ | ||
645 | index= SHOW_UBITS(name, gb, nb_bits) + level;\ | ||
646 | level = table[index].level;\ | ||
647 | n = table[index].len;\ | ||
648 | }\ | ||
649 | run= table[index].run;\ | ||
650 | SKIP_BITS(name, gb, n)\ | ||
651 | } | ||
652 | |||
653 | |||
654 | /** | ||
655 | * parses a vlc code, faster then get_vlc() | ||
656 | * @param bits is the number of bits which will be read at once, must be | ||
657 | * identical to nb_bits in init_vlc() | ||
658 | * @param max_depth is the number of times bits bits must be read to completely | ||
659 | * read the longest vlc code | ||
660 | * = (max_vlc_length + bits - 1) / bits | ||
661 | */ | ||
662 | static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2], | ||
663 | int bits, int max_depth) | ||
664 | { | ||
665 | int code; | ||
666 | |||
667 | OPEN_READER(re, s) | ||
668 | UPDATE_CACHE(re, s) | ||
669 | |||
670 | GET_VLC(code, re, s, table, bits, max_depth) | ||
671 | |||
672 | CLOSE_READER(re, s) | ||
673 | return code; | ||
674 | } | ||
675 | |||
676 | //#define TRACE | ||
677 | |||
678 | #ifdef TRACE | ||
679 | static inline void print_bin(int bits, int n){ | ||
680 | int i; | ||
681 | |||
682 | for(i=n-1; i>=0; i--){ | ||
683 | av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1); | ||
684 | } | ||
685 | for(i=n; i<24; i++) | ||
686 | av_log(NULL, AV_LOG_DEBUG, " "); | ||
687 | } | ||
688 | |||
689 | static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){ | ||
690 | int r= get_bits(s, n); | ||
691 | |||
692 | print_bin(r, n); | ||
693 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d bit @%5d in %s %s:%d\n", r, n, r, get_bits_count(s)-n, file, func, line); | ||
694 | return r; | ||
695 | } | ||
696 | static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){ | ||
697 | int show= show_bits(s, 24); | ||
698 | int pos= get_bits_count(s); | ||
699 | int r= get_vlc2(s, table, bits, max_depth); | ||
700 | int len= get_bits_count(s) - pos; | ||
701 | int bits2= show>>(24-len); | ||
702 | |||
703 | print_bin(bits2, len); | ||
704 | |||
705 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line); | ||
706 | return r; | ||
707 | } | ||
708 | static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){ | ||
709 | int show= show_bits(s, n); | ||
710 | int r= get_xbits(s, n); | ||
711 | |||
712 | print_bin(show, n); | ||
713 | av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d xbt @%5d in %s %s:%d\n", show, n, r, get_bits_count(s)-n, file, func, line); | ||
714 | return r; | ||
715 | } | ||
716 | |||
717 | #define get_bits(s, n) get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__) | ||
718 | #define get_bits1(s) get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__) | ||
719 | #define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__) | ||
720 | #define get_vlc(s, vlc) get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__) | ||
721 | #define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__) | ||
722 | |||
723 | #define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__) | ||
724 | |||
725 | #else //TRACE | ||
726 | #define tprintf(p, ...) {} | ||
727 | #endif | ||
728 | |||
729 | static inline int decode012(GetBitContext *gb){ | ||
730 | int n; | ||
731 | n = get_bits1(gb); | ||
732 | if (n == 0) | ||
733 | return 0; | ||
734 | else | ||
735 | return get_bits1(gb) + 1; | ||
736 | } | ||
737 | |||
738 | static inline int decode210(GetBitContext *gb){ | ||
739 | if (get_bits1(gb)) | ||
740 | return 0; | ||
741 | else | ||
742 | return 2 - get_bits1(gb); | ||
743 | } | ||
744 | |||
745 | static inline int get_bits_left(GetBitContext *gb) | ||
746 | { | ||
747 | return gb->size_in_bits - get_bits_count(gb); | ||
748 | } | ||
749 | |||
750 | #endif /* AVCODEC_GET_BITS_H */ | ||