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malloc padding to avoid reading past the malloc()ed area.
[libav.git] / libavcodec / bitstream.h
CommitLineData
caa336b4
MN		 1/**
2 * @file bitstream.h
3 * bitstream api header.
4 */
5
6#ifndef BITSTREAM_H
7#define BITSTREAM_H
8
9//#define ALT_BITSTREAM_WRITER
10//#define ALIGNED_BITSTREAM_WRITER
11
12#define ALT_BITSTREAM_READER
13//#define LIBMPEG2_BITSTREAM_READER
14//#define A32_BITSTREAM_READER
15#define LIBMPEG2_BITSTREAM_READER_HACK //add BERO
16
fcbc799c
MN		 17extern const uint8_t ff_reverse[256];
18
caa336b4
MN		 19#if defined(ARCH_X86) || defined(ARCH_X86_64)
20// avoid +32 for shift optimization (gcc should do that ...)
21static inline int32_t NEG_SSR32( int32_t a, int8_t s){
22 asm ("sarl %1, %0\n\t"
23 : "+r" (a)
24 : "ic" ((uint8_t)(-s))
25 );
26 return a;
27}
28static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
29 asm ("shrl %1, %0\n\t"
30 : "+r" (a)
31 : "ic" ((uint8_t)(-s))
32 );
33 return a;
34}
35#else
36# define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
37# define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
38#endif
39
40/* bit output */
41
42/* buf and buf_end must be present and used by every alternative writer. */
43typedef struct PutBitContext {
44#ifdef ALT_BITSTREAM_WRITER
45 uint8_t *buf, *buf_end;
46 int index;
47#else
48 uint32_t bit_buf;
49 int bit_left;
50 uint8_t *buf, *buf_ptr, *buf_end;
51#endif
52} PutBitContext;
53
54static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
55{
288f1e68
MB		 56 if(buffer_size < 0) {
57 buffer_size = 0;
58 buffer = NULL;
59 }
9061be9f 60
caa336b4
MN		 61 s->buf = buffer;
62 s->buf_end = s->buf + buffer_size;
63#ifdef ALT_BITSTREAM_WRITER
64 s->index=0;
65 ((uint32_t*)(s->buf))[0]=0;
66// memset(buffer, 0, buffer_size);
67#else
68 s->buf_ptr = s->buf;
69 s->bit_left=32;
70 s->bit_buf=0;
71#endif
72}
73
74/* return the number of bits output */
75static inline int put_bits_count(PutBitContext *s)
76{
77#ifdef ALT_BITSTREAM_WRITER
78 return s->index;
79#else
80 return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left;
81#endif
82}
83
84/* pad the end of the output stream with zeros */
85static inline void flush_put_bits(PutBitContext *s)
86{
87#ifdef ALT_BITSTREAM_WRITER
88 align_put_bits(s);
89#else
90 s->bit_buf<<= s->bit_left;
91 while (s->bit_left < 32) {
92 /* XXX: should test end of buffer */
93 *s->buf_ptr++=s->bit_buf >> 24;
94 s->bit_buf<<=8;
95 s->bit_left+=8;
96 }
97 s->bit_left=32;
98 s->bit_buf=0;
99#endif
100}
101
102void align_put_bits(PutBitContext *s);
344b825c 103void ff_put_string(PutBitContext * pbc, char *s, int put_zero);
caa336b4
MN		 104
105/* bit input */
106/* buffer, buffer_end and size_in_bits must be present and used by every reader */
107typedef struct GetBitContext {
108 const uint8_t *buffer, *buffer_end;
109#ifdef ALT_BITSTREAM_READER
110 int index;
111#elif defined LIBMPEG2_BITSTREAM_READER
112 uint8_t *buffer_ptr;
113 uint32_t cache;
114 int bit_count;
115#elif defined A32_BITSTREAM_READER
116 uint32_t *buffer_ptr;
117 uint32_t cache0;
118 uint32_t cache1;
119 int bit_count;
120#endif
121 int size_in_bits;
122} GetBitContext;
123
124#define VLC_TYPE int16_t
125
126typedef struct VLC {
127 int bits;
128 VLC_TYPE (*table)[2]; ///< code, bits
129 int table_size, table_allocated;
130} VLC;
131
132typedef struct RL_VLC_ELEM {
133 int16_t level;
134 int8_t len;
135 uint8_t run;
136} RL_VLC_ELEM;
137
5085d59d 138#if defined(ARCH_SPARC) || defined(ARCH_ARMV4L)
caa336b4
MN		 139#define UNALIGNED_STORES_ARE_BAD
140#endif
141
142/* used to avoid missaligned exceptions on some archs (alpha, ...) */
143#if defined(ARCH_X86) || defined(ARCH_X86_64)
144# define unaligned32(a) (*(const uint32_t*)(a))
145#else
146# ifdef __GNUC__
147static inline uint32_t unaligned32(const void *v) {
148 struct Unaligned {
149 uint32_t i;
150 } __attribute__((packed));
151
152 return ((const struct Unaligned *) v)->i;
153}
154# elif defined(__DECC)
155static inline uint32_t unaligned32(const void *v) {
156 return *(const __unaligned uint32_t *) v;
157}
158# else
159static inline uint32_t unaligned32(const void *v) {
160 return *(const uint32_t *) v;
161}
162# endif
163#endif //!ARCH_X86
164
165#ifndef ALT_BITSTREAM_WRITER
166static inline void put_bits(PutBitContext *s, int n, unsigned int value)
167{
168 unsigned int bit_buf;
169 int bit_left;
170
171#ifdef STATS
172 st_out_bit_counts[st_current_index] += n;
173#endif
174 // printf("put_bits=%d %x\n", n, value);
175 assert(n == 32 || value < (1U << n));
176
177 bit_buf = s->bit_buf;
178 bit_left = s->bit_left;
179
180 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf);
181 /* XXX: optimize */
182 if (n < bit_left) {
183 bit_buf = (bit_buf<<n) | value;
184 bit_left-=n;
185 } else {
186 bit_buf<<=bit_left;
187 bit_buf |= value >> (n - bit_left);
188#ifdef UNALIGNED_STORES_ARE_BAD
189 if (3 & (intptr_t) s->buf_ptr) {
190 s->buf_ptr[0] = bit_buf >> 24;
191 s->buf_ptr[1] = bit_buf >> 16;
192 s->buf_ptr[2] = bit_buf >> 8;
193 s->buf_ptr[3] = bit_buf ;
194 } else
195#endif
196 *(uint32_t *)s->buf_ptr = be2me_32(bit_buf);
197 //printf("bitbuf = %08x\n", bit_buf);
198 s->buf_ptr+=4;
199 bit_left+=32 - n;
200 bit_buf = value;
201 }
202
203 s->bit_buf = bit_buf;
204 s->bit_left = bit_left;
205}
206#endif
207
208
209#ifdef ALT_BITSTREAM_WRITER
210static inline void put_bits(PutBitContext *s, int n, unsigned int value)
211{
212# ifdef ALIGNED_BITSTREAM_WRITER
213# if defined(ARCH_X86) || defined(ARCH_X86_64)
214 asm volatile(
215 "movl %0, %%ecx \n\t"
216 "xorl %%eax, %%eax \n\t"
217 "shrdl %%cl, %1, %%eax \n\t"
218 "shrl %%cl, %1 \n\t"
219 "movl %0, %%ecx \n\t"
220 "shrl $3, %%ecx \n\t"
221 "andl $0xFFFFFFFC, %%ecx \n\t"
222 "bswapl %1 \n\t"
223 "orl %1, (%2, %%ecx) \n\t"
224 "bswapl %%eax \n\t"
225 "addl %3, %0 \n\t"
226 "movl %%eax, 4(%2, %%ecx) \n\t"
227 : "=&r" (s->index), "=&r" (value)
228 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n))
229 : "%eax", "%ecx"
230 );
231# else
232 int index= s->index;
233 uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
234
235 value<<= 32-n;
236
237 ptr[0] |= be2me_32(value>>(index&31));
238 ptr[1] = be2me_32(value<<(32-(index&31)));
239//if(n>24) printf("%d %d\n", n, value);
240 index+= n;
241 s->index= index;
242# endif
243# else //ALIGNED_BITSTREAM_WRITER
244# if defined(ARCH_X86) || defined(ARCH_X86_64)
245 asm volatile(
246 "movl $7, %%ecx \n\t"
247 "andl %0, %%ecx \n\t"
248 "addl %3, %%ecx \n\t"
249 "negl %%ecx \n\t"
250 "shll %%cl, %1 \n\t"
251 "bswapl %1 \n\t"
252 "movl %0, %%ecx \n\t"
253 "shrl $3, %%ecx \n\t"
254 "orl %1, (%%ecx, %2) \n\t"
255 "addl %3, %0 \n\t"
256 "movl $0, 4(%%ecx, %2) \n\t"
257 : "=&r" (s->index), "=&r" (value)
258 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value)
259 : "%ecx"
260 );
261# else
262 int index= s->index;
263 uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3));
264
265 ptr[0] |= be2me_32(value<<(32-n-(index&7) ));
266 ptr[1] = 0;
267//if(n>24) printf("%d %d\n", n, value);
268 index+= n;
269 s->index= index;
270# endif
271# endif //!ALIGNED_BITSTREAM_WRITER
272}
273#endif
274
275
276static inline uint8_t* pbBufPtr(PutBitContext *s)
277{
278#ifdef ALT_BITSTREAM_WRITER
279 return s->buf + (s->index>>3);
280#else
281 return s->buf_ptr;
282#endif
283}
284
285/**
286 *
287 * PutBitContext must be flushed & aligned to a byte boundary before calling this.
288 */
289static inline void skip_put_bytes(PutBitContext *s, int n){
290 assert((put_bits_count(s)&7)==0);
291#ifdef ALT_BITSTREAM_WRITER
292 FIXME may need some cleaning of the buffer
293 s->index += n<<3;
294#else
295 assert(s->bit_left==32);
296 s->buf_ptr += n;
297#endif
298}
299
300/**
1b781f82
MN		 301 * skips the given number of bits.
302 * must only be used if the actual values in the bitstream dont matter
303 */
304static inline void skip_put_bits(PutBitContext *s, int n){
305#ifdef ALT_BITSTREAM_WRITER
306 s->index += n;
307#else
308 s->bit_left -= n;
309 s->buf_ptr-= s->bit_left>>5;
310 s->bit_left &= 31;
311#endif
312}
313
314/**
caa336b4
MN		 315 * Changes the end of the buffer.
316 */
317static inline void set_put_bits_buffer_size(PutBitContext *s, int size){
318 s->buf_end= s->buf + size;
319}
320
321/* Bitstream reader API docs:
322name
323 abritary name which is used as prefix for the internal variables
324
325gb
326 getbitcontext
327
328OPEN_READER(name, gb)
329 loads gb into local variables
330
331CLOSE_READER(name, gb)
332 stores local vars in gb
333
334UPDATE_CACHE(name, gb)
335 refills the internal cache from the bitstream
336 after this call at least MIN_CACHE_BITS will be available,
337
338GET_CACHE(name, gb)
339 will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
340
341SHOW_UBITS(name, gb, num)
bb628dae 342 will return the next num bits
caa336b4
MN		 343
344SHOW_SBITS(name, gb, num)
bb628dae 345 will return the next num bits and do sign extension
caa336b4
MN		 346
347SKIP_BITS(name, gb, num)
348 will skip over the next num bits
bb628dae 349 note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
caa336b4
MN		 350
351SKIP_CACHE(name, gb, num)
352 will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
353
354SKIP_COUNTER(name, gb, num)
355 will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
356
357LAST_SKIP_CACHE(name, gb, num)
358 will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
359
360LAST_SKIP_BITS(name, gb, num)
bb628dae 361 is equivalent to SKIP_LAST_CACHE; SKIP_COUNTER
caa336b4
MN		 362
363for examples see get_bits, show_bits, skip_bits, get_vlc
364*/
365
366static inline int unaligned32_be(const void *v)
367{
368#ifdef CONFIG_ALIGN
369 const uint8_t *p=v;
370 return (((p[0]<<8) | p[1])<<16) | (p[2]<<8) | (p[3]);
371#else
372 return be2me_32( unaligned32(v)); //original
373#endif
374}
375
cea27ac7
MN		 376static inline int unaligned32_le(const void *v)
377{
378#ifdef CONFIG_ALIGN
379 const uint8_t *p=v;
380 return (((p[3]<<8) | p[2])<<16) | (p[1]<<8) | (p[0]);
381#else
382 return le2me_32( unaligned32(v)); //original
383#endif
384}
385
caa336b4
MN		 386#ifdef ALT_BITSTREAM_READER
387# define MIN_CACHE_BITS 25
388
389# define OPEN_READER(name, gb)\
390 int name##_index= (gb)->index;\
391 int name##_cache= 0;\
392
393# define CLOSE_READER(name, gb)\
394 (gb)->index= name##_index;\
395
cea27ac7
MN		 396# ifdef ALT_BITSTREAM_READER_LE
397# define UPDATE_CACHE(name, gb)\
398 name##_cache= unaligned32_le( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
399
400# define SKIP_CACHE(name, gb, num)\
401 name##_cache >>= (num);
402# else
caa336b4
MN		 403# define UPDATE_CACHE(name, gb)\
404 name##_cache= unaligned32_be( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
405
406# define SKIP_CACHE(name, gb, num)\
cea27ac7
MN		 407 name##_cache <<= (num);
408# endif
caa336b4
MN		 409
410// FIXME name?
411# define SKIP_COUNTER(name, gb, num)\
412 name##_index += (num);\
413
414# define SKIP_BITS(name, gb, num)\
415 {\
416 SKIP_CACHE(name, gb, num)\
417 SKIP_COUNTER(name, gb, num)\
418 }\
419
420# define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
421# define LAST_SKIP_CACHE(name, gb, num) ;
422
cea27ac7
MN		 423# ifdef ALT_BITSTREAM_READER_LE
424# define SHOW_UBITS(name, gb, num)\
425 ((name##_cache) & (NEG_USR32(0xffffffff,num)))
426# else
caa336b4
MN		 427# define SHOW_UBITS(name, gb, num)\
428 NEG_USR32(name##_cache, num)
cea27ac7 429# endif
caa336b4
MN		 430
431# define SHOW_SBITS(name, gb, num)\
432 NEG_SSR32(name##_cache, num)
433
434# define GET_CACHE(name, gb)\
435 ((uint32_t)name##_cache)
436
437static inline int get_bits_count(GetBitContext *s){
438 return s->index;
439}
440#elif defined LIBMPEG2_BITSTREAM_READER
441//libmpeg2 like reader
442
443# define MIN_CACHE_BITS 17
444
445# define OPEN_READER(name, gb)\
446 int name##_bit_count=(gb)->bit_count;\
447 int name##_cache= (gb)->cache;\
448 uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
449
450# define CLOSE_READER(name, gb)\
451 (gb)->bit_count= name##_bit_count;\
452 (gb)->cache= name##_cache;\
453 (gb)->buffer_ptr= name##_buffer_ptr;\
454
455#ifdef LIBMPEG2_BITSTREAM_READER_HACK
456
457# define UPDATE_CACHE(name, gb)\
458 if(name##_bit_count >= 0){\
459 name##_cache+= (int)be2me_16(*(uint16_t*)name##_buffer_ptr) << name##_bit_count;\
5bb8a0da 460 name##_buffer_ptr += 2;\
caa336b4
MN		 461 name##_bit_count-= 16;\
462 }\
463
464#else
465
466# define UPDATE_CACHE(name, gb)\
467 if(name##_bit_count >= 0){\
468 name##_cache+= ((name##_buffer_ptr[0]<<8) + name##_buffer_ptr[1]) << name##_bit_count;\
469 name##_buffer_ptr+=2;\
470 name##_bit_count-= 16;\
471 }\
472
473#endif
474
475# define SKIP_CACHE(name, gb, num)\
476 name##_cache <<= (num);\
477
478# define SKIP_COUNTER(name, gb, num)\
479 name##_bit_count += (num);\
480
481# define SKIP_BITS(name, gb, num)\
482 {\
483 SKIP_CACHE(name, gb, num)\
484 SKIP_COUNTER(name, gb, num)\
485 }\
486
487# define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
488# define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
489
490# define SHOW_UBITS(name, gb, num)\
491 NEG_USR32(name##_cache, num)
492
493# define SHOW_SBITS(name, gb, num)\
494 NEG_SSR32(name##_cache, num)
495
496# define GET_CACHE(name, gb)\
497 ((uint32_t)name##_cache)
498
499static inline int get_bits_count(GetBitContext *s){
500 return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
501}
502
503#elif defined A32_BITSTREAM_READER
504
505# define MIN_CACHE_BITS 32
506
507# define OPEN_READER(name, gb)\
508 int name##_bit_count=(gb)->bit_count;\
509 uint32_t name##_cache0= (gb)->cache0;\
510 uint32_t name##_cache1= (gb)->cache1;\
511 uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
512
513# define CLOSE_READER(name, gb)\
514 (gb)->bit_count= name##_bit_count;\
515 (gb)->cache0= name##_cache0;\
516 (gb)->cache1= name##_cache1;\
517 (gb)->buffer_ptr= name##_buffer_ptr;\
518
519# define UPDATE_CACHE(name, gb)\
520 if(name##_bit_count > 0){\
521 const uint32_t next= be2me_32( *name##_buffer_ptr );\
522 name##_cache0 |= NEG_USR32(next,name##_bit_count);\
523 name##_cache1 |= next<<name##_bit_count;\
524 name##_buffer_ptr++;\
525 name##_bit_count-= 32;\
526 }\
527
528#if defined(ARCH_X86) || defined(ARCH_X86_64)
529# define SKIP_CACHE(name, gb, num)\
530 asm(\
531 "shldl %2, %1, %0 \n\t"\
532 "shll %2, %1 \n\t"\
533 : "+r" (name##_cache0), "+r" (name##_cache1)\
534 : "Ic" ((uint8_t)num)\
535 );
536#else
537# define SKIP_CACHE(name, gb, num)\
538 name##_cache0 <<= (num);\
539 name##_cache0 |= NEG_USR32(name##_cache1,num);\
540 name##_cache1 <<= (num);
541#endif
542
543# define SKIP_COUNTER(name, gb, num)\
544 name##_bit_count += (num);\
545
546# define SKIP_BITS(name, gb, num)\
547 {\
548 SKIP_CACHE(name, gb, num)\
549 SKIP_COUNTER(name, gb, num)\
550 }\
551
552# define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
553# define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
554
555# define SHOW_UBITS(name, gb, num)\
556 NEG_USR32(name##_cache0, num)
557
558# define SHOW_SBITS(name, gb, num)\
559 NEG_SSR32(name##_cache0, num)
560
561# define GET_CACHE(name, gb)\
562 (name##_cache0)
563
564static inline int get_bits_count(GetBitContext *s){
565 return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
566}
567
568#endif
569
570/**
571 * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
572 * if MSB not set it is negative
573 * @param n length in bits
574 * @author BERO
575 */
576static inline int get_xbits(GetBitContext *s, int n){
577 register int tmp;
578 register int32_t cache;
579 OPEN_READER(re, s)
580 UPDATE_CACHE(re, s)
581 cache = GET_CACHE(re,s);
582 if ((int32_t)cache<0) { //MSB=1
583 tmp = NEG_USR32(cache,n);
584 } else {
585 // tmp = (-1<<n) | NEG_USR32(cache,n) + 1; mpeg12.c algo
586 // tmp = - (NEG_USR32(cache,n) ^ ((1 << n) - 1)); h263.c algo
587 tmp = - NEG_USR32(~cache,n);
588 }
589 LAST_SKIP_BITS(re, s, n)
590 CLOSE_READER(re, s)
591 return tmp;
592}
593
594static inline int get_sbits(GetBitContext *s, int n){
595 register int tmp;
596 OPEN_READER(re, s)
597 UPDATE_CACHE(re, s)
598 tmp= SHOW_SBITS(re, s, n);
599 LAST_SKIP_BITS(re, s, n)
600 CLOSE_READER(re, s)
601 return tmp;
602}
603
604/**
605 * reads 0-17 bits.
bb628dae 606 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
caa336b4
MN		 607 */
608static inline unsigned int get_bits(GetBitContext *s, int n){
609 register int tmp;
610 OPEN_READER(re, s)
611 UPDATE_CACHE(re, s)
612 tmp= SHOW_UBITS(re, s, n);
613 LAST_SKIP_BITS(re, s, n)
614 CLOSE_READER(re, s)
615 return tmp;
616}
617
618unsigned int get_bits_long(GetBitContext *s, int n);
619
620/**
621 * shows 0-17 bits.
bb628dae 622 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
caa336b4
MN		 623 */
624static inline unsigned int show_bits(GetBitContext *s, int n){
625 register int tmp;
626 OPEN_READER(re, s)
627 UPDATE_CACHE(re, s)
628 tmp= SHOW_UBITS(re, s, n);
629// CLOSE_READER(re, s)
630 return tmp;
631}
632
633unsigned int show_bits_long(GetBitContext *s, int n);
634
635static inline void skip_bits(GetBitContext *s, int n){
636 //Note gcc seems to optimize this to s->index+=n for the ALT_READER :))
637 OPEN_READER(re, s)
638 UPDATE_CACHE(re, s)
639 LAST_SKIP_BITS(re, s, n)
640 CLOSE_READER(re, s)
641}
642
643static inline unsigned int get_bits1(GetBitContext *s){
644#ifdef ALT_BITSTREAM_READER
645 int index= s->index;
646 uint8_t result= s->buffer[ index>>3 ];
cea27ac7
MN		 647#ifdef ALT_BITSTREAM_READER_LE
648 result>>= (index&0x07);
649 result&= 1;
650#else
caa336b4
MN		 651 result<<= (index&0x07);
652 result>>= 8 - 1;
cea27ac7 653#endif
caa336b4
MN		 654 index++;
655 s->index= index;
656
657 return result;
658#else
659 return get_bits(s, 1);
660#endif
661}
662
663static inline unsigned int show_bits1(GetBitContext *s){
664 return show_bits(s, 1);
665}
666
667static inline void skip_bits1(GetBitContext *s){
668 skip_bits(s, 1);
669}
670
671/**
672 * init GetBitContext.
673 * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
674 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
675 * @param bit_size the size of the buffer in bits
676 */
677static inline void init_get_bits(GetBitContext *s,
678 const uint8_t *buffer, int bit_size)
679{
9061be9f 680 int buffer_size= (bit_size+7)>>3;
288f1e68
MB		 681 if(buffer_size < 0 || bit_size < 0) {
682 buffer_size = bit_size = 0;
683 buffer = NULL;
684 }
caa336b4
MN		 685
686 s->buffer= buffer;
687 s->size_in_bits= bit_size;
688 s->buffer_end= buffer + buffer_size;
689#ifdef ALT_BITSTREAM_READER
690 s->index=0;
691#elif defined LIBMPEG2_BITSTREAM_READER
692#ifdef LIBMPEG2_BITSTREAM_READER_HACK
693 if ((int)buffer&1) {
694 /* word alignment */
695 s->cache = (*buffer++)<<24;
696 s->buffer_ptr = buffer;
697 s->bit_count = 16-8;
698 } else
699#endif
700 {
701 s->buffer_ptr = buffer;
702 s->bit_count = 16;
703 s->cache = 0;
704 }
705#elif defined A32_BITSTREAM_READER
706 s->buffer_ptr = (uint32_t*)buffer;
707 s->bit_count = 32;
708 s->cache0 = 0;
709 s->cache1 = 0;
710#endif
711 {
712 OPEN_READER(re, s)
713 UPDATE_CACHE(re, s)
714 UPDATE_CACHE(re, s)
715 CLOSE_READER(re, s)
716 }
717#ifdef A32_BITSTREAM_READER
718 s->cache1 = 0;
719#endif
720}
721
722int check_marker(GetBitContext *s, const char *msg);
723void align_get_bits(GetBitContext *s);
724int init_vlc(VLC *vlc, int nb_bits, int nb_codes,
725 const void *bits, int bits_wrap, int bits_size,
726 const void *codes, int codes_wrap, int codes_size,
cea27ac7
MN		 727 int flags);
728#define INIT_VLC_USE_STATIC 1
729#define INIT_VLC_LE 2
caa336b4
MN		 730void free_vlc(VLC *vlc);
731
732/**
733 *
734 * if the vlc code is invalid and max_depth=1 than no bits will be removed
735 * if the vlc code is invalid and max_depth>1 than the number of bits removed
736 * is undefined
737 */
738#define GET_VLC(code, name, gb, table, bits, max_depth)\
739{\
740 int n, index, nb_bits;\
741\
742 index= SHOW_UBITS(name, gb, bits);\
743 code = table[index][0];\
744 n = table[index][1];\
745\
746 if(max_depth > 1 && n < 0){\
747 LAST_SKIP_BITS(name, gb, bits)\
748 UPDATE_CACHE(name, gb)\
749\
750 nb_bits = -n;\
751\
752 index= SHOW_UBITS(name, gb, nb_bits) + code;\
753 code = table[index][0];\
754 n = table[index][1];\
755 if(max_depth > 2 && n < 0){\
756 LAST_SKIP_BITS(name, gb, nb_bits)\
757 UPDATE_CACHE(name, gb)\
758\
759 nb_bits = -n;\
760\
761 index= SHOW_UBITS(name, gb, nb_bits) + code;\
762 code = table[index][0];\
763 n = table[index][1];\
764 }\
765 }\
766 SKIP_BITS(name, gb, n)\
767}
768
e91f4bf1 769#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
caa336b4
MN		 770{\
771 int n, index, nb_bits;\
772\
773 index= SHOW_UBITS(name, gb, bits);\
774 level = table[index].level;\
775 n = table[index].len;\
776\
777 if(max_depth > 1 && n < 0){\
e91f4bf1
MN		 778 SKIP_BITS(name, gb, bits)\
779 if(need_update){\
780 UPDATE_CACHE(name, gb)\
781 }\
caa336b4
MN		 782\
783 nb_bits = -n;\
784\
785 index= SHOW_UBITS(name, gb, nb_bits) + level;\
786 level = table[index].level;\
787 n = table[index].len;\
788 }\
789 run= table[index].run;\
790 SKIP_BITS(name, gb, n)\
791}
792
793// deprecated, dont use get_vlc for new code, use get_vlc2 instead or use GET_VLC directly
794static inline int get_vlc(GetBitContext *s, VLC *vlc)
795{
796 int code;
797 VLC_TYPE (*table)[2]= vlc->table;
798
799 OPEN_READER(re, s)
800 UPDATE_CACHE(re, s)
801
802 GET_VLC(code, re, s, table, vlc->bits, 3)
803
804 CLOSE_READER(re, s)
805 return code;
806}
807
808/**
809 * parses a vlc code, faster then get_vlc()
810 * @param bits is the number of bits which will be read at once, must be
811 * identical to nb_bits in init_vlc()
812 * @param max_depth is the number of times bits bits must be readed to completly
813 * read the longest vlc code
814 * = (max_vlc_length + bits - 1) / bits
815 */
816static always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
817 int bits, int max_depth)
818{
819 int code;
820
821 OPEN_READER(re, s)
822 UPDATE_CACHE(re, s)
823
824 GET_VLC(code, re, s, table, bits, max_depth)
825
826 CLOSE_READER(re, s)
827 return code;
828}
829
830//#define TRACE
831
832#ifdef TRACE
61f040dd 833#include "avcodec.h"
caa336b4
MN		 834static inline void print_bin(int bits, int n){
835 int i;
836
837 for(i=n-1; i>=0; i--){
61f040dd 838 av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
caa336b4
MN		 839 }
840 for(i=n; i<24; i++)
61f040dd 841 av_log(NULL, AV_LOG_DEBUG, " ");
caa336b4
MN		 842}
843
61f040dd 844static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
caa336b4
MN		 845 int r= get_bits(s, n);
846
847 print_bin(r, n);
61f040dd 848 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);
caa336b4
MN		 849 return r;
850}
61f040dd 851static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){
caa336b4
MN		 852 int show= show_bits(s, 24);
853 int pos= get_bits_count(s);
854 int r= get_vlc2(s, table, bits, max_depth);
855 int len= get_bits_count(s) - pos;
856 int bits2= show>>(24-len);
857
858 print_bin(bits2, len);
859
61f040dd 860 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line);
caa336b4
MN		 861 return r;
862}
61f040dd 863static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
caa336b4
MN		 864 int show= show_bits(s, n);
865 int r= get_xbits(s, n);
866
867 print_bin(show, n);
61f040dd 868 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);
caa336b4
MN		 869 return r;
870}
871
872#define get_bits(s, n) get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
873#define get_bits1(s) get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
874#define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
875#define get_vlc(s, vlc) get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
876#define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
877
878#define tprintf(...) av_log(NULL, AV_LOG_DEBUG, __VA_ARGS__)
879
880#else //TRACE
881#define tprintf(...) {}
882#endif
883
7d8b13b4 884static inline int decode012(GetBitContext *gb){
a64a006e
MN		 885 int n;
886 n = get_bits1(gb);
887 if (n == 0)
888 return 0;
889 else
890 return get_bits1(gb) + 1;
891}
892
caa336b4 893#endif /* BITSTREAM_H */
Libav master