Use AV_WL32/AV_WB32 in bitstream.h
[libav.git] / libavcodec / bitstream.h
CommitLineData
04d7f601
DB
1/*
2 * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
3 *
b78e7197
DB
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
04d7f601
DB
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
b78e7197 9 * version 2.1 of the License, or (at your option) any later version.
04d7f601 10 *
b78e7197 11 * FFmpeg is distributed in the hope that it will be useful,
04d7f601
DB
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
b78e7197 17 * License along with FFmpeg; if not, write to the Free Software
04d7f601
DB
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
caa336b4
MN
21/**
22 * @file bitstream.h
23 * bitstream api header.
24 */
25
98790382
SS
26#ifndef AVCODEC_BITSTREAM_H
27#define AVCODEC_BITSTREAM_H
caa336b4 28
99545457
MR
29#include <stdint.h>
30#include <stdlib.h>
31#include <assert.h>
245976da
DB
32#include "libavutil/bswap.h"
33#include "libavutil/common.h"
34#include "libavutil/intreadwrite.h"
35#include "libavutil/log.h"
8fbc6aae 36
75c998a2 37#if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
1ae7a851 38# define ALT_BITSTREAM_READER
75c998a2
AJ
39#endif
40
caa336b4
MN
41//#define ALT_BITSTREAM_WRITER
42//#define ALIGNED_BITSTREAM_WRITER
727c236a 43#if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER)
b250f9c6 44# if ARCH_ARM
a1b65018
AJ
45# define A32_BITSTREAM_READER
46# else
1ae7a851 47# define ALT_BITSTREAM_READER
caa336b4
MN
48//#define LIBMPEG2_BITSTREAM_READER
49//#define A32_BITSTREAM_READER
a1b65018 50# endif
727c236a 51#endif
115329f1 52
fcbc799c
MN
53extern const uint8_t ff_reverse[256];
54
b250f9c6 55#if ARCH_X86
caa336b4
MN
56// avoid +32 for shift optimization (gcc should do that ...)
57static inline int32_t NEG_SSR32( int32_t a, int8_t s){
be449fca 58 __asm__ ("sarl %1, %0\n\t"
caa336b4
MN
59 : "+r" (a)
60 : "ic" ((uint8_t)(-s))
61 );
62 return a;
63}
64static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
be449fca 65 __asm__ ("shrl %1, %0\n\t"
caa336b4
MN
66 : "+r" (a)
67 : "ic" ((uint8_t)(-s))
68 );
69 return a;
70}
71#else
72# define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
73# define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
74#endif
75
76/* bit output */
77
78/* buf and buf_end must be present and used by every alternative writer. */
79typedef struct PutBitContext {
80#ifdef ALT_BITSTREAM_WRITER
81 uint8_t *buf, *buf_end;
82 int index;
83#else
84 uint32_t bit_buf;
85 int bit_left;
86 uint8_t *buf, *buf_ptr, *buf_end;
87#endif
88} PutBitContext;
89
90static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
91{
288f1e68
MB
92 if(buffer_size < 0) {
93 buffer_size = 0;
94 buffer = NULL;
95 }
9061be9f 96
caa336b4
MN
97 s->buf = buffer;
98 s->buf_end = s->buf + buffer_size;
99#ifdef ALT_BITSTREAM_WRITER
100 s->index=0;
101 ((uint32_t*)(s->buf))[0]=0;
102// memset(buffer, 0, buffer_size);
103#else
104 s->buf_ptr = s->buf;
105 s->bit_left=32;
106 s->bit_buf=0;
107#endif
108}
109
110/* return the number of bits output */
111static inline int put_bits_count(PutBitContext *s)
112{
113#ifdef ALT_BITSTREAM_WRITER
114 return s->index;
115#else
116 return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left;
117#endif
118}
119
120/* pad the end of the output stream with zeros */
121static inline void flush_put_bits(PutBitContext *s)
122{
123#ifdef ALT_BITSTREAM_WRITER
124 align_put_bits(s);
125#else
85803144 126#ifndef BITSTREAM_WRITER_LE
caa336b4 127 s->bit_buf<<= s->bit_left;
85803144 128#endif
caa336b4
MN
129 while (s->bit_left < 32) {
130 /* XXX: should test end of buffer */
85803144
BW
131#ifdef BITSTREAM_WRITER_LE
132 *s->buf_ptr++=s->bit_buf;
133 s->bit_buf>>=8;
134#else
caa336b4
MN
135 *s->buf_ptr++=s->bit_buf >> 24;
136 s->bit_buf<<=8;
85803144 137#endif
caa336b4
MN
138 s->bit_left+=8;
139 }
140 s->bit_left=32;
141 s->bit_buf=0;
142#endif
143}
144
145void align_put_bits(PutBitContext *s);
1701cbfa
MN
146void ff_put_string(PutBitContext * pbc, const char *s, int put_zero);
147void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length);
caa336b4
MN
148
149/* bit input */
150/* buffer, buffer_end and size_in_bits must be present and used by every reader */
151typedef struct GetBitContext {
152 const uint8_t *buffer, *buffer_end;
153#ifdef ALT_BITSTREAM_READER
154 int index;
155#elif defined LIBMPEG2_BITSTREAM_READER
156 uint8_t *buffer_ptr;
157 uint32_t cache;
158 int bit_count;
159#elif defined A32_BITSTREAM_READER
160 uint32_t *buffer_ptr;
161 uint32_t cache0;
162 uint32_t cache1;
163 int bit_count;
164#endif
165 int size_in_bits;
166} GetBitContext;
167
168#define VLC_TYPE int16_t
169
170typedef struct VLC {
171 int bits;
172 VLC_TYPE (*table)[2]; ///< code, bits
173 int table_size, table_allocated;
174} VLC;
175
176typedef struct RL_VLC_ELEM {
177 int16_t level;
178 int8_t len;
179 uint8_t run;
180} RL_VLC_ELEM;
181
caa336b4
MN
182#ifndef ALT_BITSTREAM_WRITER
183static inline void put_bits(PutBitContext *s, int n, unsigned int value)
184{
185 unsigned int bit_buf;
186 int bit_left;
187
caa336b4
MN
188 // printf("put_bits=%d %x\n", n, value);
189 assert(n == 32 || value < (1U << n));
115329f1 190
caa336b4
MN
191 bit_buf = s->bit_buf;
192 bit_left = s->bit_left;
193
194 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf);
195 /* XXX: optimize */
85803144
BW
196#ifdef BITSTREAM_WRITER_LE
197 bit_buf |= value << (32 - bit_left);
198 if (n >= bit_left) {
b250f9c6 199#if !HAVE_FAST_UNALIGNED
85803144 200 if (3 & (intptr_t) s->buf_ptr) {
724cc2df 201 AV_WL32(s->buf_ptr, bit_buf);
85803144
BW
202 } else
203#endif
204 *(uint32_t *)s->buf_ptr = le2me_32(bit_buf);
205 s->buf_ptr+=4;
206 bit_buf = (bit_left==32)?0:value >> bit_left;
207 bit_left+=32;
208 }
209 bit_left-=n;
210#else
caa336b4
MN
211 if (n < bit_left) {
212 bit_buf = (bit_buf<<n) | value;
213 bit_left-=n;
214 } else {
bb270c08 215 bit_buf<<=bit_left;
caa336b4 216 bit_buf |= value >> (n - bit_left);
b250f9c6 217#if !HAVE_FAST_UNALIGNED
caa336b4 218 if (3 & (intptr_t) s->buf_ptr) {
724cc2df 219 AV_WB32(s->buf_ptr, bit_buf);
caa336b4
MN
220 } else
221#endif
222 *(uint32_t *)s->buf_ptr = be2me_32(bit_buf);
223 //printf("bitbuf = %08x\n", bit_buf);
224 s->buf_ptr+=4;
bb270c08 225 bit_left+=32 - n;
caa336b4
MN
226 bit_buf = value;
227 }
85803144 228#endif
caa336b4
MN
229
230 s->bit_buf = bit_buf;
231 s->bit_left = bit_left;
232}
233#endif
234
235
236#ifdef ALT_BITSTREAM_WRITER
237static inline void put_bits(PutBitContext *s, int n, unsigned int value)
238{
239# ifdef ALIGNED_BITSTREAM_WRITER
b250f9c6 240# if ARCH_X86
be449fca 241 __asm__ volatile(
bb270c08
DB
242 "movl %0, %%ecx \n\t"
243 "xorl %%eax, %%eax \n\t"
244 "shrdl %%cl, %1, %%eax \n\t"
245 "shrl %%cl, %1 \n\t"
246 "movl %0, %%ecx \n\t"
247 "shrl $3, %%ecx \n\t"
248 "andl $0xFFFFFFFC, %%ecx \n\t"
249 "bswapl %1 \n\t"
250 "orl %1, (%2, %%ecx) \n\t"
251 "bswapl %%eax \n\t"
252 "addl %3, %0 \n\t"
253 "movl %%eax, 4(%2, %%ecx) \n\t"
254 : "=&r" (s->index), "=&r" (value)
255 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n))
256 : "%eax", "%ecx"
caa336b4
MN
257 );
258# else
259 int index= s->index;
260 uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
115329f1
DB
261
262 value<<= 32-n;
263
caa336b4
MN
264 ptr[0] |= be2me_32(value>>(index&31));
265 ptr[1] = be2me_32(value<<(32-(index&31)));
266//if(n>24) printf("%d %d\n", n, value);
267 index+= n;
268 s->index= index;
269# endif
270# else //ALIGNED_BITSTREAM_WRITER
b250f9c6 271# if ARCH_X86
be449fca 272 __asm__ volatile(
bb270c08
DB
273 "movl $7, %%ecx \n\t"
274 "andl %0, %%ecx \n\t"
275 "addl %3, %%ecx \n\t"
276 "negl %%ecx \n\t"
277 "shll %%cl, %1 \n\t"
278 "bswapl %1 \n\t"
279 "movl %0, %%ecx \n\t"
280 "shrl $3, %%ecx \n\t"
281 "orl %1, (%%ecx, %2) \n\t"
282 "addl %3, %0 \n\t"
283 "movl $0, 4(%%ecx, %2) \n\t"
284 : "=&r" (s->index), "=&r" (value)
285 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value)
286 : "%ecx"
caa336b4
MN
287 );
288# else
289 int index= s->index;
290 uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3));
115329f1 291
caa336b4
MN
292 ptr[0] |= be2me_32(value<<(32-n-(index&7) ));
293 ptr[1] = 0;
294//if(n>24) printf("%d %d\n", n, value);
295 index+= n;
296 s->index= index;
297# endif
298# endif //!ALIGNED_BITSTREAM_WRITER
299}
300#endif
301
6647ab80
RP
302static inline void put_sbits(PutBitContext *pb, int bits, int32_t val)
303{
304 assert(bits >= 0 && bits <= 31);
305
306 put_bits(pb, bits, val & ((1<<bits)-1));
307}
308
caa336b4
MN
309
310static inline uint8_t* pbBufPtr(PutBitContext *s)
311{
312#ifdef ALT_BITSTREAM_WRITER
bb270c08 313 return s->buf + (s->index>>3);
caa336b4 314#else
bb270c08 315 return s->buf_ptr;
caa336b4
MN
316#endif
317}
318
319/**
320 *
321 * PutBitContext must be flushed & aligned to a byte boundary before calling this.
322 */
323static inline void skip_put_bytes(PutBitContext *s, int n){
324 assert((put_bits_count(s)&7)==0);
325#ifdef ALT_BITSTREAM_WRITER
326 FIXME may need some cleaning of the buffer
bb270c08 327 s->index += n<<3;
caa336b4
MN
328#else
329 assert(s->bit_left==32);
bb270c08 330 s->buf_ptr += n;
115329f1 331#endif
caa336b4
MN
332}
333
334/**
755bfeab
DB
335 * Skips the given number of bits.
336 * Must only be used if the actual values in the bitstream do not matter.
1b781f82
MN
337 */
338static inline void skip_put_bits(PutBitContext *s, int n){
339#ifdef ALT_BITSTREAM_WRITER
340 s->index += n;
341#else
342 s->bit_left -= n;
343 s->buf_ptr-= s->bit_left>>5;
344 s->bit_left &= 31;
115329f1 345#endif
1b781f82
MN
346}
347
348/**
caa336b4
MN
349 * Changes the end of the buffer.
350 */
351static inline void set_put_bits_buffer_size(PutBitContext *s, int size){
352 s->buf_end= s->buf + size;
353}
354
355/* Bitstream reader API docs:
356name
7a7c4a7b 357 arbitrary name which is used as prefix for the internal variables
caa336b4
MN
358
359gb
360 getbitcontext
361
362OPEN_READER(name, gb)
363 loads gb into local variables
364
365CLOSE_READER(name, gb)
366 stores local vars in gb
367
368UPDATE_CACHE(name, gb)
369 refills the internal cache from the bitstream
370 after this call at least MIN_CACHE_BITS will be available,
371
372GET_CACHE(name, gb)
373 will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
374
375SHOW_UBITS(name, gb, num)
bb628dae 376 will return the next num bits
caa336b4
MN
377
378SHOW_SBITS(name, gb, num)
bb628dae 379 will return the next num bits and do sign extension
caa336b4
MN
380
381SKIP_BITS(name, gb, num)
382 will skip over the next num bits
bb628dae 383 note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
caa336b4
MN
384
385SKIP_CACHE(name, gb, num)
386 will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
387
388SKIP_COUNTER(name, gb, num)
389 will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
390
391LAST_SKIP_CACHE(name, gb, num)
392 will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
393
394LAST_SKIP_BITS(name, gb, num)
bb628dae 395 is equivalent to SKIP_LAST_CACHE; SKIP_COUNTER
caa336b4
MN
396
397for examples see get_bits, show_bits, skip_bits, get_vlc
398*/
399
caa336b4
MN
400#ifdef ALT_BITSTREAM_READER
401# define MIN_CACHE_BITS 25
402
403# define OPEN_READER(name, gb)\
404 int name##_index= (gb)->index;\
405 int name##_cache= 0;\
406
407# define CLOSE_READER(name, gb)\
408 (gb)->index= name##_index;\
409
cea27ac7
MN
410# ifdef ALT_BITSTREAM_READER_LE
411# define UPDATE_CACHE(name, gb)\
67c1b32f 412 name##_cache= AV_RL32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
cea27ac7
MN
413
414# define SKIP_CACHE(name, gb, num)\
415 name##_cache >>= (num);
416# else
caa336b4 417# define UPDATE_CACHE(name, gb)\
67c1b32f 418 name##_cache= AV_RB32( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
caa336b4
MN
419
420# define SKIP_CACHE(name, gb, num)\
cea27ac7
MN
421 name##_cache <<= (num);
422# endif
caa336b4
MN
423
424// FIXME name?
425# define SKIP_COUNTER(name, gb, num)\
426 name##_index += (num);\
427
428# define SKIP_BITS(name, gb, num)\
429 {\
430 SKIP_CACHE(name, gb, num)\
431 SKIP_COUNTER(name, gb, num)\
432 }\
433
434# define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
435# define LAST_SKIP_CACHE(name, gb, num) ;
436
cea27ac7
MN
437# ifdef ALT_BITSTREAM_READER_LE
438# define SHOW_UBITS(name, gb, num)\
439 ((name##_cache) & (NEG_USR32(0xffffffff,num)))
7da4d4cd
GM
440
441# define SHOW_SBITS(name, gb, num)\
442 NEG_SSR32((name##_cache)<<(32-(num)), num)
cea27ac7 443# else
caa336b4
MN
444# define SHOW_UBITS(name, gb, num)\
445 NEG_USR32(name##_cache, num)
446
447# define SHOW_SBITS(name, gb, num)\
448 NEG_SSR32(name##_cache, num)
7da4d4cd 449# endif
caa336b4
MN
450
451# define GET_CACHE(name, gb)\
452 ((uint32_t)name##_cache)
453
454static inline int get_bits_count(GetBitContext *s){
455 return s->index;
456}
5a7bd283
MN
457
458static inline void skip_bits_long(GetBitContext *s, int n){
6e4703ca 459 s->index += n;
5a7bd283
MN
460}
461
caa336b4
MN
462#elif defined LIBMPEG2_BITSTREAM_READER
463//libmpeg2 like reader
464
465# define MIN_CACHE_BITS 17
466
467# define OPEN_READER(name, gb)\
468 int name##_bit_count=(gb)->bit_count;\
469 int name##_cache= (gb)->cache;\
470 uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
471
472# define CLOSE_READER(name, gb)\
473 (gb)->bit_count= name##_bit_count;\
474 (gb)->cache= name##_cache;\
475 (gb)->buffer_ptr= name##_buffer_ptr;\
476
caa336b4
MN
477# define UPDATE_CACHE(name, gb)\
478 if(name##_bit_count >= 0){\
71c465a1 479 name##_cache+= AV_RB16(name##_buffer_ptr) << name##_bit_count; \
caa336b4
MN
480 name##_buffer_ptr+=2;\
481 name##_bit_count-= 16;\
482 }\
483
caa336b4
MN
484# define SKIP_CACHE(name, gb, num)\
485 name##_cache <<= (num);\
486
487# define SKIP_COUNTER(name, gb, num)\
488 name##_bit_count += (num);\
489
490# define SKIP_BITS(name, gb, num)\
491 {\
492 SKIP_CACHE(name, gb, num)\
493 SKIP_COUNTER(name, gb, num)\
494 }\
495
496# define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
497# define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
498
499# define SHOW_UBITS(name, gb, num)\
500 NEG_USR32(name##_cache, num)
501
502# define SHOW_SBITS(name, gb, num)\
503 NEG_SSR32(name##_cache, num)
504
505# define GET_CACHE(name, gb)\
506 ((uint32_t)name##_cache)
507
508static inline int get_bits_count(GetBitContext *s){
509 return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
510}
511
6e4703ca
MN
512static inline void skip_bits_long(GetBitContext *s, int n){
513 OPEN_READER(re, s)
514 re_bit_count += n;
515 re_buffer_ptr += 2*(re_bit_count>>4);
516 re_bit_count &= 15;
517 re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count);
518 UPDATE_CACHE(re, s)
519 CLOSE_READER(re, s)
520}
521
caa336b4
MN
522#elif defined A32_BITSTREAM_READER
523
524# define MIN_CACHE_BITS 32
525
526# define OPEN_READER(name, gb)\
527 int name##_bit_count=(gb)->bit_count;\
528 uint32_t name##_cache0= (gb)->cache0;\
529 uint32_t name##_cache1= (gb)->cache1;\
530 uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
531
532# define CLOSE_READER(name, gb)\
533 (gb)->bit_count= name##_bit_count;\
534 (gb)->cache0= name##_cache0;\
535 (gb)->cache1= name##_cache1;\
536 (gb)->buffer_ptr= name##_buffer_ptr;\
537
538# define UPDATE_CACHE(name, gb)\
539 if(name##_bit_count > 0){\
540 const uint32_t next= be2me_32( *name##_buffer_ptr );\
541 name##_cache0 |= NEG_USR32(next,name##_bit_count);\
542 name##_cache1 |= next<<name##_bit_count;\
543 name##_buffer_ptr++;\
544 name##_bit_count-= 32;\
545 }\
546
b250f9c6 547#if ARCH_X86
caa336b4 548# define SKIP_CACHE(name, gb, num)\
be449fca 549 __asm__(\
bb270c08
DB
550 "shldl %2, %1, %0 \n\t"\
551 "shll %2, %1 \n\t"\
caa336b4 552 : "+r" (name##_cache0), "+r" (name##_cache1)\
6ff3b2b8 553 : "Ic" ((uint8_t)(num))\
caa336b4
MN
554 );
555#else
556# define SKIP_CACHE(name, gb, num)\
557 name##_cache0 <<= (num);\
558 name##_cache0 |= NEG_USR32(name##_cache1,num);\
559 name##_cache1 <<= (num);
560#endif
561
562# define SKIP_COUNTER(name, gb, num)\
563 name##_bit_count += (num);\
564
565# define SKIP_BITS(name, gb, num)\
566 {\
567 SKIP_CACHE(name, gb, num)\
568 SKIP_COUNTER(name, gb, num)\
569 }\
570
571# define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
572# define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
573
574# define SHOW_UBITS(name, gb, num)\
575 NEG_USR32(name##_cache0, num)
576
577# define SHOW_SBITS(name, gb, num)\
578 NEG_SSR32(name##_cache0, num)
579
580# define GET_CACHE(name, gb)\
581 (name##_cache0)
582
583static inline int get_bits_count(GetBitContext *s){
584 return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
585}
586
5a7bd283
MN
587static inline void skip_bits_long(GetBitContext *s, int n){
588 OPEN_READER(re, s)
589 re_bit_count += n;
3dddf21f 590 re_buffer_ptr += re_bit_count>>5;
5a7bd283 591 re_bit_count &= 31;
1491e21c
MN
592 re_cache0 = be2me_32( re_buffer_ptr[-1] ) << re_bit_count;
593 re_cache1 = 0;
5a7bd283 594 UPDATE_CACHE(re, s)
5a7bd283
MN
595 CLOSE_READER(re, s)
596}
597
caa336b4
MN
598#endif
599
600/**
601 * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
115329f1 602 * if MSB not set it is negative
caa336b4 603 * @param n length in bits
115329f1 604 * @author BERO
caa336b4
MN
605 */
606static inline int get_xbits(GetBitContext *s, int n){
6b250e47 607 register int sign;
caa336b4
MN
608 register int32_t cache;
609 OPEN_READER(re, s)
610 UPDATE_CACHE(re, s)
611 cache = GET_CACHE(re,s);
6b250e47 612 sign=(~cache)>>31;
caa336b4
MN
613 LAST_SKIP_BITS(re, s, n)
614 CLOSE_READER(re, s)
6b250e47 615 return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
caa336b4
MN
616}
617
618static inline int get_sbits(GetBitContext *s, int n){
619 register int tmp;
620 OPEN_READER(re, s)
621 UPDATE_CACHE(re, s)
622 tmp= SHOW_SBITS(re, s, n);
623 LAST_SKIP_BITS(re, s, n)
624 CLOSE_READER(re, s)
625 return tmp;
626}
627
628/**
0ac47d63 629 * reads 1-17 bits.
bb628dae 630 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
caa336b4
MN
631 */
632static inline unsigned int get_bits(GetBitContext *s, int n){
633 register int tmp;
634 OPEN_READER(re, s)
635 UPDATE_CACHE(re, s)
636 tmp= SHOW_UBITS(re, s, n);
637 LAST_SKIP_BITS(re, s, n)
638 CLOSE_READER(re, s)
639 return tmp;
640}
641
caa336b4 642/**
0ac47d63 643 * shows 1-17 bits.
bb628dae 644 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
caa336b4
MN
645 */
646static inline unsigned int show_bits(GetBitContext *s, int n){
647 register int tmp;
648 OPEN_READER(re, s)
649 UPDATE_CACHE(re, s)
650 tmp= SHOW_UBITS(re, s, n);
651// CLOSE_READER(re, s)
652 return tmp;
653}
654
caa336b4
MN
655static inline void skip_bits(GetBitContext *s, int n){
656 //Note gcc seems to optimize this to s->index+=n for the ALT_READER :))
657 OPEN_READER(re, s)
658 UPDATE_CACHE(re, s)
659 LAST_SKIP_BITS(re, s, n)
660 CLOSE_READER(re, s)
661}
662
663static inline unsigned int get_bits1(GetBitContext *s){
664#ifdef ALT_BITSTREAM_READER
665 int index= s->index;
666 uint8_t result= s->buffer[ index>>3 ];
cea27ac7
MN
667#ifdef ALT_BITSTREAM_READER_LE
668 result>>= (index&0x07);
669 result&= 1;
670#else
caa336b4
MN
671 result<<= (index&0x07);
672 result>>= 8 - 1;
cea27ac7 673#endif
caa336b4
MN
674 index++;
675 s->index= index;
676
677 return result;
678#else
679 return get_bits(s, 1);
680#endif
681}
682
683static inline unsigned int show_bits1(GetBitContext *s){
684 return show_bits(s, 1);
685}
686
687static inline void skip_bits1(GetBitContext *s){
688 skip_bits(s, 1);
689}
690
691/**
8fbc6aae
AJ
692 * reads 0-32 bits.
693 */
694static inline unsigned int get_bits_long(GetBitContext *s, int n){
695 if(n<=17) return get_bits(s, n);
696 else{
d1121caa
RD
697#ifdef ALT_BITSTREAM_READER_LE
698 int ret= get_bits(s, 16);
699 return ret | (get_bits(s, n-16) << 16);
700#else
8fbc6aae
AJ
701 int ret= get_bits(s, 16) << (n-16);
702 return ret | get_bits(s, n-16);
d1121caa 703#endif
8fbc6aae
AJ
704 }
705}
706
707/**
708 * shows 0-32 bits.
709 */
710static inline unsigned int show_bits_long(GetBitContext *s, int n){
711 if(n<=17) return show_bits(s, n);
712 else{
713 GetBitContext gb= *s;
714 int ret= get_bits_long(s, n);
715 *s= gb;
716 return ret;
717 }
718}
719
720static inline int check_marker(GetBitContext *s, const char *msg)
721{
722 int bit= get_bits1(s);
723 if(!bit)
724 av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
725
726 return bit;
727}
728
729/**
caa336b4
MN
730 * init GetBitContext.
731 * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
732 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
733 * @param bit_size the size of the buffer in bits
734 */
735static inline void init_get_bits(GetBitContext *s,
736 const uint8_t *buffer, int bit_size)
737{
9061be9f 738 int buffer_size= (bit_size+7)>>3;
288f1e68
MB
739 if(buffer_size < 0 || bit_size < 0) {
740 buffer_size = bit_size = 0;
741 buffer = NULL;
742 }
caa336b4
MN
743
744 s->buffer= buffer;
745 s->size_in_bits= bit_size;
746 s->buffer_end= buffer + buffer_size;
747#ifdef ALT_BITSTREAM_READER
748 s->index=0;
749#elif defined LIBMPEG2_BITSTREAM_READER
6e4703ca
MN
750 s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));
751 s->bit_count = 16 + 8*((intptr_t)buffer&1);
752 skip_bits_long(s, 0);
a42ec9f4
MN
753#elif defined A32_BITSTREAM_READER
754 s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));
755 s->bit_count = 32 + 8*((intptr_t)buffer&3);
756 skip_bits_long(s, 0);
caa336b4
MN
757#endif
758}
759
ae5e7e7f 760static inline void align_get_bits(GetBitContext *s)
5a7bd283
MN
761{
762 int n= (-get_bits_count(s)) & 7;
763 if(n) skip_bits(s, n);
764}
765
b613bacc
LM
766#define init_vlc(vlc, nb_bits, nb_codes,\
767 bits, bits_wrap, bits_size,\
768 codes, codes_wrap, codes_size,\
769 flags)\
770 init_vlc_sparse(vlc, nb_bits, nb_codes,\
771 bits, bits_wrap, bits_size,\
772 codes, codes_wrap, codes_size,\
773 NULL, 0, 0, flags)
774
775int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
caa336b4
MN
776 const void *bits, int bits_wrap, int bits_size,
777 const void *codes, int codes_wrap, int codes_size,
b613bacc 778 const void *symbols, int symbols_wrap, int symbols_size,
cea27ac7 779 int flags);
ccc54864 780#define INIT_VLC_USE_STATIC 1 ///< VERY strongly deprecated and forbidden
cea27ac7 781#define INIT_VLC_LE 2
ccc54864 782#define INIT_VLC_USE_NEW_STATIC 4
caa336b4
MN
783void free_vlc(VLC *vlc);
784
d05b24ff
MN
785#define INIT_VLC_STATIC(vlc, bits, a,b,c,d,e,f,g, static_size)\
786{\
787 static VLC_TYPE table[static_size][2];\
788 (vlc)->table= table;\
789 (vlc)->table_allocated= static_size;\
790 init_vlc(vlc, bits, a,b,c,d,e,f,g, INIT_VLC_USE_NEW_STATIC);\
791}
792
793
caa336b4
MN
794/**
795 *
796 * if the vlc code is invalid and max_depth=1 than no bits will be removed
797 * if the vlc code is invalid and max_depth>1 than the number of bits removed
798 * is undefined
799 */
800#define GET_VLC(code, name, gb, table, bits, max_depth)\
801{\
802 int n, index, nb_bits;\
803\
804 index= SHOW_UBITS(name, gb, bits);\
805 code = table[index][0];\
806 n = table[index][1];\
807\
808 if(max_depth > 1 && n < 0){\
809 LAST_SKIP_BITS(name, gb, bits)\
810 UPDATE_CACHE(name, gb)\
811\
812 nb_bits = -n;\
813\
814 index= SHOW_UBITS(name, gb, nb_bits) + code;\
815 code = table[index][0];\
816 n = table[index][1];\
817 if(max_depth > 2 && n < 0){\
818 LAST_SKIP_BITS(name, gb, nb_bits)\
819 UPDATE_CACHE(name, gb)\
820\
821 nb_bits = -n;\
822\
823 index= SHOW_UBITS(name, gb, nb_bits) + code;\
824 code = table[index][0];\
825 n = table[index][1];\
826 }\
827 }\
828 SKIP_BITS(name, gb, n)\
829}
830
e91f4bf1 831#define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
caa336b4
MN
832{\
833 int n, index, nb_bits;\
834\
835 index= SHOW_UBITS(name, gb, bits);\
836 level = table[index].level;\
837 n = table[index].len;\
838\
839 if(max_depth > 1 && n < 0){\
e91f4bf1
MN
840 SKIP_BITS(name, gb, bits)\
841 if(need_update){\
842 UPDATE_CACHE(name, gb)\
843 }\
caa336b4
MN
844\
845 nb_bits = -n;\
846\
847 index= SHOW_UBITS(name, gb, nb_bits) + level;\
848 level = table[index].level;\
849 n = table[index].len;\
850 }\
851 run= table[index].run;\
852 SKIP_BITS(name, gb, n)\
853}
854
caa336b4
MN
855
856/**
857 * parses a vlc code, faster then get_vlc()
115329f1 858 * @param bits is the number of bits which will be read at once, must be
caa336b4 859 * identical to nb_bits in init_vlc()
e42dba48 860 * @param max_depth is the number of times bits bits must be read to completely
115329f1 861 * read the longest vlc code
caa336b4
MN
862 * = (max_vlc_length + bits - 1) / bits
863 */
849f1035 864static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
caa336b4
MN
865 int bits, int max_depth)
866{
867 int code;
115329f1 868
caa336b4
MN
869 OPEN_READER(re, s)
870 UPDATE_CACHE(re, s)
871
872 GET_VLC(code, re, s, table, bits, max_depth)
873
874 CLOSE_READER(re, s)
875 return code;
876}
877
878//#define TRACE
879
880#ifdef TRACE
caa336b4
MN
881static inline void print_bin(int bits, int n){
882 int i;
115329f1 883
caa336b4 884 for(i=n-1; i>=0; i--){
61f040dd 885 av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
caa336b4
MN
886 }
887 for(i=n; i<24; i++)
61f040dd 888 av_log(NULL, AV_LOG_DEBUG, " ");
caa336b4
MN
889}
890
61f040dd 891static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
caa336b4 892 int r= get_bits(s, n);
115329f1 893
caa336b4 894 print_bin(r, n);
61f040dd 895 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
896 return r;
897}
61f040dd 898static 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
899 int show= show_bits(s, 24);
900 int pos= get_bits_count(s);
901 int r= get_vlc2(s, table, bits, max_depth);
902 int len= get_bits_count(s) - pos;
903 int bits2= show>>(24-len);
115329f1 904
caa336b4 905 print_bin(bits2, len);
115329f1 906
61f040dd 907 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
908 return r;
909}
61f040dd 910static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
caa336b4
MN
911 int show= show_bits(s, n);
912 int r= get_xbits(s, n);
115329f1 913
caa336b4 914 print_bin(show, n);
61f040dd 915 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
916 return r;
917}
918
919#define get_bits(s, n) get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
920#define get_bits1(s) get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
921#define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
922#define get_vlc(s, vlc) get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
923#define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
924
a9c9a240 925#define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
caa336b4
MN
926
927#else //TRACE
a9c9a240 928#define tprintf(p, ...) {}
caa336b4
MN
929#endif
930
7d8b13b4 931static inline int decode012(GetBitContext *gb){
a64a006e
MN
932 int n;
933 n = get_bits1(gb);
934 if (n == 0)
935 return 0;
936 else
937 return get_bits1(gb) + 1;
938}
939
b44665c4
KS
940static inline int decode210(GetBitContext *gb){
941 if (get_bits1(gb))
942 return 0;
943 else
944 return 2 - get_bits1(gb);
945}
946
98790382 947#endif /* AVCODEC_BITSTREAM_H */