Comment unused code in libmad. Clean up initialization and memset'ing of decoder...
[kugel-rb.git] / apps / codecs / libwma / bitstream.h
blob782991959363b8625fd96588387fff8b351f137d
1 /*
2 * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
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.
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.
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
21 /**
22 * @file bitstream.h
23 * bitstream api header.
26 #ifndef BITSTREAM_H
27 #define BITSTREAM_H
29 #define av_always_inline inline
30 #define attribute_deprecated
32 #include <inttypes.h>
33 #include "ffmpeg_config.h"
34 #include <stdlib.h>
36 #include "ffmpeg_bswap.h"
38 //#include "log.h"
40 #if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
41 #define ALT_BITSTREAM_READER
42 #endif
44 //#define ALT_BITSTREAM_WRITER
45 //#define ALIGNED_BITSTREAM_WRITER
46 #if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER)
47 # ifdef ARCH_ARMV4L
48 # define A32_BITSTREAM_READER
49 # else
50 #define ALT_BITSTREAM_READER
51 //#define LIBMPEG2_BITSTREAM_READER
52 //#define A32_BITSTREAM_READER
53 # endif
54 #endif
55 #define LIBMPEG2_BITSTREAM_READER_HACK //add BERO
57 extern const uint8_t ff_reverse[256];
59 #if defined(ARCH_X86)
60 // avoid +32 for shift optimization (gcc should do that ...)
61 static inline int32_t NEG_SSR32( int32_t a, int8_t s){
62 asm ("sarl %1, %0\n\t"
63 : "+r" (a)
64 : "ic" ((uint8_t)(-s))
66 return a;
68 static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
69 asm ("shrl %1, %0\n\t"
70 : "+r" (a)
71 : "ic" ((uint8_t)(-s))
73 return a;
75 #else
76 # define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
77 # define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
78 #endif
80 /* bit output */
82 /* buf and buf_end must be present and used by every alternative writer. */
83 typedef struct PutBitContext {
84 #ifdef ALT_BITSTREAM_WRITER
85 uint8_t *buf, *buf_end;
86 int index;
87 #else
88 uint32_t bit_buf;
89 int bit_left;
90 uint8_t *buf, *buf_ptr, *buf_end;
91 #endif
92 } PutBitContext;
94 static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
96 if(buffer_size < 0) {
97 buffer_size = 0;
98 buffer = NULL;
101 s->buf = buffer;
102 s->buf_end = s->buf + buffer_size;
103 #ifdef ALT_BITSTREAM_WRITER
104 s->index=0;
105 ((uint32_t*)(s->buf))[0]=0;
106 // memset(buffer, 0, buffer_size);
107 #else
108 s->buf_ptr = s->buf;
109 s->bit_left=32;
110 s->bit_buf=0;
111 #endif
114 /* return the number of bits output */
115 static inline int put_bits_count(PutBitContext *s)
117 #ifdef ALT_BITSTREAM_WRITER
118 return s->index;
119 #else
120 return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left;
121 #endif
124 /* pad the end of the output stream with zeros */
125 static inline void flush_put_bits(PutBitContext *s)
127 #ifdef ALT_BITSTREAM_WRITER
128 align_put_bits(s);
129 #else
130 s->bit_buf<<= s->bit_left;
131 while (s->bit_left < 32) {
132 /* XXX: should test end of buffer */
133 *s->buf_ptr++=s->bit_buf >> 24;
134 s->bit_buf<<=8;
135 s->bit_left+=8;
137 s->bit_left=32;
138 s->bit_buf=0;
139 #endif
142 void align_put_bits(PutBitContext *s);
143 void ff_put_string(PutBitContext * pbc, char *s, int put_zero);
145 /* bit input */
146 /* buffer, buffer_end and size_in_bits must be present and used by every reader */
147 typedef struct GetBitContext {
148 const uint8_t *buffer, *buffer_end;
149 #ifdef ALT_BITSTREAM_READER
150 int index;
151 #elif defined LIBMPEG2_BITSTREAM_READER
152 uint8_t *buffer_ptr;
153 uint32_t cache;
154 int bit_count;
155 #elif defined A32_BITSTREAM_READER
156 uint32_t *buffer_ptr;
157 uint32_t cache0;
158 uint32_t cache1;
159 int bit_count;
160 #endif
161 int size_in_bits;
162 } GetBitContext;
164 #define VLC_TYPE int16_t
166 typedef struct VLC {
167 int bits;
168 VLC_TYPE (*table)[2]; ///< code, bits
169 int table_size, table_allocated;
170 } VLC;
172 typedef struct RL_VLC_ELEM {
173 int16_t level;
174 int8_t len;
175 uint8_t run;
176 } RL_VLC_ELEM;
178 #if defined(ARCH_SPARC) || defined(ARCH_ARMV4L) || defined(ARCH_MIPS) || defined(ARCH_BFIN)
179 #define UNALIGNED_STORES_ARE_BAD
180 #endif
182 /* used to avoid missaligned exceptions on some archs (alpha, ...) */
183 #if defined(ARCH_X86) || defined(CPU_COLDFIRE)
184 # define unaligned16(a) (*(const uint16_t*)(a))
185 # define unaligned32(a) (*(const uint32_t*)(a))
186 # define unaligned64(a) (*(const uint64_t*)(a))
187 #else
188 # ifdef __GNUC__
189 # define unaligned(x) \
190 static inline uint##x##_t unaligned##x(const void *v) { \
191 struct Unaligned { \
192 uint##x##_t i; \
193 } __attribute__((packed)); \
195 return ((const struct Unaligned *) v)->i; \
197 # elif defined(__DECC)
198 # define unaligned(x) \
199 static inline uint##x##_t unaligned##x(const void *v) { \
200 return *(const __unaligned uint##x##_t *) v; \
202 # else
203 # define unaligned(x) \
204 static inline uint##x##_t unaligned##x(const void *v) { \
205 return *(const uint##x##_t *) v; \
207 # endif
208 unaligned(16)
209 unaligned(32)
210 unaligned(64)
211 #undef unaligned
212 #endif /* defined(ARCH_X86) */
214 #ifndef ALT_BITSTREAM_WRITER
215 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
217 unsigned int bit_buf;
218 int bit_left;
220 // printf("put_bits=%d %x\n", n, value);
221 // assert(n == 32 || value < (1U << n));
223 bit_buf = s->bit_buf;
224 bit_left = s->bit_left;
226 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf);
227 /* XXX: optimize */
228 if (n < bit_left) {
229 bit_buf = (bit_buf<<n) | value;
230 bit_left-=n;
231 } else {
232 bit_buf<<=bit_left;
233 bit_buf |= value >> (n - bit_left);
234 #ifdef UNALIGNED_STORES_ARE_BAD
235 if (3 & (intptr_t) s->buf_ptr) {
236 s->buf_ptr[0] = bit_buf >> 24;
237 s->buf_ptr[1] = bit_buf >> 16;
238 s->buf_ptr[2] = bit_buf >> 8;
239 s->buf_ptr[3] = bit_buf ;
240 } else
241 #endif
242 *(uint32_t *)s->buf_ptr = be2me_32(bit_buf);
243 //printf("bitbuf = %08x\n", bit_buf);
244 s->buf_ptr+=4;
245 bit_left+=32 - n;
246 bit_buf = value;
249 s->bit_buf = bit_buf;
250 s->bit_left = bit_left;
252 #endif
255 #ifdef ALT_BITSTREAM_WRITER
256 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
258 # ifdef ALIGNED_BITSTREAM_WRITER
259 # if defined(ARCH_X86)
260 asm volatile(
261 "movl %0, %%ecx \n\t"
262 "xorl %%eax, %%eax \n\t"
263 "shrdl %%cl, %1, %%eax \n\t"
264 "shrl %%cl, %1 \n\t"
265 "movl %0, %%ecx \n\t"
266 "shrl $3, %%ecx \n\t"
267 "andl $0xFFFFFFFC, %%ecx \n\t"
268 "bswapl %1 \n\t"
269 "orl %1, (%2, %%ecx) \n\t"
270 "bswapl %%eax \n\t"
271 "addl %3, %0 \n\t"
272 "movl %%eax, 4(%2, %%ecx) \n\t"
273 : "=&r" (s->index), "=&r" (value)
274 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n))
275 : "%eax", "%ecx"
277 # else
278 int index= s->index;
279 uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
281 value<<= 32-n;
283 ptr[0] |= be2me_32(value>>(index&31));
284 ptr[1] = be2me_32(value<<(32-(index&31)));
285 //if(n>24) printf("%d %d\n", n, value);
286 index+= n;
287 s->index= index;
288 # endif
289 # else //ALIGNED_BITSTREAM_WRITER
290 # if defined(ARCH_X86)
291 asm volatile(
292 "movl $7, %%ecx \n\t"
293 "andl %0, %%ecx \n\t"
294 "addl %3, %%ecx \n\t"
295 "negl %%ecx \n\t"
296 "shll %%cl, %1 \n\t"
297 "bswapl %1 \n\t"
298 "movl %0, %%ecx \n\t"
299 "shrl $3, %%ecx \n\t"
300 "orl %1, (%%ecx, %2) \n\t"
301 "addl %3, %0 \n\t"
302 "movl $0, 4(%%ecx, %2) \n\t"
303 : "=&r" (s->index), "=&r" (value)
304 : "r" (s->buf), "r" (n), "0" (s->index), "1" (value)
305 : "%ecx"
307 # else
308 int index= s->index;
309 uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3));
311 ptr[0] |= be2me_32(value<<(32-n-(index&7) ));
312 ptr[1] = 0;
313 //if(n>24) printf("%d %d\n", n, value);
314 index+= n;
315 s->index= index;
316 # endif
317 # endif //!ALIGNED_BITSTREAM_WRITER
319 #endif
322 static inline uint8_t* pbBufPtr(PutBitContext *s)
324 #ifdef ALT_BITSTREAM_WRITER
325 return s->buf + (s->index>>3);
326 #else
327 return s->buf_ptr;
328 #endif
333 * PutBitContext must be flushed & aligned to a byte boundary before calling this.
335 static inline void skip_put_bytes(PutBitContext *s, int n){
336 // assert((put_bits_count(s)&7)==0);
337 #ifdef ALT_BITSTREAM_WRITER
338 FIXME may need some cleaning of the buffer
339 s->index += n<<3;
340 #else
341 // assert(s->bit_left==32);
342 s->buf_ptr += n;
343 #endif
347 * skips the given number of bits.
348 * must only be used if the actual values in the bitstream dont matter
350 static inline void skip_put_bits(PutBitContext *s, int n){
351 #ifdef ALT_BITSTREAM_WRITER
352 s->index += n;
353 #else
354 s->bit_left -= n;
355 s->buf_ptr-= s->bit_left>>5;
356 s->bit_left &= 31;
357 #endif
361 * Changes the end of the buffer.
363 static inline void set_put_bits_buffer_size(PutBitContext *s, int size){
364 s->buf_end= s->buf + size;
367 /* Bitstream reader API docs:
368 name
369 abritary name which is used as prefix for the internal variables
372 getbitcontext
374 OPEN_READER(name, gb)
375 loads gb into local variables
377 CLOSE_READER(name, gb)
378 stores local vars in gb
380 UPDATE_CACHE(name, gb)
381 refills the internal cache from the bitstream
382 after this call at least MIN_CACHE_BITS will be available,
384 GET_CACHE(name, gb)
385 will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
387 SHOW_UBITS(name, gb, num)
388 will return the next num bits
390 SHOW_SBITS(name, gb, num)
391 will return the next num bits and do sign extension
393 SKIP_BITS(name, gb, num)
394 will skip over the next num bits
395 note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
397 SKIP_CACHE(name, gb, num)
398 will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
400 SKIP_COUNTER(name, gb, num)
401 will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
403 LAST_SKIP_CACHE(name, gb, num)
404 will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
406 LAST_SKIP_BITS(name, gb, num)
407 is equivalent to SKIP_LAST_CACHE; SKIP_COUNTER
409 for examples see get_bits, show_bits, skip_bits, get_vlc
412 static inline int unaligned32_be(const void *v)
414 #ifdef CONFIG_ALIGN
415 const uint8_t *p=v;
416 return (((p[0]<<8) | p[1])<<16) | (p[2]<<8) | (p[3]);
417 #else
418 return be2me_32( unaligned32(v)); //original
419 #endif
422 static inline int unaligned32_le(const void *v)
424 #ifdef CONFIG_ALIGN
425 const uint8_t *p=v;
426 return (((p[3]<<8) | p[2])<<16) | (p[1]<<8) | (p[0]);
427 #else
428 return le2me_32( unaligned32(v)); //original
429 #endif
432 #ifdef ALT_BITSTREAM_READER
433 # define MIN_CACHE_BITS 25
435 # define OPEN_READER(name, gb)\
436 int name##_index= (gb)->index;\
437 int name##_cache= 0;\
439 # define CLOSE_READER(name, gb)\
440 (gb)->index= name##_index;\
442 # ifdef ALT_BITSTREAM_READER_LE
443 # define UPDATE_CACHE(name, gb)\
444 name##_cache= unaligned32_le( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
446 # define SKIP_CACHE(name, gb, num)\
447 name##_cache >>= (num);
448 # else
449 # define UPDATE_CACHE(name, gb)\
450 name##_cache= unaligned32_be( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
452 # define SKIP_CACHE(name, gb, num)\
453 name##_cache <<= (num);
454 # endif
456 // FIXME name?
457 # define SKIP_COUNTER(name, gb, num)\
458 name##_index += (num);\
460 # define SKIP_BITS(name, gb, num)\
462 SKIP_CACHE(name, gb, num)\
463 SKIP_COUNTER(name, gb, num)\
466 # define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
467 # define LAST_SKIP_CACHE(name, gb, num) ;
469 # ifdef ALT_BITSTREAM_READER_LE
470 # define SHOW_UBITS(name, gb, num)\
471 ((name##_cache) & (NEG_USR32(0xffffffff,num)))
473 # define SHOW_SBITS(name, gb, num)\
474 NEG_SSR32((name##_cache)<<(32-(num)), num)
475 # else
476 # define SHOW_UBITS(name, gb, num)\
477 NEG_USR32(name##_cache, num)
479 # define SHOW_SBITS(name, gb, num)\
480 NEG_SSR32(name##_cache, num)
481 # endif
483 # define GET_CACHE(name, gb)\
484 ((uint32_t)name##_cache)
486 static inline int get_bits_count(GetBitContext *s){
487 return s->index;
490 static inline void skip_bits_long(GetBitContext *s, int n){
491 s->index += n;
494 #elif defined LIBMPEG2_BITSTREAM_READER
495 //libmpeg2 like reader
497 # define MIN_CACHE_BITS 17
499 # define OPEN_READER(name, gb)\
500 int name##_bit_count=(gb)->bit_count;\
501 int name##_cache= (gb)->cache;\
502 uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
504 # define CLOSE_READER(name, gb)\
505 (gb)->bit_count= name##_bit_count;\
506 (gb)->cache= name##_cache;\
507 (gb)->buffer_ptr= name##_buffer_ptr;\
509 #ifdef LIBMPEG2_BITSTREAM_READER_HACK
511 # define UPDATE_CACHE(name, gb)\
512 if(name##_bit_count >= 0){\
513 name##_cache+= (int)be2me_16(*(uint16_t*)name##_buffer_ptr) << name##_bit_count;\
514 name##_buffer_ptr += 2;\
515 name##_bit_count-= 16;\
518 #else
520 # define UPDATE_CACHE(name, gb)\
521 if(name##_bit_count >= 0){\
522 name##_cache+= ((name##_buffer_ptr[0]<<8) + name##_buffer_ptr[1]) << name##_bit_count;\
523 name##_buffer_ptr+=2;\
524 name##_bit_count-= 16;\
527 #endif
529 # define SKIP_CACHE(name, gb, num)\
530 name##_cache <<= (num);\
532 # define SKIP_COUNTER(name, gb, num)\
533 name##_bit_count += (num);\
535 # define SKIP_BITS(name, gb, num)\
537 SKIP_CACHE(name, gb, num)\
538 SKIP_COUNTER(name, gb, num)\
541 # define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
542 # define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
544 # define SHOW_UBITS(name, gb, num)\
545 NEG_USR32(name##_cache, num)
547 # define SHOW_SBITS(name, gb, num)\
548 NEG_SSR32(name##_cache, num)
550 # define GET_CACHE(name, gb)\
551 ((uint32_t)name##_cache)
553 static inline int get_bits_count(GetBitContext *s){
554 return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
557 static inline void skip_bits_long(GetBitContext *s, int n){
558 OPEN_READER(re, s)
559 re_bit_count += n;
560 re_buffer_ptr += 2*(re_bit_count>>4);
561 re_bit_count &= 15;
562 re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count);
563 UPDATE_CACHE(re, s)
564 CLOSE_READER(re, s)
567 #elif defined A32_BITSTREAM_READER
569 # define MIN_CACHE_BITS 32
571 # define OPEN_READER(name, gb)\
572 int name##_bit_count=(gb)->bit_count;\
573 uint32_t name##_cache0= (gb)->cache0;\
574 uint32_t name##_cache1= (gb)->cache1;\
575 uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
577 # define CLOSE_READER(name, gb)\
578 (gb)->bit_count= name##_bit_count;\
579 (gb)->cache0= name##_cache0;\
580 (gb)->cache1= name##_cache1;\
581 (gb)->buffer_ptr= name##_buffer_ptr;\
583 # define UPDATE_CACHE(name, gb)\
584 if(name##_bit_count > 0){\
585 const uint32_t next= be2me_32( *name##_buffer_ptr );\
586 name##_cache0 |= NEG_USR32(next,name##_bit_count);\
587 name##_cache1 |= next<<name##_bit_count;\
588 name##_buffer_ptr++;\
589 name##_bit_count-= 32;\
592 #if defined(ARCH_X86)
593 # define SKIP_CACHE(name, gb, num)\
594 asm(\
595 "shldl %2, %1, %0 \n\t"\
596 "shll %2, %1 \n\t"\
597 : "+r" (name##_cache0), "+r" (name##_cache1)\
598 : "Ic" ((uint8_t)(num))\
600 #else
601 # define SKIP_CACHE(name, gb, num)\
602 name##_cache0 <<= (num);\
603 name##_cache0 |= NEG_USR32(name##_cache1,num);\
604 name##_cache1 <<= (num);
605 #endif
607 # define SKIP_COUNTER(name, gb, num)\
608 name##_bit_count += (num);\
610 # define SKIP_BITS(name, gb, num)\
612 SKIP_CACHE(name, gb, num)\
613 SKIP_COUNTER(name, gb, num)\
616 # define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
617 # define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
619 # define SHOW_UBITS(name, gb, num)\
620 NEG_USR32(name##_cache0, num)
622 # define SHOW_SBITS(name, gb, num)\
623 NEG_SSR32(name##_cache0, num)
625 # define GET_CACHE(name, gb)\
626 (name##_cache0)
628 static inline int get_bits_count(GetBitContext *s){
629 return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
632 static inline void skip_bits_long(GetBitContext *s, int n){
633 OPEN_READER(re, s)
634 re_bit_count += n;
635 re_buffer_ptr += re_bit_count>>5;
636 re_bit_count &= 31;
637 re_cache0 = be2me_32( re_buffer_ptr[-1] ) << re_bit_count;
638 re_cache1 = 0;
639 UPDATE_CACHE(re, s)
640 CLOSE_READER(re, s)
643 #endif
646 * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
647 * if MSB not set it is negative
648 * @param n length in bits
649 * @author BERO
651 static inline int get_xbits(GetBitContext *s, int n){
652 register int sign;
653 register int32_t cache;
654 OPEN_READER(re, s)
655 UPDATE_CACHE(re, s)
656 cache = GET_CACHE(re,s);
657 sign=(~cache)>>31;
658 LAST_SKIP_BITS(re, s, n)
659 CLOSE_READER(re, s)
660 return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
663 static inline int get_sbits(GetBitContext *s, int n){
664 register int tmp;
665 OPEN_READER(re, s)
666 UPDATE_CACHE(re, s)
667 tmp= SHOW_SBITS(re, s, n);
668 LAST_SKIP_BITS(re, s, n)
669 CLOSE_READER(re, s)
670 return tmp;
674 * reads 1-17 bits.
675 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
677 static inline unsigned int get_bits(GetBitContext *s, int n){
678 register int tmp;
679 OPEN_READER(re, s)
680 UPDATE_CACHE(re, s)
681 tmp= SHOW_UBITS(re, s, n);
682 LAST_SKIP_BITS(re, s, n)
683 CLOSE_READER(re, s)
684 return tmp;
688 * shows 1-17 bits.
689 * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
691 static inline unsigned int show_bits(GetBitContext *s, int n){
692 register int tmp;
693 OPEN_READER(re, s)
694 UPDATE_CACHE(re, s)
695 tmp= SHOW_UBITS(re, s, n);
696 // CLOSE_READER(re, s)
697 return tmp;
700 static inline void skip_bits(GetBitContext *s, int n){
701 //Note gcc seems to optimize this to s->index+=n for the ALT_READER :))
702 OPEN_READER(re, s)
703 UPDATE_CACHE(re, s)
704 LAST_SKIP_BITS(re, s, n)
705 CLOSE_READER(re, s)
708 static inline unsigned int get_bits1(GetBitContext *s){
709 #ifdef ALT_BITSTREAM_READER
710 int index= s->index;
711 uint8_t result= s->buffer[ index>>3 ];
712 #ifdef ALT_BITSTREAM_READER_LE
713 result>>= (index&0x07);
714 result&= 1;
715 #else
716 result<<= (index&0x07);
717 result>>= 8 - 1;
718 #endif
719 index++;
720 s->index= index;
722 return result;
723 #else
724 return get_bits(s, 1);
725 #endif
728 static inline unsigned int show_bits1(GetBitContext *s){
729 return show_bits(s, 1);
732 static inline void skip_bits1(GetBitContext *s){
733 skip_bits(s, 1);
737 * reads 0-32 bits.
739 static inline unsigned int get_bits_long(GetBitContext *s, int n){
740 if(n<=17) return get_bits(s, n);
741 else{
742 #ifdef ALT_BITSTREAM_READER_LE
743 int ret= get_bits(s, 16);
744 return ret | (get_bits(s, n-16) << 16);
745 #else
746 int ret= get_bits(s, 16) << (n-16);
747 return ret | get_bits(s, n-16);
748 #endif
753 * shows 0-32 bits.
755 static inline unsigned int show_bits_long(GetBitContext *s, int n){
756 if(n<=17) return show_bits(s, n);
757 else{
758 GetBitContext gb= *s;
759 int ret= get_bits_long(s, n);
760 *s= gb;
761 return ret;
766 static inline int check_marker(GetBitContext *s, const char *msg)
768 int bit= get_bits1(s);
769 if(!bit)
770 av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
772 return bit;
776 * init GetBitContext.
777 * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
778 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
779 * @param bit_size the size of the buffer in bits
781 static inline void init_get_bits(GetBitContext *s,
782 const uint8_t *buffer, int bit_size)
784 int buffer_size= (bit_size+7)>>3;
785 if(buffer_size < 0 || bit_size < 0) {
786 buffer_size = bit_size = 0;
787 buffer = NULL;
790 s->buffer= buffer;
791 s->size_in_bits= bit_size;
792 s->buffer_end= buffer + buffer_size;
793 #ifdef ALT_BITSTREAM_READER
794 s->index=0;
795 #elif defined LIBMPEG2_BITSTREAM_READER
796 s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));
797 s->bit_count = 16 + 8*((intptr_t)buffer&1);
798 skip_bits_long(s, 0);
799 #elif defined A32_BITSTREAM_READER
800 s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));
801 s->bit_count = 32 + 8*((intptr_t)buffer&3);
802 skip_bits_long(s, 0);
803 #endif
806 static inline void align_get_bits(GetBitContext *s)
808 int n= (-get_bits_count(s)) & 7;
809 if(n) skip_bits(s, n);
812 int init_vlc(VLC *vlc, int nb_bits, int nb_codes,
813 const void *bits, int bits_wrap, int bits_size,
814 const void *codes, int codes_wrap, int codes_size,
815 int flags);
816 #define INIT_VLC_USE_STATIC 1
817 #define INIT_VLC_LE 2
818 void free_vlc(VLC *vlc);
822 * if the vlc code is invalid and max_depth=1 than no bits will be removed
823 * if the vlc code is invalid and max_depth>1 than the number of bits removed
824 * is undefined
826 #define GET_VLC(code, name, gb, table, bits, max_depth)\
828 int n, index, nb_bits;\
830 index= SHOW_UBITS(name, gb, bits);\
831 code = table[index][0];\
832 n = table[index][1];\
834 if(max_depth > 1 && n < 0){\
835 LAST_SKIP_BITS(name, gb, bits)\
836 UPDATE_CACHE(name, gb)\
838 nb_bits = -n;\
840 index= SHOW_UBITS(name, gb, nb_bits) + code;\
841 code = table[index][0];\
842 n = table[index][1];\
843 if(max_depth > 2 && n < 0){\
844 LAST_SKIP_BITS(name, gb, nb_bits)\
845 UPDATE_CACHE(name, gb)\
847 nb_bits = -n;\
849 index= SHOW_UBITS(name, gb, nb_bits) + code;\
850 code = table[index][0];\
851 n = table[index][1];\
854 SKIP_BITS(name, gb, n)\
857 #define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
859 int n, index, nb_bits;\
861 index= SHOW_UBITS(name, gb, bits);\
862 level = table[index].level;\
863 n = table[index].len;\
865 if(max_depth > 1 && n < 0){\
866 SKIP_BITS(name, gb, bits)\
867 if(need_update){\
868 UPDATE_CACHE(name, gb)\
871 nb_bits = -n;\
873 index= SHOW_UBITS(name, gb, nb_bits) + level;\
874 level = table[index].level;\
875 n = table[index].len;\
877 run= table[index].run;\
878 SKIP_BITS(name, gb, n)\
883 * parses a vlc code, faster then get_vlc()
884 * @param bits is the number of bits which will be read at once, must be
885 * identical to nb_bits in init_vlc()
886 * @param max_depth is the number of times bits bits must be read to completely
887 * read the longest vlc code
888 * = (max_vlc_length + bits - 1) / bits
890 static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
891 int bits, int max_depth)
893 int code;
895 OPEN_READER(re, s)
896 UPDATE_CACHE(re, s)
898 GET_VLC(code, re, s, table, bits, max_depth)
900 CLOSE_READER(re, s)
901 return code;
904 //#define TRACE
906 #ifdef TRACE
907 static inline void print_bin(int bits, int n){
908 int i;
910 for(i=n-1; i>=0; i--){
911 av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
913 for(i=n; i<24; i++)
914 av_log(NULL, AV_LOG_DEBUG, " ");
917 static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
918 int r= get_bits(s, n);
920 print_bin(r, n);
921 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);
922 return r;
924 static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){
925 int show= show_bits(s, 24);
926 int pos= get_bits_count(s);
927 int r= get_vlc2(s, table, bits, max_depth);
928 int len= get_bits_count(s) - pos;
929 int bits2= show>>(24-len);
931 print_bin(bits2, len);
933 av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line);
934 return r;
936 static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
937 int show= show_bits(s, n);
938 int r= get_xbits(s, n);
940 print_bin(show, n);
941 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);
942 return r;
945 #define get_bits(s, n) get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
946 #define get_bits1(s) get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
947 #define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
948 #define get_vlc(s, vlc) get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
949 #define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
951 #define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
953 #else //TRACE
954 #define tprintf(p, ...) {}
955 #endif
957 static inline int decode012(GetBitContext *gb){
958 int n;
959 n = get_bits1(gb);
960 if (n == 0)
961 return 0;
962 else
963 return get_bits1(gb) + 1;
966 #endif /* BITSTREAM_H */