apps/codecs/libwma/bitstream.h

   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 bitstream.h
  23  * bitstream api header.
  24  */
  25
  26 #ifndef BITSTREAM_H
  27 #define BITSTREAM_H
  28
  29 #define av_always_inline inline
  30 #define attribute_deprecated
  31
  32 #include <inttypes.h>
  33 #include "ffmpeg_config.h"
  34 #include <stdlib.h>
  35
  36 #include "ffmpeg_bswap.h"
  37
  38 //#include "log.h"
  39
  40 #if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
  41 #define ALT_BITSTREAM_READER
  42 #endif
  43
  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
  56
  57 extern const uint8_t ff_reverse[256];
  58
  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))
  65     );
  66     return a;
  67 }
  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))
  72     );
  73     return a;
  74 }
  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
  79
  80 /* bit output */
  81
  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;
  93
  94 static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
  95 {
  96     if(buffer_size < 0) {
  97         buffer_size = 0;
  98         buffer = NULL;
  99     }
 100
 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
 112 }
 113
 114 /* return the number of bits output */
 115 static inline int put_bits_count(PutBitContext *s)
 116 {
 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
 122 }
 123
 124 /* pad the end of the output stream with zeros */
 125 static inline void flush_put_bits(PutBitContext *s)
 126 {
 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;
 136     }
 137     s->bit_left=32;
 138     s->bit_buf=0;
 139 #endif
 140 }
 141
 142 void align_put_bits(PutBitContext *s);
 143 void ff_put_string(PutBitContext * pbc, char *s, int put_zero);
 144
 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;
 163
 164 #define VLC_TYPE int16_t
 165
 166 typedef struct VLC {
 167     int bits;
 168     VLC_TYPE (*table)[2]; ///< code, bits
 169     int table_size, table_allocated;
 170 } VLC;
 171
 172 typedef struct RL_VLC_ELEM {
 173     int16_t level;
 174     int8_t len;
 175     uint8_t run;
 176 } RL_VLC_ELEM;
 177
 178 #if defined(ARCH_SPARC) || defined(ARCH_ARMV4L) || defined(ARCH_MIPS) || defined(ARCH_BFIN)
 179 #define UNALIGNED_STORES_ARE_BAD
 180 #endif
 181
 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));                          \
 194                                                         \
 195     return ((const struct Unaligned *) v)->i;           \
 196 }
 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;                \
 201 }
 202 #    else
 203 #    define unaligned(x)                                        \
 204 static inline uint##x##_t unaligned##x(const void *v) {         \
 205     return *(const uint##x##_t *) v;                            \
 206 }
 207 #    endif
 208 unaligned(16)
 209 unaligned(32)
 210 unaligned(64)
 211 #undef unaligned
 212 #endif /* defined(ARCH_X86) */
 213
 214 #ifndef ALT_BITSTREAM_WRITER
 215 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
 216 {
 217     unsigned int bit_buf;
 218     int bit_left;
 219
 220     //    printf("put_bits=%d %x\n", n, value);
 221    // assert(n == 32 || value < (1U << n));
 222
 223     bit_buf = s->bit_buf;
 224     bit_left = s->bit_left;
 225
 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;
 247     }
 248
 249     s->bit_buf = bit_buf;
 250     s->bit_left = bit_left;
 251 }
 252 #endif
 253
 254
 255 #ifdef ALT_BITSTREAM_WRITER
 256 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
 257 {
 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"
 276     );
 277 #        else
 278     int index= s->index;
 279     uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
 280
 281     value<<= 32-n;
 282
 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"
 306     );
 307 #        else
 308     int index= s->index;
 309     uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3));
 310
 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
 318 }
 319 #endif
 320
 321
 322 static inline uint8_t* pbBufPtr(PutBitContext *s)
 323 {
 324 #ifdef ALT_BITSTREAM_WRITER
 325         return s->buf + (s->index>>3);
 326 #else
 327         return s->buf_ptr;
 328 #endif
 329 }
 330
 331 /**
 332  *
 333  * PutBitContext must be flushed & aligned to a byte boundary before calling this.
 334  */
 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
 344 }
 345
 346 /**
 347  * skips the given number of bits.
 348  * must only be used if the actual values in the bitstream dont matter
 349  */
 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
 358 }
 359
 360 /**
 361  * Changes the end of the buffer.
 362  */
 363 static inline void set_put_bits_buffer_size(PutBitContext *s, int size){
 364     s->buf_end= s->buf + size;
 365 }
 366
 367 /* Bitstream reader API docs:
 368 name
 369     abritary name which is used as prefix for the internal variables
 370
 371 gb
 372     getbitcontext
 373
 374 OPEN_READER(name, gb)
 375     loads gb into local variables
 376
 377 CLOSE_READER(name, gb)
 378     stores local vars in gb
 379
 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,
 383
 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)
 386
 387 SHOW_UBITS(name, gb, num)
 388     will return the next num bits
 389
 390 SHOW_SBITS(name, gb, num)
 391     will return the next num bits and do sign extension
 392
 393 SKIP_BITS(name, gb, num)
 394     will skip over the next num bits
 395     note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
 396
 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)
 399
 400 SKIP_COUNTER(name, gb, num)
 401     will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
 402
 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
 405
 406 LAST_SKIP_BITS(name, gb, num)
 407     is equivalent to SKIP_LAST_CACHE; SKIP_COUNTER
 408
 409 for examples see get_bits, show_bits, skip_bits, get_vlc
 410 */
 411
 412 static inline int unaligned32_be(const void *v)
 413 {
 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
 420 }
 421
 422 static inline int unaligned32_le(const void *v)
 423 {
 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
 430 }
 431
 432 #ifdef ALT_BITSTREAM_READER
 433 #   define MIN_CACHE_BITS 25
 434
 435 #   define OPEN_READER(name, gb)\
 436         int name##_index= (gb)->index;\
 437         int name##_cache= 0;\
 438
 439 #   define CLOSE_READER(name, gb)\
 440         (gb)->index= name##_index;\
 441
 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);\
 445
 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);\
 451
 452 #   define SKIP_CACHE(name, gb, num)\
 453         name##_cache <<= (num);
 454 # endif
 455
 456 // FIXME name?
 457 #   define SKIP_COUNTER(name, gb, num)\
 458         name##_index += (num);\
 459
 460 #   define SKIP_BITS(name, gb, num)\
 461         {\
 462             SKIP_CACHE(name, gb, num)\
 463             SKIP_COUNTER(name, gb, num)\
 464         }\
 465
 466 #   define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
 467 #   define LAST_SKIP_CACHE(name, gb, num) ;
 468
 469 # ifdef ALT_BITSTREAM_READER_LE
 470 #   define SHOW_UBITS(name, gb, num)\
 471         ((name##_cache) & (NEG_USR32(0xffffffff,num)))
 472
 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)
 478
 479 #   define SHOW_SBITS(name, gb, num)\
 480         NEG_SSR32(name##_cache, num)
 481 # endif
 482
 483 #   define GET_CACHE(name, gb)\
 484         ((uint32_t)name##_cache)
 485
 486 static inline int get_bits_count(GetBitContext *s){
 487     return s->index;
 488 }
 489
 490 static inline void skip_bits_long(GetBitContext *s, int n){
 491     s->index += n;
 492 }
 493
 494 #elif defined LIBMPEG2_BITSTREAM_READER
 495 //libmpeg2 like reader
 496
 497 #   define MIN_CACHE_BITS 17
 498
 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;\
 503
 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;\
 508
 509 #ifdef LIBMPEG2_BITSTREAM_READER_HACK
 510
 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;\
 516     }\
 517
 518 #else
 519
 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;\
 525     }\
 526
 527 #endif
 528
 529 #   define SKIP_CACHE(name, gb, num)\
 530         name##_cache <<= (num);\
 531
 532 #   define SKIP_COUNTER(name, gb, num)\
 533         name##_bit_count += (num);\
 534
 535 #   define SKIP_BITS(name, gb, num)\
 536         {\
 537             SKIP_CACHE(name, gb, num)\
 538             SKIP_COUNTER(name, gb, num)\
 539         }\
 540
 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)
 543
 544 #   define SHOW_UBITS(name, gb, num)\
 545         NEG_USR32(name##_cache, num)
 546
 547 #   define SHOW_SBITS(name, gb, num)\
 548         NEG_SSR32(name##_cache, num)
 549
 550 #   define GET_CACHE(name, gb)\
 551         ((uint32_t)name##_cache)
 552
 553 static inline int get_bits_count(GetBitContext *s){
 554     return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
 555 }
 556
 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)
 565 }
 566
 567 #elif defined A32_BITSTREAM_READER
 568
 569 #   define MIN_CACHE_BITS 32
 570
 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;\
 576
 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;\
 582
 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;\
 590     }\
 591
 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))\
 599            );
 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
 606
 607 #   define SKIP_COUNTER(name, gb, num)\
 608         name##_bit_count += (num);\
 609
 610 #   define SKIP_BITS(name, gb, num)\
 611         {\
 612             SKIP_CACHE(name, gb, num)\
 613             SKIP_COUNTER(name, gb, num)\
 614         }\
 615
 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)
 618
 619 #   define SHOW_UBITS(name, gb, num)\
 620         NEG_USR32(name##_cache0, num)
 621
 622 #   define SHOW_SBITS(name, gb, num)\
 623         NEG_SSR32(name##_cache0, num)
 624
 625 #   define GET_CACHE(name, gb)\
 626         (name##_cache0)
 627
 628 static inline int get_bits_count(GetBitContext *s){
 629     return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
 630 }
 631
 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)
 641 }
 642
 643 #endif
 644
 645 /**
 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
 650  */
 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;
 661 }
 662
 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;
 671 }
 672
 673 /**
 674  * reads 1-17 bits.
 675  * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
 676  */
 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;
 685 }
 686
 687 /**
 688  * shows 1-17 bits.
 689  * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
 690  */
 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;
 698 }
 699
 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)
 706 }
 707
 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;
 721
 722     return result;
 723 #else
 724     return get_bits(s, 1);
 725 #endif
 726 }
 727
 728 static inline unsigned int show_bits1(GetBitContext *s){
 729     return show_bits(s, 1);
 730 }
 731
 732 static inline void skip_bits1(GetBitContext *s){
 733     skip_bits(s, 1);
 734 }
 735
 736 /**
 737  * reads 0-32 bits.
 738  */
 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
 749     }
 750 }
 751
 752 /**
 753  * shows 0-32 bits.
 754  */
 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;
 762     }
 763 }
 764
 765 /*
 766 static inline int check_marker(GetBitContext *s, const char *msg)
 767 {
 768     int bit= get_bits1(s);
 769     if(!bit)
 770         av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
 771
 772     return bit;
 773 }
 774 */
 775 /**
 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
 780  */
 781 static inline void init_get_bits(GetBitContext *s,
 782                    const uint8_t *buffer, int bit_size)
 783 {
 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;
 788     }
 789
 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
 804 }
 805
 806 static inline void align_get_bits(GetBitContext *s)
 807 {
 808     int n= (-get_bits_count(s)) & 7;
 809     if(n) skip_bits(s, n);
 810 }
 811
 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);
 819
 820 /**
 821  *
 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
 825  */
 826 #define GET_VLC(code, name, gb, table, bits, max_depth)\
 827 {\
 828     int n, index, nb_bits;\
 829 \
 830     index= SHOW_UBITS(name, gb, bits);\
 831     code = table[index][0];\
 832     n    = table[index][1];\
 833 \
 834     if(max_depth > 1 && n < 0){\
 835         LAST_SKIP_BITS(name, gb, bits)\
 836         UPDATE_CACHE(name, gb)\
 837 \
 838         nb_bits = -n;\
 839 \
 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)\
 846 \
 847             nb_bits = -n;\
 848 \
 849             index= SHOW_UBITS(name, gb, nb_bits) + code;\
 850             code = table[index][0];\
 851             n    = table[index][1];\
 852         }\
 853     }\
 854     SKIP_BITS(name, gb, n)\
 855 }
 856
 857 #define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
 858 {\
 859     int n, index, nb_bits;\
 860 \
 861     index= SHOW_UBITS(name, gb, bits);\
 862     level = table[index].level;\
 863     n     = table[index].len;\
 864 \
 865     if(max_depth > 1 && n < 0){\
 866         SKIP_BITS(name, gb, bits)\
 867         if(need_update){\
 868             UPDATE_CACHE(name, gb)\
 869         }\
 870 \
 871         nb_bits = -n;\
 872 \
 873         index= SHOW_UBITS(name, gb, nb_bits) + level;\
 874         level = table[index].level;\
 875         n     = table[index].len;\
 876     }\
 877     run= table[index].run;\
 878     SKIP_BITS(name, gb, n)\
 879 }
 880
 881
 882 /**
 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
 889  */
 890 static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
 891                                   int bits, int max_depth)
 892 {
 893     int code;
 894
 895     OPEN_READER(re, s)
 896     UPDATE_CACHE(re, s)
 897
 898     GET_VLC(code, re, s, table, bits, max_depth)
 899
 900     CLOSE_READER(re, s)
 901     return code;
 902 }
 903
 904 //#define TRACE
 905
 906 #ifdef TRACE
 907 static inline void print_bin(int bits, int n){
 908     int i;
 909
 910     for(i=n-1; i>=0; i--){
 911         av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
 912     }
 913     for(i=n; i<24; i++)
 914         av_log(NULL, AV_LOG_DEBUG, " ");
 915 }
 916
 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);
 919
 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;
 923 }
 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);
 930
 931     print_bin(bits2, len);
 932
 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;
 935 }
 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);
 939
 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;
 943 }
 944
 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__)
 950
 951 #define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
 952
 953 #else //TRACE
 954 #define tprintf(p, ...) {}
 955 #endif
 956
 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;
 964 }
 965
 966 #endif /* BITSTREAM_H */