modules/codec/wmafixed/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 <stdlib.h>
  34
  35 #ifdef __arm__
  36 #define CONFIG_ALIGN 1
  37 #endif
  38
  39 #ifdef ROCKBOX_BIG_ENDIAN
  40 #define WORDS_BIGENDIAN
  41 #endif
  42
  43 #include "bswap.h"
  44
  45 extern const uint8_t ff_log2_tab[256];
  46
  47
  48 /*misc utility functions added to make it compile */
  49 static inline int av_log2(unsigned int v)
  50 {
  51     int n;
  52
  53     n = 0;
  54     if (v & 0xffff0000) {
  55         v >>= 16;
  56         n += 16;
  57     }
  58     if (v & 0xff00) {
  59         v >>= 8;
  60         n += 8;
  61     }
  62     n += ff_log2_tab[v];
  63
  64     return n;
  65 }
  66
  67 #if defined(ALT_BITSTREAM_READER_LE) && !defined(ALT_BITSTREAM_READER)
  68 #define ALT_BITSTREAM_READER
  69 #endif
  70
  71 //#define ALT_BITSTREAM_WRITER
  72 //#define ALIGNED_BITSTREAM_WRITER
  73 #if !defined(LIBMPEG2_BITSTREAM_READER) && !defined(A32_BITSTREAM_READER) && !defined(ALT_BITSTREAM_READER)
  74 #   ifdef ARCH_ARMV4L
  75 #       define A32_BITSTREAM_READER
  76 #   else
  77 #define ALT_BITSTREAM_READER
  78 //#define LIBMPEG2_BITSTREAM_READER
  79 //#define A32_BITSTREAM_READER
  80 #   endif
  81 #endif
  82 #define LIBMPEG2_BITSTREAM_READER_HACK //add BERO
  83
  84 extern const uint8_t ff_reverse[256];
  85
  86 #if defined(ARCH_X86)
  87 // avoid +32 for shift optimization (gcc should do that ...)
  88 static inline  int32_t NEG_SSR32( int32_t a, int8_t s){
  89     asm ("sarl %1, %0\n\t"
  90          : "+r" (a)
  91          : "ic" ((uint8_t)(-s))
  92     );
  93     return a;
  94 }
  95 static inline uint32_t NEG_USR32(uint32_t a, int8_t s){
  96     asm ("shrl %1, %0\n\t"
  97          : "+r" (a)
  98          : "ic" ((uint8_t)(-s))
  99     );
 100     return a;
 101 }
 102 #else
 103 #    define NEG_SSR32(a,s) ((( int32_t)(a))>>(32-(s)))
 104 #    define NEG_USR32(a,s) (((uint32_t)(a))>>(32-(s)))
 105 #endif
 106
 107 /* bit output */
 108
 109 /* buf and buf_end must be present and used by every alternative writer. */
 110 typedef struct PutBitContext {
 111 #ifdef ALT_BITSTREAM_WRITER
 112     uint8_t *buf, *buf_end;
 113     int index;
 114 #else
 115     uint32_t bit_buf;
 116     int bit_left;
 117     uint8_t *buf, *buf_ptr, *buf_end;
 118 #endif
 119 } PutBitContext;
 120
 121 static inline void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
 122 {
 123     if(buffer_size < 0) {
 124         buffer_size = 0;
 125         buffer = NULL;
 126     }
 127
 128     s->buf = buffer;
 129     s->buf_end = s->buf + buffer_size;
 130 #ifdef ALT_BITSTREAM_WRITER
 131     s->index=0;
 132     ((uint32_t*)(s->buf))[0]=0;
 133 //    memset(buffer, 0, buffer_size);
 134 #else
 135     s->buf_ptr = s->buf;
 136     s->bit_left=32;
 137     s->bit_buf=0;
 138 #endif
 139 }
 140
 141 /* return the number of bits output */
 142 static inline int put_bits_count(PutBitContext *s)
 143 {
 144 #ifdef ALT_BITSTREAM_WRITER
 145     return s->index;
 146 #else
 147     return (s->buf_ptr - s->buf) * 8 + 32 - s->bit_left;
 148 #endif
 149 }
 150
 151 /* pad the end of the output stream with zeros */
 152 static inline void flush_put_bits(PutBitContext *s)
 153 {
 154 #ifdef ALT_BITSTREAM_WRITER
 155     align_put_bits(s);
 156 #else
 157     s->bit_buf<<= s->bit_left;
 158     while (s->bit_left < 32) {
 159         /* XXX: should test end of buffer */
 160         *s->buf_ptr++=s->bit_buf >> 24;
 161         s->bit_buf<<=8;
 162         s->bit_left+=8;
 163     }
 164     s->bit_left=32;
 165     s->bit_buf=0;
 166 #endif
 167 }
 168
 169 void align_put_bits(PutBitContext *s);
 170 void ff_put_string(PutBitContext * pbc, char *s, int put_zero);
 171
 172 /* bit input */
 173 /* buffer, buffer_end and size_in_bits must be present and used by every reader */
 174 typedef struct GetBitContext {
 175     const uint8_t *buffer, *buffer_end;
 176 #ifdef ALT_BITSTREAM_READER
 177     int index;
 178 #elif defined LIBMPEG2_BITSTREAM_READER
 179     uint8_t *buffer_ptr;
 180     uint32_t cache;
 181     int bit_count;
 182 #elif defined A32_BITSTREAM_READER
 183     uint32_t *buffer_ptr;
 184     uint32_t cache0;
 185     uint32_t cache1;
 186     int bit_count;
 187 #endif
 188     int size_in_bits;
 189 } GetBitContext;
 190
 191 #define VLC_TYPE int16_t
 192
 193 typedef struct VLC {
 194     int bits;
 195     VLC_TYPE (*table)[2]; /* code, bits */
 196     int table_size, table_allocated;
 197 } VLC;
 198
 199 typedef struct RL_VLC_ELEM {
 200     int16_t level;
 201     int8_t len;
 202     uint8_t run;
 203 } RL_VLC_ELEM;
 204
 205 #if defined(ARCH_SPARC) || defined(ARCH_ARMV4L) || defined(ARCH_MIPS) || defined(ARCH_BFIN)
 206 #define UNALIGNED_STORES_ARE_BAD
 207 #endif
 208
 209 /* used to avoid missaligned exceptions on some archs (alpha, ...) */
 210 #if defined(ARCH_X86) || defined(CPU_COLDFIRE)
 211 #    define unaligned16(a) (*(const uint16_t*)(a))
 212 #    define unaligned32(a) (*(const uint32_t*)(a))
 213 #    define unaligned64(a) (*(const uint64_t*)(a))
 214 #else
 215 #    ifdef __GNUC__
 216 #    define unaligned(x)                                \
 217 static inline uint##x##_t unaligned##x(const void *v) { \
 218     struct Unaligned {                                  \
 219         uint##x##_t i;                                  \
 220     } __attribute__((packed));                          \
 221                                                         \
 222     return ((const struct Unaligned *) v)->i;           \
 223 }
 224 #    elif defined(__DECC)
 225 #    define unaligned(x)                                        \
 226 static inline uint##x##_t unaligned##x(const void *v) {         \
 227     return *(const __unaligned uint##x##_t *) v;                \
 228 }
 229 #    else
 230 #    define unaligned(x)                                        \
 231 static inline uint##x##_t unaligned##x(const void *v) {         \
 232     return *(const uint##x##_t *) v;                            \
 233 }
 234 #    endif
 235 unaligned(16)
 236 unaligned(32)
 237 unaligned(64)
 238 #undef unaligned
 239 #endif /* defined(ARCH_X86) */
 240
 241 #ifndef ALT_BITSTREAM_WRITER
 242 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
 243 {
 244     unsigned int bit_buf;
 245     int bit_left;
 246
 247     // printf("put_bits=%d %x\n", n, value);
 248     // assert(n == 32 || value < (1U << n));
 249     bit_buf = s->bit_buf;
 250     bit_left = s->bit_left;
 251
 252     //    printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf);
 253     /* XXX: optimize */
 254     if (n < bit_left) {
 255         bit_buf = (bit_buf<<n) | value;
 256         bit_left-=n;
 257     } else {
 258         bit_buf<<=bit_left;
 259         bit_buf |= value >> (n - bit_left);
 260 #ifdef UNALIGNED_STORES_ARE_BAD
 261         if (3 & (intptr_t) s->buf_ptr) {
 262             s->buf_ptr[0] = bit_buf >> 24;
 263             s->buf_ptr[1] = bit_buf >> 16;
 264             s->buf_ptr[2] = bit_buf >>  8;
 265             s->buf_ptr[3] = bit_buf      ;
 266         } else
 267 #endif
 268         *(uint32_t *)s->buf_ptr = be2me_32(bit_buf);
 269         //printf("bitbuf = %08x\n", bit_buf);
 270         s->buf_ptr+=4;
 271         bit_left+=32 - n;
 272         bit_buf = value;
 273     }
 274
 275     s->bit_buf = bit_buf;
 276     s->bit_left = bit_left;
 277 }
 278 #endif
 279
 280 #ifdef ALT_BITSTREAM_WRITER
 281 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
 282 {
 283 #    ifdef ALIGNED_BITSTREAM_WRITER
 284 #        if defined(ARCH_X86)
 285     asm volatile(
 286         "movl %0, %%ecx                 \n\t"
 287         "xorl %%eax, %%eax              \n\t"
 288         "shrdl %%cl, %1, %%eax          \n\t"
 289         "shrl %%cl, %1                  \n\t"
 290         "movl %0, %%ecx                 \n\t"
 291         "shrl $3, %%ecx                 \n\t"
 292         "andl $0xFFFFFFFC, %%ecx        \n\t"
 293         "bswapl %1                      \n\t"
 294         "orl %1, (%2, %%ecx)            \n\t"
 295         "bswapl %%eax                   \n\t"
 296         "addl %3, %0                    \n\t"
 297         "movl %%eax, 4(%2, %%ecx)       \n\t"
 298         : "=&r" (s->index), "=&r" (value)
 299         : "r" (s->buf), "r" (n), "0" (s->index), "1" (value<<(-n))
 300         : "%eax", "%ecx"
 301     );
 302 #        else
 303     int index= s->index;
 304     uint32_t *ptr= ((uint32_t *)s->buf)+(index>>5);
 305
 306     value<<= 32-n;
 307
 308     ptr[0] |= be2me_32(value>>(index&31));
 309     ptr[1]  = be2me_32(value<<(32-(index&31)));
 310 //if(n>24) printf("%d %d\n", n, value);
 311     index+= n;
 312     s->index= index;
 313 #        endif
 314 #    else //ALIGNED_BITSTREAM_WRITER
 315 #        if defined(ARCH_X86)
 316     asm volatile(
 317         "movl $7, %%ecx                 \n\t"
 318         "andl %0, %%ecx                 \n\t"
 319         "addl %3, %%ecx                 \n\t"
 320         "negl %%ecx                     \n\t"
 321         "shll %%cl, %1                  \n\t"
 322         "bswapl %1                      \n\t"
 323         "movl %0, %%ecx                 \n\t"
 324         "shrl $3, %%ecx                 \n\t"
 325         "orl %1, (%%ecx, %2)            \n\t"
 326         "addl %3, %0                    \n\t"
 327         "movl $0, 4(%%ecx, %2)          \n\t"
 328         : "=&r" (s->index), "=&r" (value)
 329         : "r" (s->buf), "r" (n), "0" (s->index), "1" (value)
 330         : "%ecx"
 331     );
 332 #        else
 333     int index= s->index;
 334     uint32_t *ptr= (uint32_t*)(((uint8_t *)s->buf)+(index>>3));
 335
 336     ptr[0] |= be2me_32(value<<(32-n-(index&7) ));
 337     ptr[1] = 0;
 338 //if(n>24) printf("%d %d\n", n, value);
 339     index+= n;
 340     s->index= index;
 341 #        endif
 342 #    endif //!ALIGNED_BITSTREAM_WRITER
 343 }
 344 #endif
 345
 346 static inline uint8_t* pbBufPtr(PutBitContext *s)
 347 {
 348 #ifdef ALT_BITSTREAM_WRITER
 349         return s->buf + (s->index>>3);
 350 #else
 351         return s->buf_ptr;
 352 #endif
 353 }
 354
 355 /**
 356  *
 357  * PutBitContext must be flushed & aligned to a byte boundary before calling this.
 358  */
 359 static inline void skip_put_bytes(PutBitContext *s, int n){
 360        // assert((put_bits_count(s)&7)==0);
 361 #ifdef ALT_BITSTREAM_WRITER
 362         FIXME may need some cleaning of the buffer
 363         s->index += n<<3;
 364 #else
 365        // assert(s->bit_left==32);
 366         s->buf_ptr += n;
 367 #endif
 368 }
 369
 370 /**
 371  * skips the given number of bits.
 372  * must only be used if the actual values in the bitstream dont matter
 373  */
 374 static inline void skip_put_bits(PutBitContext *s, int n){
 375 #ifdef ALT_BITSTREAM_WRITER
 376     s->index += n;
 377 #else
 378     s->bit_left -= n;
 379     s->buf_ptr-= s->bit_left>>5;
 380     s->bit_left &= 31;
 381 #endif
 382 }
 383
 384 /**
 385  * Changes the end of the buffer.
 386  */
 387 static inline void set_put_bits_buffer_size(PutBitContext *s, int size){
 388     s->buf_end= s->buf + size;
 389 }
 390
 391 /* Bitstream reader API docs:
 392 name
 393     abritary name which is used as prefix for the internal variables
 394
 395 gb
 396     getbitcontext
 397
 398 OPEN_READER(name, gb)
 399     loads gb into local variables
 400
 401 CLOSE_READER(name, gb)
 402     stores local vars in gb
 403
 404 UPDATE_CACHE(name, gb)
 405     refills the internal cache from the bitstream
 406     after this call at least MIN_CACHE_BITS will be available,
 407
 408 GET_CACHE(name, gb)
 409     will output the contents of the internal cache, next bit is MSB of 32 or 64 bit (FIXME 64bit)
 410
 411 SHOW_UBITS(name, gb, num)
 412     will return the next num bits
 413
 414 SHOW_SBITS(name, gb, num)
 415     will return the next num bits and do sign extension
 416
 417 SKIP_BITS(name, gb, num)
 418     will skip over the next num bits
 419     note, this is equivalent to SKIP_CACHE; SKIP_COUNTER
 420
 421 SKIP_CACHE(name, gb, num)
 422     will remove the next num bits from the cache (note SKIP_COUNTER MUST be called before UPDATE_CACHE / CLOSE_READER)
 423
 424 SKIP_COUNTER(name, gb, num)
 425     will increment the internal bit counter (see SKIP_CACHE & SKIP_BITS)
 426
 427 LAST_SKIP_CACHE(name, gb, num)
 428     will remove the next num bits from the cache if it is needed for UPDATE_CACHE otherwise it will do nothing
 429
 430 LAST_SKIP_BITS(name, gb, num)
 431     is equivalent to SKIP_LAST_CACHE; SKIP_COUNTER
 432
 433 for examples see get_bits, show_bits, skip_bits, get_vlc
 434 */
 435
 436 static inline int unaligned32_be(const void *v)
 437 {
 438 #ifdef CONFIG_ALIGN
 439         const uint8_t *p=v;
 440         return (((p[0]<<8) | p[1])<<16) | (p[2]<<8) | (p[3]);
 441 #else
 442         return be2me_32( unaligned32(v)); //original
 443 #endif
 444 }
 445
 446 static inline int unaligned32_le(const void *v)
 447 {
 448 #ifdef CONFIG_ALIGN
 449        const uint8_t *p=v;
 450        return (((p[3]<<8) | p[2])<<16) | (p[1]<<8) | (p[0]);
 451 #else
 452        return le2me_32( unaligned32(v)); //original
 453 #endif
 454 }
 455
 456 #ifdef ALT_BITSTREAM_READER
 457 #   define MIN_CACHE_BITS 25
 458
 459 #   define OPEN_READER(name, gb)\
 460         int name##_index= (gb)->index;\
 461         int name##_cache= 0;\
 462
 463 #   define CLOSE_READER(name, gb)\
 464         (gb)->index= name##_index;\
 465
 466 # ifdef ALT_BITSTREAM_READER_LE
 467 #   define UPDATE_CACHE(name, gb)\
 468         name##_cache= unaligned32_le( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) >> (name##_index&0x07);\
 469
 470 #   define SKIP_CACHE(name, gb, num)\
 471         name##_cache >>= (num);
 472 # else
 473 #   define UPDATE_CACHE(name, gb)\
 474         name##_cache= unaligned32_be( ((const uint8_t *)(gb)->buffer)+(name##_index>>3) ) << (name##_index&0x07);\
 475
 476 #   define SKIP_CACHE(name, gb, num)\
 477         name##_cache <<= (num);
 478 # endif
 479
 480 // FIXME name?
 481 #   define SKIP_COUNTER(name, gb, num)\
 482         name##_index += (num);\
 483
 484 #   define SKIP_BITS(name, gb, num)\
 485         {\
 486             SKIP_CACHE(name, gb, num)\
 487             SKIP_COUNTER(name, gb, num)\
 488         }\
 489
 490 #   define LAST_SKIP_BITS(name, gb, num) SKIP_COUNTER(name, gb, num)
 491 #   define LAST_SKIP_CACHE(name, gb, num) ;
 492
 493 # ifdef ALT_BITSTREAM_READER_LE
 494 #   define SHOW_UBITS(name, gb, num)\
 495         ((name##_cache) & (NEG_USR32(0xffffffff,num)))
 496
 497 #   define SHOW_SBITS(name, gb, num)\
 498         NEG_SSR32((name##_cache)<<(32-(num)), num)
 499 # else
 500 #   define SHOW_UBITS(name, gb, num)\
 501         NEG_USR32(name##_cache, num)
 502
 503 #   define SHOW_SBITS(name, gb, num)\
 504         NEG_SSR32(name##_cache, num)
 505 # endif
 506
 507 #   define GET_CACHE(name, gb)\
 508         ((uint32_t)name##_cache)
 509
 510 static inline int get_bits_count(GetBitContext *s){
 511     return s->index;
 512 }
 513
 514 static inline void skip_bits_long(GetBitContext *s, int n){
 515     s->index += n;
 516 }
 517
 518 #elif defined LIBMPEG2_BITSTREAM_READER
 519 //libmpeg2 like reader
 520
 521 #   define MIN_CACHE_BITS 17
 522
 523 #   define OPEN_READER(name, gb)\
 524         int name##_bit_count=(gb)->bit_count;\
 525         int name##_cache= (gb)->cache;\
 526         uint8_t * name##_buffer_ptr=(gb)->buffer_ptr;\
 527
 528 #   define CLOSE_READER(name, gb)\
 529         (gb)->bit_count= name##_bit_count;\
 530         (gb)->cache= name##_cache;\
 531         (gb)->buffer_ptr= name##_buffer_ptr;\
 532
 533 #ifdef LIBMPEG2_BITSTREAM_READER_HACK
 534
 535 #   define UPDATE_CACHE(name, gb)\
 536     if(name##_bit_count >= 0){\
 537         name##_cache+= (int)be2me_16(*(uint16_t*)name##_buffer_ptr) << name##_bit_count;\
 538         name##_buffer_ptr += 2;\
 539         name##_bit_count-= 16;\
 540     }\
 541
 542 #else
 543
 544 #   define UPDATE_CACHE(name, gb)\
 545     if(name##_bit_count >= 0){\
 546         name##_cache+= ((name##_buffer_ptr[0]<<8) + name##_buffer_ptr[1]) << name##_bit_count;\
 547         name##_buffer_ptr+=2;\
 548         name##_bit_count-= 16;\
 549     }\
 550
 551 #endif
 552
 553 #   define SKIP_CACHE(name, gb, num)\
 554         name##_cache <<= (num);\
 555
 556 #   define SKIP_COUNTER(name, gb, num)\
 557         name##_bit_count += (num);\
 558
 559 #   define SKIP_BITS(name, gb, num)\
 560         {\
 561             SKIP_CACHE(name, gb, num)\
 562             SKIP_COUNTER(name, gb, num)\
 563         }\
 564
 565 #   define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
 566 #   define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
 567
 568 #   define SHOW_UBITS(name, gb, num)\
 569         NEG_USR32(name##_cache, num)
 570
 571 #   define SHOW_SBITS(name, gb, num)\
 572         NEG_SSR32(name##_cache, num)
 573
 574 #   define GET_CACHE(name, gb)\
 575         ((uint32_t)name##_cache)
 576
 577 static inline int get_bits_count(GetBitContext *s){
 578     return (s->buffer_ptr - s->buffer)*8 - 16 + s->bit_count;
 579 }
 580
 581 static inline void skip_bits_long(GetBitContext *s, int n){
 582     OPEN_READER(re, s)
 583     re_bit_count += n;
 584     re_buffer_ptr += 2*(re_bit_count>>4);
 585     re_bit_count &= 15;
 586     re_cache = ((re_buffer_ptr[-2]<<8) + re_buffer_ptr[-1]) << (16+re_bit_count);
 587     UPDATE_CACHE(re, s)
 588     CLOSE_READER(re, s)
 589 }
 590
 591 #elif defined A32_BITSTREAM_READER
 592
 593 #   define MIN_CACHE_BITS 32
 594
 595 #   define OPEN_READER(name, gb)\
 596         int name##_bit_count=(gb)->bit_count;\
 597         uint32_t name##_cache0= (gb)->cache0;\
 598         uint32_t name##_cache1= (gb)->cache1;\
 599         uint32_t * name##_buffer_ptr=(gb)->buffer_ptr;\
 600
 601 #   define CLOSE_READER(name, gb)\
 602         (gb)->bit_count= name##_bit_count;\
 603         (gb)->cache0= name##_cache0;\
 604         (gb)->cache1= name##_cache1;\
 605         (gb)->buffer_ptr= name##_buffer_ptr;\
 606
 607 #   define UPDATE_CACHE(name, gb)\
 608     if(name##_bit_count > 0){\
 609         const uint32_t next= be2me_32( *name##_buffer_ptr );\
 610         name##_cache0 |= NEG_USR32(next,name##_bit_count);\
 611         name##_cache1 |= next<<name##_bit_count;\
 612         name##_buffer_ptr++;\
 613         name##_bit_count-= 32;\
 614     }\
 615
 616 #if defined(ARCH_X86)
 617 #   define SKIP_CACHE(name, gb, num)\
 618         asm(\
 619             "shldl %2, %1, %0          \n\t"\
 620             "shll %2, %1               \n\t"\
 621             : "+r" (name##_cache0), "+r" (name##_cache1)\
 622             : "Ic" ((uint8_t)(num))\
 623            );
 624 #else
 625 #   define SKIP_CACHE(name, gb, num)\
 626         name##_cache0 <<= (num);\
 627         name##_cache0 |= NEG_USR32(name##_cache1,num);\
 628         name##_cache1 <<= (num);
 629 #endif
 630
 631 #   define SKIP_COUNTER(name, gb, num)\
 632         name##_bit_count += (num);\
 633
 634 #   define SKIP_BITS(name, gb, num)\
 635         {\
 636             SKIP_CACHE(name, gb, num)\
 637             SKIP_COUNTER(name, gb, num)\
 638         }\
 639
 640 #   define LAST_SKIP_BITS(name, gb, num) SKIP_BITS(name, gb, num)
 641 #   define LAST_SKIP_CACHE(name, gb, num) SKIP_CACHE(name, gb, num)
 642
 643 #   define SHOW_UBITS(name, gb, num)\
 644         NEG_USR32(name##_cache0, num)
 645
 646 #   define SHOW_SBITS(name, gb, num)\
 647         NEG_SSR32(name##_cache0, num)
 648
 649 #   define GET_CACHE(name, gb)\
 650         (name##_cache0)
 651
 652 static inline int get_bits_count(GetBitContext *s){
 653     return ((uint8_t*)s->buffer_ptr - s->buffer)*8 - 32 + s->bit_count;
 654 }
 655
 656 static inline void skip_bits_long(GetBitContext *s, int n){
 657     OPEN_READER(re, s)
 658     re_bit_count += n;
 659     re_buffer_ptr += re_bit_count>>5;
 660     re_bit_count &= 31;
 661     re_cache0 = be2me_32( re_buffer_ptr[-1] ) << re_bit_count;
 662     re_cache1 = 0;
 663     UPDATE_CACHE(re, s)
 664     CLOSE_READER(re, s)
 665 }
 666
 667 #endif
 668
 669 /**
 670  * read mpeg1 dc style vlc (sign bit + mantisse with no MSB).
 671  * if MSB not set it is negative
 672  * @param n length in bits
 673  * @author BERO
 674  */
 675 static inline int get_xbits(GetBitContext *s, int n){
 676     register int sign;
 677     register int32_t cache;
 678     OPEN_READER(re, s)
 679     UPDATE_CACHE(re, s)
 680     cache = GET_CACHE(re,s);
 681     sign=(~cache)>>31;
 682     LAST_SKIP_BITS(re, s, n)
 683     CLOSE_READER(re, s)
 684     return (NEG_USR32(sign ^ cache, n) ^ sign) - sign;
 685 }
 686
 687 static inline int get_sbits(GetBitContext *s, int n){
 688     register int tmp;
 689     OPEN_READER(re, s)
 690     UPDATE_CACHE(re, s)
 691     tmp= SHOW_SBITS(re, s, n);
 692     LAST_SKIP_BITS(re, s, n)
 693     CLOSE_READER(re, s)
 694     return tmp;
 695 }
 696
 697 /**
 698  * reads 1-17 bits.
 699  * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
 700  */
 701 static inline unsigned int get_bits(GetBitContext *s, int n){
 702     register int tmp;
 703     OPEN_READER(re, s)
 704     UPDATE_CACHE(re, s)
 705     tmp= SHOW_UBITS(re, s, n);
 706     LAST_SKIP_BITS(re, s, n)
 707     CLOSE_READER(re, s)
 708     return tmp;
 709 }
 710
 711 /**
 712  * shows 1-17 bits.
 713  * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
 714  */
 715 static inline unsigned int show_bits(GetBitContext *s, int n){
 716     register int tmp;
 717     OPEN_READER(re, s)
 718     UPDATE_CACHE(re, s)
 719     tmp= SHOW_UBITS(re, s, n);
 720 //    CLOSE_READER(re, s)
 721     return tmp;
 722 }
 723
 724 static inline void skip_bits(GetBitContext *s, int n){
 725 /* Note: gcc seems to optimize this to s->index+=n for the ALT_READER :)) */
 726     OPEN_READER(re, s)
 727     UPDATE_CACHE(re, s)
 728     LAST_SKIP_BITS(re, s, n)
 729     CLOSE_READER(re, s)
 730 }
 731
 732 static inline unsigned int get_bits1(GetBitContext *s){
 733 #ifdef ALT_BITSTREAM_READER
 734     int index= s->index;
 735     uint8_t result= s->buffer[ index>>3 ];
 736 #ifdef ALT_BITSTREAM_READER_LE
 737     result>>= (index&0x07);
 738     result&= 1;
 739 #else
 740     result<<= (index&0x07);
 741     result>>= 8 - 1;
 742 #endif
 743     index++;
 744     s->index= index;
 745
 746     return result;
 747 #else
 748     return get_bits(s, 1);
 749 #endif
 750 }
 751
 752 static inline unsigned int show_bits1(GetBitContext *s){
 753     return show_bits(s, 1);
 754 }
 755
 756 static inline void skip_bits1(GetBitContext *s){
 757     skip_bits(s, 1);
 758 }
 759
 760 /**
 761  * reads 0-32 bits.
 762  */
 763 static inline unsigned int get_bits_long(GetBitContext *s, int n){
 764     if(n<=17) return get_bits(s, n);
 765     else{
 766 #ifdef ALT_BITSTREAM_READER_LE
 767         int ret= get_bits(s, 16);
 768         return ret | (get_bits(s, n-16) << 16);
 769 #else
 770         int ret= get_bits(s, 16) << (n-16);
 771         return ret | get_bits(s, n-16);
 772 #endif
 773     }
 774 }
 775
 776 /**
 777  * shows 0-32 bits.
 778  */
 779 static inline unsigned int show_bits_long(GetBitContext *s, int n){
 780     if(n<=17) return show_bits(s, n);
 781     else{
 782         GetBitContext gb= *s;
 783         int ret= get_bits_long(s, n);
 784         *s= gb;
 785         return ret;
 786     }
 787 }
 788
 789 /*
 790 static inline int check_marker(GetBitContext *s, const char *msg)
 791 {
 792     int bit= get_bits1(s);
 793     if(!bit)
 794         av_log(NULL, AV_LOG_INFO, "Marker bit missing %s\n", msg);
 795
 796     return bit;
 797 }
 798 */
 799
 800 /**
 801  * init GetBitContext.
 802  * @param buffer bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE bytes larger then the actual read bits
 803  * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
 804  * @param bit_size the size of the buffer in bits
 805  */
 806 static inline void init_get_bits(GetBitContext *s,
 807                    const uint8_t *buffer, int bit_size)
 808 {
 809     int buffer_size= (bit_size+7)>>3;
 810     if(buffer_size < 0 || bit_size < 0) {
 811         buffer_size = bit_size = 0;
 812         buffer = NULL;
 813     }
 814
 815     s->buffer= buffer;
 816     s->size_in_bits= bit_size;
 817     s->buffer_end= buffer + buffer_size;
 818 #ifdef ALT_BITSTREAM_READER
 819     s->index=0;
 820 #elif defined LIBMPEG2_BITSTREAM_READER
 821     s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));
 822     s->bit_count = 16 + 8*((intptr_t)buffer&1);
 823     skip_bits_long(s, 0);
 824 #elif defined A32_BITSTREAM_READER
 825     s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));
 826     s->bit_count = 32 + 8*((intptr_t)buffer&3);
 827     skip_bits_long(s, 0);
 828 #endif
 829 }
 830
 831 static inline void align_get_bits(GetBitContext *s)
 832 {
 833     int n= (-get_bits_count(s)) & 7;
 834     if(n) skip_bits(s, n);
 835 }
 836
 837 int init_vlc(VLC *vlc, int nb_bits, int nb_codes,
 838              const void *bits, int bits_wrap, int bits_size,
 839              const void *codes, int codes_wrap, int codes_size,
 840              int flags);
 841 #define INIT_VLC_USE_STATIC 1
 842 #define INIT_VLC_LE         2
 843 void free_vlc(VLC *vlc);
 844
 845 /**
 846  *
 847  * if the vlc code is invalid and max_depth=1 than no bits will be removed
 848  * if the vlc code is invalid and max_depth>1 than the number of bits removed
 849  * is undefined
 850  */
 851 #define GET_VLC(code, name, gb, table, bits, max_depth)\
 852 {\
 853     int n, index, nb_bits;\
 854 \
 855     index= SHOW_UBITS(name, gb, bits);\
 856     code = table[index][0];\
 857     n    = table[index][1];\
 858 \
 859     if(max_depth > 1 && n < 0){\
 860         LAST_SKIP_BITS(name, gb, bits)\
 861         UPDATE_CACHE(name, gb)\
 862 \
 863         nb_bits = -n;\
 864 \
 865         index= SHOW_UBITS(name, gb, nb_bits) + code;\
 866         code = table[index][0];\
 867         n    = table[index][1];\
 868         if(max_depth > 2 && n < 0){\
 869             LAST_SKIP_BITS(name, gb, nb_bits)\
 870             UPDATE_CACHE(name, gb)\
 871 \
 872             nb_bits = -n;\
 873 \
 874             index= SHOW_UBITS(name, gb, nb_bits) + code;\
 875             code = table[index][0];\
 876             n    = table[index][1];\
 877         }\
 878     }\
 879     SKIP_BITS(name, gb, n)\
 880 }
 881
 882 #define GET_RL_VLC(level, run, name, gb, table, bits, max_depth, need_update)\
 883 {\
 884     int n, index, nb_bits;\
 885 \
 886     index= SHOW_UBITS(name, gb, bits);\
 887     level = table[index].level;\
 888     n     = table[index].len;\
 889 \
 890     if(max_depth > 1 && n < 0){\
 891         SKIP_BITS(name, gb, bits)\
 892         if(need_update){\
 893             UPDATE_CACHE(name, gb)\
 894         }\
 895 \
 896         nb_bits = -n;\
 897 \
 898         index= SHOW_UBITS(name, gb, nb_bits) + level;\
 899         level = table[index].level;\
 900         n     = table[index].len;\
 901     }\
 902     run= table[index].run;\
 903     SKIP_BITS(name, gb, n)\
 904 }
 905
 906
 907 /**
 908  * parses a vlc code, faster then get_vlc()
 909  * @param bits is the number of bits which will be read at once, must be
 910  *             identical to nb_bits in init_vlc()
 911  * @param max_depth is the number of times bits bits must be read to completely
 912  *                  read the longest vlc code
 913  *                  = (max_vlc_length + bits - 1) / bits
 914  */
 915 static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE (*table)[2],
 916                                   int bits, int max_depth)
 917 {
 918     int code;
 919
 920     OPEN_READER(re, s)
 921     UPDATE_CACHE(re, s)
 922
 923     GET_VLC(code, re, s, table, bits, max_depth)
 924
 925     CLOSE_READER(re, s)
 926     return code;
 927 }
 928
 929 #ifdef TRACE
 930 static inline void print_bin(int bits, int n){
 931     int i;
 932
 933     for(i=n-1; i>=0; i--){
 934         av_log(NULL, AV_LOG_DEBUG, "%d", (bits>>i)&1);
 935     }
 936     for(i=n; i<24; i++)
 937         av_log(NULL, AV_LOG_DEBUG, " ");
 938 }
 939
 940 static inline int get_bits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
 941     int r= get_bits(s, n);
 942
 943     print_bin(r, n);
 944     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);
 945     return r;
 946 }
 947
 948 static inline int get_vlc_trace(GetBitContext *s, VLC_TYPE (*table)[2], int bits, int max_depth, char *file, const char *func, int line){
 949     int show= show_bits(s, 24);
 950     int pos= get_bits_count(s);
 951     int r= get_vlc2(s, table, bits, max_depth);
 952     int len= get_bits_count(s) - pos;
 953     int bits2= show>>(24-len);
 954
 955     print_bin(bits2, len);
 956
 957     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d vlc @%5d in %s %s:%d\n", bits2, len, r, pos, file, func, line);
 958     return r;
 959 }
 960
 961 static inline int get_xbits_trace(GetBitContext *s, int n, char *file, const char *func, int line){
 962     int show= show_bits(s, n);
 963     int r= get_xbits(s, n);
 964
 965     print_bin(show, n);
 966     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);
 967     return r;
 968 }
 969
 970 #define get_bits(s, n)  get_bits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 971 #define get_bits1(s)    get_bits_trace(s, 1, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 972 #define get_xbits(s, n) get_xbits_trace(s, n, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 973 #define get_vlc(s, vlc)            get_vlc_trace(s, (vlc)->table, (vlc)->bits, 3, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 974 #define get_vlc2(s, tab, bits, max) get_vlc_trace(s, tab, bits, max, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 975
 976 #define tprintf(p, ...) av_log(p, AV_LOG_DEBUG, __VA_ARGS__)
 977
 978 #else //TRACE
 979 #define tprintf(p, ...) {}
 980 #endif
 981
 982 static inline int decode012(GetBitContext *gb){
 983     int n;
 984     n = get_bits1(gb);
 985     if (n == 0)
 986         return 0;
 987     else
 988         return get_bits1(gb) + 1;
 989 }
 990
 991 #endif /* BITSTREAM_H */