libavcodec/golomb.h

   1 /*
   2  * exp golomb vlc stuff
   3  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
   4  * Copyright (c) 2004 Alex Beregszaszi
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file libavcodec/golomb.h
  25  * @brief
  26  *     exp golomb vlc stuff
  27  * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
  28  */
  29
  30 #ifndef AVCODEC_GOLOMB_H
  31 #define AVCODEC_GOLOMB_H
  32
  33 #include <stdint.h>
  34 #include "get_bits.h"
  35 #include "put_bits.h"
  36
  37 #define INVALID_VLC           0x80000000
  38
  39 extern const uint8_t ff_golomb_vlc_len[512];
  40 extern const uint8_t ff_ue_golomb_vlc_code[512];
  41 extern const  int8_t ff_se_golomb_vlc_code[512];
  42 extern const uint8_t ff_ue_golomb_len[256];
  43
  44 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
  45 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
  46 extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
  47 extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
  48
  49
  50  /**
  51  * read unsigned exp golomb code.
  52  */
  53 static inline int get_ue_golomb(GetBitContext *gb){
  54     unsigned int buf;
  55     int log;
  56
  57     OPEN_READER(re, gb);
  58     UPDATE_CACHE(re, gb);
  59     buf=GET_CACHE(re, gb);
  60
  61     if(buf >= (1<<27)){
  62         buf >>= 32 - 9;
  63         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
  64         CLOSE_READER(re, gb);
  65
  66         return ff_ue_golomb_vlc_code[buf];
  67     }else{
  68         log= 2*av_log2(buf) - 31;
  69         buf>>= log;
  70         buf--;
  71         LAST_SKIP_BITS(re, gb, 32 - log);
  72         CLOSE_READER(re, gb);
  73
  74         return buf;
  75     }
  76 }
  77
  78  /**
  79  * read unsigned exp golomb code, constraint to a max of 31.
  80  * the return value is undefined if the stored value exceeds 31.
  81  */
  82 static inline int get_ue_golomb_31(GetBitContext *gb){
  83     unsigned int buf;
  84
  85     OPEN_READER(re, gb);
  86     UPDATE_CACHE(re, gb);
  87     buf=GET_CACHE(re, gb);
  88
  89     buf >>= 32 - 9;
  90     LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
  91     CLOSE_READER(re, gb);
  92
  93     return ff_ue_golomb_vlc_code[buf];
  94 }
  95
  96 static inline int svq3_get_ue_golomb(GetBitContext *gb){
  97     uint32_t buf;
  98
  99     OPEN_READER(re, gb);
 100     UPDATE_CACHE(re, gb);
 101     buf=GET_CACHE(re, gb);
 102
 103     if(buf&0xAA800000){
 104         buf >>= 32 - 8;
 105         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
 106         CLOSE_READER(re, gb);
 107
 108         return ff_interleaved_ue_golomb_vlc_code[buf];
 109     }else{
 110         int ret = 1;
 111
 112         while (1) {
 113             buf >>= 32 - 8;
 114             LAST_SKIP_BITS(re, gb, FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
 115
 116             if (ff_interleaved_golomb_vlc_len[buf] != 9){
 117                 ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
 118                 ret |= ff_interleaved_dirac_golomb_vlc_code[buf];
 119                 break;
 120             }
 121             ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
 122             UPDATE_CACHE(re, gb);
 123             buf = GET_CACHE(re, gb);
 124         }
 125
 126         CLOSE_READER(re, gb);
 127         return ret - 1;
 128     }
 129 }
 130
 131 /**
 132  * read unsigned truncated exp golomb code.
 133  */
 134 static inline int get_te0_golomb(GetBitContext *gb, int range){
 135     assert(range >= 1);
 136
 137     if(range==1)      return 0;
 138     else if(range==2) return get_bits1(gb)^1;
 139     else              return get_ue_golomb(gb);
 140 }
 141
 142 /**
 143  * read unsigned truncated exp golomb code.
 144  */
 145 static inline int get_te_golomb(GetBitContext *gb, int range){
 146     assert(range >= 1);
 147
 148     if(range==2) return get_bits1(gb)^1;
 149     else         return get_ue_golomb(gb);
 150 }
 151
 152
 153 /**
 154  * read signed exp golomb code.
 155  */
 156 static inline int get_se_golomb(GetBitContext *gb){
 157     unsigned int buf;
 158     int log;
 159
 160     OPEN_READER(re, gb);
 161     UPDATE_CACHE(re, gb);
 162     buf=GET_CACHE(re, gb);
 163
 164     if(buf >= (1<<27)){
 165         buf >>= 32 - 9;
 166         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
 167         CLOSE_READER(re, gb);
 168
 169         return ff_se_golomb_vlc_code[buf];
 170     }else{
 171         log= 2*av_log2(buf) - 31;
 172         buf>>= log;
 173
 174         LAST_SKIP_BITS(re, gb, 32 - log);
 175         CLOSE_READER(re, gb);
 176
 177         if(buf&1) buf= -(buf>>1);
 178         else      buf=  (buf>>1);
 179
 180         return buf;
 181     }
 182 }
 183
 184 static inline int svq3_get_se_golomb(GetBitContext *gb){
 185     unsigned int buf;
 186     int log;
 187
 188     OPEN_READER(re, gb);
 189     UPDATE_CACHE(re, gb);
 190     buf=GET_CACHE(re, gb);
 191
 192     if(buf&0xAA800000){
 193         buf >>= 32 - 8;
 194         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
 195         CLOSE_READER(re, gb);
 196
 197         return ff_interleaved_se_golomb_vlc_code[buf];
 198     }else{
 199         LAST_SKIP_BITS(re, gb, 8);
 200         UPDATE_CACHE(re, gb);
 201         buf |= 1 | (GET_CACHE(re, gb) >> 8);
 202
 203         if((buf & 0xAAAAAAAA) == 0)
 204             return INVALID_VLC;
 205
 206         for(log=31; (buf & 0x80000000) == 0; log--){
 207             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
 208         }
 209
 210         LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
 211         CLOSE_READER(re, gb);
 212
 213         return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
 214     }
 215 }
 216
 217 static inline int dirac_get_se_golomb(GetBitContext *gb){
 218     uint32_t buf;
 219     uint32_t ret;
 220
 221     ret = svq3_get_ue_golomb(gb);
 222
 223     if (ret) {
 224         OPEN_READER(re, gb);
 225         UPDATE_CACHE(re, gb);
 226         buf = SHOW_SBITS(re, gb, 1);
 227         LAST_SKIP_BITS(re, gb, 1);
 228         ret = (ret ^ buf) - buf;
 229         CLOSE_READER(re, gb);
 230     }
 231
 232     return ret;
 233 }
 234
 235 /**
 236  * read unsigned golomb rice code (ffv1).
 237  */
 238 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
 239     unsigned int buf;
 240     int log;
 241
 242     OPEN_READER(re, gb);
 243     UPDATE_CACHE(re, gb);
 244     buf=GET_CACHE(re, gb);
 245
 246     log= av_log2(buf);
 247
 248     if(log > 31-limit){
 249         buf >>= log - k;
 250         buf += (30-log)<<k;
 251         LAST_SKIP_BITS(re, gb, 32 + k - log);
 252         CLOSE_READER(re, gb);
 253
 254         return buf;
 255     }else{
 256         buf >>= 32 - limit - esc_len;
 257         LAST_SKIP_BITS(re, gb, esc_len + limit);
 258         CLOSE_READER(re, gb);
 259
 260         return buf + limit - 1;
 261     }
 262 }
 263
 264 /**
 265  * read unsigned golomb rice code (jpegls).
 266  */
 267 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
 268     unsigned int buf;
 269     int log;
 270
 271     OPEN_READER(re, gb);
 272     UPDATE_CACHE(re, gb);
 273     buf=GET_CACHE(re, gb);
 274
 275     log= av_log2(buf);
 276
 277     if(log - k >= 32-MIN_CACHE_BITS+(MIN_CACHE_BITS==32) && 32-log < limit){
 278         buf >>= log - k;
 279         buf += (30-log)<<k;
 280         LAST_SKIP_BITS(re, gb, 32 + k - log);
 281         CLOSE_READER(re, gb);
 282
 283         return buf;
 284     }else{
 285         int i;
 286         for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
 287             LAST_SKIP_BITS(re, gb, 1);
 288             UPDATE_CACHE(re, gb);
 289         }
 290         SKIP_BITS(re, gb, 1);
 291
 292         if(i < limit - 1){
 293             if(k){
 294                 buf = SHOW_UBITS(re, gb, k);
 295                 LAST_SKIP_BITS(re, gb, k);
 296             }else{
 297                 buf=0;
 298             }
 299
 300             CLOSE_READER(re, gb);
 301             return buf + (i<<k);
 302         }else if(i == limit - 1){
 303             buf = SHOW_UBITS(re, gb, esc_len);
 304             LAST_SKIP_BITS(re, gb, esc_len);
 305             CLOSE_READER(re, gb);
 306
 307             return buf + 1;
 308         }else
 309             return -1;
 310     }
 311 }
 312
 313 /**
 314  * read signed golomb rice code (ffv1).
 315  */
 316 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit, int esc_len){
 317     int v= get_ur_golomb(gb, k, limit, esc_len);
 318
 319     v++;
 320     if (v&1) return v>>1;
 321     else return -(v>>1);
 322
 323 //    return (v>>1) ^ -(v&1);
 324 }
 325
 326 /**
 327  * read signed golomb rice code (flac).
 328  */
 329 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
 330     int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
 331     return (v>>1) ^ -(v&1);
 332 }
 333
 334 /**
 335  * read unsigned golomb rice code (shorten).
 336  */
 337 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k){
 338         return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
 339 }
 340
 341 /**
 342  * read signed golomb rice code (shorten).
 343  */
 344 static inline int get_sr_golomb_shorten(GetBitContext* gb, int k)
 345 {
 346     int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
 347     if (uvar & 1)
 348         return ~(uvar >> 1);
 349     else
 350         return uvar >> 1;
 351 }
 352
 353
 354
 355 #ifdef TRACE
 356
 357 static inline int get_ue(GetBitContext *s, char *file, const char *func, int line){
 358     int show= show_bits(s, 24);
 359     int pos= get_bits_count(s);
 360     int i= get_ue_golomb(s);
 361     int len= get_bits_count(s) - pos;
 362     int bits= show>>(24-len);
 363
 364     print_bin(bits, len);
 365
 366     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
 367
 368     return i;
 369 }
 370
 371 static inline int get_se(GetBitContext *s, char *file, const char *func, int line){
 372     int show= show_bits(s, 24);
 373     int pos= get_bits_count(s);
 374     int i= get_se_golomb(s);
 375     int len= get_bits_count(s) - pos;
 376     int bits= show>>(24-len);
 377
 378     print_bin(bits, len);
 379
 380     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
 381
 382     return i;
 383 }
 384
 385 static inline int get_te(GetBitContext *s, int r, char *file, const char *func, int line){
 386     int show= show_bits(s, 24);
 387     int pos= get_bits_count(s);
 388     int i= get_te0_golomb(s, r);
 389     int len= get_bits_count(s) - pos;
 390     int bits= show>>(24-len);
 391
 392     print_bin(bits, len);
 393
 394     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
 395
 396     return i;
 397 }
 398
 399 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 400 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 401 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 402 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 403
 404 #endif
 405
 406 /**
 407  * write unsigned exp golomb code.
 408  */
 409 static inline void set_ue_golomb(PutBitContext *pb, int i){
 410     int e;
 411
 412     assert(i>=0);
 413
 414 #if 0
 415     if(i=0){
 416         put_bits(pb, 1, 1);
 417         return;
 418     }
 419 #endif
 420     if(i<256)
 421         put_bits(pb, ff_ue_golomb_len[i], i+1);
 422     else{
 423         e= av_log2(i+1);
 424
 425         put_bits(pb, 2*e+1, i+1);
 426     }
 427 }
 428
 429 /**
 430  * write truncated unsigned exp golomb code.
 431  */
 432 static inline void set_te_golomb(PutBitContext *pb, int i, int range){
 433     assert(range >= 1);
 434     assert(i<=range);
 435
 436     if(range==2) put_bits(pb, 1, i^1);
 437     else         set_ue_golomb(pb, i);
 438 }
 439
 440 /**
 441  * write signed exp golomb code. 16 bits at most.
 442  */
 443 static inline void set_se_golomb(PutBitContext *pb, int i){
 444 //    if (i>32767 || i<-32767)
 445 //        av_log(NULL,AV_LOG_ERROR,"value out of range %d\n", i);
 446 #if 0
 447     if(i<=0) i= -2*i;
 448     else     i=  2*i-1;
 449 #elif 1
 450     i= 2*i-1;
 451     if(i<0) i^= -1; //FIXME check if gcc does the right thing
 452 #else
 453     i= 2*i-1;
 454     i^= (i>>31);
 455 #endif
 456     set_ue_golomb(pb, i);
 457 }
 458
 459 /**
 460  * write unsigned golomb rice code (ffv1).
 461  */
 462 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
 463     int e;
 464
 465     assert(i>=0);
 466
 467     e= i>>k;
 468     if(e<limit){
 469         put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
 470     }else{
 471         put_bits(pb, limit + esc_len, i - limit + 1);
 472     }
 473 }
 474
 475 /**
 476  * write unsigned golomb rice code (jpegls).
 477  */
 478 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
 479     int e;
 480
 481     assert(i>=0);
 482
 483     e= (i>>k) + 1;
 484     if(e<limit){
 485         while(e > 31) {
 486             put_bits(pb, 31, 0);
 487             e -= 31;
 488         }
 489         put_bits(pb, e, 1);
 490         if(k)
 491             put_sbits(pb, k, i);
 492     }else{
 493         while(limit > 31) {
 494             put_bits(pb, 31, 0);
 495             limit -= 31;
 496         }
 497         put_bits(pb, limit  , 1);
 498         put_bits(pb, esc_len, i - 1);
 499     }
 500 }
 501
 502 /**
 503  * write signed golomb rice code (ffv1).
 504  */
 505 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
 506     int v;
 507
 508     v = -2*i-1;
 509     v ^= (v>>31);
 510
 511     set_ur_golomb(pb, v, k, limit, esc_len);
 512 }
 513
 514 /**
 515  * write signed golomb rice code (flac).
 516  */
 517 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
 518     int v;
 519
 520     v = -2*i-1;
 521     v ^= (v>>31);
 522
 523     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
 524 }
 525
 526 #endif /* AVCODEC_GOLOMB_H */