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 library 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 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 /**
  23  * @file golomb.h
  24  * @brief
  25  *     exp golomb vlc stuff
  26  * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
  27  */
  28
  29 #define INVALID_VLC           0x80000000
  30
  31 extern const uint8_t ff_golomb_vlc_len[512];
  32 extern const uint8_t ff_ue_golomb_vlc_code[512];
  33 extern const  int8_t ff_se_golomb_vlc_code[512];
  34 extern const uint8_t ff_ue_golomb_len[256];
  35
  36 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
  37 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
  38 extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
  39
  40
  41  /**
  42  * read unsigned exp golomb code.
  43  */
  44 static inline int get_ue_golomb(GetBitContext *gb){
  45     unsigned int buf;
  46     int log;
  47
  48     OPEN_READER(re, gb);
  49     UPDATE_CACHE(re, gb);
  50     buf=GET_CACHE(re, gb);
  51
  52     if(buf >= (1<<27)){
  53         buf >>= 32 - 9;
  54         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
  55         CLOSE_READER(re, gb);
  56
  57         return ff_ue_golomb_vlc_code[buf];
  58     }else{
  59         log= 2*av_log2(buf) - 31;
  60         buf>>= log;
  61         buf--;
  62         LAST_SKIP_BITS(re, gb, 32 - log);
  63         CLOSE_READER(re, gb);
  64
  65         return buf;
  66     }
  67 }
  68
  69 static inline int svq3_get_ue_golomb(GetBitContext *gb){
  70     uint32_t buf;
  71     int log;
  72
  73     OPEN_READER(re, gb);
  74     UPDATE_CACHE(re, gb);
  75     buf=GET_CACHE(re, gb);
  76
  77     if(buf&0xAA800000){
  78         buf >>= 32 - 8;
  79         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
  80         CLOSE_READER(re, gb);
  81
  82         return ff_interleaved_ue_golomb_vlc_code[buf];
  83     }else{
  84         LAST_SKIP_BITS(re, gb, 8);
  85         UPDATE_CACHE(re, gb);
  86         buf |= 1 | (GET_CACHE(re, gb) >> 8);
  87
  88         if((buf & 0xAAAAAAAA) == 0)
  89             return INVALID_VLC;
  90
  91         for(log=31; (buf & 0x80000000) == 0; log--){
  92             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
  93         }
  94
  95         LAST_SKIP_BITS(re, gb, 63 - 2*log - 8);
  96         CLOSE_READER(re, gb);
  97
  98         return ((buf << log) >> log) - 1;
  99     }
 100 }
 101
 102 /**
 103  * read unsigned truncated exp golomb code.
 104  */
 105 static inline int get_te0_golomb(GetBitContext *gb, int range){
 106     assert(range >= 1);
 107
 108     if(range==1)      return 0;
 109     else if(range==2) return get_bits1(gb)^1;
 110     else              return get_ue_golomb(gb);
 111 }
 112
 113 /**
 114  * read unsigned truncated exp golomb code.
 115  */
 116 static inline int get_te_golomb(GetBitContext *gb, int range){
 117     assert(range >= 1);
 118
 119     if(range==2) return get_bits1(gb)^1;
 120     else         return get_ue_golomb(gb);
 121 }
 122
 123
 124 /**
 125  * read signed exp golomb code.
 126  */
 127 static inline int get_se_golomb(GetBitContext *gb){
 128     unsigned int buf;
 129     int log;
 130
 131     OPEN_READER(re, gb);
 132     UPDATE_CACHE(re, gb);
 133     buf=GET_CACHE(re, gb);
 134
 135     if(buf >= (1<<27)){
 136         buf >>= 32 - 9;
 137         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
 138         CLOSE_READER(re, gb);
 139
 140         return ff_se_golomb_vlc_code[buf];
 141     }else{
 142         log= 2*av_log2(buf) - 31;
 143         buf>>= log;
 144
 145         LAST_SKIP_BITS(re, gb, 32 - log);
 146         CLOSE_READER(re, gb);
 147
 148         if(buf&1) buf= -(buf>>1);
 149         else      buf=  (buf>>1);
 150
 151         return buf;
 152     }
 153 }
 154
 155 static inline int svq3_get_se_golomb(GetBitContext *gb){
 156     unsigned int buf;
 157     int log;
 158
 159     OPEN_READER(re, gb);
 160     UPDATE_CACHE(re, gb);
 161     buf=GET_CACHE(re, gb);
 162
 163     if(buf&0xAA800000){
 164         buf >>= 32 - 8;
 165         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
 166         CLOSE_READER(re, gb);
 167
 168         return ff_interleaved_se_golomb_vlc_code[buf];
 169     }else{
 170         buf |=1;
 171         if((buf & 0xAAAAAAAA) == 0)
 172             return INVALID_VLC;
 173
 174         for(log=31; (buf & 0x80000000) == 0; log--){
 175             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
 176         }
 177
 178         LAST_SKIP_BITS(re, gb, 63 - 2*log);
 179         CLOSE_READER(re, gb);
 180
 181         return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
 182     }
 183 }
 184
 185 /**
 186  * read unsigned golomb rice code (ffv1).
 187  */
 188 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len){
 189     unsigned int buf;
 190     int log;
 191
 192     OPEN_READER(re, gb);
 193     UPDATE_CACHE(re, gb);
 194     buf=GET_CACHE(re, gb);
 195
 196     log= av_log2(buf);
 197
 198     if(log > 31-limit){
 199         buf >>= log - k;
 200         buf += (30-log)<<k;
 201         LAST_SKIP_BITS(re, gb, 32 + k - log);
 202         CLOSE_READER(re, gb);
 203
 204         return buf;
 205     }else{
 206         buf >>= 32 - limit - esc_len;
 207         LAST_SKIP_BITS(re, gb, esc_len + limit);
 208         CLOSE_READER(re, gb);
 209
 210         return buf + limit - 1;
 211     }
 212 }
 213
 214 /**
 215  * read unsigned golomb rice code (jpegls).
 216  */
 217 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len){
 218     unsigned int buf;
 219     int log;
 220
 221     OPEN_READER(re, gb);
 222     UPDATE_CACHE(re, gb);
 223     buf=GET_CACHE(re, gb);
 224
 225     log= av_log2(buf);
 226
 227     if(log > 31-11){
 228         buf >>= log - k;
 229         buf += (30-log)<<k;
 230         LAST_SKIP_BITS(re, gb, 32 + k - log);
 231         CLOSE_READER(re, gb);
 232
 233         return buf;
 234     }else{
 235         int i;
 236         for(i=0; SHOW_UBITS(re, gb, 1) == 0; i++){
 237             LAST_SKIP_BITS(re, gb, 1);
 238             UPDATE_CACHE(re, gb);
 239         }
 240         SKIP_BITS(re, gb, 1);
 241
 242         if(i < limit - 1){
 243             if(k){
 244                 buf = SHOW_UBITS(re, gb, k);
 245                 LAST_SKIP_BITS(re, gb, k);
 246             }else{
 247                 buf=0;
 248             }
 249
 250             CLOSE_READER(re, gb);
 251             return buf + (i<<k);
 252         }else if(i == limit - 1){
 253             buf = SHOW_UBITS(re, gb, esc_len);
 254             LAST_SKIP_BITS(re, gb, esc_len);
 255             CLOSE_READER(re, gb);
 256
 257             return buf + 1;
 258         }else
 259             return -1;
 260     }
 261 }
 262
 263 /**
 264  * read signed golomb rice code (ffv1).
 265  */
 266 static inline int get_sr_golomb_ffv1(GetBitContext *gb, int k, int limit, int esc_len){
 267     int v= get_ur_golomb(gb, k, limit, esc_len);
 268
 269     v++;
 270     if (v&1) return v>>1;
 271     else return -(v>>1);
 272
 273 //    return (v>>1) ^ -(v&1);
 274 }
 275 /**
 276
 277  * read signed golomb rice code (flac).
 278  */
 279 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit, int esc_len){
 280     int v= get_ur_golomb_jpegls(gb, k, limit, esc_len);
 281     return (v>>1) ^ -(v&1);
 282 }
 283
 284 /**
 285  * read signed golomb rice code (sonic).
 286  */
 287 static inline int get_sr_golomb_sonic(GetBitContext *gb, int k, int limit, int esc_len){
 288     int v= get_ur_golomb(gb, k, limit, esc_len);
 289
 290     v++;
 291     if (v&1) return -(v>>1);
 292     else return v>>1;
 293 }
 294
 295 #ifdef TRACE
 296
 297 static inline int get_ue(GetBitContext *s, char *file, char *func, int line){
 298     int show= show_bits(s, 24);
 299     int pos= get_bits_count(s);
 300     int i= get_ue_golomb(s);
 301     int len= get_bits_count(s) - pos;
 302     int bits= show>>(24-len);
 303
 304     print_bin(bits, len);
 305
 306     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
 307
 308     return i;
 309 }
 310
 311 static inline int get_se(GetBitContext *s, char *file, char *func, int line){
 312     int show= show_bits(s, 24);
 313     int pos= get_bits_count(s);
 314     int i= get_se_golomb(s);
 315     int len= get_bits_count(s) - pos;
 316     int bits= show>>(24-len);
 317
 318     print_bin(bits, len);
 319
 320     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
 321
 322     return i;
 323 }
 324
 325 static inline int get_te(GetBitContext *s, int r, char *file, char *func, int line){
 326     int show= show_bits(s, 24);
 327     int pos= get_bits_count(s);
 328     int i= get_te0_golomb(s, r);
 329     int len= get_bits_count(s) - pos;
 330     int bits= show>>(24-len);
 331
 332     print_bin(bits, len);
 333
 334     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n", bits, len, i, pos, file, func, line);
 335
 336     return i;
 337 }
 338
 339 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 340 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 341 #define get_te_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 342 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 343
 344 #endif
 345
 346 /**
 347  * write unsigned exp golomb code.
 348  */
 349 static inline void set_ue_golomb(PutBitContext *pb, int i){
 350     int e;
 351
 352     assert(i>=0);
 353
 354 #if 0
 355     if(i=0){
 356         put_bits(pb, 1, 1);
 357         return;
 358     }
 359 #endif
 360     if(i<256)
 361         put_bits(pb, ff_ue_golomb_len[i], i+1);
 362     else{
 363         e= av_log2(i+1);
 364
 365         put_bits(pb, 2*e+1, i+1);
 366     }
 367 }
 368
 369 /**
 370  * write truncated unsigned exp golomb code.
 371  */
 372 static inline void set_te_golomb(PutBitContext *pb, int i, int range){
 373     assert(range >= 1);
 374     assert(i<=range);
 375
 376     if(range==2) put_bits(pb, 1, i^1);
 377     else         set_ue_golomb(pb, i);
 378 }
 379
 380 /**
 381  * write signed exp golomb code.
 382  */
 383 static inline void set_se_golomb(PutBitContext *pb, int i){
 384 #if 0
 385     if(i<=0) i= -2*i;
 386     else     i=  2*i-1;
 387 #elif 1
 388     i= 2*i-1;
 389     if(i<0) i^= -1; //FIXME check if gcc does the right thing
 390 #else
 391     i= 2*i-1;
 392     i^= (i>>31);
 393 #endif
 394     set_ue_golomb(pb, i);
 395 }
 396
 397 /**
 398  * write unsigned golomb rice code (ffv1).
 399  */
 400 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, int esc_len){
 401     int e;
 402
 403     assert(i>=0);
 404
 405     e= i>>k;
 406     if(e<limit){
 407         put_bits(pb, e + k + 1, (1<<k) + (i&((1<<k)-1)));
 408     }else{
 409         put_bits(pb, limit + esc_len, i - limit + 1);
 410     }
 411 }
 412
 413 /**
 414  * write unsigned golomb rice code (jpegls).
 415  */
 416 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, int limit, int esc_len){
 417     int e;
 418
 419     assert(i>=0);
 420
 421     e= (i>>k) + 1;
 422     if(e<limit){
 423         put_bits(pb, e, 1);
 424         if(k)
 425             put_bits(pb, k, i&((1<<k)-1));
 426     }else{
 427         put_bits(pb, limit  , 1);
 428         put_bits(pb, esc_len, i - 1);
 429     }
 430 }
 431
 432 /**
 433  * write signed golomb rice code (ffv1).
 434  */
 435 static inline void set_sr_golomb_ffv1(PutBitContext *pb, int i, int k, int limit, int esc_len){
 436     int v;
 437
 438     v = -2*i-1;
 439     v ^= (v>>31);
 440
 441     set_ur_golomb(pb, v, k, limit, esc_len);
 442 }
 443
 444 /**
 445  * write signed golomb rice code (flac).
 446  */
 447 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, int limit, int esc_len){
 448     int v;
 449
 450     v = -2*i-1;
 451     v ^= (v>>31);
 452
 453     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
 454 }
 455
 456 /**
 457  * write signed golomb rice code (sonic).
 458  */
 459 static inline void set_sr_golomb_sonic(PutBitContext *pb, int i, int k, int limit, int esc_len){
 460     int v;
 461
 462     v = 2*i-1;
 463     if (v<0) v ^= -1;
 464
 465     set_ur_golomb(pb, v, k, limit, esc_len);
 466 }