ffmpeg/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
  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
  35 #include "get_bits.h"
  36 #include "put_bits.h"
  37
  38 #define INVALID_VLC           0x80000000
  39
  40 extern const uint8_t ff_golomb_vlc_len[512];
  41 extern const uint8_t ff_ue_golomb_vlc_code[512];
  42 extern const  int8_t ff_se_golomb_vlc_code[512];
  43 extern const uint8_t ff_ue_golomb_len[256];
  44
  45 extern const uint8_t ff_interleaved_golomb_vlc_len[256];
  46 extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
  47 extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
  48 extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];
  49
  50 /**
  51  * read unsigned exp golomb code.
  52  */
  53 static inline int get_ue_golomb(GetBitContext *gb)
  54 {
  55     unsigned int buf;
  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         int log = 2 * av_log2(buf) - 31;
  69         LAST_SKIP_BITS(re, gb, 32 - log);
  70         CLOSE_READER(re, gb);
  71         if (CONFIG_FTRAPV && log < 0) {
  72             av_log(0, AV_LOG_ERROR, "Invalid UE golomb code\n");
  73             return AVERROR_INVALIDDATA;
  74         }
  75         buf >>= log;
  76         buf--;
  77
  78         return buf;
  79     }
  80 }
  81
  82 /**
  83  * Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1.
  84  */
  85 static inline unsigned get_ue_golomb_long(GetBitContext *gb)
  86 {
  87     unsigned buf, log;
  88
  89     buf = show_bits_long(gb, 32);
  90     log = 31 - av_log2(buf);
  91     skip_bits_long(gb, log);
  92
  93     return get_bits_long(gb, log + 1) - 1;
  94 }
  95
  96 /**
  97  * read unsigned exp golomb code, constraint to a max of 31.
  98  * the return value is undefined if the stored value exceeds 31.
  99  */
 100 static inline int get_ue_golomb_31(GetBitContext *gb)
 101 {
 102     unsigned int buf;
 103
 104     OPEN_READER(re, gb);
 105     UPDATE_CACHE(re, gb);
 106     buf = GET_CACHE(re, gb);
 107
 108     buf >>= 32 - 9;
 109     LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
 110     CLOSE_READER(re, gb);
 111
 112     return ff_ue_golomb_vlc_code[buf];
 113 }
 114
 115 static inline unsigned svq3_get_ue_golomb(GetBitContext *gb)
 116 {
 117     uint32_t buf;
 118
 119     OPEN_READER(re, gb);
 120     UPDATE_CACHE(re, gb);
 121     buf = GET_CACHE(re, gb);
 122
 123     if (buf & 0xAA800000) {
 124         buf >>= 32 - 8;
 125         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
 126         CLOSE_READER(re, gb);
 127
 128         return ff_interleaved_ue_golomb_vlc_code[buf];
 129     } else {
 130         unsigned ret = 1;
 131
 132         do {
 133             buf >>= 32 - 8;
 134             LAST_SKIP_BITS(re, gb,
 135                            FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));
 136
 137             if (ff_interleaved_golomb_vlc_len[buf] != 9) {
 138                 ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
 139                 ret  |= ff_interleaved_dirac_golomb_vlc_code[buf];
 140                 break;
 141             }
 142             ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
 143             UPDATE_CACHE(re, gb);
 144             buf = GET_CACHE(re, gb);
 145         } while (ret<0x8000000U && BITS_AVAILABLE(re, gb));
 146
 147         CLOSE_READER(re, gb);
 148         return ret - 1;
 149     }
 150 }
 151
 152 /**
 153  * read unsigned truncated exp golomb code.
 154  */
 155 static inline int get_te0_golomb(GetBitContext *gb, int range)
 156 {
 157     av_assert2(range >= 1);
 158
 159     if (range == 1)
 160         return 0;
 161     else if (range == 2)
 162         return get_bits1(gb) ^ 1;
 163     else
 164         return get_ue_golomb(gb);
 165 }
 166
 167 /**
 168  * read unsigned truncated exp golomb code.
 169  */
 170 static inline int get_te_golomb(GetBitContext *gb, int range)
 171 {
 172     av_assert2(range >= 1);
 173
 174     if (range == 2)
 175         return get_bits1(gb) ^ 1;
 176     else
 177         return get_ue_golomb(gb);
 178 }
 179
 180 /**
 181  * read signed exp golomb code.
 182  */
 183 static inline int get_se_golomb(GetBitContext *gb)
 184 {
 185     unsigned int buf;
 186
 187     OPEN_READER(re, gb);
 188     UPDATE_CACHE(re, gb);
 189     buf = GET_CACHE(re, gb);
 190
 191     if (buf >= (1 << 27)) {
 192         buf >>= 32 - 9;
 193         LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
 194         CLOSE_READER(re, gb);
 195
 196         return ff_se_golomb_vlc_code[buf];
 197     } else {
 198         int log = av_log2(buf);
 199         LAST_SKIP_BITS(re, gb, 31 - log);
 200         UPDATE_CACHE(re, gb);
 201         buf = GET_CACHE(re, gb);
 202
 203         buf >>= log;
 204
 205         LAST_SKIP_BITS(re, gb, 32 - log);
 206         CLOSE_READER(re, gb);
 207
 208         if (buf & 1)
 209             buf = -(buf >> 1);
 210         else
 211             buf = (buf >> 1);
 212
 213         return buf;
 214     }
 215 }
 216
 217 static inline int get_se_golomb_long(GetBitContext *gb)
 218 {
 219     unsigned int buf = get_ue_golomb_long(gb);
 220
 221     if (buf & 1)
 222         buf = (buf + 1) >> 1;
 223     else
 224         buf = -(buf >> 1);
 225
 226     return buf;
 227 }
 228
 229 static inline int svq3_get_se_golomb(GetBitContext *gb)
 230 {
 231     unsigned int buf;
 232
 233     OPEN_READER(re, gb);
 234     UPDATE_CACHE(re, gb);
 235     buf = GET_CACHE(re, gb);
 236
 237     if (buf & 0xAA800000) {
 238         buf >>= 32 - 8;
 239         LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
 240         CLOSE_READER(re, gb);
 241
 242         return ff_interleaved_se_golomb_vlc_code[buf];
 243     } else {
 244         int log;
 245         LAST_SKIP_BITS(re, gb, 8);
 246         UPDATE_CACHE(re, gb);
 247         buf |= 1 | (GET_CACHE(re, gb) >> 8);
 248
 249         if ((buf & 0xAAAAAAAA) == 0)
 250             return INVALID_VLC;
 251
 252         for (log = 31; (buf & 0x80000000) == 0; log--)
 253             buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);
 254
 255         LAST_SKIP_BITS(re, gb, 63 - 2 * log - 8);
 256         CLOSE_READER(re, gb);
 257
 258         return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
 259     }
 260 }
 261
 262 static inline int dirac_get_se_golomb(GetBitContext *gb)
 263 {
 264     uint32_t ret = svq3_get_ue_golomb(gb);
 265
 266     if (ret) {
 267         uint32_t buf;
 268         OPEN_READER(re, gb);
 269         UPDATE_CACHE(re, gb);
 270         buf = SHOW_SBITS(re, gb, 1);
 271         LAST_SKIP_BITS(re, gb, 1);
 272         ret = (ret ^ buf) - buf;
 273         CLOSE_READER(re, gb);
 274     }
 275
 276     return ret;
 277 }
 278
 279 /**
 280  * read unsigned golomb rice code (ffv1).
 281  */
 282 static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
 283                                 int esc_len)
 284 {
 285     unsigned int buf;
 286     int log;
 287
 288     OPEN_READER(re, gb);
 289     UPDATE_CACHE(re, gb);
 290     buf = GET_CACHE(re, gb);
 291
 292     log = av_log2(buf);
 293
 294     if (log > 31 - limit) {
 295         buf >>= log - k;
 296         buf  += (30 - log) << k;
 297         LAST_SKIP_BITS(re, gb, 32 + k - log);
 298         CLOSE_READER(re, gb);
 299
 300         return buf;
 301     } else {
 302         LAST_SKIP_BITS(re, gb, limit);
 303         UPDATE_CACHE(re, gb);
 304
 305         buf = SHOW_UBITS(re, gb, esc_len);
 306
 307         LAST_SKIP_BITS(re, gb, esc_len);
 308         CLOSE_READER(re, gb);
 309
 310         return buf + limit - 1;
 311     }
 312 }
 313
 314 /**
 315  * read unsigned golomb rice code (jpegls).
 316  */
 317 static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
 318                                        int esc_len)
 319 {
 320     unsigned int buf;
 321     int log;
 322
 323     OPEN_READER(re, gb);
 324     UPDATE_CACHE(re, gb);
 325     buf = GET_CACHE(re, gb);
 326
 327     log = av_log2(buf);
 328
 329     if (log - k >= 32 - MIN_CACHE_BITS + (MIN_CACHE_BITS == 32) &&
 330         32 - log < limit) {
 331         buf >>= log - k;
 332         buf  += (30 - log) << k;
 333         LAST_SKIP_BITS(re, gb, 32 + k - log);
 334         CLOSE_READER(re, gb);
 335
 336         return buf;
 337     } else {
 338         int i;
 339         for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++) {
 340             if (gb->size_in_bits <= re_index)
 341                 return -1;
 342             LAST_SKIP_BITS(re, gb, 1);
 343             UPDATE_CACHE(re, gb);
 344         }
 345         SKIP_BITS(re, gb, 1);
 346
 347         if (i < limit - 1) {
 348             if (k) {
 349                 buf = SHOW_UBITS(re, gb, k);
 350                 LAST_SKIP_BITS(re, gb, k);
 351             } else {
 352                 buf = 0;
 353             }
 354
 355             CLOSE_READER(re, gb);
 356             return buf + (i << k);
 357         } else if (i == limit - 1) {
 358             buf = SHOW_UBITS(re, gb, esc_len);
 359             LAST_SKIP_BITS(re, gb, esc_len);
 360             CLOSE_READER(re, gb);
 361
 362             return buf + 1;
 363         } else
 364             return -1;
 365     }
 366 }
 367
 368 /**
 369  * read signed golomb rice code (ffv1).
 370  */
 371 static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
 372                                 int esc_len)
 373 {
 374     int v = get_ur_golomb(gb, k, limit, esc_len);
 375
 376     v++;
 377     if (v & 1)
 378         return v >> 1;
 379     else
 380         return -(v >> 1);
 381
 382 //    return (v>>1) ^ -(v&1);
 383 }
 384
 385 /**
 386  * read signed golomb rice code (flac).
 387  */
 388 static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit,
 389                                      int esc_len)
 390 {
 391     int v = get_ur_golomb_jpegls(gb, k, limit, esc_len);
 392     return (v >> 1) ^ -(v & 1);
 393 }
 394
 395 /**
 396  * read unsigned golomb rice code (shorten).
 397  */
 398 static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k)
 399 {
 400     return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
 401 }
 402
 403 /**
 404  * read signed golomb rice code (shorten).
 405  */
 406 static inline int get_sr_golomb_shorten(GetBitContext *gb, int k)
 407 {
 408     int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
 409     if (uvar & 1)
 410         return ~(uvar >> 1);
 411     else
 412         return uvar >> 1;
 413 }
 414
 415 #ifdef TRACE
 416
 417 static inline int get_ue(GetBitContext *s, const char *file, const char *func,
 418                          int line)
 419 {
 420     int show = show_bits(s, 24);
 421     int pos  = get_bits_count(s);
 422     int i    = get_ue_golomb(s);
 423     int len  = get_bits_count(s) - pos;
 424     int bits = show >> (24 - len);
 425
 426     print_bin(bits, len);
 427
 428     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n",
 429            bits, len, i, pos, file, func, line);
 430
 431     return i;
 432 }
 433
 434 static inline int get_se(GetBitContext *s, const char *file, const char *func,
 435                          int line)
 436 {
 437     int show = show_bits(s, 24);
 438     int pos  = get_bits_count(s);
 439     int i    = get_se_golomb(s);
 440     int len  = get_bits_count(s) - pos;
 441     int bits = show >> (24 - len);
 442
 443     print_bin(bits, len);
 444
 445     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n",
 446            bits, len, i, pos, file, func, line);
 447
 448     return i;
 449 }
 450
 451 static inline int get_te(GetBitContext *s, int r, char *file, const char *func,
 452                          int line)
 453 {
 454     int show = show_bits(s, 24);
 455     int pos  = get_bits_count(s);
 456     int i    = get_te0_golomb(s, r);
 457     int len  = get_bits_count(s) - pos;
 458     int bits = show >> (24 - len);
 459
 460     print_bin(bits, len);
 461
 462     av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n",
 463            bits, len, i, pos, file, func, line);
 464
 465     return i;
 466 }
 467
 468 #define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 469 #define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 470 #define get_te_golomb(a, r)  get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 471 #define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
 472
 473 #endif /* TRACE */
 474
 475 /**
 476  * write unsigned exp golomb code.
 477  */
 478 static inline void set_ue_golomb(PutBitContext *pb, int i)
 479 {
 480     av_assert2(i >= 0);
 481
 482 #if 0
 483     if (i = 0) {
 484         put_bits(pb, 1, 1);
 485         return;
 486     }
 487 #endif
 488     if (i < 256)
 489         put_bits(pb, ff_ue_golomb_len[i], i + 1);
 490     else {
 491         int e = av_log2(i + 1);
 492         put_bits(pb, 2 * e + 1, i + 1);
 493     }
 494 }
 495
 496 /**
 497  * write truncated unsigned exp golomb code.
 498  */
 499 static inline void set_te_golomb(PutBitContext *pb, int i, int range)
 500 {
 501     av_assert2(range >= 1);
 502     av_assert2(i <= range);
 503
 504     if (range == 2)
 505         put_bits(pb, 1, i ^ 1);
 506     else
 507         set_ue_golomb(pb, i);
 508 }
 509
 510 /**
 511  * write signed exp golomb code. 16 bits at most.
 512  */
 513 static inline void set_se_golomb(PutBitContext *pb, int i)
 514 {
 515 #if 0
 516     if (i <= 0)
 517         i = -2 * i;
 518     else
 519         i = 2 * i - 1;
 520 #elif 1
 521     i = 2 * i - 1;
 522     if (i < 0)
 523         i ^= -1;    //FIXME check if gcc does the right thing
 524 #else
 525     i  = 2 * i - 1;
 526     i ^= (i >> 31);
 527 #endif
 528     set_ue_golomb(pb, i);
 529 }
 530
 531 /**
 532  * write unsigned golomb rice code (ffv1).
 533  */
 534 static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit,
 535                                  int esc_len)
 536 {
 537     int e;
 538
 539     av_assert2(i >= 0);
 540
 541     e = i >> k;
 542     if (e < limit)
 543         put_bits(pb, e + k + 1, (1 << k) + (i & ((1 << k) - 1)));
 544     else
 545         put_bits(pb, limit + esc_len, i - limit + 1);
 546 }
 547
 548 /**
 549  * write unsigned golomb rice code (jpegls).
 550  */
 551 static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k,
 552                                         int limit, int esc_len)
 553 {
 554     int e;
 555
 556     av_assert2(i >= 0);
 557
 558     e = (i >> k) + 1;
 559     if (e < limit) {
 560         while (e > 31) {
 561             put_bits(pb, 31, 0);
 562             e -= 31;
 563         }
 564         put_bits(pb, e, 1);
 565         if (k)
 566             put_sbits(pb, k, i);
 567     } else {
 568         while (limit > 31) {
 569             put_bits(pb, 31, 0);
 570             limit -= 31;
 571         }
 572         put_bits(pb, limit, 1);
 573         put_bits(pb, esc_len, i - 1);
 574     }
 575 }
 576
 577 /**
 578  * write signed golomb rice code (ffv1).
 579  */
 580 static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit,
 581                                  int esc_len)
 582 {
 583     int v;
 584
 585     v  = -2 * i - 1;
 586     v ^= (v >> 31);
 587
 588     set_ur_golomb(pb, v, k, limit, esc_len);
 589 }
 590
 591 /**
 592  * write signed golomb rice code (flac).
 593  */
 594 static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k,
 595                                       int limit, int esc_len)
 596 {
 597     int v;
 598
 599     v  = -2 * i - 1;
 600     v ^= (v >> 31);
 601
 602     set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
 603 }
 604
 605 #endif /* AVCODEC_GOLOMB_H */