git.sesse.net Git - ffmpeg/blob - libavcodec/mpeg12dec.c

   1 /*
   2  * MPEG-1/2 decoder
   3  * Copyright (c) 2000, 2001 Fabrice Bellard
   4  * Copyright (c) 2002-2013 Michael Niedermayer <michaelni@gmx.at>
   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  * MPEG-1/2 decoder
  26  */
  27
  28 #define UNCHECKED_BITSTREAM_READER 1
  29 #include <inttypes.h>
  30
  31 #include "libavutil/attributes.h"
  32 #include "libavutil/imgutils.h"
  33 #include "libavutil/internal.h"
  34 #include "libavutil/stereo3d.h"
  35
  36 #include "avcodec.h"
  37 #include "bytestream.h"
  38 #include "error_resilience.h"
  39 #include "idctdsp.h"
  40 #include "internal.h"
  41 #include "mpeg_er.h"
  42 #include "mpeg12.h"
  43 #include "mpeg12data.h"
  44 #include "mpegutils.h"
  45 #include "mpegvideo.h"
  46 #include "mpegvideodata.h"
  47 #include "thread.h"
  48 #include "version.h"
  49 #include "vdpau_compat.h"
  50 #include "xvmc_internal.h"
  51
  52 typedef struct Mpeg1Context {
  53     MpegEncContext mpeg_enc_ctx;
  54     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
  55     int repeat_field;           /* true if we must repeat the field */
  56     AVPanScan pan_scan;         /* some temporary storage for the panscan */
  57     AVStereo3D stereo3d;
  58     int has_stereo3d;
  59     uint8_t *a53_caption;
  60     int a53_caption_size;
  61     uint8_t afd;
  62     int has_afd;
  63     int slice_count;
  64     AVRational save_aspect;
  65     int save_width, save_height, save_progressive_seq;
  66     AVRational frame_rate_ext;  /* MPEG-2 specific framerate modificator */
  67     int sync;                   /* Did we reach a sync point like a GOP/SEQ/KEYFrame? */
  68     int tmpgexs;
  69     int first_slice;
  70     int extradata_decoded;
  71 } Mpeg1Context;
  72
  73 #define MB_TYPE_ZERO_MV   0x20000000
  74
  75 static const uint32_t ptype2mb_type[7] = {
  76                     MB_TYPE_INTRA,
  77                     MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
  78                     MB_TYPE_L0,
  79                     MB_TYPE_L0 | MB_TYPE_CBP,
  80     MB_TYPE_QUANT | MB_TYPE_INTRA,
  81     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
  82     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP,
  83 };
  84
  85 static const uint32_t btype2mb_type[11] = {
  86                     MB_TYPE_INTRA,
  87                     MB_TYPE_L1,
  88                     MB_TYPE_L1   | MB_TYPE_CBP,
  89                     MB_TYPE_L0,
  90                     MB_TYPE_L0   | MB_TYPE_CBP,
  91                     MB_TYPE_L0L1,
  92                     MB_TYPE_L0L1 | MB_TYPE_CBP,
  93     MB_TYPE_QUANT | MB_TYPE_INTRA,
  94     MB_TYPE_QUANT | MB_TYPE_L1   | MB_TYPE_CBP,
  95     MB_TYPE_QUANT | MB_TYPE_L0   | MB_TYPE_CBP,
  96     MB_TYPE_QUANT | MB_TYPE_L0L1 | MB_TYPE_CBP,
  97 };
  98
  99 /* as H.263, but only 17 codes */
 100 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 101 {
 102     int code, sign, val, shift;
 103
 104     code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
 105     if (code == 0)
 106         return pred;
 107     if (code < 0)
 108         return 0xffff;
 109
 110     sign  = get_bits1(&s->gb);
 111     shift = fcode - 1;
 112     val   = code;
 113     if (shift) {
 114         val  = (val - 1) << shift;
 115         val |= get_bits(&s->gb, shift);
 116         val++;
 117     }
 118     if (sign)
 119         val = -val;
 120     val += pred;
 121
 122     /* modulo decoding */
 123     return sign_extend(val, 5 + shift);
 124 }
 125
 126 #define check_scantable_index(ctx, x)                                         \
 127     do {                                                                      \
 128         if ((x) > 63) {                                                       \
 129             av_log(ctx->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",     \
 130                    ctx->mb_x, ctx->mb_y);                                     \
 131             return AVERROR_INVALIDDATA;                                       \
 132         }                                                                     \
 133     } while (0)
 134
 135 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 136                                            int16_t *block, int n)
 137 {
 138     int level, dc, diff, i, j, run;
 139     int component;
 140     RLTable *rl                  = &ff_rl_mpeg1;
 141     uint8_t *const scantable     = s->intra_scantable.permutated;
 142     const uint16_t *quant_matrix = s->intra_matrix;
 143     const int qscale             = s->qscale;
 144
 145     /* DC coefficient */
 146     component = (n <= 3 ? 0 : n - 4 + 1);
 147     diff = decode_dc(&s->gb, component);
 148     if (diff >= 0xffff)
 149         return AVERROR_INVALIDDATA;
 150     dc  = s->last_dc[component];
 151     dc += diff;
 152     s->last_dc[component] = dc;
 153     block[0] = dc * quant_matrix[0];
 154     ff_tlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
 155     i = 0;
 156     {
 157         OPEN_READER(re, &s->gb);
 158         UPDATE_CACHE(re, &s->gb);
 159         if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 160             goto end;
 161
 162         /* now quantify & encode AC coefficients */
 163         for (;;) {
 164             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 165                        TEX_VLC_BITS, 2, 0);
 166
 167             if (level != 0) {
 168                 i += run;
 169                 check_scantable_index(s, i);
 170                 j = scantable[i];
 171                 level = (level * qscale * quant_matrix[j]) >> 4;
 172                 level = (level - 1) | 1;
 173                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 174                         SHOW_SBITS(re, &s->gb, 1);
 175                 SKIP_BITS(re, &s->gb, 1);
 176             } else {
 177                 /* escape */
 178                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 179                 LAST_SKIP_BITS(re, &s->gb, 6);
 180                 UPDATE_CACHE(re, &s->gb);
 181                 level = SHOW_SBITS(re, &s->gb, 8);
 182                 SKIP_BITS(re, &s->gb, 8);
 183                 if (level == -128) {
 184                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 185                     SKIP_BITS(re, &s->gb, 8);
 186                 } else if (level == 0) {
 187                     level = SHOW_UBITS(re, &s->gb, 8);
 188                     SKIP_BITS(re, &s->gb, 8);
 189                 }
 190                 i += run;
 191                 check_scantable_index(s, i);
 192                 j = scantable[i];
 193                 if (level < 0) {
 194                     level = -level;
 195                     level = (level * qscale * quant_matrix[j]) >> 4;
 196                     level = (level - 1) | 1;
 197                     level = -level;
 198                 } else {
 199                     level = (level * qscale * quant_matrix[j]) >> 4;
 200                     level = (level - 1) | 1;
 201                 }
 202             }
 203
 204             block[j] = level;
 205             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 206                break;
 207
 208             UPDATE_CACHE(re, &s->gb);
 209         }
 210 end:
 211         LAST_SKIP_BITS(re, &s->gb, 2);
 212         CLOSE_READER(re, &s->gb);
 213     }
 214     s->block_last_index[n] = i;
 215     return 0;
 216 }
 217
 218 int ff_mpeg1_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
 219 {
 220     return mpeg1_decode_block_intra(s, block, n);
 221 }
 222
 223 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 224                                            int16_t *block, int n)
 225 {
 226     int level, i, j, run;
 227     RLTable *rl                  = &ff_rl_mpeg1;
 228     uint8_t *const scantable     = s->intra_scantable.permutated;
 229     const uint16_t *quant_matrix = s->inter_matrix;
 230     const int qscale             = s->qscale;
 231
 232     {
 233         OPEN_READER(re, &s->gb);
 234         i = -1;
 235         // special case for first coefficient, no need to add second VLC table
 236         UPDATE_CACHE(re, &s->gb);
 237         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 238             level = (3 * qscale * quant_matrix[0]) >> 5;
 239             level = (level - 1) | 1;
 240             if (GET_CACHE(re, &s->gb) & 0x40000000)
 241                 level = -level;
 242             block[0] = level;
 243             i++;
 244             SKIP_BITS(re, &s->gb, 2);
 245             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 246                 goto end;
 247         }
 248         /* now quantify & encode AC coefficients */
 249         for (;;) {
 250             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 251                        TEX_VLC_BITS, 2, 0);
 252
 253             if (level != 0) {
 254                 i += run;
 255                 check_scantable_index(s, i);
 256                 j = scantable[i];
 257                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 258                 level = (level - 1) | 1;
 259                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 260                         SHOW_SBITS(re, &s->gb, 1);
 261                 SKIP_BITS(re, &s->gb, 1);
 262             } else {
 263                 /* escape */
 264                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 265                 LAST_SKIP_BITS(re, &s->gb, 6);
 266                 UPDATE_CACHE(re, &s->gb);
 267                 level = SHOW_SBITS(re, &s->gb, 8);
 268                 SKIP_BITS(re, &s->gb, 8);
 269                 if (level == -128) {
 270                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 271                     SKIP_BITS(re, &s->gb, 8);
 272                 } else if (level == 0) {
 273                     level = SHOW_UBITS(re, &s->gb, 8);
 274                     SKIP_BITS(re, &s->gb, 8);
 275                 }
 276                 i += run;
 277                 check_scantable_index(s, i);
 278                 j = scantable[i];
 279                 if (level < 0) {
 280                     level = -level;
 281                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 282                     level = (level - 1) | 1;
 283                     level = -level;
 284                 } else {
 285                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 286                     level = (level - 1) | 1;
 287                 }
 288             }
 289
 290             block[j] = level;
 291             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 292                 break;
 293             UPDATE_CACHE(re, &s->gb);
 294         }
 295 end:
 296         LAST_SKIP_BITS(re, &s->gb, 2);
 297         CLOSE_READER(re, &s->gb);
 298     }
 299     s->block_last_index[n] = i;
 300     return 0;
 301 }
 302
 303 /**
 304  * Note: this function can read out of range and crash for corrupt streams.
 305  * Changing this would eat up any speed benefits it has.
 306  * Do not use "fast" flag if you need the code to be robust.
 307  */
 308 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s,
 309                                                 int16_t *block, int n)
 310 {
 311     int level, i, j, run;
 312     RLTable *rl              = &ff_rl_mpeg1;
 313     uint8_t *const scantable = s->intra_scantable.permutated;
 314     const int qscale         = s->qscale;
 315
 316     {
 317         OPEN_READER(re, &s->gb);
 318         i = -1;
 319         // Special case for first coefficient, no need to add second VLC table.
 320         UPDATE_CACHE(re, &s->gb);
 321         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 322             level = (3 * qscale) >> 1;
 323             level = (level - 1) | 1;
 324             if (GET_CACHE(re, &s->gb) & 0x40000000)
 325                 level = -level;
 326             block[0] = level;
 327             i++;
 328             SKIP_BITS(re, &s->gb, 2);
 329             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 330                 goto end;
 331         }
 332
 333         /* now quantify & encode AC coefficients */
 334         for (;;) {
 335             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 336                        TEX_VLC_BITS, 2, 0);
 337
 338             if (level != 0) {
 339                 i += run;
 340                 check_scantable_index(s, i);
 341                 j = scantable[i];
 342                 level = ((level * 2 + 1) * qscale) >> 1;
 343                 level = (level - 1) | 1;
 344                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 345                         SHOW_SBITS(re, &s->gb, 1);
 346                 SKIP_BITS(re, &s->gb, 1);
 347             } else {
 348                 /* escape */
 349                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 350                 LAST_SKIP_BITS(re, &s->gb, 6);
 351                 UPDATE_CACHE(re, &s->gb);
 352                 level = SHOW_SBITS(re, &s->gb, 8);
 353                 SKIP_BITS(re, &s->gb, 8);
 354                 if (level == -128) {
 355                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 356                     SKIP_BITS(re, &s->gb, 8);
 357                 } else if (level == 0) {
 358                     level = SHOW_UBITS(re, &s->gb, 8);
 359                     SKIP_BITS(re, &s->gb, 8);
 360                 }
 361                 i += run;
 362                 check_scantable_index(s, i);
 363                 j = scantable[i];
 364                 if (level < 0) {
 365                     level = -level;
 366                     level = ((level * 2 + 1) * qscale) >> 1;
 367                     level = (level - 1) | 1;
 368                     level = -level;
 369                 } else {
 370                     level = ((level * 2 + 1) * qscale) >> 1;
 371                     level = (level - 1) | 1;
 372                 }
 373             }
 374
 375             block[j] = level;
 376             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 377                 break;
 378             UPDATE_CACHE(re, &s->gb);
 379         }
 380 end:
 381         LAST_SKIP_BITS(re, &s->gb, 2);
 382         CLOSE_READER(re, &s->gb);
 383     }
 384     s->block_last_index[n] = i;
 385     return 0;
 386 }
 387
 388 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 389                                                int16_t *block, int n)
 390 {
 391     int level, i, j, run;
 392     RLTable *rl = &ff_rl_mpeg1;
 393     uint8_t *const scantable = s->intra_scantable.permutated;
 394     const uint16_t *quant_matrix;
 395     const int qscale = s->qscale;
 396     int mismatch;
 397
 398     mismatch = 1;
 399
 400     {
 401         OPEN_READER(re, &s->gb);
 402         i = -1;
 403         if (n < 4)
 404             quant_matrix = s->inter_matrix;
 405         else
 406             quant_matrix = s->chroma_inter_matrix;
 407
 408         // Special case for first coefficient, no need to add second VLC table.
 409         UPDATE_CACHE(re, &s->gb);
 410         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 411             level = (3 * qscale * quant_matrix[0]) >> 5;
 412             if (GET_CACHE(re, &s->gb) & 0x40000000)
 413                 level = -level;
 414             block[0]  = level;
 415             mismatch ^= level;
 416             i++;
 417             SKIP_BITS(re, &s->gb, 2);
 418             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 419                 goto end;
 420         }
 421
 422         /* now quantify & encode AC coefficients */
 423         for (;;) {
 424             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 425                        TEX_VLC_BITS, 2, 0);
 426
 427             if (level != 0) {
 428                 i += run;
 429                 check_scantable_index(s, i);
 430                 j = scantable[i];
 431                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 432                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 433                         SHOW_SBITS(re, &s->gb, 1);
 434                 SKIP_BITS(re, &s->gb, 1);
 435             } else {
 436                 /* escape */
 437                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 438                 LAST_SKIP_BITS(re, &s->gb, 6);
 439                 UPDATE_CACHE(re, &s->gb);
 440                 level = SHOW_SBITS(re, &s->gb, 12);
 441                 SKIP_BITS(re, &s->gb, 12);
 442
 443                 i += run;
 444                 check_scantable_index(s, i);
 445                 j = scantable[i];
 446                 if (level < 0) {
 447                     level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 448                     level = -level;
 449                 } else {
 450                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 451                 }
 452             }
 453
 454             mismatch ^= level;
 455             block[j]  = level;
 456             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 457                 break;
 458             UPDATE_CACHE(re, &s->gb);
 459         }
 460 end:
 461         LAST_SKIP_BITS(re, &s->gb, 2);
 462         CLOSE_READER(re, &s->gb);
 463     }
 464     block[63] ^= (mismatch & 1);
 465
 466     s->block_last_index[n] = i;
 467     return 0;
 468 }
 469
 470 /**
 471  * Note: this function can read out of range and crash for corrupt streams.
 472  * Changing this would eat up any speed benefits it has.
 473  * Do not use "fast" flag if you need the code to be robust.
 474  */
 475 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 476                                                     int16_t *block, int n)
 477 {
 478     int level, i, j, run;
 479     RLTable *rl              = &ff_rl_mpeg1;
 480     uint8_t *const scantable = s->intra_scantable.permutated;
 481     const int qscale         = s->qscale;
 482     OPEN_READER(re, &s->gb);
 483     i = -1;
 484
 485     // special case for first coefficient, no need to add second VLC table
 486     UPDATE_CACHE(re, &s->gb);
 487     if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 488         level = (3 * qscale) >> 1;
 489         if (GET_CACHE(re, &s->gb) & 0x40000000)
 490             level = -level;
 491         block[0] = level;
 492         i++;
 493         SKIP_BITS(re, &s->gb, 2);
 494         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 495             goto end;
 496     }
 497
 498     /* now quantify & encode AC coefficients */
 499     for (;;) {
 500         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 501
 502         if (level != 0) {
 503             i += run;
 504             j = scantable[i];
 505             level = ((level * 2 + 1) * qscale) >> 1;
 506             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 507                     SHOW_SBITS(re, &s->gb, 1);
 508             SKIP_BITS(re, &s->gb, 1);
 509         } else {
 510             /* escape */
 511             run = SHOW_UBITS(re, &s->gb, 6) + 1;
 512             LAST_SKIP_BITS(re, &s->gb, 6);
 513             UPDATE_CACHE(re, &s->gb);
 514             level = SHOW_SBITS(re, &s->gb, 12);
 515             SKIP_BITS(re, &s->gb, 12);
 516
 517             i += run;
 518             j = scantable[i];
 519             if (level < 0) {
 520                 level = ((-level * 2 + 1) * qscale) >> 1;
 521                 level = -level;
 522             } else {
 523                 level = ((level * 2 + 1) * qscale) >> 1;
 524             }
 525         }
 526
 527         block[j] = level;
 528         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF || i > 63)
 529             break;
 530
 531         UPDATE_CACHE(re, &s->gb);
 532     }
 533 end:
 534     LAST_SKIP_BITS(re, &s->gb, 2);
 535     CLOSE_READER(re, &s->gb);
 536     s->block_last_index[n] = i;
 537     return 0;
 538 }
 539
 540 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
 541                                            int16_t *block, int n)
 542 {
 543     int level, dc, diff, i, j, run;
 544     int component;
 545     RLTable *rl;
 546     uint8_t *const scantable = s->intra_scantable.permutated;
 547     const uint16_t *quant_matrix;
 548     const int qscale = s->qscale;
 549     int mismatch;
 550
 551     /* DC coefficient */
 552     if (n < 4) {
 553         quant_matrix = s->intra_matrix;
 554         component    = 0;
 555     } else {
 556         quant_matrix = s->chroma_intra_matrix;
 557         component    = (n & 1) + 1;
 558     }
 559     diff = decode_dc(&s->gb, component);
 560     if (diff >= 0xffff)
 561         return AVERROR_INVALIDDATA;
 562     dc  = s->last_dc[component];
 563     dc += diff;
 564     s->last_dc[component] = dc;
 565     block[0] = dc << (3 - s->intra_dc_precision);
 566     ff_tlog(s->avctx, "dc=%d\n", block[0]);
 567     mismatch = block[0] ^ 1;
 568     i = 0;
 569     if (s->intra_vlc_format)
 570         rl = &ff_rl_mpeg2;
 571     else
 572         rl = &ff_rl_mpeg1;
 573
 574     {
 575         OPEN_READER(re, &s->gb);
 576         /* now quantify & encode AC coefficients */
 577         for (;;) {
 578             UPDATE_CACHE(re, &s->gb);
 579             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 580                        TEX_VLC_BITS, 2, 0);
 581
 582             if (level == 127) {
 583                 break;
 584             } else if (level != 0) {
 585                 i += run;
 586                 check_scantable_index(s, i);
 587                 j = scantable[i];
 588                 level = (level * qscale * quant_matrix[j]) >> 4;
 589                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 590                         SHOW_SBITS(re, &s->gb, 1);
 591                 LAST_SKIP_BITS(re, &s->gb, 1);
 592             } else {
 593                 /* escape */
 594                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 595                 LAST_SKIP_BITS(re, &s->gb, 6);
 596                 UPDATE_CACHE(re, &s->gb);
 597                 level = SHOW_SBITS(re, &s->gb, 12);
 598                 SKIP_BITS(re, &s->gb, 12);
 599                 i += run;
 600                 check_scantable_index(s, i);
 601                 j = scantable[i];
 602                 if (level < 0) {
 603                     level = (-level * qscale * quant_matrix[j]) >> 4;
 604                     level = -level;
 605                 } else {
 606                     level = (level * qscale * quant_matrix[j]) >> 4;
 607                 }
 608             }
 609
 610             mismatch ^= level;
 611             block[j]  = level;
 612         }
 613         CLOSE_READER(re, &s->gb);
 614     }
 615     block[63] ^= mismatch & 1;
 616
 617     s->block_last_index[n] = i;
 618     return 0;
 619 }
 620
 621 /**
 622  * Note: this function can read out of range and crash for corrupt streams.
 623  * Changing this would eat up any speed benefits it has.
 624  * Do not use "fast" flag if you need the code to be robust.
 625  */
 626 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
 627                                                 int16_t *block, int n)
 628 {
 629     int level, dc, diff, i, j, run;
 630     int component;
 631     RLTable *rl;
 632     uint8_t *const scantable = s->intra_scantable.permutated;
 633     const uint16_t *quant_matrix;
 634     const int qscale = s->qscale;
 635
 636     /* DC coefficient */
 637     if (n < 4) {
 638         quant_matrix = s->intra_matrix;
 639         component    = 0;
 640     } else {
 641         quant_matrix = s->chroma_intra_matrix;
 642         component    = (n & 1) + 1;
 643     }
 644     diff = decode_dc(&s->gb, component);
 645     if (diff >= 0xffff)
 646         return AVERROR_INVALIDDATA;
 647     dc = s->last_dc[component];
 648     dc += diff;
 649     s->last_dc[component] = dc;
 650     block[0] = dc << (3 - s->intra_dc_precision);
 651     i = 0;
 652     if (s->intra_vlc_format)
 653         rl = &ff_rl_mpeg2;
 654     else
 655         rl = &ff_rl_mpeg1;
 656
 657     {
 658         OPEN_READER(re, &s->gb);
 659         /* now quantify & encode AC coefficients */
 660         for (;;) {
 661             UPDATE_CACHE(re, &s->gb);
 662             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 663                        TEX_VLC_BITS, 2, 0);
 664
 665             if (level >= 64 || i > 63) {
 666                 break;
 667             } else if (level != 0) {
 668                 i += run;
 669                 j = scantable[i];
 670                 level = (level * qscale * quant_matrix[j]) >> 4;
 671                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 672                         SHOW_SBITS(re, &s->gb, 1);
 673                 LAST_SKIP_BITS(re, &s->gb, 1);
 674             } else {
 675                 /* escape */
 676                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 677                 LAST_SKIP_BITS(re, &s->gb, 6);
 678                 UPDATE_CACHE(re, &s->gb);
 679                 level = SHOW_SBITS(re, &s->gb, 12);
 680                 SKIP_BITS(re, &s->gb, 12);
 681                 i += run;
 682                 j = scantable[i];
 683                 if (level < 0) {
 684                     level = (-level * qscale * quant_matrix[j]) >> 4;
 685                     level = -level;
 686                 } else {
 687                     level = (level * qscale * quant_matrix[j]) >> 4;
 688                 }
 689             }
 690
 691             block[j] = level;
 692         }
 693         CLOSE_READER(re, &s->gb);
 694     }
 695
 696     s->block_last_index[n] = i;
 697     return 0;
 698 }
 699
 700 /******************************************/
 701 /* decoding */
 702
 703 static inline int get_dmv(MpegEncContext *s)
 704 {
 705     if (get_bits1(&s->gb))
 706         return 1 - (get_bits1(&s->gb) << 1);
 707     else
 708         return 0;
 709 }
 710
 711 static inline int get_qscale(MpegEncContext *s)
 712 {
 713     int qscale = get_bits(&s->gb, 5);
 714     if (s->q_scale_type)
 715         return ff_mpeg2_non_linear_qscale[qscale];
 716     else
 717         return qscale << 1;
 718 }
 719
 720
 721 /* motion type (for MPEG-2) */
 722 #define MT_FIELD 1
 723 #define MT_FRAME 2
 724 #define MT_16X8  2
 725 #define MT_DMV   3
 726
 727 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
 728 {
 729     int i, j, k, cbp, val, mb_type, motion_type;
 730     const int mb_block_count = 4 + (1 << s->chroma_format);
 731     int ret;
 732
 733     ff_tlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 734
 735     av_assert2(s->mb_skipped == 0);
 736
 737     if (s->mb_skip_run-- != 0) {
 738         if (s->pict_type == AV_PICTURE_TYPE_P) {
 739             s->mb_skipped = 1;
 740             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
 741                 MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 742         } else {
 743             int mb_type;
 744
 745             if (s->mb_x)
 746                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
 747             else
 748                 // FIXME not sure if this is allowed in MPEG at all
 749                 mb_type = s->current_picture.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1];
 750             if (IS_INTRA(mb_type)) {
 751                 av_log(s->avctx, AV_LOG_ERROR, "skip with previntra\n");
 752                 return AVERROR_INVALIDDATA;
 753             }
 754             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
 755                 mb_type | MB_TYPE_SKIP;
 756
 757             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
 758                 s->mb_skipped = 1;
 759         }
 760
 761         return 0;
 762     }
 763
 764     switch (s->pict_type) {
 765     default:
 766     case AV_PICTURE_TYPE_I:
 767         if (get_bits1(&s->gb) == 0) {
 768             if (get_bits1(&s->gb) == 0) {
 769                 av_log(s->avctx, AV_LOG_ERROR,
 770                        "invalid mb type in I Frame at %d %d\n",
 771                        s->mb_x, s->mb_y);
 772                 return AVERROR_INVALIDDATA;
 773             }
 774             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 775         } else {
 776             mb_type = MB_TYPE_INTRA;
 777         }
 778         break;
 779     case AV_PICTURE_TYPE_P:
 780         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 781         if (mb_type < 0) {
 782             av_log(s->avctx, AV_LOG_ERROR,
 783                    "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 784             return AVERROR_INVALIDDATA;
 785         }
 786         mb_type = ptype2mb_type[mb_type];
 787         break;
 788     case AV_PICTURE_TYPE_B:
 789         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 790         if (mb_type < 0) {
 791             av_log(s->avctx, AV_LOG_ERROR,
 792                    "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 793             return AVERROR_INVALIDDATA;
 794         }
 795         mb_type = btype2mb_type[mb_type];
 796         break;
 797     }
 798     ff_tlog(s->avctx, "mb_type=%x\n", mb_type);
 799 //    motion_type = 0; /* avoid warning */
 800     if (IS_INTRA(mb_type)) {
 801         s->bdsp.clear_blocks(s->block[0]);
 802
 803         if (!s->chroma_y_shift)
 804             s->bdsp.clear_blocks(s->block[6]);
 805
 806         /* compute DCT type */
 807         // FIXME: add an interlaced_dct coded var?
 808         if (s->picture_structure == PICT_FRAME &&
 809             !s->frame_pred_frame_dct)
 810             s->interlaced_dct = get_bits1(&s->gb);
 811
 812         if (IS_QUANT(mb_type))
 813             s->qscale = get_qscale(s);
 814
 815         if (s->concealment_motion_vectors) {
 816             /* just parse them */
 817             if (s->picture_structure != PICT_FRAME)
 818                 skip_bits1(&s->gb);  /* field select */
 819
 820             s->mv[0][0][0]      =
 821             s->last_mv[0][0][0] =
 822             s->last_mv[0][1][0] = mpeg_decode_motion(s, s->mpeg_f_code[0][0],
 823                                                      s->last_mv[0][0][0]);
 824             s->mv[0][0][1]      =
 825             s->last_mv[0][0][1] =
 826             s->last_mv[0][1][1] = mpeg_decode_motion(s, s->mpeg_f_code[0][1],
 827                                                      s->last_mv[0][0][1]);
 828
 829             check_marker(&s->gb, "after concealment_motion_vectors");
 830         } else {
 831             /* reset mv prediction */
 832             memset(s->last_mv, 0, sizeof(s->last_mv));
 833         }
 834         s->mb_intra = 1;
 835         // if 1, we memcpy blocks in xvmcvideo
 836         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
 837             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
 838
 839         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
 840             if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
 841                 for (i = 0; i < 6; i++)
 842                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 843             } else {
 844                 for (i = 0; i < mb_block_count; i++)
 845                     if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
 846                         return ret;
 847             }
 848         } else {
 849             for (i = 0; i < 6; i++)
 850                 if ((ret = mpeg1_decode_block_intra(s, *s->pblocks[i], i)) < 0)
 851                     return ret;
 852         }
 853     } else {
 854         if (mb_type & MB_TYPE_ZERO_MV) {
 855             av_assert2(mb_type & MB_TYPE_CBP);
 856
 857             s->mv_dir = MV_DIR_FORWARD;
 858             if (s->picture_structure == PICT_FRAME) {
 859                 if (s->picture_structure == PICT_FRAME
 860                     && !s->frame_pred_frame_dct)
 861                     s->interlaced_dct = get_bits1(&s->gb);
 862                 s->mv_type = MV_TYPE_16X16;
 863             } else {
 864                 s->mv_type            = MV_TYPE_FIELD;
 865                 mb_type              |= MB_TYPE_INTERLACED;
 866                 s->field_select[0][0] = s->picture_structure - 1;
 867             }
 868
 869             if (IS_QUANT(mb_type))
 870                 s->qscale = get_qscale(s);
 871
 872             s->last_mv[0][0][0] = 0;
 873             s->last_mv[0][0][1] = 0;
 874             s->last_mv[0][1][0] = 0;
 875             s->last_mv[0][1][1] = 0;
 876             s->mv[0][0][0]      = 0;
 877             s->mv[0][0][1]      = 0;
 878         } else {
 879             av_assert2(mb_type & MB_TYPE_L0L1);
 880             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 881             /* get additional motion vector type */
 882             if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) {
 883                 motion_type = MT_FRAME;
 884             } else {
 885                 motion_type = get_bits(&s->gb, 2);
 886                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 887                     s->interlaced_dct = get_bits1(&s->gb);
 888             }
 889
 890             if (IS_QUANT(mb_type))
 891                 s->qscale = get_qscale(s);
 892
 893             /* motion vectors */
 894             s->mv_dir = (mb_type >> 13) & 3;
 895             ff_tlog(s->avctx, "motion_type=%d\n", motion_type);
 896             switch (motion_type) {
 897             case MT_FRAME: /* or MT_16X8 */
 898                 if (s->picture_structure == PICT_FRAME) {
 899                     mb_type   |= MB_TYPE_16x16;
 900                     s->mv_type = MV_TYPE_16X16;
 901                     for (i = 0; i < 2; i++) {
 902                         if (USES_LIST(mb_type, i)) {
 903                             /* MT_FRAME */
 904                             s->mv[i][0][0]      =
 905                             s->last_mv[i][0][0] =
 906                             s->last_mv[i][1][0] =
 907                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 908                                                    s->last_mv[i][0][0]);
 909                             s->mv[i][0][1]      =
 910                             s->last_mv[i][0][1] =
 911                             s->last_mv[i][1][1] =
 912                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 913                                                    s->last_mv[i][0][1]);
 914                             /* full_pel: only for MPEG-1 */
 915                             if (s->full_pel[i]) {
 916                                 s->mv[i][0][0] <<= 1;
 917                                 s->mv[i][0][1] <<= 1;
 918                             }
 919                         }
 920                     }
 921                 } else {
 922                     mb_type   |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 923                     s->mv_type = MV_TYPE_16X8;
 924                     for (i = 0; i < 2; i++) {
 925                         if (USES_LIST(mb_type, i)) {
 926                             /* MT_16X8 */
 927                             for (j = 0; j < 2; j++) {
 928                                 s->field_select[i][j] = get_bits1(&s->gb);
 929                                 for (k = 0; k < 2; k++) {
 930                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 931                                                              s->last_mv[i][j][k]);
 932                                     s->last_mv[i][j][k] = val;
 933                                     s->mv[i][j][k]      = val;
 934                                 }
 935                             }
 936                         }
 937                     }
 938                 }
 939                 break;
 940             case MT_FIELD:
 941                 s->mv_type = MV_TYPE_FIELD;
 942                 if (s->picture_structure == PICT_FRAME) {
 943                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 944                     for (i = 0; i < 2; i++) {
 945                         if (USES_LIST(mb_type, i)) {
 946                             for (j = 0; j < 2; j++) {
 947                                 s->field_select[i][j] = get_bits1(&s->gb);
 948                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 949                                                          s->last_mv[i][j][0]);
 950                                 s->last_mv[i][j][0] = val;
 951                                 s->mv[i][j][0]      = val;
 952                                 ff_tlog(s->avctx, "fmx=%d\n", val);
 953                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 954                                                          s->last_mv[i][j][1] >> 1);
 955                                 s->last_mv[i][j][1] = 2 * val;
 956                                 s->mv[i][j][1]      = val;
 957                                 ff_tlog(s->avctx, "fmy=%d\n", val);
 958                             }
 959                         }
 960                     }
 961                 } else {
 962                     av_assert0(!s->progressive_sequence);
 963                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 964                     for (i = 0; i < 2; i++) {
 965                         if (USES_LIST(mb_type, i)) {
 966                             s->field_select[i][0] = get_bits1(&s->gb);
 967                             for (k = 0; k < 2; k++) {
 968                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 969                                                          s->last_mv[i][0][k]);
 970                                 s->last_mv[i][0][k] = val;
 971                                 s->last_mv[i][1][k] = val;
 972                                 s->mv[i][0][k]      = val;
 973                             }
 974                         }
 975                     }
 976                 }
 977                 break;
 978             case MT_DMV:
 979                 if (s->progressive_sequence){
 980                     av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
 981                     return AVERROR_INVALIDDATA;
 982                 }
 983                 s->mv_type = MV_TYPE_DMV;
 984                 for (i = 0; i < 2; i++) {
 985                     if (USES_LIST(mb_type, i)) {
 986                         int dmx, dmy, mx, my, m;
 987                         const int my_shift = s->picture_structure == PICT_FRAME;
 988
 989                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 990                                                 s->last_mv[i][0][0]);
 991                         s->last_mv[i][0][0] = mx;
 992                         s->last_mv[i][1][0] = mx;
 993                         dmx = get_dmv(s);
 994                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 995                                                  s->last_mv[i][0][1] >> my_shift);
 996                         dmy = get_dmv(s);
 997
 998
 999                         s->last_mv[i][0][1] = my << my_shift;
1000                         s->last_mv[i][1][1] = my << my_shift;
1001
1002                         s->mv[i][0][0] = mx;
1003                         s->mv[i][0][1] = my;
1004                         s->mv[i][1][0] = mx; // not used
1005                         s->mv[i][1][1] = my; // not used
1006
1007                         if (s->picture_structure == PICT_FRAME) {
1008                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
1009
1010                             // m = 1 + 2 * s->top_field_first;
1011                             m = s->top_field_first ? 1 : 3;
1012
1013                             /* top -> top pred */
1014                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1015                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1016                             m = 4 - m;
1017                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1018                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1019                         } else {
1020                             mb_type |= MB_TYPE_16x16;
1021
1022                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
1023                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
1024                             if (s->picture_structure == PICT_TOP_FIELD)
1025                                 s->mv[i][2][1]--;
1026                             else
1027                                 s->mv[i][2][1]++;
1028                         }
1029                     }
1030                 }
1031                 break;
1032             default:
1033                 av_log(s->avctx, AV_LOG_ERROR,
1034                        "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
1035                 return AVERROR_INVALIDDATA;
1036             }
1037         }
1038
1039         s->mb_intra = 0;
1040         if (HAS_CBP(mb_type)) {
1041             s->bdsp.clear_blocks(s->block[0]);
1042
1043             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1044             if (mb_block_count > 6) {
1045                 cbp <<= mb_block_count - 6;
1046                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
1047                 s->bdsp.clear_blocks(s->block[6]);
1048             }
1049             if (cbp <= 0) {
1050                 av_log(s->avctx, AV_LOG_ERROR,
1051                        "invalid cbp %d at %d %d\n", cbp, s->mb_x, s->mb_y);
1052                 return AVERROR_INVALIDDATA;
1053             }
1054
1055             // if 1, we memcpy blocks in xvmcvideo
1056             if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1057                 ff_xvmc_pack_pblocks(s, cbp);
1058
1059             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
1060                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1061                     for (i = 0; i < 6; i++) {
1062                         if (cbp & 32)
1063                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
1064                         else
1065                             s->block_last_index[i] = -1;
1066                         cbp += cbp;
1067                     }
1068                 } else {
1069                     cbp <<= 12 - mb_block_count;
1070
1071                     for (i = 0; i < mb_block_count; i++) {
1072                         if (cbp & (1 << 11)) {
1073                             if ((ret = mpeg2_decode_block_non_intra(s, *s->pblocks[i], i)) < 0)
1074                                 return ret;
1075                         } else {
1076                             s->block_last_index[i] = -1;
1077                         }
1078                         cbp += cbp;
1079                     }
1080                 }
1081             } else {
1082                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1083                     for (i = 0; i < 6; i++) {
1084                         if (cbp & 32)
1085                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
1086                         else
1087                             s->block_last_index[i] = -1;
1088                         cbp += cbp;
1089                     }
1090                 } else {
1091                     for (i = 0; i < 6; i++) {
1092                         if (cbp & 32) {
1093                             if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
1094                                 return ret;
1095                         } else {
1096                             s->block_last_index[i] = -1;
1097                         }
1098                         cbp += cbp;
1099                     }
1100                 }
1101             }
1102         } else {
1103             for (i = 0; i < 12; i++)
1104                 s->block_last_index[i] = -1;
1105         }
1106     }
1107
1108     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1109
1110     return 0;
1111 }
1112
1113 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1114 {
1115     Mpeg1Context *s    = avctx->priv_data;
1116     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1117
1118     ff_mpv_decode_defaults(s2);
1119
1120     if (   avctx->codec_tag != AV_RL32("VCR2")
1121         && avctx->codec_tag != AV_RL32("BW10"))
1122         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
1123     ff_mpv_decode_init(s2, avctx);
1124
1125     s->mpeg_enc_ctx.avctx  = avctx;
1126
1127     /* we need some permutation to store matrices,
1128      * until the decoder sets the real permutation. */
1129     ff_mpv_idct_init(s2);
1130     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1131     ff_mpeg12_init_vlcs();
1132
1133     s2->chroma_format              = 1;
1134     s->mpeg_enc_ctx_allocated      = 0;
1135     s->mpeg_enc_ctx.picture_number = 0;
1136     s->repeat_field                = 0;
1137     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1138     avctx->color_range             = AVCOL_RANGE_MPEG;
1139     return 0;
1140 }
1141
1142 static int mpeg_decode_update_thread_context(AVCodecContext *avctx,
1143                                              const AVCodecContext *avctx_from)
1144 {
1145     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1146     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1147     int err;
1148
1149     if (avctx == avctx_from               ||
1150         !ctx_from->mpeg_enc_ctx_allocated ||
1151         !s1->context_initialized)
1152         return 0;
1153
1154     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1155     if (err)
1156         return err;
1157
1158     if (!ctx->mpeg_enc_ctx_allocated)
1159         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1160
1161     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1162         s->picture_number++;
1163
1164     return 0;
1165 }
1166
1167 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1168                                  const uint8_t *new_perm)
1169 {
1170     uint16_t temp_matrix[64];
1171     int i;
1172
1173     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1174
1175     for (i = 0; i < 64; i++)
1176         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1177 }
1178
1179 static const enum AVPixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
1180 #if CONFIG_MPEG1_XVMC_HWACCEL
1181     AV_PIX_FMT_XVMC,
1182 #endif
1183 #if CONFIG_MPEG1_VDPAU_DECODER && FF_API_VDPAU
1184     AV_PIX_FMT_VDPAU_MPEG1,
1185 #endif
1186 #if CONFIG_MPEG1_VDPAU_HWACCEL
1187     AV_PIX_FMT_VDPAU,
1188 #endif
1189     AV_PIX_FMT_YUV420P,
1190     AV_PIX_FMT_NONE
1191 };
1192
1193 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1194 #if CONFIG_MPEG2_XVMC_HWACCEL
1195     AV_PIX_FMT_XVMC,
1196 #endif
1197 #if CONFIG_MPEG_VDPAU_DECODER && FF_API_VDPAU
1198     AV_PIX_FMT_VDPAU_MPEG2,
1199 #endif
1200 #if CONFIG_MPEG2_VDPAU_HWACCEL
1201     AV_PIX_FMT_VDPAU,
1202 #endif
1203 #if CONFIG_MPEG2_DXVA2_HWACCEL
1204     AV_PIX_FMT_DXVA2_VLD,
1205 #endif
1206 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1207     AV_PIX_FMT_D3D11VA_VLD,
1208 #endif
1209 #if CONFIG_MPEG2_VAAPI_HWACCEL
1210     AV_PIX_FMT_VAAPI,
1211 #endif
1212 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1213     AV_PIX_FMT_VIDEOTOOLBOX,
1214 #endif
1215     AV_PIX_FMT_YUV420P,
1216     AV_PIX_FMT_NONE
1217 };
1218
1219 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1220     AV_PIX_FMT_YUV422P,
1221     AV_PIX_FMT_NONE
1222 };
1223
1224 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1225     AV_PIX_FMT_YUV444P,
1226     AV_PIX_FMT_NONE
1227 };
1228
1229 #if FF_API_VDPAU
1230 static inline int uses_vdpau(AVCodecContext *avctx) {
1231     return avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG1 || avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG2;
1232 }
1233 #endif
1234
1235 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1236 {
1237     Mpeg1Context *s1  = avctx->priv_data;
1238     MpegEncContext *s = &s1->mpeg_enc_ctx;
1239     const enum AVPixelFormat *pix_fmts;
1240
1241     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1242         return AV_PIX_FMT_GRAY8;
1243
1244     if (s->chroma_format < 2)
1245         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1246                                 mpeg1_hwaccel_pixfmt_list_420 :
1247                                 mpeg2_hwaccel_pixfmt_list_420;
1248     else if (s->chroma_format == 2)
1249         pix_fmts = mpeg12_pixfmt_list_422;
1250     else
1251         pix_fmts = mpeg12_pixfmt_list_444;
1252
1253     return ff_thread_get_format(avctx, pix_fmts);
1254 }
1255
1256 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1257 {
1258     // until then pix_fmt may be changed right after codec init
1259     if (avctx->hwaccel
1260 #if FF_API_VDPAU
1261         || uses_vdpau(avctx)
1262 #endif
1263         )
1264         if (avctx->idct_algo == FF_IDCT_AUTO)
1265             avctx->idct_algo = FF_IDCT_SIMPLE;
1266
1267     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1268         Mpeg1Context *s1 = avctx->priv_data;
1269         MpegEncContext *s = &s1->mpeg_enc_ctx;
1270
1271         s->pack_pblocks = 1;
1272 #if FF_API_XVMC
1273 FF_DISABLE_DEPRECATION_WARNINGS
1274         avctx->xvmc_acceleration = 2;
1275 FF_ENABLE_DEPRECATION_WARNINGS
1276 #endif /* FF_API_XVMC */
1277     }
1278 }
1279
1280 /* Call this function when we know all parameters.
1281  * It may be called in different places for MPEG-1 and MPEG-2. */
1282 static int mpeg_decode_postinit(AVCodecContext *avctx)
1283 {
1284     Mpeg1Context *s1  = avctx->priv_data;
1285     MpegEncContext *s = &s1->mpeg_enc_ctx;
1286     uint8_t old_permutation[64];
1287     int ret;
1288
1289     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1290         // MPEG-1 aspect
1291         avctx->sample_aspect_ratio = av_d2q(1.0 / ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1292     } else { // MPEG-2
1293         // MPEG-2 aspect
1294         if (s->aspect_ratio_info > 1) {
1295             AVRational dar =
1296                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1297                                   (AVRational) { s1->pan_scan.width,
1298                                                  s1->pan_scan.height }),
1299                          (AVRational) { s->width, s->height });
1300
1301             /* We ignore the spec here and guess a bit as reality does not
1302              * match the spec, see for example res_change_ffmpeg_aspect.ts
1303              * and sequence-display-aspect.mpg.
1304              * issue1613, 621, 562 */
1305             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1306                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1307                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1308                 s->avctx->sample_aspect_ratio =
1309                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1310                              (AVRational) { s->width, s->height });
1311             } else {
1312                 s->avctx->sample_aspect_ratio =
1313                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1314                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1315 // issue1613 4/3 16/9 -> 16/9
1316 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1317 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1318 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1319                 ff_dlog(avctx, "aspect A %d/%d\n",
1320                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1321                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1322                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1323                         s->avctx->sample_aspect_ratio.den);
1324             }
1325         } else {
1326             s->avctx->sample_aspect_ratio =
1327                 ff_mpeg2_aspect[s->aspect_ratio_info];
1328         }
1329     } // MPEG-2
1330
1331     if (av_image_check_sar(s->width, s->height,
1332                            avctx->sample_aspect_ratio) < 0) {
1333         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1334                 avctx->sample_aspect_ratio.num,
1335                 avctx->sample_aspect_ratio.den);
1336         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1337     }
1338
1339     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1340         avctx->coded_width       != s->width                ||
1341         avctx->coded_height      != s->height               ||
1342         s1->save_width           != s->width                ||
1343         s1->save_height          != s->height               ||
1344         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1345         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1346         0) {
1347         if (s1->mpeg_enc_ctx_allocated) {
1348             ParseContext pc = s->parse_context;
1349             s->parse_context.buffer = 0;
1350             ff_mpv_common_end(s);
1351             s->parse_context = pc;
1352             s1->mpeg_enc_ctx_allocated = 0;
1353         }
1354
1355         ret = ff_set_dimensions(avctx, s->width, s->height);
1356         if (ret < 0)
1357             return ret;
1358
1359         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1360             avctx->rc_max_rate = s->bit_rate;
1361         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1362                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1363             avctx->bit_rate = s->bit_rate;
1364         }
1365         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1366         s1->save_width           = s->width;
1367         s1->save_height          = s->height;
1368         s1->save_progressive_seq = s->progressive_sequence;
1369
1370         /* low_delay may be forced, in this case we will have B-frames
1371          * that behave like P-frames. */
1372         avctx->has_b_frames = !s->low_delay;
1373
1374         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1375             // MPEG-1 fps
1376             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1377             avctx->ticks_per_frame     = 1;
1378
1379             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1380         } else { // MPEG-2
1381             // MPEG-2 fps
1382             av_reduce(&s->avctx->framerate.num,
1383                       &s->avctx->framerate.den,
1384                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1385                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1386                       1 << 30);
1387             avctx->ticks_per_frame = 2;
1388
1389             switch (s->chroma_format) {
1390             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1391             case 2:
1392             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1393             default: av_assert0(0);
1394             }
1395         } // MPEG-2
1396
1397         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1398         setup_hwaccel_for_pixfmt(avctx);
1399
1400         /* Quantization matrices may need reordering
1401          * if DCT permutation is changed. */
1402         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1403
1404         ff_mpv_idct_init(s);
1405         if ((ret = ff_mpv_common_init(s)) < 0)
1406             return ret;
1407
1408         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1409         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1410         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1411         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1412
1413         s1->mpeg_enc_ctx_allocated = 1;
1414     }
1415     return 0;
1416 }
1417
1418 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1419                                 int buf_size)
1420 {
1421     Mpeg1Context *s1  = avctx->priv_data;
1422     MpegEncContext *s = &s1->mpeg_enc_ctx;
1423     int ref, f_code, vbv_delay;
1424
1425     init_get_bits(&s->gb, buf, buf_size * 8);
1426
1427     ref = get_bits(&s->gb, 10); /* temporal ref */
1428     s->pict_type = get_bits(&s->gb, 3);
1429     if (s->pict_type == 0 || s->pict_type > 3)
1430         return AVERROR_INVALIDDATA;
1431
1432     vbv_delay = get_bits(&s->gb, 16);
1433     s->vbv_delay = vbv_delay;
1434     if (s->pict_type == AV_PICTURE_TYPE_P ||
1435         s->pict_type == AV_PICTURE_TYPE_B) {
1436         s->full_pel[0] = get_bits1(&s->gb);
1437         f_code = get_bits(&s->gb, 3);
1438         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1439             return AVERROR_INVALIDDATA;
1440         f_code += !f_code;
1441         s->mpeg_f_code[0][0] = f_code;
1442         s->mpeg_f_code[0][1] = f_code;
1443     }
1444     if (s->pict_type == AV_PICTURE_TYPE_B) {
1445         s->full_pel[1] = get_bits1(&s->gb);
1446         f_code = get_bits(&s->gb, 3);
1447         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1448             return AVERROR_INVALIDDATA;
1449         f_code += !f_code;
1450         s->mpeg_f_code[1][0] = f_code;
1451         s->mpeg_f_code[1][1] = f_code;
1452     }
1453     s->current_picture.f->pict_type = s->pict_type;
1454     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1455
1456     if (avctx->debug & FF_DEBUG_PICT_INFO)
1457         av_log(avctx, AV_LOG_DEBUG,
1458                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1459
1460     s->y_dc_scale = 8;
1461     s->c_dc_scale = 8;
1462     return 0;
1463 }
1464
1465 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1466 {
1467     MpegEncContext *s = &s1->mpeg_enc_ctx;
1468     int horiz_size_ext, vert_size_ext;
1469     int bit_rate_ext;
1470
1471     skip_bits(&s->gb, 1); /* profile and level esc*/
1472     s->avctx->profile       = get_bits(&s->gb, 3);
1473     s->avctx->level         = get_bits(&s->gb, 4);
1474     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1475     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1476
1477     if (!s->chroma_format) {
1478         s->chroma_format = 1;
1479         av_log(s->avctx, AV_LOG_WARNING, "Chroma format invalid\n");
1480     }
1481
1482     horiz_size_ext          = get_bits(&s->gb, 2);
1483     vert_size_ext           = get_bits(&s->gb, 2);
1484     s->width  |= (horiz_size_ext << 12);
1485     s->height |= (vert_size_ext  << 12);
1486     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1487     s->bit_rate += (bit_rate_ext << 18) * 400LL;
1488     check_marker(&s->gb, "after bit rate extension");
1489     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1490
1491     s->low_delay = get_bits1(&s->gb);
1492     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1493         s->low_delay = 1;
1494
1495     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1496     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1497
1498     ff_dlog(s->avctx, "sequence extension\n");
1499     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1500
1501     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1502         av_log(s->avctx, AV_LOG_DEBUG,
1503                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%"PRId64"\n",
1504                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1505                s->avctx->rc_buffer_size, s->bit_rate);
1506 }
1507
1508 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1509 {
1510     MpegEncContext *s = &s1->mpeg_enc_ctx;
1511     int color_description, w, h;
1512
1513     skip_bits(&s->gb, 3); /* video format */
1514     color_description = get_bits1(&s->gb);
1515     if (color_description) {
1516         s->avctx->color_primaries = get_bits(&s->gb, 8);
1517         s->avctx->color_trc       = get_bits(&s->gb, 8);
1518         s->avctx->colorspace      = get_bits(&s->gb, 8);
1519     }
1520     w = get_bits(&s->gb, 14);
1521     skip_bits(&s->gb, 1); // marker
1522     h = get_bits(&s->gb, 14);
1523     // remaining 3 bits are zero padding
1524
1525     s1->pan_scan.width  = 16 * w;
1526     s1->pan_scan.height = 16 * h;
1527
1528     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1529         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1530 }
1531
1532 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1533 {
1534     MpegEncContext *s = &s1->mpeg_enc_ctx;
1535     int i, nofco;
1536
1537     nofco = 1;
1538     if (s->progressive_sequence) {
1539         if (s->repeat_first_field) {
1540             nofco++;
1541             if (s->top_field_first)
1542                 nofco++;
1543         }
1544     } else {
1545         if (s->picture_structure == PICT_FRAME) {
1546             nofco++;
1547             if (s->repeat_first_field)
1548                 nofco++;
1549         }
1550     }
1551     for (i = 0; i < nofco; i++) {
1552         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1553         skip_bits(&s->gb, 1); // marker
1554         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1555         skip_bits(&s->gb, 1); // marker
1556     }
1557
1558     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1559         av_log(s->avctx, AV_LOG_DEBUG,
1560                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1561                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1562                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1563                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1564 }
1565
1566 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1567                        uint16_t matrix1[64], int intra)
1568 {
1569     int i;
1570
1571     for (i = 0; i < 64; i++) {
1572         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1573         int v = get_bits(&s->gb, 8);
1574         if (v == 0) {
1575             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1576             return AVERROR_INVALIDDATA;
1577         }
1578         if (intra && i == 0 && v != 8) {
1579             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1580             v = 8; // needed by pink.mpg / issue1046
1581         }
1582         matrix0[j] = v;
1583         if (matrix1)
1584             matrix1[j] = v;
1585     }
1586     return 0;
1587 }
1588
1589 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1590 {
1591     ff_dlog(s->avctx, "matrix extension\n");
1592
1593     if (get_bits1(&s->gb))
1594         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1595     if (get_bits1(&s->gb))
1596         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1597     if (get_bits1(&s->gb))
1598         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1599     if (get_bits1(&s->gb))
1600         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1601 }
1602
1603 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1604 {
1605     MpegEncContext *s = &s1->mpeg_enc_ctx;
1606
1607     s->full_pel[0]       = s->full_pel[1] = 0;
1608     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1609     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1610     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1611     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1612     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1613         av_log(s->avctx, AV_LOG_ERROR,
1614                "Missing picture start code, guessing missing values\n");
1615         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1616             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1617                 s->pict_type = AV_PICTURE_TYPE_I;
1618             else
1619                 s->pict_type = AV_PICTURE_TYPE_P;
1620         } else
1621             s->pict_type = AV_PICTURE_TYPE_B;
1622         s->current_picture.f->pict_type = s->pict_type;
1623         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1624     }
1625     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1626     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1627     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1628     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1629
1630     s->intra_dc_precision         = get_bits(&s->gb, 2);
1631     s->picture_structure          = get_bits(&s->gb, 2);
1632     s->top_field_first            = get_bits1(&s->gb);
1633     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1634     s->concealment_motion_vectors = get_bits1(&s->gb);
1635     s->q_scale_type               = get_bits1(&s->gb);
1636     s->intra_vlc_format           = get_bits1(&s->gb);
1637     s->alternate_scan             = get_bits1(&s->gb);
1638     s->repeat_first_field         = get_bits1(&s->gb);
1639     s->chroma_420_type            = get_bits1(&s->gb);
1640     s->progressive_frame          = get_bits1(&s->gb);
1641
1642     if (s->alternate_scan) {
1643         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1644         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1645     } else {
1646         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1647         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1648     }
1649
1650     /* composite display not parsed */
1651     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1652     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1653     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1654     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1655     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1656     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1657     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1658     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1659     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1660 }
1661
1662 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1663 {
1664     AVCodecContext *avctx = s->avctx;
1665     Mpeg1Context *s1      = (Mpeg1Context *) s;
1666     int ret;
1667
1668     /* start frame decoding */
1669     if (s->first_field || s->picture_structure == PICT_FRAME) {
1670         AVFrameSideData *pan_scan;
1671
1672         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1673             return ret;
1674
1675         ff_mpeg_er_frame_start(s);
1676
1677         /* first check if we must repeat the frame */
1678         s->current_picture_ptr->f->repeat_pict = 0;
1679         if (s->repeat_first_field) {
1680             if (s->progressive_sequence) {
1681                 if (s->top_field_first)
1682                     s->current_picture_ptr->f->repeat_pict = 4;
1683                 else
1684                     s->current_picture_ptr->f->repeat_pict = 2;
1685             } else if (s->progressive_frame) {
1686                 s->current_picture_ptr->f->repeat_pict = 1;
1687             }
1688         }
1689
1690         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1691                                           AV_FRAME_DATA_PANSCAN,
1692                                           sizeof(s1->pan_scan));
1693         if (!pan_scan)
1694             return AVERROR(ENOMEM);
1695         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1696
1697         if (s1->a53_caption) {
1698             AVFrameSideData *sd = av_frame_new_side_data(
1699                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1700                 s1->a53_caption_size);
1701             if (sd)
1702                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1703             av_freep(&s1->a53_caption);
1704             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
1705         }
1706
1707         if (s1->has_stereo3d) {
1708             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1709             if (!stereo)
1710                 return AVERROR(ENOMEM);
1711
1712             *stereo = s1->stereo3d;
1713             s1->has_stereo3d = 0;
1714         }
1715
1716         if (s1->has_afd) {
1717             AVFrameSideData *sd =
1718                 av_frame_new_side_data(s->current_picture_ptr->f,
1719                                        AV_FRAME_DATA_AFD, 1);
1720             if (!sd)
1721                 return AVERROR(ENOMEM);
1722
1723             *sd->data   = s1->afd;
1724             s1->has_afd = 0;
1725         }
1726
1727         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1728             ff_thread_finish_setup(avctx);
1729     } else { // second field
1730         int i;
1731
1732         if (!s->current_picture_ptr) {
1733             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1734             return AVERROR_INVALIDDATA;
1735         }
1736
1737         if (s->avctx->hwaccel &&
1738             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1739             if ((ret = s->avctx->hwaccel->end_frame(s->avctx)) < 0) {
1740                 av_log(avctx, AV_LOG_ERROR,
1741                        "hardware accelerator failed to decode first field\n");
1742                 return ret;
1743             }
1744         }
1745
1746         for (i = 0; i < 4; i++) {
1747             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1748             if (s->picture_structure == PICT_BOTTOM_FIELD)
1749                 s->current_picture.f->data[i] +=
1750                     s->current_picture_ptr->f->linesize[i];
1751         }
1752     }
1753
1754     if (avctx->hwaccel) {
1755         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1756             return ret;
1757     }
1758
1759     return 0;
1760 }
1761
1762 #define DECODE_SLICE_ERROR -1
1763 #define DECODE_SLICE_OK     0
1764
1765 /**
1766  * Decode a slice.
1767  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1768  * @return DECODE_SLICE_ERROR if the slice is damaged,
1769  *         DECODE_SLICE_OK if this slice is OK
1770  */
1771 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1772                              const uint8_t **buf, int buf_size)
1773 {
1774     AVCodecContext *avctx = s->avctx;
1775     const int lowres      = s->avctx->lowres;
1776     const int field_pic   = s->picture_structure != PICT_FRAME;
1777     int ret;
1778
1779     s->resync_mb_x =
1780     s->resync_mb_y = -1;
1781
1782     av_assert0(mb_y < s->mb_height);
1783
1784     init_get_bits(&s->gb, *buf, buf_size * 8);
1785     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1786         skip_bits(&s->gb, 3);
1787
1788     ff_mpeg1_clean_buffers(s);
1789     s->interlaced_dct = 0;
1790
1791     s->qscale = get_qscale(s);
1792
1793     if (s->qscale == 0) {
1794         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1795         return AVERROR_INVALIDDATA;
1796     }
1797
1798     /* extra slice info */
1799     if (skip_1stop_8data_bits(&s->gb) < 0)
1800         return AVERROR_INVALIDDATA;
1801
1802     s->mb_x = 0;
1803
1804     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1805         skip_bits1(&s->gb);
1806     } else {
1807         while (get_bits_left(&s->gb) > 0) {
1808             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1809                                 MBINCR_VLC_BITS, 2);
1810             if (code < 0) {
1811                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1812                 return AVERROR_INVALIDDATA;
1813             }
1814             if (code >= 33) {
1815                 if (code == 33)
1816                     s->mb_x += 33;
1817                 /* otherwise, stuffing, nothing to do */
1818             } else {
1819                 s->mb_x += code;
1820                 break;
1821             }
1822         }
1823     }
1824
1825     if (s->mb_x >= (unsigned) s->mb_width) {
1826         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1827         return AVERROR_INVALIDDATA;
1828     }
1829
1830     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1831         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1832         int start_code = -1;
1833         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1834         if (buf_end < *buf + buf_size)
1835             buf_end -= 4;
1836         s->mb_y = mb_y;
1837         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1838             return DECODE_SLICE_ERROR;
1839         *buf = buf_end;
1840         return DECODE_SLICE_OK;
1841     }
1842
1843     s->resync_mb_x = s->mb_x;
1844     s->resync_mb_y = s->mb_y = mb_y;
1845     s->mb_skip_run = 0;
1846     ff_init_block_index(s);
1847
1848     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1849         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1850             av_log(s->avctx, AV_LOG_DEBUG,
1851                    "qp:%d fc:%2d%2d%2d%2d %s %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",
1852                    s->qscale,
1853                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1854                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1855                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1856                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1857                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1858                    s->progressive_sequence ? "ps"  : "",
1859                    s->progressive_frame    ? "pf"  : "",
1860                    s->alternate_scan       ? "alt" : "",
1861                    s->top_field_first      ? "top" : "",
1862                    s->intra_dc_precision, s->picture_structure,
1863                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1864                    s->q_scale_type, s->intra_vlc_format,
1865                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1866         }
1867     }
1868
1869     for (;;) {
1870         // If 1, we memcpy blocks in xvmcvideo.
1871         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1872             ff_xvmc_init_block(s); // set s->block
1873
1874         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1875             return ret;
1876
1877         // Note motion_val is normally NULL unless we want to extract the MVs.
1878         if (s->current_picture.motion_val[0] && !s->encoding) {
1879             const int wrap = s->b8_stride;
1880             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1881             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1882             int motion_x, motion_y, dir, i;
1883
1884             for (i = 0; i < 2; i++) {
1885                 for (dir = 0; dir < 2; dir++) {
1886                     if (s->mb_intra ||
1887                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1888                         motion_x = motion_y = 0;
1889                     } else if (s->mv_type == MV_TYPE_16X16 ||
1890                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1891                         motion_x = s->mv[dir][0][0];
1892                         motion_y = s->mv[dir][0][1];
1893                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1894                         motion_x = s->mv[dir][i][0];
1895                         motion_y = s->mv[dir][i][1];
1896                     }
1897
1898                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1899                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1900                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1901                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1902                     s->current_picture.ref_index [dir][b8_xy]     =
1903                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1904                     av_assert2(s->field_select[dir][i] == 0 ||
1905                                s->field_select[dir][i] == 1);
1906                 }
1907                 xy    += wrap;
1908                 b8_xy += 2;
1909             }
1910         }
1911
1912         s->dest[0] += 16 >> lowres;
1913         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1914         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1915
1916         ff_mpv_decode_mb(s, s->block);
1917
1918         if (++s->mb_x >= s->mb_width) {
1919             const int mb_size = 16 >> s->avctx->lowres;
1920
1921             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1922             ff_mpv_report_decode_progress(s);
1923
1924             s->mb_x  = 0;
1925             s->mb_y += 1 << field_pic;
1926
1927             if (s->mb_y >= s->mb_height) {
1928                 int left   = get_bits_left(&s->gb);
1929                 int is_d10 = s->chroma_format == 2 &&
1930                              s->pict_type == AV_PICTURE_TYPE_I &&
1931                              avctx->profile == 0 && avctx->level == 5 &&
1932                              s->intra_dc_precision == 2 &&
1933                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1934                              s->progressive_frame == 0
1935                              /* vbv_delay == 0xBBB || 0xE10 */;
1936
1937                 if (left >= 32 && !is_d10) {
1938                     GetBitContext gb = s->gb;
1939                     align_get_bits(&gb);
1940                     if (show_bits(&gb, 24) == 0x060E2B) {
1941                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1942                         is_d10 = 1;
1943                     }
1944                 }
1945
1946                 if (left < 0 ||
1947                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1948                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1949                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n",
1950                            left, show_bits(&s->gb, FFMIN(left, 23)));
1951                     return AVERROR_INVALIDDATA;
1952                 } else
1953                     goto eos;
1954             }
1955             // There are some files out there which are missing the last slice
1956             // in cases where the slice is completely outside the visible
1957             // area, we detect this here instead of running into the end expecting
1958             // more data
1959             if (s->mb_y >= ((s->height + 15) >> 4) &&
1960                 !s->progressive_sequence &&
1961                 get_bits_left(&s->gb) <= 8 &&
1962                 get_bits_left(&s->gb) >= 0 &&
1963                 s->mb_skip_run == -1 &&
1964                 show_bits(&s->gb, 8) == 0)
1965                 goto eos;
1966
1967             ff_init_block_index(s);
1968         }
1969
1970         /* skip mb handling */
1971         if (s->mb_skip_run == -1) {
1972             /* read increment again */
1973             s->mb_skip_run = 0;
1974             for (;;) {
1975                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1976                                     MBINCR_VLC_BITS, 2);
1977                 if (code < 0) {
1978                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1979                     return AVERROR_INVALIDDATA;
1980                 }
1981                 if (code >= 33) {
1982                     if (code == 33) {
1983                         s->mb_skip_run += 33;
1984                     } else if (code == 35) {
1985                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1986                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1987                             return AVERROR_INVALIDDATA;
1988                         }
1989                         goto eos; /* end of slice */
1990                     }
1991                     /* otherwise, stuffing, nothing to do */
1992                 } else {
1993                     s->mb_skip_run += code;
1994                     break;
1995                 }
1996             }
1997             if (s->mb_skip_run) {
1998                 int i;
1999                 if (s->pict_type == AV_PICTURE_TYPE_I) {
2000                     av_log(s->avctx, AV_LOG_ERROR,
2001                            "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
2002                     return AVERROR_INVALIDDATA;
2003                 }
2004
2005                 /* skip mb */
2006                 s->mb_intra = 0;
2007                 for (i = 0; i < 12; i++)
2008                     s->block_last_index[i] = -1;
2009                 if (s->picture_structure == PICT_FRAME)
2010                     s->mv_type = MV_TYPE_16X16;
2011                 else
2012                     s->mv_type = MV_TYPE_FIELD;
2013                 if (s->pict_type == AV_PICTURE_TYPE_P) {
2014                     /* if P type, zero motion vector is implied */
2015                     s->mv_dir             = MV_DIR_FORWARD;
2016                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
2017                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
2018                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
2019                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
2020                 } else {
2021                     /* if B type, reuse previous vectors and directions */
2022                     s->mv[0][0][0] = s->last_mv[0][0][0];
2023                     s->mv[0][0][1] = s->last_mv[0][0][1];
2024                     s->mv[1][0][0] = s->last_mv[1][0][0];
2025                     s->mv[1][0][1] = s->last_mv[1][0][1];
2026                 }
2027             }
2028         }
2029     }
2030 eos: // end of slice
2031     if (get_bits_left(&s->gb) < 0) {
2032         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
2033         return AVERROR_INVALIDDATA;
2034     }
2035     *buf += (get_bits_count(&s->gb) - 1) / 8;
2036     ff_dlog(s, "Slice start:%d %d  end:%d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
2037     return 0;
2038 }
2039
2040 static int slice_decode_thread(AVCodecContext *c, void *arg)
2041 {
2042     MpegEncContext *s   = *(void **) arg;
2043     const uint8_t *buf  = s->gb.buffer;
2044     int mb_y            = s->start_mb_y;
2045     const int field_pic = s->picture_structure != PICT_FRAME;
2046
2047     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
2048
2049     for (;;) {
2050         uint32_t start_code;
2051         int ret;
2052
2053         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
2054         emms_c();
2055         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
2056                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
2057                 s->start_mb_y, s->end_mb_y, s->er.error_count);
2058         if (ret < 0) {
2059             if (c->err_recognition & AV_EF_EXPLODE)
2060                 return ret;
2061             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2062                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2063                                 s->mb_x, s->mb_y,
2064                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2065         } else {
2066             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2067                             s->mb_x - 1, s->mb_y,
2068                             ER_AC_END | ER_DC_END | ER_MV_END);
2069         }
2070
2071         if (s->mb_y == s->end_mb_y)
2072             return 0;
2073
2074         start_code = -1;
2075         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2076         mb_y       = start_code - SLICE_MIN_START_CODE;
2077         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2078             mb_y += (*buf&0xE0)<<2;
2079         mb_y <<= field_pic;
2080         if (s->picture_structure == PICT_BOTTOM_FIELD)
2081             mb_y++;
2082         if (mb_y < 0 || mb_y >= s->end_mb_y)
2083             return AVERROR_INVALIDDATA;
2084     }
2085 }
2086
2087 /**
2088  * Handle slice ends.
2089  * @return 1 if it seems to be the last slice
2090  */
2091 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2092 {
2093     Mpeg1Context *s1  = avctx->priv_data;
2094     MpegEncContext *s = &s1->mpeg_enc_ctx;
2095
2096     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2097         return 0;
2098
2099     if (s->avctx->hwaccel) {
2100         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2101         if (ret < 0) {
2102             av_log(avctx, AV_LOG_ERROR,
2103                    "hardware accelerator failed to decode picture\n");
2104             return ret;
2105         }
2106     }
2107
2108     /* end of slice reached */
2109     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2110         /* end of image */
2111
2112         ff_er_frame_end(&s->er);
2113
2114         ff_mpv_frame_end(s);
2115
2116         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2117             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2118             if (ret < 0)
2119                 return ret;
2120             ff_print_debug_info(s, s->current_picture_ptr, pict);
2121             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2122         } else {
2123             if (avctx->active_thread_type & FF_THREAD_FRAME)
2124                 s->picture_number++;
2125             /* latency of 1 frame for I- and P-frames */
2126             /* XXX: use another variable than picture_number */
2127             if (s->last_picture_ptr) {
2128                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2129                 if (ret < 0)
2130                     return ret;
2131                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2132                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2133             }
2134         }
2135
2136         return 1;
2137     } else {
2138         return 0;
2139     }
2140 }
2141
2142 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2143                                  const uint8_t *buf, int buf_size)
2144 {
2145     Mpeg1Context *s1  = avctx->priv_data;
2146     MpegEncContext *s = &s1->mpeg_enc_ctx;
2147     int width, height;
2148     int i, v, j;
2149
2150     init_get_bits(&s->gb, buf, buf_size * 8);
2151
2152     width  = get_bits(&s->gb, 12);
2153     height = get_bits(&s->gb, 12);
2154     if (width == 0 || height == 0) {
2155         av_log(avctx, AV_LOG_WARNING,
2156                "Invalid horizontal or vertical size value.\n");
2157         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2158             return AVERROR_INVALIDDATA;
2159     }
2160     s->aspect_ratio_info = get_bits(&s->gb, 4);
2161     if (s->aspect_ratio_info == 0) {
2162         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2163         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2164             return AVERROR_INVALIDDATA;
2165     }
2166     s->frame_rate_index = get_bits(&s->gb, 4);
2167     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2168         av_log(avctx, AV_LOG_WARNING,
2169                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2170         s->frame_rate_index = 1;
2171     }
2172     s->bit_rate = get_bits(&s->gb, 18) * 400LL;
2173     if (check_marker(&s->gb, "in sequence header") == 0) {
2174         return AVERROR_INVALIDDATA;
2175     }
2176
2177     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2178     skip_bits(&s->gb, 1);
2179
2180     /* get matrix */
2181     if (get_bits1(&s->gb)) {
2182         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2183     } else {
2184         for (i = 0; i < 64; i++) {
2185             j = s->idsp.idct_permutation[i];
2186             v = ff_mpeg1_default_intra_matrix[i];
2187             s->intra_matrix[j]        = v;
2188             s->chroma_intra_matrix[j] = v;
2189         }
2190     }
2191     if (get_bits1(&s->gb)) {
2192         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2193     } else {
2194         for (i = 0; i < 64; i++) {
2195             int j = s->idsp.idct_permutation[i];
2196             v = ff_mpeg1_default_non_intra_matrix[i];
2197             s->inter_matrix[j]        = v;
2198             s->chroma_inter_matrix[j] = v;
2199         }
2200     }
2201
2202     if (show_bits(&s->gb, 23) != 0) {
2203         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2204         return AVERROR_INVALIDDATA;
2205     }
2206
2207     s->width  = width;
2208     s->height = height;
2209
2210     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2211     s->progressive_sequence = 1;
2212     s->progressive_frame    = 1;
2213     s->picture_structure    = PICT_FRAME;
2214     s->first_field          = 0;
2215     s->frame_pred_frame_dct = 1;
2216     s->chroma_format        = 1;
2217     s->codec_id             =
2218     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2219     s->out_format           = FMT_MPEG1;
2220     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2221     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2222         s->low_delay = 1;
2223
2224     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2225         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%"PRId64", aspect_ratio_info: %d \n",
2226                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2227
2228     return 0;
2229 }
2230
2231 static int vcr2_init_sequence(AVCodecContext *avctx)
2232 {
2233     Mpeg1Context *s1  = avctx->priv_data;
2234     MpegEncContext *s = &s1->mpeg_enc_ctx;
2235     int i, v, ret;
2236
2237     /* start new MPEG-1 context decoding */
2238     s->out_format = FMT_MPEG1;
2239     if (s1->mpeg_enc_ctx_allocated) {
2240         ff_mpv_common_end(s);
2241         s1->mpeg_enc_ctx_allocated = 0;
2242     }
2243     s->width            = avctx->coded_width;
2244     s->height           = avctx->coded_height;
2245     avctx->has_b_frames = 0; // true?
2246     s->low_delay        = 1;
2247
2248     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2249     setup_hwaccel_for_pixfmt(avctx);
2250
2251     ff_mpv_idct_init(s);
2252     if ((ret = ff_mpv_common_init(s)) < 0)
2253         return ret;
2254     s1->mpeg_enc_ctx_allocated = 1;
2255
2256     for (i = 0; i < 64; i++) {
2257         int j = s->idsp.idct_permutation[i];
2258         v = ff_mpeg1_default_intra_matrix[i];
2259         s->intra_matrix[j]        = v;
2260         s->chroma_intra_matrix[j] = v;
2261
2262         v = ff_mpeg1_default_non_intra_matrix[i];
2263         s->inter_matrix[j]        = v;
2264         s->chroma_inter_matrix[j] = v;
2265     }
2266
2267     s->progressive_sequence  = 1;
2268     s->progressive_frame     = 1;
2269     s->picture_structure     = PICT_FRAME;
2270     s->first_field           = 0;
2271     s->frame_pred_frame_dct  = 1;
2272     s->chroma_format         = 1;
2273     if (s->codec_tag == AV_RL32("BW10")) {
2274         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2275     } else {
2276         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2277         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2278     }
2279     s1->save_width           = s->width;
2280     s1->save_height          = s->height;
2281     s1->save_progressive_seq = s->progressive_sequence;
2282     return 0;
2283 }
2284
2285 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2286                               const uint8_t *p, int buf_size)
2287 {
2288     Mpeg1Context *s1 = avctx->priv_data;
2289
2290     if (buf_size >= 6 &&
2291         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2292         p[4] == 3 && (p[5] & 0x40)) {
2293         /* extract A53 Part 4 CC data */
2294         int cc_count = p[5] & 0x1f;
2295         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2296             av_freep(&s1->a53_caption);
2297             s1->a53_caption_size = cc_count * 3;
2298             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2299             if (s1->a53_caption)
2300                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2301         }
2302         return 1;
2303     } else if (buf_size >= 11 &&
2304                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2305         /* extract DVD CC data */
2306         int cc_count = 0;
2307         int i;
2308         // There is a caption count field in the data, but it is often
2309         // incorect.  So count the number of captions present.
2310         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2311             cc_count++;
2312         // Transform the DVD format into A53 Part 4 format
2313         if (cc_count > 0) {
2314             av_freep(&s1->a53_caption);
2315             s1->a53_caption_size = cc_count * 6;
2316             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2317             if (s1->a53_caption) {
2318                 uint8_t field1 = !!(p[4] & 0x80);
2319                 uint8_t *cap = s1->a53_caption;
2320                 p += 5;
2321                 for (i = 0; i < cc_count; i++) {
2322                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2323                     cap[1] = p[1];
2324                     cap[2] = p[2];
2325                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2326                     cap[4] = p[4];
2327                     cap[5] = p[5];
2328                     cap += 6;
2329                     p += 6;
2330                 }
2331             }
2332         }
2333         return 1;
2334     }
2335     return 0;
2336 }
2337
2338 static void mpeg_decode_user_data(AVCodecContext *avctx,
2339                                   const uint8_t *p, int buf_size)
2340 {
2341     Mpeg1Context *s = avctx->priv_data;
2342     const uint8_t *buf_end = p + buf_size;
2343     Mpeg1Context *s1 = avctx->priv_data;
2344
2345 #if 0
2346     int i;
2347     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2348         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2349     }
2350     av_log(avctx, AV_LOG_ERROR, "\n");
2351 #endif
2352
2353     if (buf_size > 29){
2354         int i;
2355         for(i=0; i<20; i++)
2356             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2357                 s->tmpgexs= 1;
2358             }
2359     }
2360     /* we parse the DTG active format information */
2361     if (buf_end - p >= 5 &&
2362         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2363         int flags = p[4];
2364         p += 5;
2365         if (flags & 0x80) {
2366             /* skip event id */
2367             p += 2;
2368         }
2369         if (flags & 0x40) {
2370             if (buf_end - p < 1)
2371                 return;
2372 #if FF_API_AFD
2373 FF_DISABLE_DEPRECATION_WARNINGS
2374             avctx->dtg_active_format = p[0] & 0x0f;
2375 FF_ENABLE_DEPRECATION_WARNINGS
2376 #endif /* FF_API_AFD */
2377             s1->has_afd = 1;
2378             s1->afd     = p[0] & 0x0f;
2379         }
2380     } else if (buf_end - p >= 6 &&
2381                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2382                p[4] == 0x03) { // S3D_video_format_length
2383         // the 0x7F mask ignores the reserved_bit value
2384         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2385
2386         if (S3D_video_format_type == 0x03 ||
2387             S3D_video_format_type == 0x04 ||
2388             S3D_video_format_type == 0x08 ||
2389             S3D_video_format_type == 0x23) {
2390
2391             s1->has_stereo3d = 1;
2392
2393             switch (S3D_video_format_type) {
2394             case 0x03:
2395                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2396                 break;
2397             case 0x04:
2398                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2399                 break;
2400             case 0x08:
2401                 s1->stereo3d.type = AV_STEREO3D_2D;
2402                 break;
2403             case 0x23:
2404                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2405                 break;
2406             }
2407         }
2408     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2409         return;
2410     }
2411 }
2412
2413 static void mpeg_decode_gop(AVCodecContext *avctx,
2414                             const uint8_t *buf, int buf_size)
2415 {
2416     Mpeg1Context *s1  = avctx->priv_data;
2417     MpegEncContext *s = &s1->mpeg_enc_ctx;
2418     int broken_link;
2419     int64_t tc;
2420
2421     init_get_bits(&s->gb, buf, buf_size * 8);
2422
2423     tc = avctx->timecode_frame_start = get_bits(&s->gb, 25);
2424
2425     s->closed_gop = get_bits1(&s->gb);
2426     /* broken_link indicate that after editing the
2427      * reference frames of the first B-Frames after GOP I-Frame
2428      * are missing (open gop) */
2429     broken_link = get_bits1(&s->gb);
2430
2431     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2432         char tcbuf[AV_TIMECODE_STR_SIZE];
2433         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2434         av_log(s->avctx, AV_LOG_DEBUG,
2435                "GOP (%s) closed_gop=%d broken_link=%d\n",
2436                tcbuf, s->closed_gop, broken_link);
2437     }
2438 }
2439
2440 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2441                          int *got_output, const uint8_t *buf, int buf_size)
2442 {
2443     Mpeg1Context *s = avctx->priv_data;
2444     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2445     const uint8_t *buf_ptr = buf;
2446     const uint8_t *buf_end = buf + buf_size;
2447     int ret, input_size;
2448     int last_code = 0, skip_frame = 0;
2449     int picture_start_code_seen = 0;
2450
2451     for (;;) {
2452         /* find next start code */
2453         uint32_t start_code = -1;
2454         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2455         if (start_code > 0x1ff) {
2456             if (!skip_frame) {
2457                 if (HAVE_THREADS &&
2458                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2459                     !avctx->hwaccel) {
2460                     int i;
2461                     av_assert0(avctx->thread_count > 1);
2462
2463                     avctx->execute(avctx, slice_decode_thread,
2464                                    &s2->thread_context[0], NULL,
2465                                    s->slice_count, sizeof(void *));
2466                     for (i = 0; i < s->slice_count; i++)
2467                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2468                 }
2469
2470 #if FF_API_VDPAU
2471                 if ((CONFIG_MPEG_VDPAU_DECODER || CONFIG_MPEG1_VDPAU_DECODER)
2472                     && uses_vdpau(avctx))
2473                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2474 #endif
2475
2476                 ret = slice_end(avctx, picture);
2477                 if (ret < 0)
2478                     return ret;
2479                 else if (ret) {
2480                     // FIXME: merge with the stuff in mpeg_decode_slice
2481                     if (s2->last_picture_ptr || s2->low_delay)
2482                         *got_output = 1;
2483                 }
2484             }
2485             s2->pict_type = 0;
2486
2487             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2488                 return AVERROR_INVALIDDATA;
2489
2490             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2491         }
2492
2493         input_size = buf_end - buf_ptr;
2494
2495         if (avctx->debug & FF_DEBUG_STARTCODE)
2496             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2497                    start_code, buf_ptr - buf, input_size);
2498
2499         /* prepare data for next start code */
2500         switch (start_code) {
2501         case SEQ_START_CODE:
2502             if (last_code == 0) {
2503                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2504                 if (buf != avctx->extradata)
2505                     s->sync = 1;
2506             } else {
2507                 av_log(avctx, AV_LOG_ERROR,
2508                        "ignoring SEQ_START_CODE after %X\n", last_code);
2509                 if (avctx->err_recognition & AV_EF_EXPLODE)
2510                     return AVERROR_INVALIDDATA;
2511             }
2512             break;
2513
2514         case PICTURE_START_CODE:
2515             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2516                /* If it's a frame picture, there can't be more than one picture header.
2517                   Yet, it does happen and we need to handle it. */
2518                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2519                break;
2520             }
2521             picture_start_code_seen = 1;
2522
2523             if (s2->width <= 0 || s2->height <= 0) {
2524                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2525                        s2->width, s2->height);
2526                 return AVERROR_INVALIDDATA;
2527             }
2528
2529             if (s->tmpgexs){
2530                 s2->intra_dc_precision= 3;
2531                 s2->intra_matrix[0]= 1;
2532             }
2533             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2534                 !avctx->hwaccel && s->slice_count) {
2535                 int i;
2536
2537                 avctx->execute(avctx, slice_decode_thread,
2538                                s2->thread_context, NULL,
2539                                s->slice_count, sizeof(void *));
2540                 for (i = 0; i < s->slice_count; i++)
2541                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2542                 s->slice_count = 0;
2543             }
2544             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2545                 ret = mpeg_decode_postinit(avctx);
2546                 if (ret < 0) {
2547                     av_log(avctx, AV_LOG_ERROR,
2548                            "mpeg_decode_postinit() failure\n");
2549                     return ret;
2550                 }
2551
2552                 /* We have a complete image: we try to decompress it. */
2553                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2554                     s2->pict_type = 0;
2555                 s->first_slice = 1;
2556                 last_code      = PICTURE_START_CODE;
2557             } else {
2558                 av_log(avctx, AV_LOG_ERROR,
2559                        "ignoring pic after %X\n", last_code);
2560                 if (avctx->err_recognition & AV_EF_EXPLODE)
2561                     return AVERROR_INVALIDDATA;
2562             }
2563             break;
2564         case EXT_START_CODE:
2565             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2566
2567             switch (get_bits(&s2->gb, 4)) {
2568             case 0x1:
2569                 if (last_code == 0) {
2570                     mpeg_decode_sequence_extension(s);
2571                 } else {
2572                     av_log(avctx, AV_LOG_ERROR,
2573                            "ignoring seq ext after %X\n", last_code);
2574                     if (avctx->err_recognition & AV_EF_EXPLODE)
2575                         return AVERROR_INVALIDDATA;
2576                 }
2577                 break;
2578             case 0x2:
2579                 mpeg_decode_sequence_display_extension(s);
2580                 break;
2581             case 0x3:
2582                 mpeg_decode_quant_matrix_extension(s2);
2583                 break;
2584             case 0x7:
2585                 mpeg_decode_picture_display_extension(s);
2586                 break;
2587             case 0x8:
2588                 if (last_code == PICTURE_START_CODE) {
2589                     mpeg_decode_picture_coding_extension(s);
2590                 } else {
2591                     av_log(avctx, AV_LOG_ERROR,
2592                            "ignoring pic cod ext after %X\n", last_code);
2593                     if (avctx->err_recognition & AV_EF_EXPLODE)
2594                         return AVERROR_INVALIDDATA;
2595                 }
2596                 break;
2597             }
2598             break;
2599         case USER_START_CODE:
2600             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2601             break;
2602         case GOP_START_CODE:
2603             if (last_code == 0) {
2604                 s2->first_field = 0;
2605                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2606                 s->sync = 1;
2607             } else {
2608                 av_log(avctx, AV_LOG_ERROR,
2609                        "ignoring GOP_START_CODE after %X\n", last_code);
2610                 if (avctx->err_recognition & AV_EF_EXPLODE)
2611                     return AVERROR_INVALIDDATA;
2612             }
2613             break;
2614         default:
2615             if (start_code >= SLICE_MIN_START_CODE &&
2616                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2617                 if (s2->progressive_sequence && !s2->progressive_frame) {
2618                     s2->progressive_frame = 1;
2619                     av_log(s2->avctx, AV_LOG_ERROR,
2620                            "interlaced frame in progressive sequence, ignoring\n");
2621                 }
2622
2623                 if (s2->picture_structure == 0 ||
2624                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2625                     av_log(s2->avctx, AV_LOG_ERROR,
2626                            "picture_structure %d invalid, ignoring\n",
2627                            s2->picture_structure);
2628                     s2->picture_structure = PICT_FRAME;
2629                 }
2630
2631                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2632                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2633
2634                 if (s2->picture_structure == PICT_FRAME) {
2635                     s2->first_field = 0;
2636                     s2->v_edge_pos  = 16 * s2->mb_height;
2637                 } else {
2638                     s2->first_field ^= 1;
2639                     s2->v_edge_pos   = 8 * s2->mb_height;
2640                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2641                 }
2642             }
2643             if (start_code >= SLICE_MIN_START_CODE &&
2644                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2645                 const int field_pic = s2->picture_structure != PICT_FRAME;
2646                 int mb_y = start_code - SLICE_MIN_START_CODE;
2647                 last_code = SLICE_MIN_START_CODE;
2648                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2649                     mb_y += (*buf_ptr&0xE0)<<2;
2650
2651                 mb_y <<= field_pic;
2652                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2653                     mb_y++;
2654
2655                 if (buf_end - buf_ptr < 2) {
2656                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2657                     return AVERROR_INVALIDDATA;
2658                 }
2659
2660                 if (mb_y >= s2->mb_height) {
2661                     av_log(s2->avctx, AV_LOG_ERROR,
2662                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2663                     return AVERROR_INVALIDDATA;
2664                 }
2665
2666                 if (!s2->last_picture_ptr) {
2667                     /* Skip B-frames if we do not have reference frames and
2668                      * GOP is not closed. */
2669                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2670                         if (!s2->closed_gop) {
2671                             skip_frame = 1;
2672                             break;
2673                         }
2674                     }
2675                 }
2676                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2677                     s->sync = 1;
2678                 if (!s2->next_picture_ptr) {
2679                     /* Skip P-frames if we do not have a reference frame or
2680                      * we have an invalid header. */
2681                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2682                         skip_frame = 1;
2683                         break;
2684                     }
2685                 }
2686                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2687                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2688                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2689                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2690                     avctx->skip_frame >= AVDISCARD_ALL) {
2691                     skip_frame = 1;
2692                     break;
2693                 }
2694
2695                 if (!s->mpeg_enc_ctx_allocated)
2696                     break;
2697
2698                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2699                     if (mb_y < avctx->skip_top ||
2700                         mb_y >= s2->mb_height - avctx->skip_bottom)
2701                         break;
2702                 }
2703
2704                 if (!s2->pict_type) {
2705                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2706                     if (avctx->err_recognition & AV_EF_EXPLODE)
2707                         return AVERROR_INVALIDDATA;
2708                     break;
2709                 }
2710
2711                 if (s->first_slice) {
2712                     skip_frame     = 0;
2713                     s->first_slice = 0;
2714                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2715                         return ret;
2716                 }
2717                 if (!s2->current_picture_ptr) {
2718                     av_log(avctx, AV_LOG_ERROR,
2719                            "current_picture not initialized\n");
2720                     return AVERROR_INVALIDDATA;
2721                 }
2722
2723 #if FF_API_VDPAU
2724                 if (uses_vdpau(avctx)) {
2725                     s->slice_count++;
2726                     break;
2727                 }
2728 #endif
2729
2730                 if (HAVE_THREADS &&
2731                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2732                     !avctx->hwaccel) {
2733                     int threshold = (s2->mb_height * s->slice_count +
2734                                      s2->slice_context_count / 2) /
2735                                     s2->slice_context_count;
2736                     av_assert0(avctx->thread_count > 1);
2737                     if (threshold <= mb_y) {
2738                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2739
2740                         thread_context->start_mb_y = mb_y;
2741                         thread_context->end_mb_y   = s2->mb_height;
2742                         if (s->slice_count) {
2743                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2744                             ret = ff_update_duplicate_context(thread_context, s2);
2745                             if (ret < 0)
2746                                 return ret;
2747                         }
2748                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2749                         s->slice_count++;
2750                     }
2751                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2752                 } else {
2753                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2754                     emms_c();
2755
2756                     if (ret < 0) {
2757                         if (avctx->err_recognition & AV_EF_EXPLODE)
2758                             return ret;
2759                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2760                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2761                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2762                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2763                     } else {
2764                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2765                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2766                                         ER_AC_END | ER_DC_END | ER_MV_END);
2767                     }
2768                 }
2769             }
2770             break;
2771         }
2772     }
2773 }
2774
2775 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2776                              int *got_output, AVPacket *avpkt)
2777 {
2778     const uint8_t *buf = avpkt->data;
2779     int ret;
2780     int buf_size = avpkt->size;
2781     Mpeg1Context *s = avctx->priv_data;
2782     AVFrame *picture = data;
2783     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2784
2785     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2786         /* special case for last picture */
2787         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2788             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2789             if (ret < 0)
2790                 return ret;
2791
2792             s2->next_picture_ptr = NULL;
2793
2794             *got_output = 1;
2795         }
2796         return buf_size;
2797     }
2798
2799     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2800         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2801                                            buf_size, NULL);
2802
2803         if (ff_combine_frame(&s2->parse_context, next,
2804                              (const uint8_t **) &buf, &buf_size) < 0)
2805             return buf_size;
2806     }
2807
2808     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2809     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2810                                            || s2->codec_tag == AV_RL32("BW10")
2811                                           ))
2812         vcr2_init_sequence(avctx);
2813
2814     s->slice_count = 0;
2815
2816     if (avctx->extradata && !s->extradata_decoded) {
2817         ret = decode_chunks(avctx, picture, got_output,
2818                             avctx->extradata, avctx->extradata_size);
2819         if (*got_output) {
2820             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2821             *got_output = 0;
2822         }
2823         s->extradata_decoded = 1;
2824         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2825             s2->current_picture_ptr = NULL;
2826             return ret;
2827         }
2828     }
2829
2830     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2831     if (ret<0 || *got_output)
2832         s2->current_picture_ptr = NULL;
2833
2834     return ret;
2835 }
2836
2837 static void flush(AVCodecContext *avctx)
2838 {
2839     Mpeg1Context *s = avctx->priv_data;
2840
2841     s->sync       = 0;
2842
2843     ff_mpeg_flush(avctx);
2844 }
2845
2846 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2847 {
2848     Mpeg1Context *s = avctx->priv_data;
2849
2850     if (s->mpeg_enc_ctx_allocated)
2851         ff_mpv_common_end(&s->mpeg_enc_ctx);
2852     av_freep(&s->a53_caption);
2853     return 0;
2854 }
2855
2856 static const AVProfile mpeg2_video_profiles[] = {
2857     { FF_PROFILE_MPEG2_422,          "4:2:2"              },
2858     { FF_PROFILE_MPEG2_HIGH,         "High"               },
2859     { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
2860     { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
2861     { FF_PROFILE_MPEG2_MAIN,         "Main"               },
2862     { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
2863     { FF_PROFILE_RESERVED,           "Reserved"           },
2864     { FF_PROFILE_RESERVED,           "Reserved"           },
2865     { FF_PROFILE_UNKNOWN                                  },
2866 };
2867
2868 AVCodec ff_mpeg1video_decoder = {
2869     .name                  = "mpeg1video",
2870     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2871     .type                  = AVMEDIA_TYPE_VIDEO,
2872     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2873     .priv_data_size        = sizeof(Mpeg1Context),
2874     .init                  = mpeg_decode_init,
2875     .close                 = mpeg_decode_end,
2876     .decode                = mpeg_decode_frame,
2877     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2878                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2879                              AV_CODEC_CAP_SLICE_THREADS,
2880     .flush                 = flush,
2881     .max_lowres            = 3,
2882     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2883 };
2884
2885 AVCodec ff_mpeg2video_decoder = {
2886     .name           = "mpeg2video",
2887     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2888     .type           = AVMEDIA_TYPE_VIDEO,
2889     .id             = AV_CODEC_ID_MPEG2VIDEO,
2890     .priv_data_size = sizeof(Mpeg1Context),
2891     .init           = mpeg_decode_init,
2892     .close          = mpeg_decode_end,
2893     .decode         = mpeg_decode_frame,
2894     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2895                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2896                       AV_CODEC_CAP_SLICE_THREADS,
2897     .flush          = flush,
2898     .max_lowres     = 3,
2899     .profiles       = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
2900 };
2901
2902 //legacy decoder
2903 AVCodec ff_mpegvideo_decoder = {
2904     .name           = "mpegvideo",
2905     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2906     .type           = AVMEDIA_TYPE_VIDEO,
2907     .id             = AV_CODEC_ID_MPEG2VIDEO,
2908     .priv_data_size = sizeof(Mpeg1Context),
2909     .init           = mpeg_decode_init,
2910     .close          = mpeg_decode_end,
2911     .decode         = mpeg_decode_frame,
2912     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2913     .flush          = flush,
2914     .max_lowres     = 3,
2915 };
2916
2917 #if FF_API_XVMC
2918 #if CONFIG_MPEG_XVMC_DECODER
2919 FF_DISABLE_DEPRECATION_WARNINGS
2920 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
2921 {
2922     if (avctx->active_thread_type & FF_THREAD_SLICE)
2923         return -1;
2924     if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
2925         return -1;
2926     if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
2927         ff_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2928     }
2929     mpeg_decode_init(avctx);
2930
2931     avctx->pix_fmt           = AV_PIX_FMT_XVMC_MPEG2_IDCT;
2932     avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
2933
2934     return 0;
2935 }
2936
2937 AVCodec ff_mpeg_xvmc_decoder = {
2938     .name           = "mpegvideo_xvmc",
2939     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2940     .type           = AVMEDIA_TYPE_VIDEO,
2941     .id             = AV_CODEC_ID_MPEG2VIDEO_XVMC,
2942     .priv_data_size = sizeof(Mpeg1Context),
2943     .init           = mpeg_mc_decode_init,
2944     .close          = mpeg_decode_end,
2945     .decode         = mpeg_decode_frame,
2946     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2947                       AV_CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL |
2948                       AV_CODEC_CAP_DELAY,
2949     .flush          = flush,
2950 };
2951 FF_ENABLE_DEPRECATION_WARNINGS
2952 #endif
2953 #endif /* FF_API_XVMC */
2954
2955 #if CONFIG_MPEG_VDPAU_DECODER && FF_API_VDPAU
2956 AVCodec ff_mpeg_vdpau_decoder = {
2957     .name           = "mpegvideo_vdpau",
2958     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2959     .type           = AVMEDIA_TYPE_VIDEO,
2960     .id             = AV_CODEC_ID_MPEG2VIDEO,
2961     .priv_data_size = sizeof(Mpeg1Context),
2962     .init           = mpeg_decode_init,
2963     .close          = mpeg_decode_end,
2964     .decode         = mpeg_decode_frame,
2965     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2966                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2967     .flush          = flush,
2968 };
2969 #endif
2970
2971 #if CONFIG_MPEG1_VDPAU_DECODER && FF_API_VDPAU
2972 AVCodec ff_mpeg1_vdpau_decoder = {
2973     .name           = "mpeg1video_vdpau",
2974     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2975     .type           = AVMEDIA_TYPE_VIDEO,
2976     .id             = AV_CODEC_ID_MPEG1VIDEO,
2977     .priv_data_size = sizeof(Mpeg1Context),
2978     .init           = mpeg_decode_init,
2979     .close          = mpeg_decode_end,
2980     .decode         = mpeg_decode_frame,
2981     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2982                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2983     .flush          = flush,
2984 };
2985 #endif