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   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 static const uint8_t non_linear_qscale[32] = {
 100      0,  1,  2,  3,  4,  5,   6,   7,
 101      8, 10, 12, 14, 16, 18,  20,  22,
 102     24, 28, 32, 36, 40, 44,  48,  52,
 103     56, 64, 72, 80, 88, 96, 104, 112,
 104 };
 105
 106 /* as H.263, but only 17 codes */
 107 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 108 {
 109     int code, sign, val, shift;
 110
 111     code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
 112     if (code == 0)
 113         return pred;
 114     if (code < 0)
 115         return 0xffff;
 116
 117     sign  = get_bits1(&s->gb);
 118     shift = fcode - 1;
 119     val   = code;
 120     if (shift) {
 121         val  = (val - 1) << shift;
 122         val |= get_bits(&s->gb, shift);
 123         val++;
 124     }
 125     if (sign)
 126         val = -val;
 127     val += pred;
 128
 129     /* modulo decoding */
 130     return sign_extend(val, 5 + shift);
 131 }
 132
 133 #define check_scantable_index(ctx, x)                                         \
 134     do {                                                                      \
 135         if ((x) > 63) {                                                       \
 136             av_log(ctx->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",     \
 137                    ctx->mb_x, ctx->mb_y);                                     \
 138             return AVERROR_INVALIDDATA;                                       \
 139         }                                                                     \
 140     } while (0)
 141
 142 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 143                                            int16_t *block, int n)
 144 {
 145     int level, dc, diff, i, j, run;
 146     int component;
 147     RLTable *rl                  = &ff_rl_mpeg1;
 148     uint8_t *const scantable     = s->intra_scantable.permutated;
 149     const uint16_t *quant_matrix = s->intra_matrix;
 150     const int qscale             = s->qscale;
 151
 152     /* DC coefficient */
 153     component = (n <= 3 ? 0 : n - 4 + 1);
 154     diff = decode_dc(&s->gb, component);
 155     if (diff >= 0xffff)
 156         return AVERROR_INVALIDDATA;
 157     dc  = s->last_dc[component];
 158     dc += diff;
 159     s->last_dc[component] = dc;
 160     block[0] = dc * quant_matrix[0];
 161     ff_tlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
 162     i = 0;
 163     {
 164         OPEN_READER(re, &s->gb);
 165         UPDATE_CACHE(re, &s->gb);
 166         if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 167             goto end;
 168
 169         /* now quantify & encode AC coefficients */
 170         for (;;) {
 171             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 172                        TEX_VLC_BITS, 2, 0);
 173
 174             if (level != 0) {
 175                 i += run;
 176                 check_scantable_index(s, i);
 177                 j = scantable[i];
 178                 level = (level * qscale * quant_matrix[j]) >> 4;
 179                 level = (level - 1) | 1;
 180                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 181                         SHOW_SBITS(re, &s->gb, 1);
 182                 SKIP_BITS(re, &s->gb, 1);
 183             } else {
 184                 /* escape */
 185                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 186                 LAST_SKIP_BITS(re, &s->gb, 6);
 187                 UPDATE_CACHE(re, &s->gb);
 188                 level = SHOW_SBITS(re, &s->gb, 8);
 189                 SKIP_BITS(re, &s->gb, 8);
 190                 if (level == -128) {
 191                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 192                     SKIP_BITS(re, &s->gb, 8);
 193                 } else if (level == 0) {
 194                     level = SHOW_UBITS(re, &s->gb, 8);
 195                     SKIP_BITS(re, &s->gb, 8);
 196                 }
 197                 i += run;
 198                 check_scantable_index(s, i);
 199                 j = scantable[i];
 200                 if (level < 0) {
 201                     level = -level;
 202                     level = (level * qscale * quant_matrix[j]) >> 4;
 203                     level = (level - 1) | 1;
 204                     level = -level;
 205                 } else {
 206                     level = (level * qscale * quant_matrix[j]) >> 4;
 207                     level = (level - 1) | 1;
 208                 }
 209             }
 210
 211             block[j] = level;
 212             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 213                break;
 214
 215             UPDATE_CACHE(re, &s->gb);
 216         }
 217 end:
 218         LAST_SKIP_BITS(re, &s->gb, 2);
 219         CLOSE_READER(re, &s->gb);
 220     }
 221     s->block_last_index[n] = i;
 222     return 0;
 223 }
 224
 225 int ff_mpeg1_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
 226 {
 227     return mpeg1_decode_block_intra(s, block, n);
 228 }
 229
 230 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 231                                            int16_t *block, int n)
 232 {
 233     int level, i, j, run;
 234     RLTable *rl                  = &ff_rl_mpeg1;
 235     uint8_t *const scantable     = s->intra_scantable.permutated;
 236     const uint16_t *quant_matrix = s->inter_matrix;
 237     const int qscale             = s->qscale;
 238
 239     {
 240         OPEN_READER(re, &s->gb);
 241         i = -1;
 242         // special case for first coefficient, no need to add second VLC table
 243         UPDATE_CACHE(re, &s->gb);
 244         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 245             level = (3 * qscale * quant_matrix[0]) >> 5;
 246             level = (level - 1) | 1;
 247             if (GET_CACHE(re, &s->gb) & 0x40000000)
 248                 level = -level;
 249             block[0] = level;
 250             i++;
 251             SKIP_BITS(re, &s->gb, 2);
 252             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 253                 goto end;
 254         }
 255         /* now quantify & encode AC coefficients */
 256         for (;;) {
 257             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 258                        TEX_VLC_BITS, 2, 0);
 259
 260             if (level != 0) {
 261                 i += run;
 262                 check_scantable_index(s, i);
 263                 j = scantable[i];
 264                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 265                 level = (level - 1) | 1;
 266                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 267                         SHOW_SBITS(re, &s->gb, 1);
 268                 SKIP_BITS(re, &s->gb, 1);
 269             } else {
 270                 /* escape */
 271                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 272                 LAST_SKIP_BITS(re, &s->gb, 6);
 273                 UPDATE_CACHE(re, &s->gb);
 274                 level = SHOW_SBITS(re, &s->gb, 8);
 275                 SKIP_BITS(re, &s->gb, 8);
 276                 if (level == -128) {
 277                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 278                     SKIP_BITS(re, &s->gb, 8);
 279                 } else if (level == 0) {
 280                     level = SHOW_UBITS(re, &s->gb, 8);
 281                     SKIP_BITS(re, &s->gb, 8);
 282                 }
 283                 i += run;
 284                 check_scantable_index(s, i);
 285                 j = scantable[i];
 286                 if (level < 0) {
 287                     level = -level;
 288                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 289                     level = (level - 1) | 1;
 290                     level = -level;
 291                 } else {
 292                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 293                     level = (level - 1) | 1;
 294                 }
 295             }
 296
 297             block[j] = level;
 298             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 299                 break;
 300             UPDATE_CACHE(re, &s->gb);
 301         }
 302 end:
 303         LAST_SKIP_BITS(re, &s->gb, 2);
 304         CLOSE_READER(re, &s->gb);
 305     }
 306     s->block_last_index[n] = i;
 307     return 0;
 308 }
 309
 310 /**
 311  * Note: this function can read out of range and crash for corrupt streams.
 312  * Changing this would eat up any speed benefits it has.
 313  * Do not use "fast" flag if you need the code to be robust.
 314  */
 315 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s,
 316                                                 int16_t *block, int n)
 317 {
 318     int level, i, j, run;
 319     RLTable *rl              = &ff_rl_mpeg1;
 320     uint8_t *const scantable = s->intra_scantable.permutated;
 321     const int qscale         = s->qscale;
 322
 323     {
 324         OPEN_READER(re, &s->gb);
 325         i = -1;
 326         // Special case for first coefficient, no need to add second VLC table.
 327         UPDATE_CACHE(re, &s->gb);
 328         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 329             level = (3 * qscale) >> 1;
 330             level = (level - 1) | 1;
 331             if (GET_CACHE(re, &s->gb) & 0x40000000)
 332                 level = -level;
 333             block[0] = level;
 334             i++;
 335             SKIP_BITS(re, &s->gb, 2);
 336             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 337                 goto end;
 338         }
 339
 340         /* now quantify & encode AC coefficients */
 341         for (;;) {
 342             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 343                        TEX_VLC_BITS, 2, 0);
 344
 345             if (level != 0) {
 346                 i += run;
 347                 check_scantable_index(s, i);
 348                 j = scantable[i];
 349                 level = ((level * 2 + 1) * qscale) >> 1;
 350                 level = (level - 1) | 1;
 351                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 352                         SHOW_SBITS(re, &s->gb, 1);
 353                 SKIP_BITS(re, &s->gb, 1);
 354             } else {
 355                 /* escape */
 356                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 357                 LAST_SKIP_BITS(re, &s->gb, 6);
 358                 UPDATE_CACHE(re, &s->gb);
 359                 level = SHOW_SBITS(re, &s->gb, 8);
 360                 SKIP_BITS(re, &s->gb, 8);
 361                 if (level == -128) {
 362                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 363                     SKIP_BITS(re, &s->gb, 8);
 364                 } else if (level == 0) {
 365                     level = SHOW_UBITS(re, &s->gb, 8);
 366                     SKIP_BITS(re, &s->gb, 8);
 367                 }
 368                 i += run;
 369                 check_scantable_index(s, i);
 370                 j = scantable[i];
 371                 if (level < 0) {
 372                     level = -level;
 373                     level = ((level * 2 + 1) * qscale) >> 1;
 374                     level = (level - 1) | 1;
 375                     level = -level;
 376                 } else {
 377                     level = ((level * 2 + 1) * qscale) >> 1;
 378                     level = (level - 1) | 1;
 379                 }
 380             }
 381
 382             block[j] = level;
 383             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 384                 break;
 385             UPDATE_CACHE(re, &s->gb);
 386         }
 387 end:
 388         LAST_SKIP_BITS(re, &s->gb, 2);
 389         CLOSE_READER(re, &s->gb);
 390     }
 391     s->block_last_index[n] = i;
 392     return 0;
 393 }
 394
 395 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 396                                                int16_t *block, int n)
 397 {
 398     int level, i, j, run;
 399     RLTable *rl = &ff_rl_mpeg1;
 400     uint8_t *const scantable = s->intra_scantable.permutated;
 401     const uint16_t *quant_matrix;
 402     const int qscale = s->qscale;
 403     int mismatch;
 404
 405     mismatch = 1;
 406
 407     {
 408         OPEN_READER(re, &s->gb);
 409         i = -1;
 410         if (n < 4)
 411             quant_matrix = s->inter_matrix;
 412         else
 413             quant_matrix = s->chroma_inter_matrix;
 414
 415         // Special case for first coefficient, no need to add second VLC table.
 416         UPDATE_CACHE(re, &s->gb);
 417         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 418             level = (3 * qscale * quant_matrix[0]) >> 5;
 419             if (GET_CACHE(re, &s->gb) & 0x40000000)
 420                 level = -level;
 421             block[0]  = level;
 422             mismatch ^= level;
 423             i++;
 424             SKIP_BITS(re, &s->gb, 2);
 425             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 426                 goto end;
 427         }
 428
 429         /* now quantify & encode AC coefficients */
 430         for (;;) {
 431             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 432                        TEX_VLC_BITS, 2, 0);
 433
 434             if (level != 0) {
 435                 i += run;
 436                 check_scantable_index(s, i);
 437                 j = scantable[i];
 438                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 439                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 440                         SHOW_SBITS(re, &s->gb, 1);
 441                 SKIP_BITS(re, &s->gb, 1);
 442             } else {
 443                 /* escape */
 444                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 445                 LAST_SKIP_BITS(re, &s->gb, 6);
 446                 UPDATE_CACHE(re, &s->gb);
 447                 level = SHOW_SBITS(re, &s->gb, 12);
 448                 SKIP_BITS(re, &s->gb, 12);
 449
 450                 i += run;
 451                 check_scantable_index(s, i);
 452                 j = scantable[i];
 453                 if (level < 0) {
 454                     level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 455                     level = -level;
 456                 } else {
 457                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 458                 }
 459             }
 460
 461             mismatch ^= level;
 462             block[j]  = level;
 463             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 464                 break;
 465             UPDATE_CACHE(re, &s->gb);
 466         }
 467 end:
 468         LAST_SKIP_BITS(re, &s->gb, 2);
 469         CLOSE_READER(re, &s->gb);
 470     }
 471     block[63] ^= (mismatch & 1);
 472
 473     s->block_last_index[n] = i;
 474     return 0;
 475 }
 476
 477 /**
 478  * Note: this function can read out of range and crash for corrupt streams.
 479  * Changing this would eat up any speed benefits it has.
 480  * Do not use "fast" flag if you need the code to be robust.
 481  */
 482 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 483                                                     int16_t *block, int n)
 484 {
 485     int level, i, j, run;
 486     RLTable *rl              = &ff_rl_mpeg1;
 487     uint8_t *const scantable = s->intra_scantable.permutated;
 488     const int qscale         = s->qscale;
 489     OPEN_READER(re, &s->gb);
 490     i = -1;
 491
 492     // special case for first coefficient, no need to add second VLC table
 493     UPDATE_CACHE(re, &s->gb);
 494     if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 495         level = (3 * qscale) >> 1;
 496         if (GET_CACHE(re, &s->gb) & 0x40000000)
 497             level = -level;
 498         block[0] = level;
 499         i++;
 500         SKIP_BITS(re, &s->gb, 2);
 501         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 502             goto end;
 503     }
 504
 505     /* now quantify & encode AC coefficients */
 506     for (;;) {
 507         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 508
 509         if (level != 0) {
 510             i += run;
 511             j = scantable[i];
 512             level = ((level * 2 + 1) * qscale) >> 1;
 513             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 514                     SHOW_SBITS(re, &s->gb, 1);
 515             SKIP_BITS(re, &s->gb, 1);
 516         } else {
 517             /* escape */
 518             run = SHOW_UBITS(re, &s->gb, 6) + 1;
 519             LAST_SKIP_BITS(re, &s->gb, 6);
 520             UPDATE_CACHE(re, &s->gb);
 521             level = SHOW_SBITS(re, &s->gb, 12);
 522             SKIP_BITS(re, &s->gb, 12);
 523
 524             i += run;
 525             j = scantable[i];
 526             if (level < 0) {
 527                 level = ((-level * 2 + 1) * qscale) >> 1;
 528                 level = -level;
 529             } else {
 530                 level = ((level * 2 + 1) * qscale) >> 1;
 531             }
 532         }
 533
 534         block[j] = level;
 535         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF || i > 63)
 536             break;
 537
 538         UPDATE_CACHE(re, &s->gb);
 539     }
 540 end:
 541     LAST_SKIP_BITS(re, &s->gb, 2);
 542     CLOSE_READER(re, &s->gb);
 543     s->block_last_index[n] = i;
 544     return 0;
 545 }
 546
 547 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
 548                                            int16_t *block, int n)
 549 {
 550     int level, dc, diff, i, j, run;
 551     int component;
 552     RLTable *rl;
 553     uint8_t *const scantable = s->intra_scantable.permutated;
 554     const uint16_t *quant_matrix;
 555     const int qscale = s->qscale;
 556     int mismatch;
 557
 558     /* DC coefficient */
 559     if (n < 4) {
 560         quant_matrix = s->intra_matrix;
 561         component    = 0;
 562     } else {
 563         quant_matrix = s->chroma_intra_matrix;
 564         component    = (n & 1) + 1;
 565     }
 566     diff = decode_dc(&s->gb, component);
 567     if (diff >= 0xffff)
 568         return AVERROR_INVALIDDATA;
 569     dc  = s->last_dc[component];
 570     dc += diff;
 571     s->last_dc[component] = dc;
 572     block[0] = dc << (3 - s->intra_dc_precision);
 573     ff_tlog(s->avctx, "dc=%d\n", block[0]);
 574     mismatch = block[0] ^ 1;
 575     i = 0;
 576     if (s->intra_vlc_format)
 577         rl = &ff_rl_mpeg2;
 578     else
 579         rl = &ff_rl_mpeg1;
 580
 581     {
 582         OPEN_READER(re, &s->gb);
 583         /* now quantify & encode AC coefficients */
 584         for (;;) {
 585             UPDATE_CACHE(re, &s->gb);
 586             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 587                        TEX_VLC_BITS, 2, 0);
 588
 589             if (level == 127) {
 590                 break;
 591             } else if (level != 0) {
 592                 i += run;
 593                 check_scantable_index(s, i);
 594                 j = scantable[i];
 595                 level = (level * qscale * quant_matrix[j]) >> 4;
 596                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 597                         SHOW_SBITS(re, &s->gb, 1);
 598                 LAST_SKIP_BITS(re, &s->gb, 1);
 599             } else {
 600                 /* escape */
 601                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 602                 LAST_SKIP_BITS(re, &s->gb, 6);
 603                 UPDATE_CACHE(re, &s->gb);
 604                 level = SHOW_SBITS(re, &s->gb, 12);
 605                 SKIP_BITS(re, &s->gb, 12);
 606                 i += run;
 607                 check_scantable_index(s, i);
 608                 j = scantable[i];
 609                 if (level < 0) {
 610                     level = (-level * qscale * quant_matrix[j]) >> 4;
 611                     level = -level;
 612                 } else {
 613                     level = (level * qscale * quant_matrix[j]) >> 4;
 614                 }
 615             }
 616
 617             mismatch ^= level;
 618             block[j]  = level;
 619         }
 620         CLOSE_READER(re, &s->gb);
 621     }
 622     block[63] ^= mismatch & 1;
 623
 624     s->block_last_index[n] = i;
 625     return 0;
 626 }
 627
 628 /**
 629  * Note: this function can read out of range and crash for corrupt streams.
 630  * Changing this would eat up any speed benefits it has.
 631  * Do not use "fast" flag if you need the code to be robust.
 632  */
 633 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
 634                                                 int16_t *block, int n)
 635 {
 636     int level, dc, diff, i, j, run;
 637     int component;
 638     RLTable *rl;
 639     uint8_t *const scantable = s->intra_scantable.permutated;
 640     const uint16_t *quant_matrix;
 641     const int qscale = s->qscale;
 642
 643     /* DC coefficient */
 644     if (n < 4) {
 645         quant_matrix = s->intra_matrix;
 646         component    = 0;
 647     } else {
 648         quant_matrix = s->chroma_intra_matrix;
 649         component    = (n & 1) + 1;
 650     }
 651     diff = decode_dc(&s->gb, component);
 652     if (diff >= 0xffff)
 653         return AVERROR_INVALIDDATA;
 654     dc = s->last_dc[component];
 655     dc += diff;
 656     s->last_dc[component] = dc;
 657     block[0] = dc << (3 - s->intra_dc_precision);
 658     i = 0;
 659     if (s->intra_vlc_format)
 660         rl = &ff_rl_mpeg2;
 661     else
 662         rl = &ff_rl_mpeg1;
 663
 664     {
 665         OPEN_READER(re, &s->gb);
 666         /* now quantify & encode AC coefficients */
 667         for (;;) {
 668             UPDATE_CACHE(re, &s->gb);
 669             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 670                        TEX_VLC_BITS, 2, 0);
 671
 672             if (level >= 64 || i > 63) {
 673                 break;
 674             } else if (level != 0) {
 675                 i += run;
 676                 j = scantable[i];
 677                 level = (level * qscale * quant_matrix[j]) >> 4;
 678                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 679                         SHOW_SBITS(re, &s->gb, 1);
 680                 LAST_SKIP_BITS(re, &s->gb, 1);
 681             } else {
 682                 /* escape */
 683                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 684                 LAST_SKIP_BITS(re, &s->gb, 6);
 685                 UPDATE_CACHE(re, &s->gb);
 686                 level = SHOW_SBITS(re, &s->gb, 12);
 687                 SKIP_BITS(re, &s->gb, 12);
 688                 i += run;
 689                 j = scantable[i];
 690                 if (level < 0) {
 691                     level = (-level * qscale * quant_matrix[j]) >> 4;
 692                     level = -level;
 693                 } else {
 694                     level = (level * qscale * quant_matrix[j]) >> 4;
 695                 }
 696             }
 697
 698             block[j] = level;
 699         }
 700         CLOSE_READER(re, &s->gb);
 701     }
 702
 703     s->block_last_index[n] = i;
 704     return 0;
 705 }
 706
 707 /******************************************/
 708 /* decoding */
 709
 710 static inline int get_dmv(MpegEncContext *s)
 711 {
 712     if (get_bits1(&s->gb))
 713         return 1 - (get_bits1(&s->gb) << 1);
 714     else
 715         return 0;
 716 }
 717
 718 static inline int get_qscale(MpegEncContext *s)
 719 {
 720     int qscale = get_bits(&s->gb, 5);
 721     if (s->q_scale_type)
 722         return non_linear_qscale[qscale];
 723     else
 724         return qscale << 1;
 725 }
 726
 727
 728 /* motion type (for MPEG-2) */
 729 #define MT_FIELD 1
 730 #define MT_FRAME 2
 731 #define MT_16X8  2
 732 #define MT_DMV   3
 733
 734 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
 735 {
 736     int i, j, k, cbp, val, mb_type, motion_type;
 737     const int mb_block_count = 4 + (1 << s->chroma_format);
 738     int ret;
 739
 740     ff_tlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 741
 742     av_assert2(s->mb_skipped == 0);
 743
 744     if (s->mb_skip_run-- != 0) {
 745         if (s->pict_type == AV_PICTURE_TYPE_P) {
 746             s->mb_skipped = 1;
 747             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
 748                 MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 749         } else {
 750             int mb_type;
 751
 752             if (s->mb_x)
 753                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
 754             else
 755                 // FIXME not sure if this is allowed in MPEG at all
 756                 mb_type = s->current_picture.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1];
 757             if (IS_INTRA(mb_type)) {
 758                 av_log(s->avctx, AV_LOG_ERROR, "skip with previntra\n");
 759                 return AVERROR_INVALIDDATA;
 760             }
 761             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
 762                 mb_type | MB_TYPE_SKIP;
 763
 764             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
 765                 s->mb_skipped = 1;
 766         }
 767
 768         return 0;
 769     }
 770
 771     switch (s->pict_type) {
 772     default:
 773     case AV_PICTURE_TYPE_I:
 774         if (get_bits1(&s->gb) == 0) {
 775             if (get_bits1(&s->gb) == 0) {
 776                 av_log(s->avctx, AV_LOG_ERROR,
 777                        "invalid mb type in I Frame at %d %d\n",
 778                        s->mb_x, s->mb_y);
 779                 return AVERROR_INVALIDDATA;
 780             }
 781             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 782         } else {
 783             mb_type = MB_TYPE_INTRA;
 784         }
 785         break;
 786     case AV_PICTURE_TYPE_P:
 787         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 788         if (mb_type < 0) {
 789             av_log(s->avctx, AV_LOG_ERROR,
 790                    "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 791             return AVERROR_INVALIDDATA;
 792         }
 793         mb_type = ptype2mb_type[mb_type];
 794         break;
 795     case AV_PICTURE_TYPE_B:
 796         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 797         if (mb_type < 0) {
 798             av_log(s->avctx, AV_LOG_ERROR,
 799                    "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 800             return AVERROR_INVALIDDATA;
 801         }
 802         mb_type = btype2mb_type[mb_type];
 803         break;
 804     }
 805     ff_tlog(s->avctx, "mb_type=%x\n", mb_type);
 806 //    motion_type = 0; /* avoid warning */
 807     if (IS_INTRA(mb_type)) {
 808         s->bdsp.clear_blocks(s->block[0]);
 809
 810         if (!s->chroma_y_shift)
 811             s->bdsp.clear_blocks(s->block[6]);
 812
 813         /* compute DCT type */
 814         // FIXME: add an interlaced_dct coded var?
 815         if (s->picture_structure == PICT_FRAME &&
 816             !s->frame_pred_frame_dct)
 817             s->interlaced_dct = get_bits1(&s->gb);
 818
 819         if (IS_QUANT(mb_type))
 820             s->qscale = get_qscale(s);
 821
 822         if (s->concealment_motion_vectors) {
 823             /* just parse them */
 824             if (s->picture_structure != PICT_FRAME)
 825                 skip_bits1(&s->gb);  /* field select */
 826
 827             s->mv[0][0][0]      =
 828             s->last_mv[0][0][0] =
 829             s->last_mv[0][1][0] = mpeg_decode_motion(s, s->mpeg_f_code[0][0],
 830                                                      s->last_mv[0][0][0]);
 831             s->mv[0][0][1]      =
 832             s->last_mv[0][0][1] =
 833             s->last_mv[0][1][1] = mpeg_decode_motion(s, s->mpeg_f_code[0][1],
 834                                                      s->last_mv[0][0][1]);
 835
 836             check_marker(&s->gb, "after concealment_motion_vectors");
 837         } else {
 838             /* reset mv prediction */
 839             memset(s->last_mv, 0, sizeof(s->last_mv));
 840         }
 841         s->mb_intra = 1;
 842         // if 1, we memcpy blocks in xvmcvideo
 843         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
 844             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
 845
 846         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
 847             if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
 848                 for (i = 0; i < 6; i++)
 849                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 850             } else {
 851                 for (i = 0; i < mb_block_count; i++)
 852                     if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
 853                         return ret;
 854             }
 855         } else {
 856             for (i = 0; i < 6; i++)
 857                 if ((ret = mpeg1_decode_block_intra(s, *s->pblocks[i], i)) < 0)
 858                     return ret;
 859         }
 860     } else {
 861         if (mb_type & MB_TYPE_ZERO_MV) {
 862             av_assert2(mb_type & MB_TYPE_CBP);
 863
 864             s->mv_dir = MV_DIR_FORWARD;
 865             if (s->picture_structure == PICT_FRAME) {
 866                 if (s->picture_structure == PICT_FRAME
 867                     && !s->frame_pred_frame_dct)
 868                     s->interlaced_dct = get_bits1(&s->gb);
 869                 s->mv_type = MV_TYPE_16X16;
 870             } else {
 871                 s->mv_type            = MV_TYPE_FIELD;
 872                 mb_type              |= MB_TYPE_INTERLACED;
 873                 s->field_select[0][0] = s->picture_structure - 1;
 874             }
 875
 876             if (IS_QUANT(mb_type))
 877                 s->qscale = get_qscale(s);
 878
 879             s->last_mv[0][0][0] = 0;
 880             s->last_mv[0][0][1] = 0;
 881             s->last_mv[0][1][0] = 0;
 882             s->last_mv[0][1][1] = 0;
 883             s->mv[0][0][0]      = 0;
 884             s->mv[0][0][1]      = 0;
 885         } else {
 886             av_assert2(mb_type & MB_TYPE_L0L1);
 887             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 888             /* get additional motion vector type */
 889             if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) {
 890                 motion_type = MT_FRAME;
 891             } else {
 892                 motion_type = get_bits(&s->gb, 2);
 893                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 894                     s->interlaced_dct = get_bits1(&s->gb);
 895             }
 896
 897             if (IS_QUANT(mb_type))
 898                 s->qscale = get_qscale(s);
 899
 900             /* motion vectors */
 901             s->mv_dir = (mb_type >> 13) & 3;
 902             ff_tlog(s->avctx, "motion_type=%d\n", motion_type);
 903             switch (motion_type) {
 904             case MT_FRAME: /* or MT_16X8 */
 905                 if (s->picture_structure == PICT_FRAME) {
 906                     mb_type   |= MB_TYPE_16x16;
 907                     s->mv_type = MV_TYPE_16X16;
 908                     for (i = 0; i < 2; i++) {
 909                         if (USES_LIST(mb_type, i)) {
 910                             /* MT_FRAME */
 911                             s->mv[i][0][0]      =
 912                             s->last_mv[i][0][0] =
 913                             s->last_mv[i][1][0] =
 914                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 915                                                    s->last_mv[i][0][0]);
 916                             s->mv[i][0][1]      =
 917                             s->last_mv[i][0][1] =
 918                             s->last_mv[i][1][1] =
 919                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 920                                                    s->last_mv[i][0][1]);
 921                             /* full_pel: only for MPEG-1 */
 922                             if (s->full_pel[i]) {
 923                                 s->mv[i][0][0] <<= 1;
 924                                 s->mv[i][0][1] <<= 1;
 925                             }
 926                         }
 927                     }
 928                 } else {
 929                     mb_type   |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 930                     s->mv_type = MV_TYPE_16X8;
 931                     for (i = 0; i < 2; i++) {
 932                         if (USES_LIST(mb_type, i)) {
 933                             /* MT_16X8 */
 934                             for (j = 0; j < 2; j++) {
 935                                 s->field_select[i][j] = get_bits1(&s->gb);
 936                                 for (k = 0; k < 2; k++) {
 937                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 938                                                              s->last_mv[i][j][k]);
 939                                     s->last_mv[i][j][k] = val;
 940                                     s->mv[i][j][k]      = val;
 941                                 }
 942                             }
 943                         }
 944                     }
 945                 }
 946                 break;
 947             case MT_FIELD:
 948                 s->mv_type = MV_TYPE_FIELD;
 949                 if (s->picture_structure == PICT_FRAME) {
 950                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 951                     for (i = 0; i < 2; i++) {
 952                         if (USES_LIST(mb_type, i)) {
 953                             for (j = 0; j < 2; j++) {
 954                                 s->field_select[i][j] = get_bits1(&s->gb);
 955                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 956                                                          s->last_mv[i][j][0]);
 957                                 s->last_mv[i][j][0] = val;
 958                                 s->mv[i][j][0]      = val;
 959                                 ff_tlog(s->avctx, "fmx=%d\n", val);
 960                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 961                                                          s->last_mv[i][j][1] >> 1);
 962                                 s->last_mv[i][j][1] = 2 * val;
 963                                 s->mv[i][j][1]      = val;
 964                                 ff_tlog(s->avctx, "fmy=%d\n", val);
 965                             }
 966                         }
 967                     }
 968                 } else {
 969                     av_assert0(!s->progressive_sequence);
 970                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 971                     for (i = 0; i < 2; i++) {
 972                         if (USES_LIST(mb_type, i)) {
 973                             s->field_select[i][0] = get_bits1(&s->gb);
 974                             for (k = 0; k < 2; k++) {
 975                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 976                                                          s->last_mv[i][0][k]);
 977                                 s->last_mv[i][0][k] = val;
 978                                 s->last_mv[i][1][k] = val;
 979                                 s->mv[i][0][k]      = val;
 980                             }
 981                         }
 982                     }
 983                 }
 984                 break;
 985             case MT_DMV:
 986                 if (s->progressive_sequence){
 987                     av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
 988                     return AVERROR_INVALIDDATA;
 989                 }
 990                 s->mv_type = MV_TYPE_DMV;
 991                 for (i = 0; i < 2; i++) {
 992                     if (USES_LIST(mb_type, i)) {
 993                         int dmx, dmy, mx, my, m;
 994                         const int my_shift = s->picture_structure == PICT_FRAME;
 995
 996                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 997                                                 s->last_mv[i][0][0]);
 998                         s->last_mv[i][0][0] = mx;
 999                         s->last_mv[i][1][0] = mx;
1000                         dmx = get_dmv(s);
1001                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
1002                                                  s->last_mv[i][0][1] >> my_shift);
1003                         dmy = get_dmv(s);
1004
1005
1006                         s->last_mv[i][0][1] = my << my_shift;
1007                         s->last_mv[i][1][1] = my << my_shift;
1008
1009                         s->mv[i][0][0] = mx;
1010                         s->mv[i][0][1] = my;
1011                         s->mv[i][1][0] = mx; // not used
1012                         s->mv[i][1][1] = my; // not used
1013
1014                         if (s->picture_structure == PICT_FRAME) {
1015                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
1016
1017                             // m = 1 + 2 * s->top_field_first;
1018                             m = s->top_field_first ? 1 : 3;
1019
1020                             /* top -> top pred */
1021                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1022                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1023                             m = 4 - m;
1024                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1025                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1026                         } else {
1027                             mb_type |= MB_TYPE_16x16;
1028
1029                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
1030                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
1031                             if (s->picture_structure == PICT_TOP_FIELD)
1032                                 s->mv[i][2][1]--;
1033                             else
1034                                 s->mv[i][2][1]++;
1035                         }
1036                     }
1037                 }
1038                 break;
1039             default:
1040                 av_log(s->avctx, AV_LOG_ERROR,
1041                        "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
1042                 return AVERROR_INVALIDDATA;
1043             }
1044         }
1045
1046         s->mb_intra = 0;
1047         if (HAS_CBP(mb_type)) {
1048             s->bdsp.clear_blocks(s->block[0]);
1049
1050             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1051             if (mb_block_count > 6) {
1052                 cbp <<= mb_block_count - 6;
1053                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
1054                 s->bdsp.clear_blocks(s->block[6]);
1055             }
1056             if (cbp <= 0) {
1057                 av_log(s->avctx, AV_LOG_ERROR,
1058                        "invalid cbp %d at %d %d\n", cbp, s->mb_x, s->mb_y);
1059                 return AVERROR_INVALIDDATA;
1060             }
1061
1062             // if 1, we memcpy blocks in xvmcvideo
1063             if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1064                 ff_xvmc_pack_pblocks(s, cbp);
1065
1066             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
1067                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1068                     for (i = 0; i < 6; i++) {
1069                         if (cbp & 32)
1070                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
1071                         else
1072                             s->block_last_index[i] = -1;
1073                         cbp += cbp;
1074                     }
1075                 } else {
1076                     cbp <<= 12 - mb_block_count;
1077
1078                     for (i = 0; i < mb_block_count; i++) {
1079                         if (cbp & (1 << 11)) {
1080                             if ((ret = mpeg2_decode_block_non_intra(s, *s->pblocks[i], i)) < 0)
1081                                 return ret;
1082                         } else {
1083                             s->block_last_index[i] = -1;
1084                         }
1085                         cbp += cbp;
1086                     }
1087                 }
1088             } else {
1089                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1090                     for (i = 0; i < 6; i++) {
1091                         if (cbp & 32)
1092                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
1093                         else
1094                             s->block_last_index[i] = -1;
1095                         cbp += cbp;
1096                     }
1097                 } else {
1098                     for (i = 0; i < 6; i++) {
1099                         if (cbp & 32) {
1100                             if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
1101                                 return ret;
1102                         } else {
1103                             s->block_last_index[i] = -1;
1104                         }
1105                         cbp += cbp;
1106                     }
1107                 }
1108             }
1109         } else {
1110             for (i = 0; i < 12; i++)
1111                 s->block_last_index[i] = -1;
1112         }
1113     }
1114
1115     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1116
1117     return 0;
1118 }
1119
1120 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1121 {
1122     Mpeg1Context *s    = avctx->priv_data;
1123     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1124
1125     ff_mpv_decode_defaults(s2);
1126
1127     if (   avctx->codec_tag != AV_RL32("VCR2")
1128         && avctx->codec_tag != AV_RL32("BW10"))
1129         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
1130     ff_mpv_decode_init(s2, avctx);
1131
1132     s->mpeg_enc_ctx.avctx  = avctx;
1133
1134     /* we need some permutation to store matrices,
1135      * until the decoder sets the real permutation. */
1136     ff_mpv_idct_init(s2);
1137     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1138     ff_mpeg12_init_vlcs();
1139
1140     s->mpeg_enc_ctx_allocated      = 0;
1141     s->mpeg_enc_ctx.picture_number = 0;
1142     s->repeat_field                = 0;
1143     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1144     avctx->color_range             = AVCOL_RANGE_MPEG;
1145     return 0;
1146 }
1147
1148 static int mpeg_decode_update_thread_context(AVCodecContext *avctx,
1149                                              const AVCodecContext *avctx_from)
1150 {
1151     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1152     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1153     int err;
1154
1155     if (avctx == avctx_from               ||
1156         !ctx_from->mpeg_enc_ctx_allocated ||
1157         !s1->context_initialized)
1158         return 0;
1159
1160     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1161     if (err)
1162         return err;
1163
1164     if (!ctx->mpeg_enc_ctx_allocated)
1165         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1166
1167     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1168         s->picture_number++;
1169
1170     return 0;
1171 }
1172
1173 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1174                                  const uint8_t *new_perm)
1175 {
1176     uint16_t temp_matrix[64];
1177     int i;
1178
1179     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1180
1181     for (i = 0; i < 64; i++)
1182         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1183 }
1184
1185 static const enum AVPixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
1186 #if CONFIG_MPEG1_XVMC_HWACCEL
1187     AV_PIX_FMT_XVMC,
1188 #endif
1189 #if CONFIG_MPEG1_VDPAU_DECODER && FF_API_VDPAU
1190     AV_PIX_FMT_VDPAU_MPEG1,
1191 #endif
1192 #if CONFIG_MPEG1_VDPAU_HWACCEL
1193     AV_PIX_FMT_VDPAU,
1194 #endif
1195     AV_PIX_FMT_YUV420P,
1196     AV_PIX_FMT_NONE
1197 };
1198
1199 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1200 #if CONFIG_MPEG2_XVMC_HWACCEL
1201     AV_PIX_FMT_XVMC,
1202 #endif
1203 #if CONFIG_MPEG_VDPAU_DECODER && FF_API_VDPAU
1204     AV_PIX_FMT_VDPAU_MPEG2,
1205 #endif
1206 #if CONFIG_MPEG2_VDPAU_HWACCEL
1207     AV_PIX_FMT_VDPAU,
1208 #endif
1209 #if CONFIG_MPEG2_DXVA2_HWACCEL
1210     AV_PIX_FMT_DXVA2_VLD,
1211 #endif
1212 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1213     AV_PIX_FMT_D3D11VA_VLD,
1214 #endif
1215 #if CONFIG_MPEG2_VAAPI_HWACCEL
1216     AV_PIX_FMT_VAAPI,
1217 #endif
1218 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1219     AV_PIX_FMT_VIDEOTOOLBOX,
1220 #endif
1221     AV_PIX_FMT_YUV420P,
1222     AV_PIX_FMT_NONE
1223 };
1224
1225 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1226     AV_PIX_FMT_YUV422P,
1227     AV_PIX_FMT_NONE
1228 };
1229
1230 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1231     AV_PIX_FMT_YUV444P,
1232     AV_PIX_FMT_NONE
1233 };
1234
1235 #if FF_API_VDPAU
1236 static inline int uses_vdpau(AVCodecContext *avctx) {
1237     return avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG1 || avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG2;
1238 }
1239 #endif
1240
1241 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1242 {
1243     Mpeg1Context *s1  = avctx->priv_data;
1244     MpegEncContext *s = &s1->mpeg_enc_ctx;
1245     const enum AVPixelFormat *pix_fmts;
1246
1247     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1248         return AV_PIX_FMT_GRAY8;
1249
1250     if (s->chroma_format < 2)
1251         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1252                                 mpeg1_hwaccel_pixfmt_list_420 :
1253                                 mpeg2_hwaccel_pixfmt_list_420;
1254     else if (s->chroma_format == 2)
1255         pix_fmts = mpeg12_pixfmt_list_422;
1256     else
1257         pix_fmts = mpeg12_pixfmt_list_444;
1258
1259     return ff_thread_get_format(avctx, pix_fmts);
1260 }
1261
1262 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1263 {
1264     // until then pix_fmt may be changed right after codec init
1265     if (avctx->hwaccel
1266 #if FF_API_VDPAU
1267         || uses_vdpau(avctx)
1268 #endif
1269         )
1270         if (avctx->idct_algo == FF_IDCT_AUTO)
1271             avctx->idct_algo = FF_IDCT_SIMPLE;
1272
1273     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1274         Mpeg1Context *s1 = avctx->priv_data;
1275         MpegEncContext *s = &s1->mpeg_enc_ctx;
1276
1277         s->pack_pblocks = 1;
1278 #if FF_API_XVMC
1279         avctx->xvmc_acceleration = 2;
1280 #endif /* FF_API_XVMC */
1281     }
1282 }
1283
1284 /* Call this function when we know all parameters.
1285  * It may be called in different places for MPEG-1 and MPEG-2. */
1286 static int mpeg_decode_postinit(AVCodecContext *avctx)
1287 {
1288     Mpeg1Context *s1  = avctx->priv_data;
1289     MpegEncContext *s = &s1->mpeg_enc_ctx;
1290     uint8_t old_permutation[64];
1291     int ret;
1292
1293     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1294         // MPEG-1 aspect
1295         avctx->sample_aspect_ratio = av_d2q(1.0 / ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1296     } else { // MPEG-2
1297         // MPEG-2 aspect
1298         if (s->aspect_ratio_info > 1) {
1299             AVRational dar =
1300                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1301                                   (AVRational) { s1->pan_scan.width,
1302                                                  s1->pan_scan.height }),
1303                          (AVRational) { s->width, s->height });
1304
1305             /* We ignore the spec here and guess a bit as reality does not
1306              * match the spec, see for example res_change_ffmpeg_aspect.ts
1307              * and sequence-display-aspect.mpg.
1308              * issue1613, 621, 562 */
1309             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1310                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1311                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1312                 s->avctx->sample_aspect_ratio =
1313                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1314                              (AVRational) { s->width, s->height });
1315             } else {
1316                 s->avctx->sample_aspect_ratio =
1317                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1318                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1319 // issue1613 4/3 16/9 -> 16/9
1320 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1321 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1322 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1323                 ff_dlog(avctx, "aspect A %d/%d\n",
1324                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1325                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1326                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1327                         s->avctx->sample_aspect_ratio.den);
1328             }
1329         } else {
1330             s->avctx->sample_aspect_ratio =
1331                 ff_mpeg2_aspect[s->aspect_ratio_info];
1332         }
1333     } // MPEG-2
1334
1335     if (av_image_check_sar(s->width, s->height,
1336                            avctx->sample_aspect_ratio) < 0) {
1337         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1338                 avctx->sample_aspect_ratio.num,
1339                 avctx->sample_aspect_ratio.den);
1340         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1341     }
1342
1343     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1344         avctx->coded_width       != s->width                ||
1345         avctx->coded_height      != s->height               ||
1346         s1->save_width           != s->width                ||
1347         s1->save_height          != s->height               ||
1348         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1349         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1350         0) {
1351         if (s1->mpeg_enc_ctx_allocated) {
1352             ParseContext pc = s->parse_context;
1353             s->parse_context.buffer = 0;
1354             ff_mpv_common_end(s);
1355             s->parse_context = pc;
1356             s1->mpeg_enc_ctx_allocated = 0;
1357         }
1358
1359         ret = ff_set_dimensions(avctx, s->width, s->height);
1360         if (ret < 0)
1361             return ret;
1362
1363         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1364             avctx->rc_max_rate = s->bit_rate;
1365         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1366                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1367             avctx->bit_rate = s->bit_rate;
1368         }
1369         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1370         s1->save_width           = s->width;
1371         s1->save_height          = s->height;
1372         s1->save_progressive_seq = s->progressive_sequence;
1373
1374         /* low_delay may be forced, in this case we will have B-frames
1375          * that behave like P-frames. */
1376         avctx->has_b_frames = !s->low_delay;
1377
1378         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1379             // MPEG-1 fps
1380             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1381             avctx->ticks_per_frame     = 1;
1382
1383             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1384         } else { // MPEG-2
1385             // MPEG-2 fps
1386             av_reduce(&s->avctx->framerate.num,
1387                       &s->avctx->framerate.den,
1388                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1389                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1390                       1 << 30);
1391             avctx->ticks_per_frame = 2;
1392
1393             switch (s->chroma_format) {
1394             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1395             case 2:
1396             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1397             default: av_assert0(0);
1398             }
1399         } // MPEG-2
1400
1401         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1402         setup_hwaccel_for_pixfmt(avctx);
1403
1404         /* Quantization matrices may need reordering
1405          * if DCT permutation is changed. */
1406         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1407
1408         ff_mpv_idct_init(s);
1409         if ((ret = ff_mpv_common_init(s)) < 0)
1410             return ret;
1411
1412         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1413         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1414         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1415         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1416
1417         s1->mpeg_enc_ctx_allocated = 1;
1418     }
1419     return 0;
1420 }
1421
1422 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1423                                 int buf_size)
1424 {
1425     Mpeg1Context *s1  = avctx->priv_data;
1426     MpegEncContext *s = &s1->mpeg_enc_ctx;
1427     int ref, f_code, vbv_delay;
1428
1429     init_get_bits(&s->gb, buf, buf_size * 8);
1430
1431     ref = get_bits(&s->gb, 10); /* temporal ref */
1432     s->pict_type = get_bits(&s->gb, 3);
1433     if (s->pict_type == 0 || s->pict_type > 3)
1434         return AVERROR_INVALIDDATA;
1435
1436     vbv_delay = get_bits(&s->gb, 16);
1437     s->vbv_delay = vbv_delay;
1438     if (s->pict_type == AV_PICTURE_TYPE_P ||
1439         s->pict_type == AV_PICTURE_TYPE_B) {
1440         s->full_pel[0] = get_bits1(&s->gb);
1441         f_code = get_bits(&s->gb, 3);
1442         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1443             return AVERROR_INVALIDDATA;
1444         f_code += !f_code;
1445         s->mpeg_f_code[0][0] = f_code;
1446         s->mpeg_f_code[0][1] = f_code;
1447     }
1448     if (s->pict_type == AV_PICTURE_TYPE_B) {
1449         s->full_pel[1] = get_bits1(&s->gb);
1450         f_code = get_bits(&s->gb, 3);
1451         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1452             return AVERROR_INVALIDDATA;
1453         f_code += !f_code;
1454         s->mpeg_f_code[1][0] = f_code;
1455         s->mpeg_f_code[1][1] = f_code;
1456     }
1457     s->current_picture.f->pict_type = s->pict_type;
1458     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1459
1460     if (avctx->debug & FF_DEBUG_PICT_INFO)
1461         av_log(avctx, AV_LOG_DEBUG,
1462                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1463
1464     s->y_dc_scale = 8;
1465     s->c_dc_scale = 8;
1466     return 0;
1467 }
1468
1469 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1470 {
1471     MpegEncContext *s = &s1->mpeg_enc_ctx;
1472     int horiz_size_ext, vert_size_ext;
1473     int bit_rate_ext;
1474
1475     skip_bits(&s->gb, 1); /* profile and level esc*/
1476     s->avctx->profile       = get_bits(&s->gb, 3);
1477     s->avctx->level         = get_bits(&s->gb, 4);
1478     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1479     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1480
1481     if (!s->chroma_format) {
1482         s->chroma_format = 1;
1483         av_log(s->avctx, AV_LOG_WARNING, "Chroma format invalid\n");
1484     }
1485
1486     horiz_size_ext          = get_bits(&s->gb, 2);
1487     vert_size_ext           = get_bits(&s->gb, 2);
1488     s->width  |= (horiz_size_ext << 12);
1489     s->height |= (vert_size_ext  << 12);
1490     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1491     s->bit_rate += (bit_rate_ext << 18) * 400;
1492     check_marker(&s->gb, "after bit rate extension");
1493     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1494
1495     s->low_delay = get_bits1(&s->gb);
1496     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1497         s->low_delay = 1;
1498
1499     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1500     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1501
1502     ff_dlog(s->avctx, "sequence extension\n");
1503     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1504
1505     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1506         av_log(s->avctx, AV_LOG_DEBUG,
1507                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%d\n",
1508                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1509                s->avctx->rc_buffer_size, s->bit_rate);
1510 }
1511
1512 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1513 {
1514     MpegEncContext *s = &s1->mpeg_enc_ctx;
1515     int color_description, w, h;
1516
1517     skip_bits(&s->gb, 3); /* video format */
1518     color_description = get_bits1(&s->gb);
1519     if (color_description) {
1520         s->avctx->color_primaries = get_bits(&s->gb, 8);
1521         s->avctx->color_trc       = get_bits(&s->gb, 8);
1522         s->avctx->colorspace      = get_bits(&s->gb, 8);
1523     }
1524     w = get_bits(&s->gb, 14);
1525     skip_bits(&s->gb, 1); // marker
1526     h = get_bits(&s->gb, 14);
1527     // remaining 3 bits are zero padding
1528
1529     s1->pan_scan.width  = 16 * w;
1530     s1->pan_scan.height = 16 * h;
1531
1532     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1533         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1534 }
1535
1536 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1537 {
1538     MpegEncContext *s = &s1->mpeg_enc_ctx;
1539     int i, nofco;
1540
1541     nofco = 1;
1542     if (s->progressive_sequence) {
1543         if (s->repeat_first_field) {
1544             nofco++;
1545             if (s->top_field_first)
1546                 nofco++;
1547         }
1548     } else {
1549         if (s->picture_structure == PICT_FRAME) {
1550             nofco++;
1551             if (s->repeat_first_field)
1552                 nofco++;
1553         }
1554     }
1555     for (i = 0; i < nofco; i++) {
1556         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1557         skip_bits(&s->gb, 1); // marker
1558         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1559         skip_bits(&s->gb, 1); // marker
1560     }
1561
1562     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1563         av_log(s->avctx, AV_LOG_DEBUG,
1564                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1565                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1566                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1567                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1568 }
1569
1570 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1571                        uint16_t matrix1[64], int intra)
1572 {
1573     int i;
1574
1575     for (i = 0; i < 64; i++) {
1576         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1577         int v = get_bits(&s->gb, 8);
1578         if (v == 0) {
1579             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1580             return AVERROR_INVALIDDATA;
1581         }
1582         if (intra && i == 0 && v != 8) {
1583             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1584             v = 8; // needed by pink.mpg / issue1046
1585         }
1586         matrix0[j] = v;
1587         if (matrix1)
1588             matrix1[j] = v;
1589     }
1590     return 0;
1591 }
1592
1593 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1594 {
1595     ff_dlog(s->avctx, "matrix extension\n");
1596
1597     if (get_bits1(&s->gb))
1598         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1599     if (get_bits1(&s->gb))
1600         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1601     if (get_bits1(&s->gb))
1602         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1603     if (get_bits1(&s->gb))
1604         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1605 }
1606
1607 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1608 {
1609     MpegEncContext *s = &s1->mpeg_enc_ctx;
1610
1611     s->full_pel[0]       = s->full_pel[1] = 0;
1612     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1613     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1614     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1615     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1616     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1617         av_log(s->avctx, AV_LOG_ERROR,
1618                "Missing picture start code, guessing missing values\n");
1619         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1620             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1621                 s->pict_type = AV_PICTURE_TYPE_I;
1622             else
1623                 s->pict_type = AV_PICTURE_TYPE_P;
1624         } else
1625             s->pict_type = AV_PICTURE_TYPE_B;
1626         s->current_picture.f->pict_type = s->pict_type;
1627         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1628     }
1629     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1630     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1631     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1632     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1633
1634     s->intra_dc_precision         = get_bits(&s->gb, 2);
1635     s->picture_structure          = get_bits(&s->gb, 2);
1636     s->top_field_first            = get_bits1(&s->gb);
1637     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1638     s->concealment_motion_vectors = get_bits1(&s->gb);
1639     s->q_scale_type               = get_bits1(&s->gb);
1640     s->intra_vlc_format           = get_bits1(&s->gb);
1641     s->alternate_scan             = get_bits1(&s->gb);
1642     s->repeat_first_field         = get_bits1(&s->gb);
1643     s->chroma_420_type            = get_bits1(&s->gb);
1644     s->progressive_frame          = get_bits1(&s->gb);
1645
1646     if (s->alternate_scan) {
1647         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1648         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1649     } else {
1650         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1651         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1652     }
1653
1654     /* composite display not parsed */
1655     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1656     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1657     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1658     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1659     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1660     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1661     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1662     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1663     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1664 }
1665
1666 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1667 {
1668     AVCodecContext *avctx = s->avctx;
1669     Mpeg1Context *s1      = (Mpeg1Context *) s;
1670     int ret;
1671
1672     /* start frame decoding */
1673     if (s->first_field || s->picture_structure == PICT_FRAME) {
1674         AVFrameSideData *pan_scan;
1675
1676         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1677             return ret;
1678
1679         ff_mpeg_er_frame_start(s);
1680
1681         /* first check if we must repeat the frame */
1682         s->current_picture_ptr->f->repeat_pict = 0;
1683         if (s->repeat_first_field) {
1684             if (s->progressive_sequence) {
1685                 if (s->top_field_first)
1686                     s->current_picture_ptr->f->repeat_pict = 4;
1687                 else
1688                     s->current_picture_ptr->f->repeat_pict = 2;
1689             } else if (s->progressive_frame) {
1690                 s->current_picture_ptr->f->repeat_pict = 1;
1691             }
1692         }
1693
1694         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1695                                           AV_FRAME_DATA_PANSCAN,
1696                                           sizeof(s1->pan_scan));
1697         if (!pan_scan)
1698             return AVERROR(ENOMEM);
1699         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1700
1701         if (s1->a53_caption) {
1702             AVFrameSideData *sd = av_frame_new_side_data(
1703                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1704                 s1->a53_caption_size);
1705             if (sd)
1706                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1707             av_freep(&s1->a53_caption);
1708             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
1709         }
1710
1711         if (s1->has_stereo3d) {
1712             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1713             if (!stereo)
1714                 return AVERROR(ENOMEM);
1715
1716             *stereo = s1->stereo3d;
1717             s1->has_stereo3d = 0;
1718         }
1719
1720         if (s1->has_afd) {
1721             AVFrameSideData *sd =
1722                 av_frame_new_side_data(s->current_picture_ptr->f,
1723                                        AV_FRAME_DATA_AFD, 1);
1724             if (!sd)
1725                 return AVERROR(ENOMEM);
1726
1727             *sd->data   = s1->afd;
1728             s1->has_afd = 0;
1729         }
1730
1731         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1732             ff_thread_finish_setup(avctx);
1733     } else { // second field
1734         int i;
1735
1736         if (!s->current_picture_ptr) {
1737             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1738             return AVERROR_INVALIDDATA;
1739         }
1740
1741         if (s->avctx->hwaccel &&
1742             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1743             if ((ret = s->avctx->hwaccel->end_frame(s->avctx)) < 0) {
1744                 av_log(avctx, AV_LOG_ERROR,
1745                        "hardware accelerator failed to decode first field\n");
1746                 return ret;
1747             }
1748         }
1749
1750         for (i = 0; i < 4; i++) {
1751             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1752             if (s->picture_structure == PICT_BOTTOM_FIELD)
1753                 s->current_picture.f->data[i] +=
1754                     s->current_picture_ptr->f->linesize[i];
1755         }
1756     }
1757
1758     if (avctx->hwaccel) {
1759         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1760             return ret;
1761     }
1762
1763     return 0;
1764 }
1765
1766 #define DECODE_SLICE_ERROR -1
1767 #define DECODE_SLICE_OK     0
1768
1769 /**
1770  * Decode a slice.
1771  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1772  * @return DECODE_SLICE_ERROR if the slice is damaged,
1773  *         DECODE_SLICE_OK if this slice is OK
1774  */
1775 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1776                              const uint8_t **buf, int buf_size)
1777 {
1778     AVCodecContext *avctx = s->avctx;
1779     const int lowres      = s->avctx->lowres;
1780     const int field_pic   = s->picture_structure != PICT_FRAME;
1781     int ret;
1782
1783     s->resync_mb_x =
1784     s->resync_mb_y = -1;
1785
1786     av_assert0(mb_y < s->mb_height);
1787
1788     init_get_bits(&s->gb, *buf, buf_size * 8);
1789     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1790         skip_bits(&s->gb, 3);
1791
1792     ff_mpeg1_clean_buffers(s);
1793     s->interlaced_dct = 0;
1794
1795     s->qscale = get_qscale(s);
1796
1797     if (s->qscale == 0) {
1798         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1799         return AVERROR_INVALIDDATA;
1800     }
1801
1802     /* extra slice info */
1803     if (skip_1stop_8data_bits(&s->gb) < 0)
1804         return AVERROR_INVALIDDATA;
1805
1806     s->mb_x = 0;
1807
1808     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1809         skip_bits1(&s->gb);
1810     } else {
1811         while (get_bits_left(&s->gb) > 0) {
1812             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1813                                 MBINCR_VLC_BITS, 2);
1814             if (code < 0) {
1815                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1816                 return AVERROR_INVALIDDATA;
1817             }
1818             if (code >= 33) {
1819                 if (code == 33)
1820                     s->mb_x += 33;
1821                 /* otherwise, stuffing, nothing to do */
1822             } else {
1823                 s->mb_x += code;
1824                 break;
1825             }
1826         }
1827     }
1828
1829     if (s->mb_x >= (unsigned) s->mb_width) {
1830         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1831         return AVERROR_INVALIDDATA;
1832     }
1833
1834     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1835         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1836         int start_code = -1;
1837         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1838         if (buf_end < *buf + buf_size)
1839             buf_end -= 4;
1840         s->mb_y = mb_y;
1841         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1842             return DECODE_SLICE_ERROR;
1843         *buf = buf_end;
1844         return DECODE_SLICE_OK;
1845     }
1846
1847     s->resync_mb_x = s->mb_x;
1848     s->resync_mb_y = s->mb_y = mb_y;
1849     s->mb_skip_run = 0;
1850     ff_init_block_index(s);
1851
1852     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1853         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1854             av_log(s->avctx, AV_LOG_DEBUG,
1855                    "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",
1856                    s->qscale,
1857                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1858                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1859                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1860                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1861                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1862                    s->progressive_sequence ? "ps"  : "",
1863                    s->progressive_frame    ? "pf"  : "",
1864                    s->alternate_scan       ? "alt" : "",
1865                    s->top_field_first      ? "top" : "",
1866                    s->intra_dc_precision, s->picture_structure,
1867                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1868                    s->q_scale_type, s->intra_vlc_format,
1869                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1870         }
1871     }
1872
1873     for (;;) {
1874         // If 1, we memcpy blocks in xvmcvideo.
1875         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1876             ff_xvmc_init_block(s); // set s->block
1877
1878         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1879             return ret;
1880
1881         // Note motion_val is normally NULL unless we want to extract the MVs.
1882         if (s->current_picture.motion_val[0] && !s->encoding) {
1883             const int wrap = s->b8_stride;
1884             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1885             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1886             int motion_x, motion_y, dir, i;
1887
1888             for (i = 0; i < 2; i++) {
1889                 for (dir = 0; dir < 2; dir++) {
1890                     if (s->mb_intra ||
1891                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1892                         motion_x = motion_y = 0;
1893                     } else if (s->mv_type == MV_TYPE_16X16 ||
1894                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1895                         motion_x = s->mv[dir][0][0];
1896                         motion_y = s->mv[dir][0][1];
1897                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1898                         motion_x = s->mv[dir][i][0];
1899                         motion_y = s->mv[dir][i][1];
1900                     }
1901
1902                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1903                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1904                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1905                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1906                     s->current_picture.ref_index [dir][b8_xy]     =
1907                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1908                     av_assert2(s->field_select[dir][i] == 0 ||
1909                                s->field_select[dir][i] == 1);
1910                 }
1911                 xy    += wrap;
1912                 b8_xy += 2;
1913             }
1914         }
1915
1916         s->dest[0] += 16 >> lowres;
1917         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1918         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1919
1920         ff_mpv_decode_mb(s, s->block);
1921
1922         if (++s->mb_x >= s->mb_width) {
1923             const int mb_size = 16 >> s->avctx->lowres;
1924
1925             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1926             ff_mpv_report_decode_progress(s);
1927
1928             s->mb_x  = 0;
1929             s->mb_y += 1 << field_pic;
1930
1931             if (s->mb_y >= s->mb_height) {
1932                 int left   = get_bits_left(&s->gb);
1933                 int is_d10 = s->chroma_format == 2 &&
1934                              s->pict_type == AV_PICTURE_TYPE_I &&
1935                              avctx->profile == 0 && avctx->level == 5 &&
1936                              s->intra_dc_precision == 2 &&
1937                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1938                              s->progressive_frame == 0
1939                              /* vbv_delay == 0xBBB || 0xE10 */;
1940
1941                 if (left >= 32 && !is_d10) {
1942                     GetBitContext gb = s->gb;
1943                     align_get_bits(&gb);
1944                     if (show_bits(&gb, 24) == 0x060E2B) {
1945                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1946                         is_d10 = 1;
1947                     }
1948                 }
1949
1950                 if (left < 0 ||
1951                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1952                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1953                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n",
1954                            left, show_bits(&s->gb, FFMIN(left, 23)));
1955                     return AVERROR_INVALIDDATA;
1956                 } else
1957                     goto eos;
1958             }
1959             // There are some files out there which are missing the last slice
1960             // in cases where the slice is completely outside the visible
1961             // area, we detect this here instead of running into the end expecting
1962             // more data
1963             if (s->mb_y >= ((s->height + 15) >> 4) &&
1964                 !s->progressive_sequence &&
1965                 get_bits_left(&s->gb) <= 8 &&
1966                 get_bits_left(&s->gb) >= 0 &&
1967                 s->mb_skip_run == -1 &&
1968                 show_bits(&s->gb, 8) == 0)
1969                 goto eos;
1970
1971             ff_init_block_index(s);
1972         }
1973
1974         /* skip mb handling */
1975         if (s->mb_skip_run == -1) {
1976             /* read increment again */
1977             s->mb_skip_run = 0;
1978             for (;;) {
1979                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1980                                     MBINCR_VLC_BITS, 2);
1981                 if (code < 0) {
1982                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1983                     return AVERROR_INVALIDDATA;
1984                 }
1985                 if (code >= 33) {
1986                     if (code == 33) {
1987                         s->mb_skip_run += 33;
1988                     } else if (code == 35) {
1989                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1990                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1991                             return AVERROR_INVALIDDATA;
1992                         }
1993                         goto eos; /* end of slice */
1994                     }
1995                     /* otherwise, stuffing, nothing to do */
1996                 } else {
1997                     s->mb_skip_run += code;
1998                     break;
1999                 }
2000             }
2001             if (s->mb_skip_run) {
2002                 int i;
2003                 if (s->pict_type == AV_PICTURE_TYPE_I) {
2004                     av_log(s->avctx, AV_LOG_ERROR,
2005                            "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
2006                     return AVERROR_INVALIDDATA;
2007                 }
2008
2009                 /* skip mb */
2010                 s->mb_intra = 0;
2011                 for (i = 0; i < 12; i++)
2012                     s->block_last_index[i] = -1;
2013                 if (s->picture_structure == PICT_FRAME)
2014                     s->mv_type = MV_TYPE_16X16;
2015                 else
2016                     s->mv_type = MV_TYPE_FIELD;
2017                 if (s->pict_type == AV_PICTURE_TYPE_P) {
2018                     /* if P type, zero motion vector is implied */
2019                     s->mv_dir             = MV_DIR_FORWARD;
2020                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
2021                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
2022                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
2023                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
2024                 } else {
2025                     /* if B type, reuse previous vectors and directions */
2026                     s->mv[0][0][0] = s->last_mv[0][0][0];
2027                     s->mv[0][0][1] = s->last_mv[0][0][1];
2028                     s->mv[1][0][0] = s->last_mv[1][0][0];
2029                     s->mv[1][0][1] = s->last_mv[1][0][1];
2030                 }
2031             }
2032         }
2033     }
2034 eos: // end of slice
2035     if (get_bits_left(&s->gb) < 0) {
2036         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
2037         return AVERROR_INVALIDDATA;
2038     }
2039     *buf += (get_bits_count(&s->gb) - 1) / 8;
2040     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);
2041     return 0;
2042 }
2043
2044 static int slice_decode_thread(AVCodecContext *c, void *arg)
2045 {
2046     MpegEncContext *s   = *(void **) arg;
2047     const uint8_t *buf  = s->gb.buffer;
2048     int mb_y            = s->start_mb_y;
2049     const int field_pic = s->picture_structure != PICT_FRAME;
2050
2051     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
2052
2053     for (;;) {
2054         uint32_t start_code;
2055         int ret;
2056
2057         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
2058         emms_c();
2059         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
2060                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
2061                 s->start_mb_y, s->end_mb_y, s->er.error_count);
2062         if (ret < 0) {
2063             if (c->err_recognition & AV_EF_EXPLODE)
2064                 return ret;
2065             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2066                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2067                                 s->mb_x, s->mb_y,
2068                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2069         } else {
2070             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2071                             s->mb_x - 1, s->mb_y,
2072                             ER_AC_END | ER_DC_END | ER_MV_END);
2073         }
2074
2075         if (s->mb_y == s->end_mb_y)
2076             return 0;
2077
2078         start_code = -1;
2079         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2080         mb_y       = start_code - SLICE_MIN_START_CODE;
2081         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2082             mb_y += (*buf&0xE0)<<2;
2083         mb_y <<= field_pic;
2084         if (s->picture_structure == PICT_BOTTOM_FIELD)
2085             mb_y++;
2086         if (mb_y < 0 || mb_y >= s->end_mb_y)
2087             return AVERROR_INVALIDDATA;
2088     }
2089 }
2090
2091 /**
2092  * Handle slice ends.
2093  * @return 1 if it seems to be the last slice
2094  */
2095 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2096 {
2097     Mpeg1Context *s1  = avctx->priv_data;
2098     MpegEncContext *s = &s1->mpeg_enc_ctx;
2099
2100     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2101         return 0;
2102
2103     if (s->avctx->hwaccel) {
2104         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2105         if (ret < 0) {
2106             av_log(avctx, AV_LOG_ERROR,
2107                    "hardware accelerator failed to decode picture\n");
2108             return ret;
2109         }
2110     }
2111
2112     /* end of slice reached */
2113     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2114         /* end of image */
2115
2116         ff_er_frame_end(&s->er);
2117
2118         ff_mpv_frame_end(s);
2119
2120         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2121             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2122             if (ret < 0)
2123                 return ret;
2124             ff_print_debug_info(s, s->current_picture_ptr, pict);
2125             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2126         } else {
2127             if (avctx->active_thread_type & FF_THREAD_FRAME)
2128                 s->picture_number++;
2129             /* latency of 1 frame for I- and P-frames */
2130             /* XXX: use another variable than picture_number */
2131             if (s->last_picture_ptr) {
2132                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2133                 if (ret < 0)
2134                     return ret;
2135                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2136                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2137             }
2138         }
2139
2140         return 1;
2141     } else {
2142         return 0;
2143     }
2144 }
2145
2146 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2147                                  const uint8_t *buf, int buf_size)
2148 {
2149     Mpeg1Context *s1  = avctx->priv_data;
2150     MpegEncContext *s = &s1->mpeg_enc_ctx;
2151     int width, height;
2152     int i, v, j;
2153
2154     init_get_bits(&s->gb, buf, buf_size * 8);
2155
2156     width  = get_bits(&s->gb, 12);
2157     height = get_bits(&s->gb, 12);
2158     if (width == 0 || height == 0) {
2159         av_log(avctx, AV_LOG_WARNING,
2160                "Invalid horizontal or vertical size value.\n");
2161         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2162             return AVERROR_INVALIDDATA;
2163     }
2164     s->aspect_ratio_info = get_bits(&s->gb, 4);
2165     if (s->aspect_ratio_info == 0) {
2166         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2167         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2168             return AVERROR_INVALIDDATA;
2169     }
2170     s->frame_rate_index = get_bits(&s->gb, 4);
2171     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2172         av_log(avctx, AV_LOG_WARNING,
2173                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2174         s->frame_rate_index = 1;
2175     }
2176     s->bit_rate = get_bits(&s->gb, 18) * 400;
2177     if (check_marker(&s->gb, "in sequence header") == 0) {
2178         return AVERROR_INVALIDDATA;
2179     }
2180     s->width  = width;
2181     s->height = height;
2182
2183     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2184     skip_bits(&s->gb, 1);
2185
2186     /* get matrix */
2187     if (get_bits1(&s->gb)) {
2188         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2189     } else {
2190         for (i = 0; i < 64; i++) {
2191             j = s->idsp.idct_permutation[i];
2192             v = ff_mpeg1_default_intra_matrix[i];
2193             s->intra_matrix[j]        = v;
2194             s->chroma_intra_matrix[j] = v;
2195         }
2196     }
2197     if (get_bits1(&s->gb)) {
2198         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2199     } else {
2200         for (i = 0; i < 64; i++) {
2201             int j = s->idsp.idct_permutation[i];
2202             v = ff_mpeg1_default_non_intra_matrix[i];
2203             s->inter_matrix[j]        = v;
2204             s->chroma_inter_matrix[j] = v;
2205         }
2206     }
2207
2208     if (show_bits(&s->gb, 23) != 0) {
2209         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2210         return AVERROR_INVALIDDATA;
2211     }
2212
2213     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2214     s->progressive_sequence = 1;
2215     s->progressive_frame    = 1;
2216     s->picture_structure    = PICT_FRAME;
2217     s->first_field          = 0;
2218     s->frame_pred_frame_dct = 1;
2219     s->chroma_format        = 1;
2220     s->codec_id             =
2221     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2222     s->out_format           = FMT_MPEG1;
2223     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2224     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2225         s->low_delay = 1;
2226
2227     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2228         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d, aspect_ratio_info: %d \n",
2229                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2230
2231     return 0;
2232 }
2233
2234 static int vcr2_init_sequence(AVCodecContext *avctx)
2235 {
2236     Mpeg1Context *s1  = avctx->priv_data;
2237     MpegEncContext *s = &s1->mpeg_enc_ctx;
2238     int i, v, ret;
2239
2240     /* start new MPEG-1 context decoding */
2241     s->out_format = FMT_MPEG1;
2242     if (s1->mpeg_enc_ctx_allocated) {
2243         ff_mpv_common_end(s);
2244         s1->mpeg_enc_ctx_allocated = 0;
2245     }
2246     s->width            = avctx->coded_width;
2247     s->height           = avctx->coded_height;
2248     avctx->has_b_frames = 0; // true?
2249     s->low_delay        = 1;
2250
2251     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2252     setup_hwaccel_for_pixfmt(avctx);
2253
2254     ff_mpv_idct_init(s);
2255     if ((ret = ff_mpv_common_init(s)) < 0)
2256         return ret;
2257     s1->mpeg_enc_ctx_allocated = 1;
2258
2259     for (i = 0; i < 64; i++) {
2260         int j = s->idsp.idct_permutation[i];
2261         v = ff_mpeg1_default_intra_matrix[i];
2262         s->intra_matrix[j]        = v;
2263         s->chroma_intra_matrix[j] = v;
2264
2265         v = ff_mpeg1_default_non_intra_matrix[i];
2266         s->inter_matrix[j]        = v;
2267         s->chroma_inter_matrix[j] = v;
2268     }
2269
2270     s->progressive_sequence  = 1;
2271     s->progressive_frame     = 1;
2272     s->picture_structure     = PICT_FRAME;
2273     s->first_field           = 0;
2274     s->frame_pred_frame_dct  = 1;
2275     s->chroma_format         = 1;
2276     if (s->codec_tag == AV_RL32("BW10")) {
2277         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2278     } else {
2279         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2280         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2281     }
2282     s1->save_width           = s->width;
2283     s1->save_height          = s->height;
2284     s1->save_progressive_seq = s->progressive_sequence;
2285     return 0;
2286 }
2287
2288 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2289                               const uint8_t *p, int buf_size)
2290 {
2291     Mpeg1Context *s1 = avctx->priv_data;
2292
2293     if (buf_size >= 6 &&
2294         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2295         p[4] == 3 && (p[5] & 0x40)) {
2296         /* extract A53 Part 4 CC data */
2297         int cc_count = p[5] & 0x1f;
2298         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2299             av_freep(&s1->a53_caption);
2300             s1->a53_caption_size = cc_count * 3;
2301             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2302             if (s1->a53_caption)
2303                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2304         }
2305         return 1;
2306     } else if (buf_size >= 11 &&
2307                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2308         /* extract DVD CC data */
2309         int cc_count = 0;
2310         int i;
2311         // There is a caption count field in the data, but it is often
2312         // incorect.  So count the number of captions present.
2313         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2314             cc_count++;
2315         // Transform the DVD format into A53 Part 4 format
2316         if (cc_count > 0) {
2317             av_freep(&s1->a53_caption);
2318             s1->a53_caption_size = cc_count * 6;
2319             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2320             if (s1->a53_caption) {
2321                 uint8_t field1 = !!(p[4] & 0x80);
2322                 uint8_t *cap = s1->a53_caption;
2323                 p += 5;
2324                 for (i = 0; i < cc_count; i++) {
2325                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2326                     cap[1] = p[1];
2327                     cap[2] = p[2];
2328                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2329                     cap[4] = p[4];
2330                     cap[5] = p[5];
2331                     cap += 6;
2332                     p += 6;
2333                 }
2334             }
2335         }
2336         return 1;
2337     }
2338     return 0;
2339 }
2340
2341 static void mpeg_decode_user_data(AVCodecContext *avctx,
2342                                   const uint8_t *p, int buf_size)
2343 {
2344     Mpeg1Context *s = avctx->priv_data;
2345     const uint8_t *buf_end = p + buf_size;
2346     Mpeg1Context *s1 = avctx->priv_data;
2347
2348 #if 0
2349     int i;
2350     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2351         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2352     }
2353     av_log(avctx, AV_LOG_ERROR, "\n");
2354 #endif
2355
2356     if (buf_size > 29){
2357         int i;
2358         for(i=0; i<20; i++)
2359             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2360                 s->tmpgexs= 1;
2361             }
2362     }
2363     /* we parse the DTG active format information */
2364     if (buf_end - p >= 5 &&
2365         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2366         int flags = p[4];
2367         p += 5;
2368         if (flags & 0x80) {
2369             /* skip event id */
2370             p += 2;
2371         }
2372         if (flags & 0x40) {
2373             if (buf_end - p < 1)
2374                 return;
2375 #if FF_API_AFD
2376 FF_DISABLE_DEPRECATION_WARNINGS
2377             avctx->dtg_active_format = p[0] & 0x0f;
2378 FF_ENABLE_DEPRECATION_WARNINGS
2379 #endif /* FF_API_AFD */
2380             s1->has_afd = 1;
2381             s1->afd     = p[0] & 0x0f;
2382         }
2383     } else if (buf_end - p >= 6 &&
2384                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2385                p[4] == 0x03) { // S3D_video_format_length
2386         // the 0x7F mask ignores the reserved_bit value
2387         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2388
2389         if (S3D_video_format_type == 0x03 ||
2390             S3D_video_format_type == 0x04 ||
2391             S3D_video_format_type == 0x08 ||
2392             S3D_video_format_type == 0x23) {
2393
2394             s1->has_stereo3d = 1;
2395
2396             switch (S3D_video_format_type) {
2397             case 0x03:
2398                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2399                 break;
2400             case 0x04:
2401                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2402                 break;
2403             case 0x08:
2404                 s1->stereo3d.type = AV_STEREO3D_2D;
2405                 break;
2406             case 0x23:
2407                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2408                 break;
2409             }
2410         }
2411     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2412         return;
2413     }
2414 }
2415
2416 static void mpeg_decode_gop(AVCodecContext *avctx,
2417                             const uint8_t *buf, int buf_size)
2418 {
2419     Mpeg1Context *s1  = avctx->priv_data;
2420     MpegEncContext *s = &s1->mpeg_enc_ctx;
2421     int broken_link;
2422     int64_t tc;
2423
2424     init_get_bits(&s->gb, buf, buf_size * 8);
2425
2426     tc = avctx->timecode_frame_start = get_bits(&s->gb, 25);
2427
2428     s->closed_gop = get_bits1(&s->gb);
2429     /* broken_link indicate that after editing the
2430      * reference frames of the first B-Frames after GOP I-Frame
2431      * are missing (open gop) */
2432     broken_link = get_bits1(&s->gb);
2433
2434     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2435         char tcbuf[AV_TIMECODE_STR_SIZE];
2436         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2437         av_log(s->avctx, AV_LOG_DEBUG,
2438                "GOP (%s) closed_gop=%d broken_link=%d\n",
2439                tcbuf, s->closed_gop, broken_link);
2440     }
2441 }
2442
2443 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2444                          int *got_output, const uint8_t *buf, int buf_size)
2445 {
2446     Mpeg1Context *s = avctx->priv_data;
2447     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2448     const uint8_t *buf_ptr = buf;
2449     const uint8_t *buf_end = buf + buf_size;
2450     int ret, input_size;
2451     int last_code = 0, skip_frame = 0;
2452     int picture_start_code_seen = 0;
2453
2454     for (;;) {
2455         /* find next start code */
2456         uint32_t start_code = -1;
2457         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2458         if (start_code > 0x1ff) {
2459             if (!skip_frame) {
2460                 if (HAVE_THREADS &&
2461                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2462                     !avctx->hwaccel) {
2463                     int i;
2464                     av_assert0(avctx->thread_count > 1);
2465
2466                     avctx->execute(avctx, slice_decode_thread,
2467                                    &s2->thread_context[0], NULL,
2468                                    s->slice_count, sizeof(void *));
2469                     for (i = 0; i < s->slice_count; i++)
2470                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2471                 }
2472
2473 #if FF_API_VDPAU
2474                 if ((CONFIG_MPEG_VDPAU_DECODER || CONFIG_MPEG1_VDPAU_DECODER)
2475                     && uses_vdpau(avctx))
2476                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2477 #endif
2478
2479                 ret = slice_end(avctx, picture);
2480                 if (ret < 0)
2481                     return ret;
2482                 else if (ret) {
2483                     // FIXME: merge with the stuff in mpeg_decode_slice
2484                     if (s2->last_picture_ptr || s2->low_delay)
2485                         *got_output = 1;
2486                 }
2487             }
2488             s2->pict_type = 0;
2489
2490             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2491                 return AVERROR_INVALIDDATA;
2492
2493             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2494         }
2495
2496         input_size = buf_end - buf_ptr;
2497
2498         if (avctx->debug & FF_DEBUG_STARTCODE)
2499             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2500                    start_code, buf_ptr - buf, input_size);
2501
2502         /* prepare data for next start code */
2503         switch (start_code) {
2504         case SEQ_START_CODE:
2505             if (last_code == 0) {
2506                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2507                 if (buf != avctx->extradata)
2508                     s->sync = 1;
2509             } else {
2510                 av_log(avctx, AV_LOG_ERROR,
2511                        "ignoring SEQ_START_CODE after %X\n", last_code);
2512                 if (avctx->err_recognition & AV_EF_EXPLODE)
2513                     return AVERROR_INVALIDDATA;
2514             }
2515             break;
2516
2517         case PICTURE_START_CODE:
2518             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2519                /* If it's a frame picture, there can't be more than one picture header.
2520                   Yet, it does happen and we need to handle it. */
2521                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2522                break;
2523             }
2524             picture_start_code_seen = 1;
2525
2526             if (s2->width <= 0 || s2->height <= 0) {
2527                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2528                        s2->width, s2->height);
2529                 return AVERROR_INVALIDDATA;
2530             }
2531
2532             if (s->tmpgexs){
2533                 s2->intra_dc_precision= 3;
2534                 s2->intra_matrix[0]= 1;
2535             }
2536             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2537                 !avctx->hwaccel && s->slice_count) {
2538                 int i;
2539
2540                 avctx->execute(avctx, slice_decode_thread,
2541                                s2->thread_context, NULL,
2542                                s->slice_count, sizeof(void *));
2543                 for (i = 0; i < s->slice_count; i++)
2544                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2545                 s->slice_count = 0;
2546             }
2547             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2548                 ret = mpeg_decode_postinit(avctx);
2549                 if (ret < 0) {
2550                     av_log(avctx, AV_LOG_ERROR,
2551                            "mpeg_decode_postinit() failure\n");
2552                     return ret;
2553                 }
2554
2555                 /* We have a complete image: we try to decompress it. */
2556                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2557                     s2->pict_type = 0;
2558                 s->first_slice = 1;
2559                 last_code      = PICTURE_START_CODE;
2560             } else {
2561                 av_log(avctx, AV_LOG_ERROR,
2562                        "ignoring pic after %X\n", last_code);
2563                 if (avctx->err_recognition & AV_EF_EXPLODE)
2564                     return AVERROR_INVALIDDATA;
2565             }
2566             break;
2567         case EXT_START_CODE:
2568             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2569
2570             switch (get_bits(&s2->gb, 4)) {
2571             case 0x1:
2572                 if (last_code == 0) {
2573                     mpeg_decode_sequence_extension(s);
2574                 } else {
2575                     av_log(avctx, AV_LOG_ERROR,
2576                            "ignoring seq ext after %X\n", last_code);
2577                     if (avctx->err_recognition & AV_EF_EXPLODE)
2578                         return AVERROR_INVALIDDATA;
2579                 }
2580                 break;
2581             case 0x2:
2582                 mpeg_decode_sequence_display_extension(s);
2583                 break;
2584             case 0x3:
2585                 mpeg_decode_quant_matrix_extension(s2);
2586                 break;
2587             case 0x7:
2588                 mpeg_decode_picture_display_extension(s);
2589                 break;
2590             case 0x8:
2591                 if (last_code == PICTURE_START_CODE) {
2592                     mpeg_decode_picture_coding_extension(s);
2593                 } else {
2594                     av_log(avctx, AV_LOG_ERROR,
2595                            "ignoring pic cod ext after %X\n", last_code);
2596                     if (avctx->err_recognition & AV_EF_EXPLODE)
2597                         return AVERROR_INVALIDDATA;
2598                 }
2599                 break;
2600             }
2601             break;
2602         case USER_START_CODE:
2603             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2604             break;
2605         case GOP_START_CODE:
2606             if (last_code == 0) {
2607                 s2->first_field = 0;
2608                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2609                 s->sync = 1;
2610             } else {
2611                 av_log(avctx, AV_LOG_ERROR,
2612                        "ignoring GOP_START_CODE after %X\n", last_code);
2613                 if (avctx->err_recognition & AV_EF_EXPLODE)
2614                     return AVERROR_INVALIDDATA;
2615             }
2616             break;
2617         default:
2618             if (start_code >= SLICE_MIN_START_CODE &&
2619                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2620                 if (s2->progressive_sequence && !s2->progressive_frame) {
2621                     s2->progressive_frame = 1;
2622                     av_log(s2->avctx, AV_LOG_ERROR,
2623                            "interlaced frame in progressive sequence, ignoring\n");
2624                 }
2625
2626                 if (s2->picture_structure == 0 ||
2627                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2628                     av_log(s2->avctx, AV_LOG_ERROR,
2629                            "picture_structure %d invalid, ignoring\n",
2630                            s2->picture_structure);
2631                     s2->picture_structure = PICT_FRAME;
2632                 }
2633
2634                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2635                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2636
2637                 if (s2->picture_structure == PICT_FRAME) {
2638                     s2->first_field = 0;
2639                     s2->v_edge_pos  = 16 * s2->mb_height;
2640                 } else {
2641                     s2->first_field ^= 1;
2642                     s2->v_edge_pos   = 8 * s2->mb_height;
2643                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2644                 }
2645             }
2646             if (start_code >= SLICE_MIN_START_CODE &&
2647                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2648                 const int field_pic = s2->picture_structure != PICT_FRAME;
2649                 int mb_y = start_code - SLICE_MIN_START_CODE;
2650                 last_code = SLICE_MIN_START_CODE;
2651                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2652                     mb_y += (*buf_ptr&0xE0)<<2;
2653
2654                 mb_y <<= field_pic;
2655                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2656                     mb_y++;
2657
2658                 if (buf_end - buf_ptr < 2) {
2659                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2660                     return AVERROR_INVALIDDATA;
2661                 }
2662
2663                 if (mb_y >= s2->mb_height) {
2664                     av_log(s2->avctx, AV_LOG_ERROR,
2665                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2666                     return AVERROR_INVALIDDATA;
2667                 }
2668
2669                 if (!s2->last_picture_ptr) {
2670                     /* Skip B-frames if we do not have reference frames and
2671                      * GOP is not closed. */
2672                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2673                         if (!s2->closed_gop) {
2674                             skip_frame = 1;
2675                             break;
2676                         }
2677                     }
2678                 }
2679                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2680                     s->sync = 1;
2681                 if (!s2->next_picture_ptr) {
2682                     /* Skip P-frames if we do not have a reference frame or
2683                      * we have an invalid header. */
2684                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2685                         skip_frame = 1;
2686                         break;
2687                     }
2688                 }
2689                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2690                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2691                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2692                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2693                     avctx->skip_frame >= AVDISCARD_ALL) {
2694                     skip_frame = 1;
2695                     break;
2696                 }
2697
2698                 if (!s->mpeg_enc_ctx_allocated)
2699                     break;
2700
2701                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2702                     if (mb_y < avctx->skip_top ||
2703                         mb_y >= s2->mb_height - avctx->skip_bottom)
2704                         break;
2705                 }
2706
2707                 if (!s2->pict_type) {
2708                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2709                     if (avctx->err_recognition & AV_EF_EXPLODE)
2710                         return AVERROR_INVALIDDATA;
2711                     break;
2712                 }
2713
2714                 if (s->first_slice) {
2715                     skip_frame     = 0;
2716                     s->first_slice = 0;
2717                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2718                         return ret;
2719                 }
2720                 if (!s2->current_picture_ptr) {
2721                     av_log(avctx, AV_LOG_ERROR,
2722                            "current_picture not initialized\n");
2723                     return AVERROR_INVALIDDATA;
2724                 }
2725
2726 #if FF_API_VDPAU
2727                 if (uses_vdpau(avctx)) {
2728                     s->slice_count++;
2729                     break;
2730                 }
2731 #endif
2732
2733                 if (HAVE_THREADS &&
2734                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2735                     !avctx->hwaccel) {
2736                     int threshold = (s2->mb_height * s->slice_count +
2737                                      s2->slice_context_count / 2) /
2738                                     s2->slice_context_count;
2739                     av_assert0(avctx->thread_count > 1);
2740                     if (threshold <= mb_y) {
2741                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2742
2743                         thread_context->start_mb_y = mb_y;
2744                         thread_context->end_mb_y   = s2->mb_height;
2745                         if (s->slice_count) {
2746                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2747                             ret = ff_update_duplicate_context(thread_context, s2);
2748                             if (ret < 0)
2749                                 return ret;
2750                         }
2751                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2752                         s->slice_count++;
2753                     }
2754                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2755                 } else {
2756                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2757                     emms_c();
2758
2759                     if (ret < 0) {
2760                         if (avctx->err_recognition & AV_EF_EXPLODE)
2761                             return ret;
2762                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2763                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2764                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2765                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2766                     } else {
2767                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2768                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2769                                         ER_AC_END | ER_DC_END | ER_MV_END);
2770                     }
2771                 }
2772             }
2773             break;
2774         }
2775     }
2776 }
2777
2778 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2779                              int *got_output, AVPacket *avpkt)
2780 {
2781     const uint8_t *buf = avpkt->data;
2782     int ret;
2783     int buf_size = avpkt->size;
2784     Mpeg1Context *s = avctx->priv_data;
2785     AVFrame *picture = data;
2786     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2787
2788     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2789         /* special case for last picture */
2790         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2791             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2792             if (ret < 0)
2793                 return ret;
2794
2795             s2->next_picture_ptr = NULL;
2796
2797             *got_output = 1;
2798         }
2799         return buf_size;
2800     }
2801
2802     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2803         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2804                                            buf_size, NULL);
2805
2806         if (ff_combine_frame(&s2->parse_context, next,
2807                              (const uint8_t **) &buf, &buf_size) < 0)
2808             return buf_size;
2809     }
2810
2811     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2812     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2813                                            || s2->codec_tag == AV_RL32("BW10")
2814                                           ))
2815         vcr2_init_sequence(avctx);
2816
2817     s->slice_count = 0;
2818
2819     if (avctx->extradata && !s->extradata_decoded) {
2820         ret = decode_chunks(avctx, picture, got_output,
2821                             avctx->extradata, avctx->extradata_size);
2822         if (*got_output) {
2823             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2824             *got_output = 0;
2825         }
2826         s->extradata_decoded = 1;
2827         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2828             s2->current_picture_ptr = NULL;
2829             return ret;
2830         }
2831     }
2832
2833     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2834     if (ret<0 || *got_output)
2835         s2->current_picture_ptr = NULL;
2836
2837     return ret;
2838 }
2839
2840 static void flush(AVCodecContext *avctx)
2841 {
2842     Mpeg1Context *s = avctx->priv_data;
2843
2844     s->sync       = 0;
2845
2846     ff_mpeg_flush(avctx);
2847 }
2848
2849 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2850 {
2851     Mpeg1Context *s = avctx->priv_data;
2852
2853     if (s->mpeg_enc_ctx_allocated)
2854         ff_mpv_common_end(&s->mpeg_enc_ctx);
2855     av_freep(&s->a53_caption);
2856     return 0;
2857 }
2858
2859 static const AVProfile mpeg2_video_profiles[] = {
2860     { FF_PROFILE_MPEG2_422,          "4:2:2"              },
2861     { FF_PROFILE_MPEG2_HIGH,         "High"               },
2862     { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
2863     { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
2864     { FF_PROFILE_MPEG2_MAIN,         "Main"               },
2865     { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
2866     { FF_PROFILE_RESERVED,           "Reserved"           },
2867     { FF_PROFILE_RESERVED,           "Reserved"           },
2868     { FF_PROFILE_UNKNOWN                                  },
2869 };
2870
2871 AVCodec ff_mpeg1video_decoder = {
2872     .name                  = "mpeg1video",
2873     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2874     .type                  = AVMEDIA_TYPE_VIDEO,
2875     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2876     .priv_data_size        = sizeof(Mpeg1Context),
2877     .init                  = mpeg_decode_init,
2878     .close                 = mpeg_decode_end,
2879     .decode                = mpeg_decode_frame,
2880     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2881                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2882                              AV_CODEC_CAP_SLICE_THREADS,
2883     .flush                 = flush,
2884     .max_lowres            = 3,
2885     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2886 };
2887
2888 AVCodec ff_mpeg2video_decoder = {
2889     .name           = "mpeg2video",
2890     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2891     .type           = AVMEDIA_TYPE_VIDEO,
2892     .id             = AV_CODEC_ID_MPEG2VIDEO,
2893     .priv_data_size = sizeof(Mpeg1Context),
2894     .init           = mpeg_decode_init,
2895     .close          = mpeg_decode_end,
2896     .decode         = mpeg_decode_frame,
2897     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2898                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2899                       AV_CODEC_CAP_SLICE_THREADS,
2900     .flush          = flush,
2901     .max_lowres     = 3,
2902     .profiles       = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
2903 };
2904
2905 //legacy decoder
2906 AVCodec ff_mpegvideo_decoder = {
2907     .name           = "mpegvideo",
2908     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2909     .type           = AVMEDIA_TYPE_VIDEO,
2910     .id             = AV_CODEC_ID_MPEG2VIDEO,
2911     .priv_data_size = sizeof(Mpeg1Context),
2912     .init           = mpeg_decode_init,
2913     .close          = mpeg_decode_end,
2914     .decode         = mpeg_decode_frame,
2915     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2916     .flush          = flush,
2917     .max_lowres     = 3,
2918 };
2919
2920 #if FF_API_XVMC
2921 #if CONFIG_MPEG_XVMC_DECODER
2922 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
2923 {
2924     if (avctx->active_thread_type & FF_THREAD_SLICE)
2925         return -1;
2926     if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
2927         return -1;
2928     if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
2929         ff_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2930     }
2931     mpeg_decode_init(avctx);
2932
2933     avctx->pix_fmt           = AV_PIX_FMT_XVMC_MPEG2_IDCT;
2934     avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
2935
2936     return 0;
2937 }
2938
2939 AVCodec ff_mpeg_xvmc_decoder = {
2940     .name           = "mpegvideo_xvmc",
2941     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2942     .type           = AVMEDIA_TYPE_VIDEO,
2943     .id             = AV_CODEC_ID_MPEG2VIDEO_XVMC,
2944     .priv_data_size = sizeof(Mpeg1Context),
2945     .init           = mpeg_mc_decode_init,
2946     .close          = mpeg_decode_end,
2947     .decode         = mpeg_decode_frame,
2948     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2949                       AV_CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL |
2950                       AV_CODEC_CAP_DELAY,
2951     .flush          = flush,
2952 };
2953
2954 #endif
2955 #endif /* FF_API_XVMC */
2956
2957 #if CONFIG_MPEG_VDPAU_DECODER && FF_API_VDPAU
2958 AVCodec ff_mpeg_vdpau_decoder = {
2959     .name           = "mpegvideo_vdpau",
2960     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2961     .type           = AVMEDIA_TYPE_VIDEO,
2962     .id             = AV_CODEC_ID_MPEG2VIDEO,
2963     .priv_data_size = sizeof(Mpeg1Context),
2964     .init           = mpeg_decode_init,
2965     .close          = mpeg_decode_end,
2966     .decode         = mpeg_decode_frame,
2967     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2968                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2969     .flush          = flush,
2970 };
2971 #endif
2972
2973 #if CONFIG_MPEG1_VDPAU_DECODER && FF_API_VDPAU
2974 AVCodec ff_mpeg1_vdpau_decoder = {
2975     .name           = "mpeg1video_vdpau",
2976     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2977     .type           = AVMEDIA_TYPE_VIDEO,
2978     .id             = AV_CODEC_ID_MPEG1VIDEO,
2979     .priv_data_size = sizeof(Mpeg1Context),
2980     .init           = mpeg_decode_init,
2981     .close          = mpeg_decode_end,
2982     .decode         = mpeg_decode_frame,
2983     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2984                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2985     .flush          = flush,
2986 };
2987 #endif