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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_HWACCEL
1190     AV_PIX_FMT_VDPAU_MPEG1,
1191     AV_PIX_FMT_VDPAU,
1192 #endif
1193     AV_PIX_FMT_YUV420P,
1194     AV_PIX_FMT_NONE
1195 };
1196
1197 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1198 #if CONFIG_MPEG2_XVMC_HWACCEL
1199     AV_PIX_FMT_XVMC,
1200 #endif
1201 #if CONFIG_MPEG2_VDPAU_HWACCEL
1202     AV_PIX_FMT_VDPAU_MPEG2,
1203     AV_PIX_FMT_VDPAU,
1204 #endif
1205 #if CONFIG_MPEG2_DXVA2_HWACCEL
1206     AV_PIX_FMT_DXVA2_VLD,
1207 #endif
1208 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1209     AV_PIX_FMT_D3D11VA_VLD,
1210 #endif
1211 #if CONFIG_MPEG2_VAAPI_HWACCEL
1212     AV_PIX_FMT_VAAPI_VLD,
1213 #endif
1214 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1215     AV_PIX_FMT_VIDEOTOOLBOX,
1216 #endif
1217     AV_PIX_FMT_YUV420P,
1218     AV_PIX_FMT_NONE
1219 };
1220
1221 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1222     AV_PIX_FMT_YUV422P,
1223     AV_PIX_FMT_NONE
1224 };
1225
1226 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1227     AV_PIX_FMT_YUV444P,
1228     AV_PIX_FMT_NONE
1229 };
1230
1231 static inline int uses_vdpau(AVCodecContext *avctx) {
1232     return avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG1 || avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG2;
1233 }
1234
1235 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1236 {
1237     Mpeg1Context *s1  = avctx->priv_data;
1238     MpegEncContext *s = &s1->mpeg_enc_ctx;
1239     const enum AVPixelFormat *pix_fmts;
1240
1241     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1242         return AV_PIX_FMT_GRAY8;
1243
1244     if (s->chroma_format < 2)
1245         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1246                                 mpeg1_hwaccel_pixfmt_list_420 :
1247                                 mpeg2_hwaccel_pixfmt_list_420;
1248     else if (s->chroma_format == 2)
1249         pix_fmts = mpeg12_pixfmt_list_422;
1250     else
1251         pix_fmts = mpeg12_pixfmt_list_444;
1252
1253     return ff_thread_get_format(avctx, pix_fmts);
1254 }
1255
1256 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1257 {
1258     // until then pix_fmt may be changed right after codec init
1259     if (avctx->hwaccel || uses_vdpau(avctx))
1260         if (avctx->idct_algo == FF_IDCT_AUTO)
1261             avctx->idct_algo = FF_IDCT_SIMPLE;
1262
1263     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1264         Mpeg1Context *s1 = avctx->priv_data;
1265         MpegEncContext *s = &s1->mpeg_enc_ctx;
1266
1267         s->pack_pblocks = 1;
1268 #if FF_API_XVMC
1269         avctx->xvmc_acceleration = 2;
1270 #endif /* FF_API_XVMC */
1271     }
1272 }
1273
1274 /* Call this function when we know all parameters.
1275  * It may be called in different places for MPEG-1 and MPEG-2. */
1276 static int mpeg_decode_postinit(AVCodecContext *avctx)
1277 {
1278     Mpeg1Context *s1  = avctx->priv_data;
1279     MpegEncContext *s = &s1->mpeg_enc_ctx;
1280     uint8_t old_permutation[64];
1281     int ret;
1282
1283     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1284         // MPEG-1 aspect
1285         avctx->sample_aspect_ratio = av_d2q(1.0 / ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1286     } else { // MPEG-2
1287         // MPEG-2 aspect
1288         if (s->aspect_ratio_info > 1) {
1289             AVRational dar =
1290                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1291                                   (AVRational) { s1->pan_scan.width,
1292                                                  s1->pan_scan.height }),
1293                          (AVRational) { s->width, s->height });
1294
1295             /* We ignore the spec here and guess a bit as reality does not
1296              * match the spec, see for example res_change_ffmpeg_aspect.ts
1297              * and sequence-display-aspect.mpg.
1298              * issue1613, 621, 562 */
1299             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1300                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1301                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1302                 s->avctx->sample_aspect_ratio =
1303                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1304                              (AVRational) { s->width, s->height });
1305             } else {
1306                 s->avctx->sample_aspect_ratio =
1307                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1308                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1309 // issue1613 4/3 16/9 -> 16/9
1310 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1311 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1312 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1313                 ff_dlog(avctx, "aspect A %d/%d\n",
1314                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1315                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1316                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1317                         s->avctx->sample_aspect_ratio.den);
1318             }
1319         } else {
1320             s->avctx->sample_aspect_ratio =
1321                 ff_mpeg2_aspect[s->aspect_ratio_info];
1322         }
1323     } // MPEG-2
1324
1325     if (av_image_check_sar(s->width, s->height,
1326                            avctx->sample_aspect_ratio) < 0) {
1327         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1328                 avctx->sample_aspect_ratio.num,
1329                 avctx->sample_aspect_ratio.den);
1330         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1331     }
1332
1333     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1334         avctx->coded_width       != s->width                ||
1335         avctx->coded_height      != s->height               ||
1336         s1->save_width           != s->width                ||
1337         s1->save_height          != s->height               ||
1338         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1339         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1340         0) {
1341         if (s1->mpeg_enc_ctx_allocated) {
1342             ParseContext pc = s->parse_context;
1343             s->parse_context.buffer = 0;
1344             ff_mpv_common_end(s);
1345             s->parse_context = pc;
1346             s1->mpeg_enc_ctx_allocated = 0;
1347         }
1348
1349         ret = ff_set_dimensions(avctx, s->width, s->height);
1350         if (ret < 0)
1351             return ret;
1352
1353         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1354             avctx->rc_max_rate = s->bit_rate;
1355         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1356                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1357             avctx->bit_rate = s->bit_rate;
1358         }
1359         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1360         s1->save_width           = s->width;
1361         s1->save_height          = s->height;
1362         s1->save_progressive_seq = s->progressive_sequence;
1363
1364         /* low_delay may be forced, in this case we will have B-frames
1365          * that behave like P-frames. */
1366         avctx->has_b_frames = !s->low_delay;
1367
1368         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1369             // MPEG-1 fps
1370             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1371             avctx->ticks_per_frame     = 1;
1372
1373             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1374         } else { // MPEG-2
1375             // MPEG-2 fps
1376             av_reduce(&s->avctx->framerate.num,
1377                       &s->avctx->framerate.den,
1378                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1379                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1380                       1 << 30);
1381             avctx->ticks_per_frame = 2;
1382
1383             switch (s->chroma_format) {
1384             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1385             case 2:
1386             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1387             }
1388         } // MPEG-2
1389
1390         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1391         setup_hwaccel_for_pixfmt(avctx);
1392
1393         /* Quantization matrices may need reordering
1394          * if DCT permutation is changed. */
1395         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1396
1397         ff_mpv_idct_init(s);
1398         if ((ret = ff_mpv_common_init(s)) < 0)
1399             return ret;
1400
1401         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1402         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1403         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1404         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1405
1406         s1->mpeg_enc_ctx_allocated = 1;
1407     }
1408     return 0;
1409 }
1410
1411 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1412                                 int buf_size)
1413 {
1414     Mpeg1Context *s1  = avctx->priv_data;
1415     MpegEncContext *s = &s1->mpeg_enc_ctx;
1416     int ref, f_code, vbv_delay;
1417
1418     init_get_bits(&s->gb, buf, buf_size * 8);
1419
1420     ref = get_bits(&s->gb, 10); /* temporal ref */
1421     s->pict_type = get_bits(&s->gb, 3);
1422     if (s->pict_type == 0 || s->pict_type > 3)
1423         return AVERROR_INVALIDDATA;
1424
1425     vbv_delay = get_bits(&s->gb, 16);
1426     s->vbv_delay = vbv_delay;
1427     if (s->pict_type == AV_PICTURE_TYPE_P ||
1428         s->pict_type == AV_PICTURE_TYPE_B) {
1429         s->full_pel[0] = get_bits1(&s->gb);
1430         f_code = get_bits(&s->gb, 3);
1431         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1432             return AVERROR_INVALIDDATA;
1433         f_code += !f_code;
1434         s->mpeg_f_code[0][0] = f_code;
1435         s->mpeg_f_code[0][1] = f_code;
1436     }
1437     if (s->pict_type == AV_PICTURE_TYPE_B) {
1438         s->full_pel[1] = get_bits1(&s->gb);
1439         f_code = get_bits(&s->gb, 3);
1440         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1441             return AVERROR_INVALIDDATA;
1442         f_code += !f_code;
1443         s->mpeg_f_code[1][0] = f_code;
1444         s->mpeg_f_code[1][1] = f_code;
1445     }
1446     s->current_picture.f->pict_type = s->pict_type;
1447     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1448
1449     if (avctx->debug & FF_DEBUG_PICT_INFO)
1450         av_log(avctx, AV_LOG_DEBUG,
1451                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1452
1453     s->y_dc_scale = 8;
1454     s->c_dc_scale = 8;
1455     return 0;
1456 }
1457
1458 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1459 {
1460     MpegEncContext *s = &s1->mpeg_enc_ctx;
1461     int horiz_size_ext, vert_size_ext;
1462     int bit_rate_ext;
1463
1464     skip_bits(&s->gb, 1); /* profile and level esc*/
1465     s->avctx->profile       = get_bits(&s->gb, 3);
1466     s->avctx->level         = get_bits(&s->gb, 4);
1467     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1468     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1469     horiz_size_ext          = get_bits(&s->gb, 2);
1470     vert_size_ext           = get_bits(&s->gb, 2);
1471     s->width  |= (horiz_size_ext << 12);
1472     s->height |= (vert_size_ext  << 12);
1473     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1474     s->bit_rate += (bit_rate_ext << 18) * 400;
1475     check_marker(&s->gb, "after bit rate extension");
1476     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1477
1478     s->low_delay = get_bits1(&s->gb);
1479     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1480         s->low_delay = 1;
1481
1482     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1483     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1484
1485     ff_dlog(s->avctx, "sequence extension\n");
1486     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1487
1488     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1489         av_log(s->avctx, AV_LOG_DEBUG,
1490                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%d\n",
1491                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1492                s->avctx->rc_buffer_size, s->bit_rate);
1493 }
1494
1495 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1496 {
1497     MpegEncContext *s = &s1->mpeg_enc_ctx;
1498     int color_description, w, h;
1499
1500     skip_bits(&s->gb, 3); /* video format */
1501     color_description = get_bits1(&s->gb);
1502     if (color_description) {
1503         s->avctx->color_primaries = get_bits(&s->gb, 8);
1504         s->avctx->color_trc       = get_bits(&s->gb, 8);
1505         s->avctx->colorspace      = get_bits(&s->gb, 8);
1506     }
1507     w = get_bits(&s->gb, 14);
1508     skip_bits(&s->gb, 1); // marker
1509     h = get_bits(&s->gb, 14);
1510     // remaining 3 bits are zero padding
1511
1512     s1->pan_scan.width  = 16 * w;
1513     s1->pan_scan.height = 16 * h;
1514
1515     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1516         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1517 }
1518
1519 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1520 {
1521     MpegEncContext *s = &s1->mpeg_enc_ctx;
1522     int i, nofco;
1523
1524     nofco = 1;
1525     if (s->progressive_sequence) {
1526         if (s->repeat_first_field) {
1527             nofco++;
1528             if (s->top_field_first)
1529                 nofco++;
1530         }
1531     } else {
1532         if (s->picture_structure == PICT_FRAME) {
1533             nofco++;
1534             if (s->repeat_first_field)
1535                 nofco++;
1536         }
1537     }
1538     for (i = 0; i < nofco; i++) {
1539         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1540         skip_bits(&s->gb, 1); // marker
1541         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1542         skip_bits(&s->gb, 1); // marker
1543     }
1544
1545     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1546         av_log(s->avctx, AV_LOG_DEBUG,
1547                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1548                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1549                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1550                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1551 }
1552
1553 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1554                        uint16_t matrix1[64], int intra)
1555 {
1556     int i;
1557
1558     for (i = 0; i < 64; i++) {
1559         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1560         int v = get_bits(&s->gb, 8);
1561         if (v == 0) {
1562             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1563             return AVERROR_INVALIDDATA;
1564         }
1565         if (intra && i == 0 && v != 8) {
1566             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1567             v = 8; // needed by pink.mpg / issue1046
1568         }
1569         matrix0[j] = v;
1570         if (matrix1)
1571             matrix1[j] = v;
1572     }
1573     return 0;
1574 }
1575
1576 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1577 {
1578     ff_dlog(s->avctx, "matrix extension\n");
1579
1580     if (get_bits1(&s->gb))
1581         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1582     if (get_bits1(&s->gb))
1583         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1584     if (get_bits1(&s->gb))
1585         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1586     if (get_bits1(&s->gb))
1587         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1588 }
1589
1590 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1591 {
1592     MpegEncContext *s = &s1->mpeg_enc_ctx;
1593
1594     s->full_pel[0]       = s->full_pel[1] = 0;
1595     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1596     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1597     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1598     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1599     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1600         av_log(s->avctx, AV_LOG_ERROR,
1601                "Missing picture start code, guessing missing values\n");
1602         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1603             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1604                 s->pict_type = AV_PICTURE_TYPE_I;
1605             else
1606                 s->pict_type = AV_PICTURE_TYPE_P;
1607         } else
1608             s->pict_type = AV_PICTURE_TYPE_B;
1609         s->current_picture.f->pict_type = s->pict_type;
1610         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1611     }
1612     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1613     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1614     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1615     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1616
1617     s->intra_dc_precision         = get_bits(&s->gb, 2);
1618     s->picture_structure          = get_bits(&s->gb, 2);
1619     s->top_field_first            = get_bits1(&s->gb);
1620     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1621     s->concealment_motion_vectors = get_bits1(&s->gb);
1622     s->q_scale_type               = get_bits1(&s->gb);
1623     s->intra_vlc_format           = get_bits1(&s->gb);
1624     s->alternate_scan             = get_bits1(&s->gb);
1625     s->repeat_first_field         = get_bits1(&s->gb);
1626     s->chroma_420_type            = get_bits1(&s->gb);
1627     s->progressive_frame          = get_bits1(&s->gb);
1628
1629     if (s->alternate_scan) {
1630         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1631         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1632     } else {
1633         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1634         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1635     }
1636
1637     /* composite display not parsed */
1638     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1639     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1640     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1641     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1642     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1643     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1644     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1645     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1646     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1647 }
1648
1649 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1650 {
1651     AVCodecContext *avctx = s->avctx;
1652     Mpeg1Context *s1      = (Mpeg1Context *) s;
1653     int ret;
1654
1655     /* start frame decoding */
1656     if (s->first_field || s->picture_structure == PICT_FRAME) {
1657         AVFrameSideData *pan_scan;
1658
1659         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1660             return ret;
1661
1662         ff_mpeg_er_frame_start(s);
1663
1664         /* first check if we must repeat the frame */
1665         s->current_picture_ptr->f->repeat_pict = 0;
1666         if (s->repeat_first_field) {
1667             if (s->progressive_sequence) {
1668                 if (s->top_field_first)
1669                     s->current_picture_ptr->f->repeat_pict = 4;
1670                 else
1671                     s->current_picture_ptr->f->repeat_pict = 2;
1672             } else if (s->progressive_frame) {
1673                 s->current_picture_ptr->f->repeat_pict = 1;
1674             }
1675         }
1676
1677         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1678                                           AV_FRAME_DATA_PANSCAN,
1679                                           sizeof(s1->pan_scan));
1680         if (!pan_scan)
1681             return AVERROR(ENOMEM);
1682         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1683
1684         if (s1->a53_caption) {
1685             AVFrameSideData *sd = av_frame_new_side_data(
1686                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1687                 s1->a53_caption_size);
1688             if (sd)
1689                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1690             av_freep(&s1->a53_caption);
1691             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
1692         }
1693
1694         if (s1->has_stereo3d) {
1695             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1696             if (!stereo)
1697                 return AVERROR(ENOMEM);
1698
1699             *stereo = s1->stereo3d;
1700             s1->has_stereo3d = 0;
1701         }
1702
1703         if (s1->has_afd) {
1704             AVFrameSideData *sd =
1705                 av_frame_new_side_data(s->current_picture_ptr->f,
1706                                        AV_FRAME_DATA_AFD, 1);
1707             if (!sd)
1708                 return AVERROR(ENOMEM);
1709
1710             *sd->data   = s1->afd;
1711             s1->has_afd = 0;
1712         }
1713
1714         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1715             ff_thread_finish_setup(avctx);
1716     } else { // second field
1717         int i;
1718
1719         if (!s->current_picture_ptr) {
1720             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1721             return AVERROR_INVALIDDATA;
1722         }
1723
1724         if (s->avctx->hwaccel &&
1725             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1726             if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1727                 av_log(avctx, AV_LOG_ERROR,
1728                        "hardware accelerator failed to decode first field\n");
1729         }
1730
1731         for (i = 0; i < 4; i++) {
1732             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1733             if (s->picture_structure == PICT_BOTTOM_FIELD)
1734                 s->current_picture.f->data[i] +=
1735                     s->current_picture_ptr->f->linesize[i];
1736         }
1737     }
1738
1739     if (avctx->hwaccel) {
1740         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1741             return ret;
1742     }
1743
1744     return 0;
1745 }
1746
1747 #define DECODE_SLICE_ERROR -1
1748 #define DECODE_SLICE_OK     0
1749
1750 /**
1751  * Decode a slice.
1752  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1753  * @return DECODE_SLICE_ERROR if the slice is damaged,
1754  *         DECODE_SLICE_OK if this slice is OK
1755  */
1756 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1757                              const uint8_t **buf, int buf_size)
1758 {
1759     AVCodecContext *avctx = s->avctx;
1760     const int lowres      = s->avctx->lowres;
1761     const int field_pic   = s->picture_structure != PICT_FRAME;
1762     int ret;
1763
1764     s->resync_mb_x =
1765     s->resync_mb_y = -1;
1766
1767     av_assert0(mb_y < s->mb_height);
1768
1769     init_get_bits(&s->gb, *buf, buf_size * 8);
1770     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1771         skip_bits(&s->gb, 3);
1772
1773     ff_mpeg1_clean_buffers(s);
1774     s->interlaced_dct = 0;
1775
1776     s->qscale = get_qscale(s);
1777
1778     if (s->qscale == 0) {
1779         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1780         return AVERROR_INVALIDDATA;
1781     }
1782
1783     /* extra slice info */
1784     if (skip_1stop_8data_bits(&s->gb) < 0)
1785         return AVERROR_INVALIDDATA;
1786
1787     s->mb_x = 0;
1788
1789     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1790         skip_bits1(&s->gb);
1791     } else {
1792         while (get_bits_left(&s->gb) > 0) {
1793             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1794                                 MBINCR_VLC_BITS, 2);
1795             if (code < 0) {
1796                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1797                 return AVERROR_INVALIDDATA;
1798             }
1799             if (code >= 33) {
1800                 if (code == 33)
1801                     s->mb_x += 33;
1802                 /* otherwise, stuffing, nothing to do */
1803             } else {
1804                 s->mb_x += code;
1805                 break;
1806             }
1807         }
1808     }
1809
1810     if (s->mb_x >= (unsigned) s->mb_width) {
1811         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1812         return AVERROR_INVALIDDATA;
1813     }
1814
1815     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1816         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1817         int start_code = -1;
1818         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1819         if (buf_end < *buf + buf_size)
1820             buf_end -= 4;
1821         s->mb_y = mb_y;
1822         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1823             return DECODE_SLICE_ERROR;
1824         *buf = buf_end;
1825         return DECODE_SLICE_OK;
1826     }
1827
1828     s->resync_mb_x = s->mb_x;
1829     s->resync_mb_y = s->mb_y = mb_y;
1830     s->mb_skip_run = 0;
1831     ff_init_block_index(s);
1832
1833     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1834         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1835             av_log(s->avctx, AV_LOG_DEBUG,
1836                    "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",
1837                    s->qscale,
1838                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1839                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1840                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1841                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1842                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1843                    s->progressive_sequence ? "ps"  : "",
1844                    s->progressive_frame    ? "pf"  : "",
1845                    s->alternate_scan       ? "alt" : "",
1846                    s->top_field_first      ? "top" : "",
1847                    s->intra_dc_precision, s->picture_structure,
1848                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1849                    s->q_scale_type, s->intra_vlc_format,
1850                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1851         }
1852     }
1853
1854     for (;;) {
1855         // If 1, we memcpy blocks in xvmcvideo.
1856         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1857             ff_xvmc_init_block(s); // set s->block
1858
1859         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1860             return ret;
1861
1862         // Note motion_val is normally NULL unless we want to extract the MVs.
1863         if (s->current_picture.motion_val[0] && !s->encoding) {
1864             const int wrap = s->b8_stride;
1865             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1866             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1867             int motion_x, motion_y, dir, i;
1868
1869             for (i = 0; i < 2; i++) {
1870                 for (dir = 0; dir < 2; dir++) {
1871                     if (s->mb_intra ||
1872                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1873                         motion_x = motion_y = 0;
1874                     } else if (s->mv_type == MV_TYPE_16X16 ||
1875                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1876                         motion_x = s->mv[dir][0][0];
1877                         motion_y = s->mv[dir][0][1];
1878                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1879                         motion_x = s->mv[dir][i][0];
1880                         motion_y = s->mv[dir][i][1];
1881                     }
1882
1883                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1884                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1885                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1886                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1887                     s->current_picture.ref_index [dir][b8_xy]     =
1888                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1889                     av_assert2(s->field_select[dir][i] == 0 ||
1890                                s->field_select[dir][i] == 1);
1891                 }
1892                 xy    += wrap;
1893                 b8_xy += 2;
1894             }
1895         }
1896
1897         s->dest[0] += 16 >> lowres;
1898         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1899         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1900
1901         ff_mpv_decode_mb(s, s->block);
1902
1903         if (++s->mb_x >= s->mb_width) {
1904             const int mb_size = 16 >> s->avctx->lowres;
1905
1906             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1907             ff_mpv_report_decode_progress(s);
1908
1909             s->mb_x  = 0;
1910             s->mb_y += 1 << field_pic;
1911
1912             if (s->mb_y >= s->mb_height) {
1913                 int left   = get_bits_left(&s->gb);
1914                 int is_d10 = s->chroma_format == 2 &&
1915                              s->pict_type == AV_PICTURE_TYPE_I &&
1916                              avctx->profile == 0 && avctx->level == 5 &&
1917                              s->intra_dc_precision == 2 &&
1918                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1919                              s->progressive_frame == 0
1920                              /* vbv_delay == 0xBBB || 0xE10 */;
1921
1922                 if (left >= 32 && !is_d10) {
1923                     GetBitContext gb = s->gb;
1924                     align_get_bits(&gb);
1925                     if (show_bits(&gb, 24) == 0x060E2B) {
1926                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1927                         is_d10 = 1;
1928                     }
1929                 }
1930
1931                 if (left < 0 ||
1932                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1933                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1934                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n",
1935                            left, show_bits(&s->gb, FFMIN(left, 23)));
1936                     return AVERROR_INVALIDDATA;
1937                 } else
1938                     goto eos;
1939             }
1940             // There are some files out there which are missing the last slice
1941             // in cases where the slice is completely outside the visible
1942             // area, we detect this here instead of running into the end expecting
1943             // more data
1944             if (s->mb_y >= ((s->height + 15) >> 4) &&
1945                 !s->progressive_sequence &&
1946                 get_bits_left(&s->gb) <= 8 &&
1947                 get_bits_left(&s->gb) >= 0 &&
1948                 s->mb_skip_run == -1 &&
1949                 show_bits(&s->gb, 8) == 0)
1950                 goto eos;
1951
1952             ff_init_block_index(s);
1953         }
1954
1955         /* skip mb handling */
1956         if (s->mb_skip_run == -1) {
1957             /* read increment again */
1958             s->mb_skip_run = 0;
1959             for (;;) {
1960                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1961                                     MBINCR_VLC_BITS, 2);
1962                 if (code < 0) {
1963                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1964                     return AVERROR_INVALIDDATA;
1965                 }
1966                 if (code >= 33) {
1967                     if (code == 33) {
1968                         s->mb_skip_run += 33;
1969                     } else if (code == 35) {
1970                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1971                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1972                             return AVERROR_INVALIDDATA;
1973                         }
1974                         goto eos; /* end of slice */
1975                     }
1976                     /* otherwise, stuffing, nothing to do */
1977                 } else {
1978                     s->mb_skip_run += code;
1979                     break;
1980                 }
1981             }
1982             if (s->mb_skip_run) {
1983                 int i;
1984                 if (s->pict_type == AV_PICTURE_TYPE_I) {
1985                     av_log(s->avctx, AV_LOG_ERROR,
1986                            "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1987                     return AVERROR_INVALIDDATA;
1988                 }
1989
1990                 /* skip mb */
1991                 s->mb_intra = 0;
1992                 for (i = 0; i < 12; i++)
1993                     s->block_last_index[i] = -1;
1994                 if (s->picture_structure == PICT_FRAME)
1995                     s->mv_type = MV_TYPE_16X16;
1996                 else
1997                     s->mv_type = MV_TYPE_FIELD;
1998                 if (s->pict_type == AV_PICTURE_TYPE_P) {
1999                     /* if P type, zero motion vector is implied */
2000                     s->mv_dir             = MV_DIR_FORWARD;
2001                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
2002                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
2003                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
2004                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
2005                 } else {
2006                     /* if B type, reuse previous vectors and directions */
2007                     s->mv[0][0][0] = s->last_mv[0][0][0];
2008                     s->mv[0][0][1] = s->last_mv[0][0][1];
2009                     s->mv[1][0][0] = s->last_mv[1][0][0];
2010                     s->mv[1][0][1] = s->last_mv[1][0][1];
2011                 }
2012             }
2013         }
2014     }
2015 eos: // end of slice
2016     if (get_bits_left(&s->gb) < 0) {
2017         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
2018         return AVERROR_INVALIDDATA;
2019     }
2020     *buf += (get_bits_count(&s->gb) - 1) / 8;
2021     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);
2022     return 0;
2023 }
2024
2025 static int slice_decode_thread(AVCodecContext *c, void *arg)
2026 {
2027     MpegEncContext *s   = *(void **) arg;
2028     const uint8_t *buf  = s->gb.buffer;
2029     int mb_y            = s->start_mb_y;
2030     const int field_pic = s->picture_structure != PICT_FRAME;
2031
2032     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
2033
2034     for (;;) {
2035         uint32_t start_code;
2036         int ret;
2037
2038         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
2039         emms_c();
2040         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
2041                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
2042                 s->start_mb_y, s->end_mb_y, s->er.error_count);
2043         if (ret < 0) {
2044             if (c->err_recognition & AV_EF_EXPLODE)
2045                 return ret;
2046             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2047                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2048                                 s->mb_x, s->mb_y,
2049                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2050         } else {
2051             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2052                             s->mb_x - 1, s->mb_y,
2053                             ER_AC_END | ER_DC_END | ER_MV_END);
2054         }
2055
2056         if (s->mb_y == s->end_mb_y)
2057             return 0;
2058
2059         start_code = -1;
2060         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2061         mb_y       = start_code - SLICE_MIN_START_CODE;
2062         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2063             mb_y += (*buf&0xE0)<<2;
2064         mb_y <<= field_pic;
2065         if (s->picture_structure == PICT_BOTTOM_FIELD)
2066             mb_y++;
2067         if (mb_y < 0 || mb_y >= s->end_mb_y)
2068             return AVERROR_INVALIDDATA;
2069     }
2070 }
2071
2072 /**
2073  * Handle slice ends.
2074  * @return 1 if it seems to be the last slice
2075  */
2076 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2077 {
2078     Mpeg1Context *s1  = avctx->priv_data;
2079     MpegEncContext *s = &s1->mpeg_enc_ctx;
2080
2081     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2082         return 0;
2083
2084     if (s->avctx->hwaccel) {
2085         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
2086             av_log(avctx, AV_LOG_ERROR,
2087                    "hardware accelerator failed to decode picture\n");
2088     }
2089
2090     /* end of slice reached */
2091     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2092         /* end of image */
2093
2094         ff_er_frame_end(&s->er);
2095
2096         ff_mpv_frame_end(s);
2097
2098         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2099             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2100             if (ret < 0)
2101                 return ret;
2102             ff_print_debug_info(s, s->current_picture_ptr, pict);
2103             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2104         } else {
2105             if (avctx->active_thread_type & FF_THREAD_FRAME)
2106                 s->picture_number++;
2107             /* latency of 1 frame for I- and P-frames */
2108             /* XXX: use another variable than picture_number */
2109             if (s->last_picture_ptr) {
2110                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2111                 if (ret < 0)
2112                     return ret;
2113                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2114                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2115             }
2116         }
2117
2118         return 1;
2119     } else {
2120         return 0;
2121     }
2122 }
2123
2124 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2125                                  const uint8_t *buf, int buf_size)
2126 {
2127     Mpeg1Context *s1  = avctx->priv_data;
2128     MpegEncContext *s = &s1->mpeg_enc_ctx;
2129     int width, height;
2130     int i, v, j;
2131
2132     init_get_bits(&s->gb, buf, buf_size * 8);
2133
2134     width  = get_bits(&s->gb, 12);
2135     height = get_bits(&s->gb, 12);
2136     if (width == 0 || height == 0) {
2137         av_log(avctx, AV_LOG_WARNING,
2138                "Invalid horizontal or vertical size value.\n");
2139         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2140             return AVERROR_INVALIDDATA;
2141     }
2142     s->aspect_ratio_info = get_bits(&s->gb, 4);
2143     if (s->aspect_ratio_info == 0) {
2144         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2145         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2146             return AVERROR_INVALIDDATA;
2147     }
2148     s->frame_rate_index = get_bits(&s->gb, 4);
2149     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2150         av_log(avctx, AV_LOG_WARNING,
2151                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2152         s->frame_rate_index = 1;
2153     }
2154     s->bit_rate = get_bits(&s->gb, 18) * 400;
2155     if (check_marker(&s->gb, "in sequence header") == 0) {
2156         return AVERROR_INVALIDDATA;
2157     }
2158     s->width  = width;
2159     s->height = height;
2160
2161     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2162     skip_bits(&s->gb, 1);
2163
2164     /* get matrix */
2165     if (get_bits1(&s->gb)) {
2166         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2167     } else {
2168         for (i = 0; i < 64; i++) {
2169             j = s->idsp.idct_permutation[i];
2170             v = ff_mpeg1_default_intra_matrix[i];
2171             s->intra_matrix[j]        = v;
2172             s->chroma_intra_matrix[j] = v;
2173         }
2174     }
2175     if (get_bits1(&s->gb)) {
2176         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2177     } else {
2178         for (i = 0; i < 64; i++) {
2179             int j = s->idsp.idct_permutation[i];
2180             v = ff_mpeg1_default_non_intra_matrix[i];
2181             s->inter_matrix[j]        = v;
2182             s->chroma_inter_matrix[j] = v;
2183         }
2184     }
2185
2186     if (show_bits(&s->gb, 23) != 0) {
2187         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2188         return AVERROR_INVALIDDATA;
2189     }
2190
2191     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2192     s->progressive_sequence = 1;
2193     s->progressive_frame    = 1;
2194     s->picture_structure    = PICT_FRAME;
2195     s->first_field          = 0;
2196     s->frame_pred_frame_dct = 1;
2197     s->chroma_format        = 1;
2198     s->codec_id             =
2199     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2200     s->out_format           = FMT_MPEG1;
2201     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2202     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2203         s->low_delay = 1;
2204
2205     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2206         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d, aspect_ratio_info: %d \n",
2207                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2208
2209     return 0;
2210 }
2211
2212 static int vcr2_init_sequence(AVCodecContext *avctx)
2213 {
2214     Mpeg1Context *s1  = avctx->priv_data;
2215     MpegEncContext *s = &s1->mpeg_enc_ctx;
2216     int i, v, ret;
2217
2218     /* start new MPEG-1 context decoding */
2219     s->out_format = FMT_MPEG1;
2220     if (s1->mpeg_enc_ctx_allocated) {
2221         ff_mpv_common_end(s);
2222         s1->mpeg_enc_ctx_allocated = 0;
2223     }
2224     s->width            = avctx->coded_width;
2225     s->height           = avctx->coded_height;
2226     avctx->has_b_frames = 0; // true?
2227     s->low_delay        = 1;
2228
2229     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2230     setup_hwaccel_for_pixfmt(avctx);
2231
2232     ff_mpv_idct_init(s);
2233     if ((ret = ff_mpv_common_init(s)) < 0)
2234         return ret;
2235     s1->mpeg_enc_ctx_allocated = 1;
2236
2237     for (i = 0; i < 64; i++) {
2238         int j = s->idsp.idct_permutation[i];
2239         v = ff_mpeg1_default_intra_matrix[i];
2240         s->intra_matrix[j]        = v;
2241         s->chroma_intra_matrix[j] = v;
2242
2243         v = ff_mpeg1_default_non_intra_matrix[i];
2244         s->inter_matrix[j]        = v;
2245         s->chroma_inter_matrix[j] = v;
2246     }
2247
2248     s->progressive_sequence  = 1;
2249     s->progressive_frame     = 1;
2250     s->picture_structure     = PICT_FRAME;
2251     s->first_field           = 0;
2252     s->frame_pred_frame_dct  = 1;
2253     s->chroma_format         = 1;
2254     if (s->codec_tag == AV_RL32("BW10")) {
2255         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2256     } else {
2257         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2258         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2259     }
2260     s1->save_width           = s->width;
2261     s1->save_height          = s->height;
2262     s1->save_progressive_seq = s->progressive_sequence;
2263     return 0;
2264 }
2265
2266 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2267                               const uint8_t *p, int buf_size)
2268 {
2269     Mpeg1Context *s1 = avctx->priv_data;
2270
2271     if (buf_size >= 6 &&
2272         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2273         p[4] == 3 && (p[5] & 0x40)) {
2274         /* extract A53 Part 4 CC data */
2275         int cc_count = p[5] & 0x1f;
2276         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2277             av_freep(&s1->a53_caption);
2278             s1->a53_caption_size = cc_count * 3;
2279             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2280             if (s1->a53_caption)
2281                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2282         }
2283         return 1;
2284     } else if (buf_size >= 11 &&
2285                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2286         /* extract DVD CC data */
2287         int cc_count = 0;
2288         int i;
2289         // There is a caption count field in the data, but it is often
2290         // incorect.  So count the number of captions present.
2291         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2292             cc_count++;
2293         // Transform the DVD format into A53 Part 4 format
2294         if (cc_count > 0) {
2295             av_freep(&s1->a53_caption);
2296             s1->a53_caption_size = cc_count * 6;
2297             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2298             if (s1->a53_caption) {
2299                 uint8_t field1 = !!(p[4] & 0x80);
2300                 uint8_t *cap = s1->a53_caption;
2301                 p += 5;
2302                 for (i = 0; i < cc_count; i++) {
2303                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2304                     cap[1] = p[1];
2305                     cap[2] = p[2];
2306                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2307                     cap[4] = p[4];
2308                     cap[5] = p[5];
2309                     cap += 6;
2310                     p += 6;
2311                 }
2312             }
2313         }
2314         return 1;
2315     }
2316     return 0;
2317 }
2318
2319 static void mpeg_decode_user_data(AVCodecContext *avctx,
2320                                   const uint8_t *p, int buf_size)
2321 {
2322     Mpeg1Context *s = avctx->priv_data;
2323     const uint8_t *buf_end = p + buf_size;
2324     Mpeg1Context *s1 = avctx->priv_data;
2325
2326 #if 0
2327     int i;
2328     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2329         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2330     }
2331     av_log(avctx, AV_LOG_ERROR, "\n");
2332 #endif
2333
2334     if (buf_size > 29){
2335         int i;
2336         for(i=0; i<20; i++)
2337             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2338                 s->tmpgexs= 1;
2339             }
2340     }
2341     /* we parse the DTG active format information */
2342     if (buf_end - p >= 5 &&
2343         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2344         int flags = p[4];
2345         p += 5;
2346         if (flags & 0x80) {
2347             /* skip event id */
2348             p += 2;
2349         }
2350         if (flags & 0x40) {
2351             if (buf_end - p < 1)
2352                 return;
2353 #if FF_API_AFD
2354 FF_DISABLE_DEPRECATION_WARNINGS
2355             avctx->dtg_active_format = p[0] & 0x0f;
2356 FF_ENABLE_DEPRECATION_WARNINGS
2357 #endif /* FF_API_AFD */
2358             s1->has_afd = 1;
2359             s1->afd     = p[0] & 0x0f;
2360         }
2361     } else if (buf_end - p >= 6 &&
2362                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2363                p[4] == 0x03) { // S3D_video_format_length
2364         // the 0x7F mask ignores the reserved_bit value
2365         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2366
2367         if (S3D_video_format_type == 0x03 ||
2368             S3D_video_format_type == 0x04 ||
2369             S3D_video_format_type == 0x08 ||
2370             S3D_video_format_type == 0x23) {
2371
2372             s1->has_stereo3d = 1;
2373
2374             switch (S3D_video_format_type) {
2375             case 0x03:
2376                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2377                 break;
2378             case 0x04:
2379                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2380                 break;
2381             case 0x08:
2382                 s1->stereo3d.type = AV_STEREO3D_2D;
2383                 break;
2384             case 0x23:
2385                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2386                 break;
2387             }
2388         }
2389     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2390         return;
2391     }
2392 }
2393
2394 static void mpeg_decode_gop(AVCodecContext *avctx,
2395                             const uint8_t *buf, int buf_size)
2396 {
2397     Mpeg1Context *s1  = avctx->priv_data;
2398     MpegEncContext *s = &s1->mpeg_enc_ctx;
2399     int broken_link;
2400     int64_t tc;
2401
2402     init_get_bits(&s->gb, buf, buf_size * 8);
2403
2404     tc = avctx->timecode_frame_start = get_bits(&s->gb, 25);
2405
2406     s->closed_gop = get_bits1(&s->gb);
2407     /* broken_link indicate that after editing the
2408      * reference frames of the first B-Frames after GOP I-Frame
2409      * are missing (open gop) */
2410     broken_link = get_bits1(&s->gb);
2411
2412     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2413         char tcbuf[AV_TIMECODE_STR_SIZE];
2414         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2415         av_log(s->avctx, AV_LOG_DEBUG,
2416                "GOP (%s) closed_gop=%d broken_link=%d\n",
2417                tcbuf, s->closed_gop, broken_link);
2418     }
2419 }
2420
2421 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2422                          int *got_output, const uint8_t *buf, int buf_size)
2423 {
2424     Mpeg1Context *s = avctx->priv_data;
2425     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2426     const uint8_t *buf_ptr = buf;
2427     const uint8_t *buf_end = buf + buf_size;
2428     int ret, input_size;
2429     int last_code = 0, skip_frame = 0;
2430     int picture_start_code_seen = 0;
2431
2432     for (;;) {
2433         /* find next start code */
2434         uint32_t start_code = -1;
2435         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2436         if (start_code > 0x1ff) {
2437             if (!skip_frame) {
2438                 if (HAVE_THREADS &&
2439                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2440                     !avctx->hwaccel) {
2441                     int i;
2442                     av_assert0(avctx->thread_count > 1);
2443
2444                     avctx->execute(avctx, slice_decode_thread,
2445                                    &s2->thread_context[0], NULL,
2446                                    s->slice_count, sizeof(void *));
2447                     for (i = 0; i < s->slice_count; i++)
2448                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2449                 }
2450
2451                 if ((CONFIG_MPEG_VDPAU_DECODER || CONFIG_MPEG1_VDPAU_DECODER)
2452                     && uses_vdpau(avctx))
2453                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2454
2455                 ret = slice_end(avctx, picture);
2456                 if (ret < 0)
2457                     return ret;
2458                 else if (ret) {
2459                     // FIXME: merge with the stuff in mpeg_decode_slice
2460                     if (s2->last_picture_ptr || s2->low_delay)
2461                         *got_output = 1;
2462                 }
2463             }
2464             s2->pict_type = 0;
2465
2466             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2467                 return AVERROR_INVALIDDATA;
2468
2469             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2470         }
2471
2472         input_size = buf_end - buf_ptr;
2473
2474         if (avctx->debug & FF_DEBUG_STARTCODE)
2475             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2476                    start_code, buf_ptr - buf, input_size);
2477
2478         /* prepare data for next start code */
2479         switch (start_code) {
2480         case SEQ_START_CODE:
2481             if (last_code == 0) {
2482                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2483                 if (buf != avctx->extradata)
2484                     s->sync = 1;
2485             } else {
2486                 av_log(avctx, AV_LOG_ERROR,
2487                        "ignoring SEQ_START_CODE after %X\n", last_code);
2488                 if (avctx->err_recognition & AV_EF_EXPLODE)
2489                     return AVERROR_INVALIDDATA;
2490             }
2491             break;
2492
2493         case PICTURE_START_CODE:
2494             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2495                /* If it's a frame picture, there can't be more than one picture header.
2496                   Yet, it does happen and we need to handle it. */
2497                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2498                break;
2499             }
2500             picture_start_code_seen = 1;
2501
2502             if (s2->width <= 0 || s2->height <= 0) {
2503                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2504                        s2->width, s2->height);
2505                 return AVERROR_INVALIDDATA;
2506             }
2507
2508             if (s->tmpgexs){
2509                 s2->intra_dc_precision= 3;
2510                 s2->intra_matrix[0]= 1;
2511             }
2512             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2513                 !avctx->hwaccel && s->slice_count) {
2514                 int i;
2515
2516                 avctx->execute(avctx, slice_decode_thread,
2517                                s2->thread_context, NULL,
2518                                s->slice_count, sizeof(void *));
2519                 for (i = 0; i < s->slice_count; i++)
2520                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2521                 s->slice_count = 0;
2522             }
2523             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2524                 ret = mpeg_decode_postinit(avctx);
2525                 if (ret < 0) {
2526                     av_log(avctx, AV_LOG_ERROR,
2527                            "mpeg_decode_postinit() failure\n");
2528                     return ret;
2529                 }
2530
2531                 /* We have a complete image: we try to decompress it. */
2532                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2533                     s2->pict_type = 0;
2534                 s->first_slice = 1;
2535                 last_code      = PICTURE_START_CODE;
2536             } else {
2537                 av_log(avctx, AV_LOG_ERROR,
2538                        "ignoring pic after %X\n", last_code);
2539                 if (avctx->err_recognition & AV_EF_EXPLODE)
2540                     return AVERROR_INVALIDDATA;
2541             }
2542             break;
2543         case EXT_START_CODE:
2544             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2545
2546             switch (get_bits(&s2->gb, 4)) {
2547             case 0x1:
2548                 if (last_code == 0) {
2549                     mpeg_decode_sequence_extension(s);
2550                 } else {
2551                     av_log(avctx, AV_LOG_ERROR,
2552                            "ignoring seq ext after %X\n", last_code);
2553                     if (avctx->err_recognition & AV_EF_EXPLODE)
2554                         return AVERROR_INVALIDDATA;
2555                 }
2556                 break;
2557             case 0x2:
2558                 mpeg_decode_sequence_display_extension(s);
2559                 break;
2560             case 0x3:
2561                 mpeg_decode_quant_matrix_extension(s2);
2562                 break;
2563             case 0x7:
2564                 mpeg_decode_picture_display_extension(s);
2565                 break;
2566             case 0x8:
2567                 if (last_code == PICTURE_START_CODE) {
2568                     mpeg_decode_picture_coding_extension(s);
2569                 } else {
2570                     av_log(avctx, AV_LOG_ERROR,
2571                            "ignoring pic cod ext after %X\n", last_code);
2572                     if (avctx->err_recognition & AV_EF_EXPLODE)
2573                         return AVERROR_INVALIDDATA;
2574                 }
2575                 break;
2576             }
2577             break;
2578         case USER_START_CODE:
2579             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2580             break;
2581         case GOP_START_CODE:
2582             if (last_code == 0) {
2583                 s2->first_field = 0;
2584                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2585                 s->sync = 1;
2586             } else {
2587                 av_log(avctx, AV_LOG_ERROR,
2588                        "ignoring GOP_START_CODE after %X\n", last_code);
2589                 if (avctx->err_recognition & AV_EF_EXPLODE)
2590                     return AVERROR_INVALIDDATA;
2591             }
2592             break;
2593         default:
2594             if (start_code >= SLICE_MIN_START_CODE &&
2595                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2596                 if (s2->progressive_sequence && !s2->progressive_frame) {
2597                     s2->progressive_frame = 1;
2598                     av_log(s2->avctx, AV_LOG_ERROR,
2599                            "interlaced frame in progressive sequence, ignoring\n");
2600                 }
2601
2602                 if (s2->picture_structure == 0 ||
2603                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2604                     av_log(s2->avctx, AV_LOG_ERROR,
2605                            "picture_structure %d invalid, ignoring\n",
2606                            s2->picture_structure);
2607                     s2->picture_structure = PICT_FRAME;
2608                 }
2609
2610                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2611                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2612
2613                 if (s2->picture_structure == PICT_FRAME) {
2614                     s2->first_field = 0;
2615                     s2->v_edge_pos  = 16 * s2->mb_height;
2616                 } else {
2617                     s2->first_field ^= 1;
2618                     s2->v_edge_pos   = 8 * s2->mb_height;
2619                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2620                 }
2621             }
2622             if (start_code >= SLICE_MIN_START_CODE &&
2623                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2624                 const int field_pic = s2->picture_structure != PICT_FRAME;
2625                 int mb_y = start_code - SLICE_MIN_START_CODE;
2626                 last_code = SLICE_MIN_START_CODE;
2627                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2628                     mb_y += (*buf_ptr&0xE0)<<2;
2629
2630                 mb_y <<= field_pic;
2631                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2632                     mb_y++;
2633
2634                 if (buf_end - buf_ptr < 2) {
2635                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2636                     return AVERROR_INVALIDDATA;
2637                 }
2638
2639                 if (mb_y >= s2->mb_height) {
2640                     av_log(s2->avctx, AV_LOG_ERROR,
2641                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2642                     return AVERROR_INVALIDDATA;
2643                 }
2644
2645                 if (!s2->last_picture_ptr) {
2646                     /* Skip B-frames if we do not have reference frames and
2647                      * GOP is not closed. */
2648                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2649                         if (!s2->closed_gop) {
2650                             skip_frame = 1;
2651                             break;
2652                         }
2653                     }
2654                 }
2655                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2656                     s->sync = 1;
2657                 if (!s2->next_picture_ptr) {
2658                     /* Skip P-frames if we do not have a reference frame or
2659                      * we have an invalid header. */
2660                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2661                         skip_frame = 1;
2662                         break;
2663                     }
2664                 }
2665                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2666                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2667                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2668                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2669                     avctx->skip_frame >= AVDISCARD_ALL) {
2670                     skip_frame = 1;
2671                     break;
2672                 }
2673
2674                 if (!s->mpeg_enc_ctx_allocated)
2675                     break;
2676
2677                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2678                     if (mb_y < avctx->skip_top ||
2679                         mb_y >= s2->mb_height - avctx->skip_bottom)
2680                         break;
2681                 }
2682
2683                 if (!s2->pict_type) {
2684                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2685                     if (avctx->err_recognition & AV_EF_EXPLODE)
2686                         return AVERROR_INVALIDDATA;
2687                     break;
2688                 }
2689
2690                 if (s->first_slice) {
2691                     skip_frame     = 0;
2692                     s->first_slice = 0;
2693                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2694                         return ret;
2695                 }
2696                 if (!s2->current_picture_ptr) {
2697                     av_log(avctx, AV_LOG_ERROR,
2698                            "current_picture not initialized\n");
2699                     return AVERROR_INVALIDDATA;
2700                 }
2701
2702                 if (uses_vdpau(avctx)) {
2703                     s->slice_count++;
2704                     break;
2705                 }
2706
2707                 if (HAVE_THREADS &&
2708                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2709                     !avctx->hwaccel) {
2710                     int threshold = (s2->mb_height * s->slice_count +
2711                                      s2->slice_context_count / 2) /
2712                                     s2->slice_context_count;
2713                     av_assert0(avctx->thread_count > 1);
2714                     if (threshold <= mb_y) {
2715                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2716
2717                         thread_context->start_mb_y = mb_y;
2718                         thread_context->end_mb_y   = s2->mb_height;
2719                         if (s->slice_count) {
2720                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2721                             ret = ff_update_duplicate_context(thread_context, s2);
2722                             if (ret < 0)
2723                                 return ret;
2724                         }
2725                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2726                         s->slice_count++;
2727                     }
2728                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2729                 } else {
2730                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2731                     emms_c();
2732
2733                     if (ret < 0) {
2734                         if (avctx->err_recognition & AV_EF_EXPLODE)
2735                             return ret;
2736                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2737                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2738                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2739                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2740                     } else {
2741                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2742                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2743                                         ER_AC_END | ER_DC_END | ER_MV_END);
2744                     }
2745                 }
2746             }
2747             break;
2748         }
2749     }
2750 }
2751
2752 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2753                              int *got_output, AVPacket *avpkt)
2754 {
2755     const uint8_t *buf = avpkt->data;
2756     int ret;
2757     int buf_size = avpkt->size;
2758     Mpeg1Context *s = avctx->priv_data;
2759     AVFrame *picture = data;
2760     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2761
2762     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2763         /* special case for last picture */
2764         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2765             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2766             if (ret < 0)
2767                 return ret;
2768
2769             s2->next_picture_ptr = NULL;
2770
2771             *got_output = 1;
2772         }
2773         return buf_size;
2774     }
2775
2776     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2777         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2778                                            buf_size, NULL);
2779
2780         if (ff_combine_frame(&s2->parse_context, next,
2781                              (const uint8_t **) &buf, &buf_size) < 0)
2782             return buf_size;
2783     }
2784
2785     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2786     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2787                                            || s2->codec_tag == AV_RL32("BW10")
2788                                           ))
2789         vcr2_init_sequence(avctx);
2790
2791     s->slice_count = 0;
2792
2793     if (avctx->extradata && !s->extradata_decoded) {
2794         ret = decode_chunks(avctx, picture, got_output,
2795                             avctx->extradata, avctx->extradata_size);
2796         if (*got_output) {
2797             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2798             *got_output = 0;
2799         }
2800         s->extradata_decoded = 1;
2801         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2802             s2->current_picture_ptr = NULL;
2803             return ret;
2804         }
2805     }
2806
2807     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2808     if (ret<0 || *got_output)
2809         s2->current_picture_ptr = NULL;
2810
2811     return ret;
2812 }
2813
2814 static void flush(AVCodecContext *avctx)
2815 {
2816     Mpeg1Context *s = avctx->priv_data;
2817
2818     s->sync       = 0;
2819
2820     ff_mpeg_flush(avctx);
2821 }
2822
2823 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2824 {
2825     Mpeg1Context *s = avctx->priv_data;
2826
2827     if (s->mpeg_enc_ctx_allocated)
2828         ff_mpv_common_end(&s->mpeg_enc_ctx);
2829     av_freep(&s->a53_caption);
2830     return 0;
2831 }
2832
2833 static const AVProfile mpeg2_video_profiles[] = {
2834     { FF_PROFILE_MPEG2_422,          "4:2:2"              },
2835     { FF_PROFILE_MPEG2_HIGH,         "High"               },
2836     { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
2837     { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
2838     { FF_PROFILE_MPEG2_MAIN,         "Main"               },
2839     { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
2840     { FF_PROFILE_RESERVED,           "Reserved"           },
2841     { FF_PROFILE_RESERVED,           "Reserved"           },
2842     { FF_PROFILE_UNKNOWN                                  },
2843 };
2844
2845 AVCodec ff_mpeg1video_decoder = {
2846     .name                  = "mpeg1video",
2847     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2848     .type                  = AVMEDIA_TYPE_VIDEO,
2849     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2850     .priv_data_size        = sizeof(Mpeg1Context),
2851     .init                  = mpeg_decode_init,
2852     .close                 = mpeg_decode_end,
2853     .decode                = mpeg_decode_frame,
2854     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2855                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2856                              AV_CODEC_CAP_SLICE_THREADS,
2857     .flush                 = flush,
2858     .max_lowres            = 3,
2859     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2860 };
2861
2862 AVCodec ff_mpeg2video_decoder = {
2863     .name           = "mpeg2video",
2864     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2865     .type           = AVMEDIA_TYPE_VIDEO,
2866     .id             = AV_CODEC_ID_MPEG2VIDEO,
2867     .priv_data_size = sizeof(Mpeg1Context),
2868     .init           = mpeg_decode_init,
2869     .close          = mpeg_decode_end,
2870     .decode         = mpeg_decode_frame,
2871     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2872                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2873                       AV_CODEC_CAP_SLICE_THREADS,
2874     .flush          = flush,
2875     .max_lowres     = 3,
2876     .profiles       = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
2877 };
2878
2879 //legacy decoder
2880 AVCodec ff_mpegvideo_decoder = {
2881     .name           = "mpegvideo",
2882     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2883     .type           = AVMEDIA_TYPE_VIDEO,
2884     .id             = AV_CODEC_ID_MPEG2VIDEO,
2885     .priv_data_size = sizeof(Mpeg1Context),
2886     .init           = mpeg_decode_init,
2887     .close          = mpeg_decode_end,
2888     .decode         = mpeg_decode_frame,
2889     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2890     .flush          = flush,
2891     .max_lowres     = 3,
2892 };
2893
2894 #if FF_API_XVMC
2895 #if CONFIG_MPEG_XVMC_DECODER
2896 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
2897 {
2898     if (avctx->active_thread_type & FF_THREAD_SLICE)
2899         return -1;
2900     if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
2901         return -1;
2902     if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
2903         ff_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2904     }
2905     mpeg_decode_init(avctx);
2906
2907     avctx->pix_fmt           = AV_PIX_FMT_XVMC_MPEG2_IDCT;
2908     avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
2909
2910     return 0;
2911 }
2912
2913 AVCodec ff_mpeg_xvmc_decoder = {
2914     .name           = "mpegvideo_xvmc",
2915     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2916     .type           = AVMEDIA_TYPE_VIDEO,
2917     .id             = AV_CODEC_ID_MPEG2VIDEO_XVMC,
2918     .priv_data_size = sizeof(Mpeg1Context),
2919     .init           = mpeg_mc_decode_init,
2920     .close          = mpeg_decode_end,
2921     .decode         = mpeg_decode_frame,
2922     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2923                       AV_CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL |
2924                       AV_CODEC_CAP_DELAY,
2925     .flush          = flush,
2926 };
2927
2928 #endif
2929 #endif /* FF_API_XVMC */
2930
2931 #if CONFIG_MPEG_VDPAU_DECODER
2932 AVCodec ff_mpeg_vdpau_decoder = {
2933     .name           = "mpegvideo_vdpau",
2934     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2935     .type           = AVMEDIA_TYPE_VIDEO,
2936     .id             = AV_CODEC_ID_MPEG2VIDEO,
2937     .priv_data_size = sizeof(Mpeg1Context),
2938     .init           = mpeg_decode_init,
2939     .close          = mpeg_decode_end,
2940     .decode         = mpeg_decode_frame,
2941     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2942                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2943     .flush          = flush,
2944 };
2945 #endif
2946
2947 #if CONFIG_MPEG1_VDPAU_DECODER
2948 AVCodec ff_mpeg1_vdpau_decoder = {
2949     .name           = "mpeg1video_vdpau",
2950     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2951     .type           = AVMEDIA_TYPE_VIDEO,
2952     .id             = AV_CODEC_ID_MPEG1VIDEO,
2953     .priv_data_size = sizeof(Mpeg1Context),
2954     .init           = mpeg_decode_init,
2955     .close          = mpeg_decode_end,
2956     .decode         = mpeg_decode_frame,
2957     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2958                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2959     .flush          = flush,
2960 };
2961 #endif