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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 ((ret = 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                 return ret;
1730             }
1731         }
1732
1733         for (i = 0; i < 4; i++) {
1734             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1735             if (s->picture_structure == PICT_BOTTOM_FIELD)
1736                 s->current_picture.f->data[i] +=
1737                     s->current_picture_ptr->f->linesize[i];
1738         }
1739     }
1740
1741     if (avctx->hwaccel) {
1742         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1743             return ret;
1744     }
1745
1746     return 0;
1747 }
1748
1749 #define DECODE_SLICE_ERROR -1
1750 #define DECODE_SLICE_OK     0
1751
1752 /**
1753  * Decode a slice.
1754  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1755  * @return DECODE_SLICE_ERROR if the slice is damaged,
1756  *         DECODE_SLICE_OK if this slice is OK
1757  */
1758 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1759                              const uint8_t **buf, int buf_size)
1760 {
1761     AVCodecContext *avctx = s->avctx;
1762     const int lowres      = s->avctx->lowres;
1763     const int field_pic   = s->picture_structure != PICT_FRAME;
1764     int ret;
1765
1766     s->resync_mb_x =
1767     s->resync_mb_y = -1;
1768
1769     av_assert0(mb_y < s->mb_height);
1770
1771     init_get_bits(&s->gb, *buf, buf_size * 8);
1772     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1773         skip_bits(&s->gb, 3);
1774
1775     ff_mpeg1_clean_buffers(s);
1776     s->interlaced_dct = 0;
1777
1778     s->qscale = get_qscale(s);
1779
1780     if (s->qscale == 0) {
1781         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1782         return AVERROR_INVALIDDATA;
1783     }
1784
1785     /* extra slice info */
1786     if (skip_1stop_8data_bits(&s->gb) < 0)
1787         return AVERROR_INVALIDDATA;
1788
1789     s->mb_x = 0;
1790
1791     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1792         skip_bits1(&s->gb);
1793     } else {
1794         while (get_bits_left(&s->gb) > 0) {
1795             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1796                                 MBINCR_VLC_BITS, 2);
1797             if (code < 0) {
1798                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1799                 return AVERROR_INVALIDDATA;
1800             }
1801             if (code >= 33) {
1802                 if (code == 33)
1803                     s->mb_x += 33;
1804                 /* otherwise, stuffing, nothing to do */
1805             } else {
1806                 s->mb_x += code;
1807                 break;
1808             }
1809         }
1810     }
1811
1812     if (s->mb_x >= (unsigned) s->mb_width) {
1813         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1814         return AVERROR_INVALIDDATA;
1815     }
1816
1817     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1818         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1819         int start_code = -1;
1820         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1821         if (buf_end < *buf + buf_size)
1822             buf_end -= 4;
1823         s->mb_y = mb_y;
1824         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1825             return DECODE_SLICE_ERROR;
1826         *buf = buf_end;
1827         return DECODE_SLICE_OK;
1828     }
1829
1830     s->resync_mb_x = s->mb_x;
1831     s->resync_mb_y = s->mb_y = mb_y;
1832     s->mb_skip_run = 0;
1833     ff_init_block_index(s);
1834
1835     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1836         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1837             av_log(s->avctx, AV_LOG_DEBUG,
1838                    "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",
1839                    s->qscale,
1840                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1841                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1842                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1843                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1844                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1845                    s->progressive_sequence ? "ps"  : "",
1846                    s->progressive_frame    ? "pf"  : "",
1847                    s->alternate_scan       ? "alt" : "",
1848                    s->top_field_first      ? "top" : "",
1849                    s->intra_dc_precision, s->picture_structure,
1850                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1851                    s->q_scale_type, s->intra_vlc_format,
1852                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1853         }
1854     }
1855
1856     for (;;) {
1857         // If 1, we memcpy blocks in xvmcvideo.
1858         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1859             ff_xvmc_init_block(s); // set s->block
1860
1861         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1862             return ret;
1863
1864         // Note motion_val is normally NULL unless we want to extract the MVs.
1865         if (s->current_picture.motion_val[0] && !s->encoding) {
1866             const int wrap = s->b8_stride;
1867             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1868             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1869             int motion_x, motion_y, dir, i;
1870
1871             for (i = 0; i < 2; i++) {
1872                 for (dir = 0; dir < 2; dir++) {
1873                     if (s->mb_intra ||
1874                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1875                         motion_x = motion_y = 0;
1876                     } else if (s->mv_type == MV_TYPE_16X16 ||
1877                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1878                         motion_x = s->mv[dir][0][0];
1879                         motion_y = s->mv[dir][0][1];
1880                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1881                         motion_x = s->mv[dir][i][0];
1882                         motion_y = s->mv[dir][i][1];
1883                     }
1884
1885                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1886                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1887                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1888                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1889                     s->current_picture.ref_index [dir][b8_xy]     =
1890                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1891                     av_assert2(s->field_select[dir][i] == 0 ||
1892                                s->field_select[dir][i] == 1);
1893                 }
1894                 xy    += wrap;
1895                 b8_xy += 2;
1896             }
1897         }
1898
1899         s->dest[0] += 16 >> lowres;
1900         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1901         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1902
1903         ff_mpv_decode_mb(s, s->block);
1904
1905         if (++s->mb_x >= s->mb_width) {
1906             const int mb_size = 16 >> s->avctx->lowres;
1907
1908             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1909             ff_mpv_report_decode_progress(s);
1910
1911             s->mb_x  = 0;
1912             s->mb_y += 1 << field_pic;
1913
1914             if (s->mb_y >= s->mb_height) {
1915                 int left   = get_bits_left(&s->gb);
1916                 int is_d10 = s->chroma_format == 2 &&
1917                              s->pict_type == AV_PICTURE_TYPE_I &&
1918                              avctx->profile == 0 && avctx->level == 5 &&
1919                              s->intra_dc_precision == 2 &&
1920                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1921                              s->progressive_frame == 0
1922                              /* vbv_delay == 0xBBB || 0xE10 */;
1923
1924                 if (left >= 32 && !is_d10) {
1925                     GetBitContext gb = s->gb;
1926                     align_get_bits(&gb);
1927                     if (show_bits(&gb, 24) == 0x060E2B) {
1928                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1929                         is_d10 = 1;
1930                     }
1931                 }
1932
1933                 if (left < 0 ||
1934                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1935                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1936                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n",
1937                            left, show_bits(&s->gb, FFMIN(left, 23)));
1938                     return AVERROR_INVALIDDATA;
1939                 } else
1940                     goto eos;
1941             }
1942             // There are some files out there which are missing the last slice
1943             // in cases where the slice is completely outside the visible
1944             // area, we detect this here instead of running into the end expecting
1945             // more data
1946             if (s->mb_y >= ((s->height + 15) >> 4) &&
1947                 !s->progressive_sequence &&
1948                 get_bits_left(&s->gb) <= 8 &&
1949                 get_bits_left(&s->gb) >= 0 &&
1950                 s->mb_skip_run == -1 &&
1951                 show_bits(&s->gb, 8) == 0)
1952                 goto eos;
1953
1954             ff_init_block_index(s);
1955         }
1956
1957         /* skip mb handling */
1958         if (s->mb_skip_run == -1) {
1959             /* read increment again */
1960             s->mb_skip_run = 0;
1961             for (;;) {
1962                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1963                                     MBINCR_VLC_BITS, 2);
1964                 if (code < 0) {
1965                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1966                     return AVERROR_INVALIDDATA;
1967                 }
1968                 if (code >= 33) {
1969                     if (code == 33) {
1970                         s->mb_skip_run += 33;
1971                     } else if (code == 35) {
1972                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1973                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1974                             return AVERROR_INVALIDDATA;
1975                         }
1976                         goto eos; /* end of slice */
1977                     }
1978                     /* otherwise, stuffing, nothing to do */
1979                 } else {
1980                     s->mb_skip_run += code;
1981                     break;
1982                 }
1983             }
1984             if (s->mb_skip_run) {
1985                 int i;
1986                 if (s->pict_type == AV_PICTURE_TYPE_I) {
1987                     av_log(s->avctx, AV_LOG_ERROR,
1988                            "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1989                     return AVERROR_INVALIDDATA;
1990                 }
1991
1992                 /* skip mb */
1993                 s->mb_intra = 0;
1994                 for (i = 0; i < 12; i++)
1995                     s->block_last_index[i] = -1;
1996                 if (s->picture_structure == PICT_FRAME)
1997                     s->mv_type = MV_TYPE_16X16;
1998                 else
1999                     s->mv_type = MV_TYPE_FIELD;
2000                 if (s->pict_type == AV_PICTURE_TYPE_P) {
2001                     /* if P type, zero motion vector is implied */
2002                     s->mv_dir             = MV_DIR_FORWARD;
2003                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
2004                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
2005                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
2006                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
2007                 } else {
2008                     /* if B type, reuse previous vectors and directions */
2009                     s->mv[0][0][0] = s->last_mv[0][0][0];
2010                     s->mv[0][0][1] = s->last_mv[0][0][1];
2011                     s->mv[1][0][0] = s->last_mv[1][0][0];
2012                     s->mv[1][0][1] = s->last_mv[1][0][1];
2013                 }
2014             }
2015         }
2016     }
2017 eos: // end of slice
2018     if (get_bits_left(&s->gb) < 0) {
2019         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
2020         return AVERROR_INVALIDDATA;
2021     }
2022     *buf += (get_bits_count(&s->gb) - 1) / 8;
2023     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);
2024     return 0;
2025 }
2026
2027 static int slice_decode_thread(AVCodecContext *c, void *arg)
2028 {
2029     MpegEncContext *s   = *(void **) arg;
2030     const uint8_t *buf  = s->gb.buffer;
2031     int mb_y            = s->start_mb_y;
2032     const int field_pic = s->picture_structure != PICT_FRAME;
2033
2034     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
2035
2036     for (;;) {
2037         uint32_t start_code;
2038         int ret;
2039
2040         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
2041         emms_c();
2042         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
2043                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
2044                 s->start_mb_y, s->end_mb_y, s->er.error_count);
2045         if (ret < 0) {
2046             if (c->err_recognition & AV_EF_EXPLODE)
2047                 return ret;
2048             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2049                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2050                                 s->mb_x, s->mb_y,
2051                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2052         } else {
2053             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2054                             s->mb_x - 1, s->mb_y,
2055                             ER_AC_END | ER_DC_END | ER_MV_END);
2056         }
2057
2058         if (s->mb_y == s->end_mb_y)
2059             return 0;
2060
2061         start_code = -1;
2062         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2063         mb_y       = start_code - SLICE_MIN_START_CODE;
2064         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2065             mb_y += (*buf&0xE0)<<2;
2066         mb_y <<= field_pic;
2067         if (s->picture_structure == PICT_BOTTOM_FIELD)
2068             mb_y++;
2069         if (mb_y < 0 || mb_y >= s->end_mb_y)
2070             return AVERROR_INVALIDDATA;
2071     }
2072 }
2073
2074 /**
2075  * Handle slice ends.
2076  * @return 1 if it seems to be the last slice
2077  */
2078 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2079 {
2080     Mpeg1Context *s1  = avctx->priv_data;
2081     MpegEncContext *s = &s1->mpeg_enc_ctx;
2082
2083     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2084         return 0;
2085
2086     if (s->avctx->hwaccel) {
2087         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2088         if (ret < 0) {
2089             av_log(avctx, AV_LOG_ERROR,
2090                    "hardware accelerator failed to decode picture\n");
2091             return ret;
2092         }
2093     }
2094
2095     /* end of slice reached */
2096     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2097         /* end of image */
2098
2099         ff_er_frame_end(&s->er);
2100
2101         ff_mpv_frame_end(s);
2102
2103         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2104             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2105             if (ret < 0)
2106                 return ret;
2107             ff_print_debug_info(s, s->current_picture_ptr, pict);
2108             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2109         } else {
2110             if (avctx->active_thread_type & FF_THREAD_FRAME)
2111                 s->picture_number++;
2112             /* latency of 1 frame for I- and P-frames */
2113             /* XXX: use another variable than picture_number */
2114             if (s->last_picture_ptr) {
2115                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2116                 if (ret < 0)
2117                     return ret;
2118                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2119                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2120             }
2121         }
2122
2123         return 1;
2124     } else {
2125         return 0;
2126     }
2127 }
2128
2129 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2130                                  const uint8_t *buf, int buf_size)
2131 {
2132     Mpeg1Context *s1  = avctx->priv_data;
2133     MpegEncContext *s = &s1->mpeg_enc_ctx;
2134     int width, height;
2135     int i, v, j;
2136
2137     init_get_bits(&s->gb, buf, buf_size * 8);
2138
2139     width  = get_bits(&s->gb, 12);
2140     height = get_bits(&s->gb, 12);
2141     if (width == 0 || height == 0) {
2142         av_log(avctx, AV_LOG_WARNING,
2143                "Invalid horizontal or vertical size value.\n");
2144         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2145             return AVERROR_INVALIDDATA;
2146     }
2147     s->aspect_ratio_info = get_bits(&s->gb, 4);
2148     if (s->aspect_ratio_info == 0) {
2149         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2150         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2151             return AVERROR_INVALIDDATA;
2152     }
2153     s->frame_rate_index = get_bits(&s->gb, 4);
2154     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2155         av_log(avctx, AV_LOG_WARNING,
2156                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2157         s->frame_rate_index = 1;
2158     }
2159     s->bit_rate = get_bits(&s->gb, 18) * 400;
2160     if (check_marker(&s->gb, "in sequence header") == 0) {
2161         return AVERROR_INVALIDDATA;
2162     }
2163     s->width  = width;
2164     s->height = height;
2165
2166     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2167     skip_bits(&s->gb, 1);
2168
2169     /* get matrix */
2170     if (get_bits1(&s->gb)) {
2171         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2172     } else {
2173         for (i = 0; i < 64; i++) {
2174             j = s->idsp.idct_permutation[i];
2175             v = ff_mpeg1_default_intra_matrix[i];
2176             s->intra_matrix[j]        = v;
2177             s->chroma_intra_matrix[j] = v;
2178         }
2179     }
2180     if (get_bits1(&s->gb)) {
2181         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2182     } else {
2183         for (i = 0; i < 64; i++) {
2184             int j = s->idsp.idct_permutation[i];
2185             v = ff_mpeg1_default_non_intra_matrix[i];
2186             s->inter_matrix[j]        = v;
2187             s->chroma_inter_matrix[j] = v;
2188         }
2189     }
2190
2191     if (show_bits(&s->gb, 23) != 0) {
2192         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2193         return AVERROR_INVALIDDATA;
2194     }
2195
2196     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2197     s->progressive_sequence = 1;
2198     s->progressive_frame    = 1;
2199     s->picture_structure    = PICT_FRAME;
2200     s->first_field          = 0;
2201     s->frame_pred_frame_dct = 1;
2202     s->chroma_format        = 1;
2203     s->codec_id             =
2204     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2205     s->out_format           = FMT_MPEG1;
2206     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2207     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2208         s->low_delay = 1;
2209
2210     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2211         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d, aspect_ratio_info: %d \n",
2212                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2213
2214     return 0;
2215 }
2216
2217 static int vcr2_init_sequence(AVCodecContext *avctx)
2218 {
2219     Mpeg1Context *s1  = avctx->priv_data;
2220     MpegEncContext *s = &s1->mpeg_enc_ctx;
2221     int i, v, ret;
2222
2223     /* start new MPEG-1 context decoding */
2224     s->out_format = FMT_MPEG1;
2225     if (s1->mpeg_enc_ctx_allocated) {
2226         ff_mpv_common_end(s);
2227         s1->mpeg_enc_ctx_allocated = 0;
2228     }
2229     s->width            = avctx->coded_width;
2230     s->height           = avctx->coded_height;
2231     avctx->has_b_frames = 0; // true?
2232     s->low_delay        = 1;
2233
2234     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2235     setup_hwaccel_for_pixfmt(avctx);
2236
2237     ff_mpv_idct_init(s);
2238     if ((ret = ff_mpv_common_init(s)) < 0)
2239         return ret;
2240     s1->mpeg_enc_ctx_allocated = 1;
2241
2242     for (i = 0; i < 64; i++) {
2243         int j = s->idsp.idct_permutation[i];
2244         v = ff_mpeg1_default_intra_matrix[i];
2245         s->intra_matrix[j]        = v;
2246         s->chroma_intra_matrix[j] = v;
2247
2248         v = ff_mpeg1_default_non_intra_matrix[i];
2249         s->inter_matrix[j]        = v;
2250         s->chroma_inter_matrix[j] = v;
2251     }
2252
2253     s->progressive_sequence  = 1;
2254     s->progressive_frame     = 1;
2255     s->picture_structure     = PICT_FRAME;
2256     s->first_field           = 0;
2257     s->frame_pred_frame_dct  = 1;
2258     s->chroma_format         = 1;
2259     if (s->codec_tag == AV_RL32("BW10")) {
2260         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2261     } else {
2262         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2263         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2264     }
2265     s1->save_width           = s->width;
2266     s1->save_height          = s->height;
2267     s1->save_progressive_seq = s->progressive_sequence;
2268     return 0;
2269 }
2270
2271 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2272                               const uint8_t *p, int buf_size)
2273 {
2274     Mpeg1Context *s1 = avctx->priv_data;
2275
2276     if (buf_size >= 6 &&
2277         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2278         p[4] == 3 && (p[5] & 0x40)) {
2279         /* extract A53 Part 4 CC data */
2280         int cc_count = p[5] & 0x1f;
2281         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2282             av_freep(&s1->a53_caption);
2283             s1->a53_caption_size = cc_count * 3;
2284             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2285             if (s1->a53_caption)
2286                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2287         }
2288         return 1;
2289     } else if (buf_size >= 11 &&
2290                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2291         /* extract DVD CC data */
2292         int cc_count = 0;
2293         int i;
2294         // There is a caption count field in the data, but it is often
2295         // incorect.  So count the number of captions present.
2296         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2297             cc_count++;
2298         // Transform the DVD format into A53 Part 4 format
2299         if (cc_count > 0) {
2300             av_freep(&s1->a53_caption);
2301             s1->a53_caption_size = cc_count * 6;
2302             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2303             if (s1->a53_caption) {
2304                 uint8_t field1 = !!(p[4] & 0x80);
2305                 uint8_t *cap = s1->a53_caption;
2306                 p += 5;
2307                 for (i = 0; i < cc_count; i++) {
2308                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2309                     cap[1] = p[1];
2310                     cap[2] = p[2];
2311                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2312                     cap[4] = p[4];
2313                     cap[5] = p[5];
2314                     cap += 6;
2315                     p += 6;
2316                 }
2317             }
2318         }
2319         return 1;
2320     }
2321     return 0;
2322 }
2323
2324 static void mpeg_decode_user_data(AVCodecContext *avctx,
2325                                   const uint8_t *p, int buf_size)
2326 {
2327     Mpeg1Context *s = avctx->priv_data;
2328     const uint8_t *buf_end = p + buf_size;
2329     Mpeg1Context *s1 = avctx->priv_data;
2330
2331 #if 0
2332     int i;
2333     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2334         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2335     }
2336     av_log(avctx, AV_LOG_ERROR, "\n");
2337 #endif
2338
2339     if (buf_size > 29){
2340         int i;
2341         for(i=0; i<20; i++)
2342             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2343                 s->tmpgexs= 1;
2344             }
2345     }
2346     /* we parse the DTG active format information */
2347     if (buf_end - p >= 5 &&
2348         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2349         int flags = p[4];
2350         p += 5;
2351         if (flags & 0x80) {
2352             /* skip event id */
2353             p += 2;
2354         }
2355         if (flags & 0x40) {
2356             if (buf_end - p < 1)
2357                 return;
2358 #if FF_API_AFD
2359 FF_DISABLE_DEPRECATION_WARNINGS
2360             avctx->dtg_active_format = p[0] & 0x0f;
2361 FF_ENABLE_DEPRECATION_WARNINGS
2362 #endif /* FF_API_AFD */
2363             s1->has_afd = 1;
2364             s1->afd     = p[0] & 0x0f;
2365         }
2366     } else if (buf_end - p >= 6 &&
2367                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2368                p[4] == 0x03) { // S3D_video_format_length
2369         // the 0x7F mask ignores the reserved_bit value
2370         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2371
2372         if (S3D_video_format_type == 0x03 ||
2373             S3D_video_format_type == 0x04 ||
2374             S3D_video_format_type == 0x08 ||
2375             S3D_video_format_type == 0x23) {
2376
2377             s1->has_stereo3d = 1;
2378
2379             switch (S3D_video_format_type) {
2380             case 0x03:
2381                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2382                 break;
2383             case 0x04:
2384                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2385                 break;
2386             case 0x08:
2387                 s1->stereo3d.type = AV_STEREO3D_2D;
2388                 break;
2389             case 0x23:
2390                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2391                 break;
2392             }
2393         }
2394     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2395         return;
2396     }
2397 }
2398
2399 static void mpeg_decode_gop(AVCodecContext *avctx,
2400                             const uint8_t *buf, int buf_size)
2401 {
2402     Mpeg1Context *s1  = avctx->priv_data;
2403     MpegEncContext *s = &s1->mpeg_enc_ctx;
2404     int broken_link;
2405     int64_t tc;
2406
2407     init_get_bits(&s->gb, buf, buf_size * 8);
2408
2409     tc = avctx->timecode_frame_start = get_bits(&s->gb, 25);
2410
2411     s->closed_gop = get_bits1(&s->gb);
2412     /* broken_link indicate that after editing the
2413      * reference frames of the first B-Frames after GOP I-Frame
2414      * are missing (open gop) */
2415     broken_link = get_bits1(&s->gb);
2416
2417     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2418         char tcbuf[AV_TIMECODE_STR_SIZE];
2419         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2420         av_log(s->avctx, AV_LOG_DEBUG,
2421                "GOP (%s) closed_gop=%d broken_link=%d\n",
2422                tcbuf, s->closed_gop, broken_link);
2423     }
2424 }
2425
2426 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2427                          int *got_output, const uint8_t *buf, int buf_size)
2428 {
2429     Mpeg1Context *s = avctx->priv_data;
2430     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2431     const uint8_t *buf_ptr = buf;
2432     const uint8_t *buf_end = buf + buf_size;
2433     int ret, input_size;
2434     int last_code = 0, skip_frame = 0;
2435     int picture_start_code_seen = 0;
2436
2437     for (;;) {
2438         /* find next start code */
2439         uint32_t start_code = -1;
2440         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2441         if (start_code > 0x1ff) {
2442             if (!skip_frame) {
2443                 if (HAVE_THREADS &&
2444                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2445                     !avctx->hwaccel) {
2446                     int i;
2447                     av_assert0(avctx->thread_count > 1);
2448
2449                     avctx->execute(avctx, slice_decode_thread,
2450                                    &s2->thread_context[0], NULL,
2451                                    s->slice_count, sizeof(void *));
2452                     for (i = 0; i < s->slice_count; i++)
2453                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2454                 }
2455
2456                 if ((CONFIG_MPEG_VDPAU_DECODER || CONFIG_MPEG1_VDPAU_DECODER)
2457                     && uses_vdpau(avctx))
2458                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2459
2460                 ret = slice_end(avctx, picture);
2461                 if (ret < 0)
2462                     return ret;
2463                 else if (ret) {
2464                     // FIXME: merge with the stuff in mpeg_decode_slice
2465                     if (s2->last_picture_ptr || s2->low_delay)
2466                         *got_output = 1;
2467                 }
2468             }
2469             s2->pict_type = 0;
2470
2471             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2472                 return AVERROR_INVALIDDATA;
2473
2474             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2475         }
2476
2477         input_size = buf_end - buf_ptr;
2478
2479         if (avctx->debug & FF_DEBUG_STARTCODE)
2480             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2481                    start_code, buf_ptr - buf, input_size);
2482
2483         /* prepare data for next start code */
2484         switch (start_code) {
2485         case SEQ_START_CODE:
2486             if (last_code == 0) {
2487                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2488                 if (buf != avctx->extradata)
2489                     s->sync = 1;
2490             } else {
2491                 av_log(avctx, AV_LOG_ERROR,
2492                        "ignoring SEQ_START_CODE after %X\n", last_code);
2493                 if (avctx->err_recognition & AV_EF_EXPLODE)
2494                     return AVERROR_INVALIDDATA;
2495             }
2496             break;
2497
2498         case PICTURE_START_CODE:
2499             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2500                /* If it's a frame picture, there can't be more than one picture header.
2501                   Yet, it does happen and we need to handle it. */
2502                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2503                break;
2504             }
2505             picture_start_code_seen = 1;
2506
2507             if (s2->width <= 0 || s2->height <= 0) {
2508                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2509                        s2->width, s2->height);
2510                 return AVERROR_INVALIDDATA;
2511             }
2512
2513             if (s->tmpgexs){
2514                 s2->intra_dc_precision= 3;
2515                 s2->intra_matrix[0]= 1;
2516             }
2517             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2518                 !avctx->hwaccel && s->slice_count) {
2519                 int i;
2520
2521                 avctx->execute(avctx, slice_decode_thread,
2522                                s2->thread_context, NULL,
2523                                s->slice_count, sizeof(void *));
2524                 for (i = 0; i < s->slice_count; i++)
2525                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2526                 s->slice_count = 0;
2527             }
2528             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2529                 ret = mpeg_decode_postinit(avctx);
2530                 if (ret < 0) {
2531                     av_log(avctx, AV_LOG_ERROR,
2532                            "mpeg_decode_postinit() failure\n");
2533                     return ret;
2534                 }
2535
2536                 /* We have a complete image: we try to decompress it. */
2537                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2538                     s2->pict_type = 0;
2539                 s->first_slice = 1;
2540                 last_code      = PICTURE_START_CODE;
2541             } else {
2542                 av_log(avctx, AV_LOG_ERROR,
2543                        "ignoring pic after %X\n", last_code);
2544                 if (avctx->err_recognition & AV_EF_EXPLODE)
2545                     return AVERROR_INVALIDDATA;
2546             }
2547             break;
2548         case EXT_START_CODE:
2549             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2550
2551             switch (get_bits(&s2->gb, 4)) {
2552             case 0x1:
2553                 if (last_code == 0) {
2554                     mpeg_decode_sequence_extension(s);
2555                 } else {
2556                     av_log(avctx, AV_LOG_ERROR,
2557                            "ignoring seq ext after %X\n", last_code);
2558                     if (avctx->err_recognition & AV_EF_EXPLODE)
2559                         return AVERROR_INVALIDDATA;
2560                 }
2561                 break;
2562             case 0x2:
2563                 mpeg_decode_sequence_display_extension(s);
2564                 break;
2565             case 0x3:
2566                 mpeg_decode_quant_matrix_extension(s2);
2567                 break;
2568             case 0x7:
2569                 mpeg_decode_picture_display_extension(s);
2570                 break;
2571             case 0x8:
2572                 if (last_code == PICTURE_START_CODE) {
2573                     mpeg_decode_picture_coding_extension(s);
2574                 } else {
2575                     av_log(avctx, AV_LOG_ERROR,
2576                            "ignoring pic cod ext after %X\n", last_code);
2577                     if (avctx->err_recognition & AV_EF_EXPLODE)
2578                         return AVERROR_INVALIDDATA;
2579                 }
2580                 break;
2581             }
2582             break;
2583         case USER_START_CODE:
2584             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2585             break;
2586         case GOP_START_CODE:
2587             if (last_code == 0) {
2588                 s2->first_field = 0;
2589                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2590                 s->sync = 1;
2591             } else {
2592                 av_log(avctx, AV_LOG_ERROR,
2593                        "ignoring GOP_START_CODE after %X\n", last_code);
2594                 if (avctx->err_recognition & AV_EF_EXPLODE)
2595                     return AVERROR_INVALIDDATA;
2596             }
2597             break;
2598         default:
2599             if (start_code >= SLICE_MIN_START_CODE &&
2600                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2601                 if (s2->progressive_sequence && !s2->progressive_frame) {
2602                     s2->progressive_frame = 1;
2603                     av_log(s2->avctx, AV_LOG_ERROR,
2604                            "interlaced frame in progressive sequence, ignoring\n");
2605                 }
2606
2607                 if (s2->picture_structure == 0 ||
2608                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2609                     av_log(s2->avctx, AV_LOG_ERROR,
2610                            "picture_structure %d invalid, ignoring\n",
2611                            s2->picture_structure);
2612                     s2->picture_structure = PICT_FRAME;
2613                 }
2614
2615                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2616                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2617
2618                 if (s2->picture_structure == PICT_FRAME) {
2619                     s2->first_field = 0;
2620                     s2->v_edge_pos  = 16 * s2->mb_height;
2621                 } else {
2622                     s2->first_field ^= 1;
2623                     s2->v_edge_pos   = 8 * s2->mb_height;
2624                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2625                 }
2626             }
2627             if (start_code >= SLICE_MIN_START_CODE &&
2628                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2629                 const int field_pic = s2->picture_structure != PICT_FRAME;
2630                 int mb_y = start_code - SLICE_MIN_START_CODE;
2631                 last_code = SLICE_MIN_START_CODE;
2632                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2633                     mb_y += (*buf_ptr&0xE0)<<2;
2634
2635                 mb_y <<= field_pic;
2636                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2637                     mb_y++;
2638
2639                 if (buf_end - buf_ptr < 2) {
2640                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2641                     return AVERROR_INVALIDDATA;
2642                 }
2643
2644                 if (mb_y >= s2->mb_height) {
2645                     av_log(s2->avctx, AV_LOG_ERROR,
2646                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2647                     return AVERROR_INVALIDDATA;
2648                 }
2649
2650                 if (!s2->last_picture_ptr) {
2651                     /* Skip B-frames if we do not have reference frames and
2652                      * GOP is not closed. */
2653                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2654                         if (!s2->closed_gop) {
2655                             skip_frame = 1;
2656                             break;
2657                         }
2658                     }
2659                 }
2660                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2661                     s->sync = 1;
2662                 if (!s2->next_picture_ptr) {
2663                     /* Skip P-frames if we do not have a reference frame or
2664                      * we have an invalid header. */
2665                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2666                         skip_frame = 1;
2667                         break;
2668                     }
2669                 }
2670                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2671                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2672                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2673                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2674                     avctx->skip_frame >= AVDISCARD_ALL) {
2675                     skip_frame = 1;
2676                     break;
2677                 }
2678
2679                 if (!s->mpeg_enc_ctx_allocated)
2680                     break;
2681
2682                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2683                     if (mb_y < avctx->skip_top ||
2684                         mb_y >= s2->mb_height - avctx->skip_bottom)
2685                         break;
2686                 }
2687
2688                 if (!s2->pict_type) {
2689                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2690                     if (avctx->err_recognition & AV_EF_EXPLODE)
2691                         return AVERROR_INVALIDDATA;
2692                     break;
2693                 }
2694
2695                 if (s->first_slice) {
2696                     skip_frame     = 0;
2697                     s->first_slice = 0;
2698                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2699                         return ret;
2700                 }
2701                 if (!s2->current_picture_ptr) {
2702                     av_log(avctx, AV_LOG_ERROR,
2703                            "current_picture not initialized\n");
2704                     return AVERROR_INVALIDDATA;
2705                 }
2706
2707                 if (uses_vdpau(avctx)) {
2708                     s->slice_count++;
2709                     break;
2710                 }
2711
2712                 if (HAVE_THREADS &&
2713                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2714                     !avctx->hwaccel) {
2715                     int threshold = (s2->mb_height * s->slice_count +
2716                                      s2->slice_context_count / 2) /
2717                                     s2->slice_context_count;
2718                     av_assert0(avctx->thread_count > 1);
2719                     if (threshold <= mb_y) {
2720                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2721
2722                         thread_context->start_mb_y = mb_y;
2723                         thread_context->end_mb_y   = s2->mb_height;
2724                         if (s->slice_count) {
2725                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2726                             ret = ff_update_duplicate_context(thread_context, s2);
2727                             if (ret < 0)
2728                                 return ret;
2729                         }
2730                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2731                         s->slice_count++;
2732                     }
2733                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2734                 } else {
2735                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2736                     emms_c();
2737
2738                     if (ret < 0) {
2739                         if (avctx->err_recognition & AV_EF_EXPLODE)
2740                             return ret;
2741                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2742                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2743                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2744                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2745                     } else {
2746                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2747                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2748                                         ER_AC_END | ER_DC_END | ER_MV_END);
2749                     }
2750                 }
2751             }
2752             break;
2753         }
2754     }
2755 }
2756
2757 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2758                              int *got_output, AVPacket *avpkt)
2759 {
2760     const uint8_t *buf = avpkt->data;
2761     int ret;
2762     int buf_size = avpkt->size;
2763     Mpeg1Context *s = avctx->priv_data;
2764     AVFrame *picture = data;
2765     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2766
2767     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2768         /* special case for last picture */
2769         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2770             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2771             if (ret < 0)
2772                 return ret;
2773
2774             s2->next_picture_ptr = NULL;
2775
2776             *got_output = 1;
2777         }
2778         return buf_size;
2779     }
2780
2781     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2782         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2783                                            buf_size, NULL);
2784
2785         if (ff_combine_frame(&s2->parse_context, next,
2786                              (const uint8_t **) &buf, &buf_size) < 0)
2787             return buf_size;
2788     }
2789
2790     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2791     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2792                                            || s2->codec_tag == AV_RL32("BW10")
2793                                           ))
2794         vcr2_init_sequence(avctx);
2795
2796     s->slice_count = 0;
2797
2798     if (avctx->extradata && !s->extradata_decoded) {
2799         ret = decode_chunks(avctx, picture, got_output,
2800                             avctx->extradata, avctx->extradata_size);
2801         if (*got_output) {
2802             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2803             *got_output = 0;
2804         }
2805         s->extradata_decoded = 1;
2806         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2807             s2->current_picture_ptr = NULL;
2808             return ret;
2809         }
2810     }
2811
2812     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2813     if (ret<0 || *got_output)
2814         s2->current_picture_ptr = NULL;
2815
2816     return ret;
2817 }
2818
2819 static void flush(AVCodecContext *avctx)
2820 {
2821     Mpeg1Context *s = avctx->priv_data;
2822
2823     s->sync       = 0;
2824
2825     ff_mpeg_flush(avctx);
2826 }
2827
2828 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2829 {
2830     Mpeg1Context *s = avctx->priv_data;
2831
2832     if (s->mpeg_enc_ctx_allocated)
2833         ff_mpv_common_end(&s->mpeg_enc_ctx);
2834     av_freep(&s->a53_caption);
2835     return 0;
2836 }
2837
2838 static const AVProfile mpeg2_video_profiles[] = {
2839     { FF_PROFILE_MPEG2_422,          "4:2:2"              },
2840     { FF_PROFILE_MPEG2_HIGH,         "High"               },
2841     { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
2842     { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
2843     { FF_PROFILE_MPEG2_MAIN,         "Main"               },
2844     { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
2845     { FF_PROFILE_RESERVED,           "Reserved"           },
2846     { FF_PROFILE_RESERVED,           "Reserved"           },
2847     { FF_PROFILE_UNKNOWN                                  },
2848 };
2849
2850 AVCodec ff_mpeg1video_decoder = {
2851     .name                  = "mpeg1video",
2852     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2853     .type                  = AVMEDIA_TYPE_VIDEO,
2854     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2855     .priv_data_size        = sizeof(Mpeg1Context),
2856     .init                  = mpeg_decode_init,
2857     .close                 = mpeg_decode_end,
2858     .decode                = mpeg_decode_frame,
2859     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2860                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2861                              AV_CODEC_CAP_SLICE_THREADS,
2862     .flush                 = flush,
2863     .max_lowres            = 3,
2864     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2865 };
2866
2867 AVCodec ff_mpeg2video_decoder = {
2868     .name           = "mpeg2video",
2869     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2870     .type           = AVMEDIA_TYPE_VIDEO,
2871     .id             = AV_CODEC_ID_MPEG2VIDEO,
2872     .priv_data_size = sizeof(Mpeg1Context),
2873     .init           = mpeg_decode_init,
2874     .close          = mpeg_decode_end,
2875     .decode         = mpeg_decode_frame,
2876     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2877                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2878                       AV_CODEC_CAP_SLICE_THREADS,
2879     .flush          = flush,
2880     .max_lowres     = 3,
2881     .profiles       = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
2882 };
2883
2884 //legacy decoder
2885 AVCodec ff_mpegvideo_decoder = {
2886     .name           = "mpegvideo",
2887     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2888     .type           = AVMEDIA_TYPE_VIDEO,
2889     .id             = AV_CODEC_ID_MPEG2VIDEO,
2890     .priv_data_size = sizeof(Mpeg1Context),
2891     .init           = mpeg_decode_init,
2892     .close          = mpeg_decode_end,
2893     .decode         = mpeg_decode_frame,
2894     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2895     .flush          = flush,
2896     .max_lowres     = 3,
2897 };
2898
2899 #if FF_API_XVMC
2900 #if CONFIG_MPEG_XVMC_DECODER
2901 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
2902 {
2903     if (avctx->active_thread_type & FF_THREAD_SLICE)
2904         return -1;
2905     if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
2906         return -1;
2907     if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
2908         ff_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2909     }
2910     mpeg_decode_init(avctx);
2911
2912     avctx->pix_fmt           = AV_PIX_FMT_XVMC_MPEG2_IDCT;
2913     avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
2914
2915     return 0;
2916 }
2917
2918 AVCodec ff_mpeg_xvmc_decoder = {
2919     .name           = "mpegvideo_xvmc",
2920     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2921     .type           = AVMEDIA_TYPE_VIDEO,
2922     .id             = AV_CODEC_ID_MPEG2VIDEO_XVMC,
2923     .priv_data_size = sizeof(Mpeg1Context),
2924     .init           = mpeg_mc_decode_init,
2925     .close          = mpeg_decode_end,
2926     .decode         = mpeg_decode_frame,
2927     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2928                       AV_CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL |
2929                       AV_CODEC_CAP_DELAY,
2930     .flush          = flush,
2931 };
2932
2933 #endif
2934 #endif /* FF_API_XVMC */
2935
2936 #if CONFIG_MPEG_VDPAU_DECODER
2937 AVCodec ff_mpeg_vdpau_decoder = {
2938     .name           = "mpegvideo_vdpau",
2939     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2940     .type           = AVMEDIA_TYPE_VIDEO,
2941     .id             = AV_CODEC_ID_MPEG2VIDEO,
2942     .priv_data_size = sizeof(Mpeg1Context),
2943     .init           = mpeg_decode_init,
2944     .close          = mpeg_decode_end,
2945     .decode         = mpeg_decode_frame,
2946     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2947                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2948     .flush          = flush,
2949 };
2950 #endif
2951
2952 #if CONFIG_MPEG1_VDPAU_DECODER
2953 AVCodec ff_mpeg1_vdpau_decoder = {
2954     .name           = "mpeg1video_vdpau",
2955     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2956     .type           = AVMEDIA_TYPE_VIDEO,
2957     .id             = AV_CODEC_ID_MPEG1VIDEO,
2958     .priv_data_size = sizeof(Mpeg1Context),
2959     .init           = mpeg_decode_init,
2960     .close          = mpeg_decode_end,
2961     .decode         = mpeg_decode_frame,
2962     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2963                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2964     .flush          = flush,
2965 };
2966 #endif