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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 "profiles.h"
  48 #include "thread.h"
  49 #include "version.h"
  50 #include "vdpau_compat.h"
  51 #include "xvmc_internal.h"
  52
  53 typedef struct Mpeg1Context {
  54     MpegEncContext mpeg_enc_ctx;
  55     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
  56     int repeat_field;           /* true if we must repeat the field */
  57     AVPanScan pan_scan;         /* some temporary storage for the panscan */
  58     AVStereo3D stereo3d;
  59     int has_stereo3d;
  60     uint8_t *a53_caption;
  61     int a53_caption_size;
  62     uint8_t afd;
  63     int has_afd;
  64     int slice_count;
  65     AVRational save_aspect;
  66     int save_width, save_height, save_progressive_seq;
  67     AVRational frame_rate_ext;  /* MPEG-2 specific framerate modificator */
  68     int sync;                   /* Did we reach a sync point like a GOP/SEQ/KEYFrame? */
  69     int tmpgexs;
  70     int first_slice;
  71     int extradata_decoded;
  72 } Mpeg1Context;
  73
  74 #define MB_TYPE_ZERO_MV   0x20000000
  75
  76 static const uint32_t ptype2mb_type[7] = {
  77                     MB_TYPE_INTRA,
  78                     MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
  79                     MB_TYPE_L0,
  80                     MB_TYPE_L0 | MB_TYPE_CBP,
  81     MB_TYPE_QUANT | MB_TYPE_INTRA,
  82     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP | MB_TYPE_ZERO_MV | MB_TYPE_16x16,
  83     MB_TYPE_QUANT | MB_TYPE_L0 | MB_TYPE_CBP,
  84 };
  85
  86 static const uint32_t btype2mb_type[11] = {
  87                     MB_TYPE_INTRA,
  88                     MB_TYPE_L1,
  89                     MB_TYPE_L1   | MB_TYPE_CBP,
  90                     MB_TYPE_L0,
  91                     MB_TYPE_L0   | MB_TYPE_CBP,
  92                     MB_TYPE_L0L1,
  93                     MB_TYPE_L0L1 | MB_TYPE_CBP,
  94     MB_TYPE_QUANT | MB_TYPE_INTRA,
  95     MB_TYPE_QUANT | MB_TYPE_L1   | MB_TYPE_CBP,
  96     MB_TYPE_QUANT | MB_TYPE_L0   | MB_TYPE_CBP,
  97     MB_TYPE_QUANT | MB_TYPE_L0L1 | MB_TYPE_CBP,
  98 };
  99
 100 /* as H.263, but only 17 codes */
 101 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 102 {
 103     int code, sign, val, shift;
 104
 105     code = get_vlc2(&s->gb, ff_mv_vlc.table, MV_VLC_BITS, 2);
 106     if (code == 0)
 107         return pred;
 108     if (code < 0)
 109         return 0xffff;
 110
 111     sign  = get_bits1(&s->gb);
 112     shift = fcode - 1;
 113     val   = code;
 114     if (shift) {
 115         val  = (val - 1) << shift;
 116         val |= get_bits(&s->gb, shift);
 117         val++;
 118     }
 119     if (sign)
 120         val = -val;
 121     val += pred;
 122
 123     /* modulo decoding */
 124     return sign_extend(val, 5 + shift);
 125 }
 126
 127 #define check_scantable_index(ctx, x)                                         \
 128     do {                                                                      \
 129         if ((x) > 63) {                                                       \
 130             av_log(ctx->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n",     \
 131                    ctx->mb_x, ctx->mb_y);                                     \
 132             return AVERROR_INVALIDDATA;                                       \
 133         }                                                                     \
 134     } while (0)
 135
 136 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 137                                            int16_t *block, int n)
 138 {
 139     int level, dc, diff, i, j, run;
 140     int component;
 141     RLTable *rl                  = &ff_rl_mpeg1;
 142     uint8_t *const scantable     = s->intra_scantable.permutated;
 143     const uint16_t *quant_matrix = s->intra_matrix;
 144     const int qscale             = s->qscale;
 145
 146     /* DC coefficient */
 147     component = (n <= 3 ? 0 : n - 4 + 1);
 148     diff = decode_dc(&s->gb, component);
 149     if (diff >= 0xffff)
 150         return AVERROR_INVALIDDATA;
 151     dc  = s->last_dc[component];
 152     dc += diff;
 153     s->last_dc[component] = dc;
 154     block[0] = dc * quant_matrix[0];
 155     ff_tlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
 156     i = 0;
 157     {
 158         OPEN_READER(re, &s->gb);
 159         UPDATE_CACHE(re, &s->gb);
 160         if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 161             goto end;
 162
 163         /* now quantify & encode AC coefficients */
 164         for (;;) {
 165             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 166                        TEX_VLC_BITS, 2, 0);
 167
 168             if (level != 0) {
 169                 i += run;
 170                 check_scantable_index(s, i);
 171                 j = scantable[i];
 172                 level = (level * qscale * quant_matrix[j]) >> 4;
 173                 level = (level - 1) | 1;
 174                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 175                         SHOW_SBITS(re, &s->gb, 1);
 176                 SKIP_BITS(re, &s->gb, 1);
 177             } else {
 178                 /* escape */
 179                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 180                 LAST_SKIP_BITS(re, &s->gb, 6);
 181                 UPDATE_CACHE(re, &s->gb);
 182                 level = SHOW_SBITS(re, &s->gb, 8);
 183                 SKIP_BITS(re, &s->gb, 8);
 184                 if (level == -128) {
 185                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 186                     SKIP_BITS(re, &s->gb, 8);
 187                 } else if (level == 0) {
 188                     level = SHOW_UBITS(re, &s->gb, 8);
 189                     SKIP_BITS(re, &s->gb, 8);
 190                 }
 191                 i += run;
 192                 check_scantable_index(s, i);
 193                 j = scantable[i];
 194                 if (level < 0) {
 195                     level = -level;
 196                     level = (level * qscale * quant_matrix[j]) >> 4;
 197                     level = (level - 1) | 1;
 198                     level = -level;
 199                 } else {
 200                     level = (level * qscale * quant_matrix[j]) >> 4;
 201                     level = (level - 1) | 1;
 202                 }
 203             }
 204
 205             block[j] = level;
 206             if (((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 207                break;
 208
 209             UPDATE_CACHE(re, &s->gb);
 210         }
 211 end:
 212         LAST_SKIP_BITS(re, &s->gb, 2);
 213         CLOSE_READER(re, &s->gb);
 214     }
 215     s->block_last_index[n] = i;
 216     return 0;
 217 }
 218
 219 int ff_mpeg1_decode_block_intra(MpegEncContext *s, int16_t *block, int n)
 220 {
 221     return mpeg1_decode_block_intra(s, block, n);
 222 }
 223
 224 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 225                                            int16_t *block, int n)
 226 {
 227     int level, i, j, run;
 228     RLTable *rl                  = &ff_rl_mpeg1;
 229     uint8_t *const scantable     = s->intra_scantable.permutated;
 230     const uint16_t *quant_matrix = s->inter_matrix;
 231     const int qscale             = s->qscale;
 232
 233     {
 234         OPEN_READER(re, &s->gb);
 235         i = -1;
 236         // special case for first coefficient, no need to add second VLC table
 237         UPDATE_CACHE(re, &s->gb);
 238         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 239             level = (3 * qscale * quant_matrix[0]) >> 5;
 240             level = (level - 1) | 1;
 241             if (GET_CACHE(re, &s->gb) & 0x40000000)
 242                 level = -level;
 243             block[0] = level;
 244             i++;
 245             SKIP_BITS(re, &s->gb, 2);
 246             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 247                 goto end;
 248         }
 249         /* now quantify & encode AC coefficients */
 250         for (;;) {
 251             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 252                        TEX_VLC_BITS, 2, 0);
 253
 254             if (level != 0) {
 255                 i += run;
 256                 check_scantable_index(s, i);
 257                 j = scantable[i];
 258                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 259                 level = (level - 1) | 1;
 260                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 261                         SHOW_SBITS(re, &s->gb, 1);
 262                 SKIP_BITS(re, &s->gb, 1);
 263             } else {
 264                 /* escape */
 265                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 266                 LAST_SKIP_BITS(re, &s->gb, 6);
 267                 UPDATE_CACHE(re, &s->gb);
 268                 level = SHOW_SBITS(re, &s->gb, 8);
 269                 SKIP_BITS(re, &s->gb, 8);
 270                 if (level == -128) {
 271                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 272                     SKIP_BITS(re, &s->gb, 8);
 273                 } else if (level == 0) {
 274                     level = SHOW_UBITS(re, &s->gb, 8);
 275                     SKIP_BITS(re, &s->gb, 8);
 276                 }
 277                 i += run;
 278                 check_scantable_index(s, i);
 279                 j = scantable[i];
 280                 if (level < 0) {
 281                     level = -level;
 282                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 283                     level = (level - 1) | 1;
 284                     level = -level;
 285                 } else {
 286                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 287                     level = (level - 1) | 1;
 288                 }
 289             }
 290
 291             block[j] = level;
 292             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 293                 break;
 294             UPDATE_CACHE(re, &s->gb);
 295         }
 296 end:
 297         LAST_SKIP_BITS(re, &s->gb, 2);
 298         CLOSE_READER(re, &s->gb);
 299     }
 300     s->block_last_index[n] = i;
 301     return 0;
 302 }
 303
 304 /**
 305  * Note: this function can read out of range and crash for corrupt streams.
 306  * Changing this would eat up any speed benefits it has.
 307  * Do not use "fast" flag if you need the code to be robust.
 308  */
 309 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s,
 310                                                 int16_t *block, int n)
 311 {
 312     int level, i, j, run;
 313     RLTable *rl              = &ff_rl_mpeg1;
 314     uint8_t *const scantable = s->intra_scantable.permutated;
 315     const int qscale         = s->qscale;
 316
 317     {
 318         OPEN_READER(re, &s->gb);
 319         i = -1;
 320         // Special case for first coefficient, no need to add second VLC table.
 321         UPDATE_CACHE(re, &s->gb);
 322         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 323             level = (3 * qscale) >> 1;
 324             level = (level - 1) | 1;
 325             if (GET_CACHE(re, &s->gb) & 0x40000000)
 326                 level = -level;
 327             block[0] = level;
 328             i++;
 329             SKIP_BITS(re, &s->gb, 2);
 330             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 331                 goto end;
 332         }
 333
 334         /* now quantify & encode AC coefficients */
 335         for (;;) {
 336             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 337                        TEX_VLC_BITS, 2, 0);
 338
 339             if (level != 0) {
 340                 i += run;
 341                 check_scantable_index(s, i);
 342                 j = scantable[i];
 343                 level = ((level * 2 + 1) * qscale) >> 1;
 344                 level = (level - 1) | 1;
 345                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 346                         SHOW_SBITS(re, &s->gb, 1);
 347                 SKIP_BITS(re, &s->gb, 1);
 348             } else {
 349                 /* escape */
 350                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 351                 LAST_SKIP_BITS(re, &s->gb, 6);
 352                 UPDATE_CACHE(re, &s->gb);
 353                 level = SHOW_SBITS(re, &s->gb, 8);
 354                 SKIP_BITS(re, &s->gb, 8);
 355                 if (level == -128) {
 356                     level = SHOW_UBITS(re, &s->gb, 8) - 256;
 357                     SKIP_BITS(re, &s->gb, 8);
 358                 } else if (level == 0) {
 359                     level = SHOW_UBITS(re, &s->gb, 8);
 360                     SKIP_BITS(re, &s->gb, 8);
 361                 }
 362                 i += run;
 363                 check_scantable_index(s, i);
 364                 j = scantable[i];
 365                 if (level < 0) {
 366                     level = -level;
 367                     level = ((level * 2 + 1) * qscale) >> 1;
 368                     level = (level - 1) | 1;
 369                     level = -level;
 370                 } else {
 371                     level = ((level * 2 + 1) * qscale) >> 1;
 372                     level = (level - 1) | 1;
 373                 }
 374             }
 375
 376             block[j] = level;
 377             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 378                 break;
 379             UPDATE_CACHE(re, &s->gb);
 380         }
 381 end:
 382         LAST_SKIP_BITS(re, &s->gb, 2);
 383         CLOSE_READER(re, &s->gb);
 384     }
 385     s->block_last_index[n] = i;
 386     return 0;
 387 }
 388
 389 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 390                                                int16_t *block, int n)
 391 {
 392     int level, i, j, run;
 393     RLTable *rl = &ff_rl_mpeg1;
 394     uint8_t *const scantable = s->intra_scantable.permutated;
 395     const uint16_t *quant_matrix;
 396     const int qscale = s->qscale;
 397     int mismatch;
 398
 399     mismatch = 1;
 400
 401     {
 402         OPEN_READER(re, &s->gb);
 403         i = -1;
 404         if (n < 4)
 405             quant_matrix = s->inter_matrix;
 406         else
 407             quant_matrix = s->chroma_inter_matrix;
 408
 409         // Special case for first coefficient, no need to add second VLC table.
 410         UPDATE_CACHE(re, &s->gb);
 411         if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 412             level = (3 * qscale * quant_matrix[0]) >> 5;
 413             if (GET_CACHE(re, &s->gb) & 0x40000000)
 414                 level = -level;
 415             block[0]  = level;
 416             mismatch ^= level;
 417             i++;
 418             SKIP_BITS(re, &s->gb, 2);
 419             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 420                 goto end;
 421         }
 422
 423         /* now quantify & encode AC coefficients */
 424         for (;;) {
 425             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 426                        TEX_VLC_BITS, 2, 0);
 427
 428             if (level != 0) {
 429                 i += run;
 430                 check_scantable_index(s, i);
 431                 j = scantable[i];
 432                 level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 433                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 434                         SHOW_SBITS(re, &s->gb, 1);
 435                 SKIP_BITS(re, &s->gb, 1);
 436             } else {
 437                 /* escape */
 438                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 439                 LAST_SKIP_BITS(re, &s->gb, 6);
 440                 UPDATE_CACHE(re, &s->gb);
 441                 level = SHOW_SBITS(re, &s->gb, 12);
 442                 SKIP_BITS(re, &s->gb, 12);
 443
 444                 i += run;
 445                 check_scantable_index(s, i);
 446                 j = scantable[i];
 447                 if (level < 0) {
 448                     level = ((-level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 449                     level = -level;
 450                 } else {
 451                     level = ((level * 2 + 1) * qscale * quant_matrix[j]) >> 5;
 452                 }
 453             }
 454
 455             mismatch ^= level;
 456             block[j]  = level;
 457             if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 458                 break;
 459             UPDATE_CACHE(re, &s->gb);
 460         }
 461 end:
 462         LAST_SKIP_BITS(re, &s->gb, 2);
 463         CLOSE_READER(re, &s->gb);
 464     }
 465     block[63] ^= (mismatch & 1);
 466
 467     s->block_last_index[n] = i;
 468     return 0;
 469 }
 470
 471 /**
 472  * Note: this function can read out of range and crash for corrupt streams.
 473  * Changing this would eat up any speed benefits it has.
 474  * Do not use "fast" flag if you need the code to be robust.
 475  */
 476 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 477                                                     int16_t *block, int n)
 478 {
 479     int level, i, j, run;
 480     RLTable *rl              = &ff_rl_mpeg1;
 481     uint8_t *const scantable = s->intra_scantable.permutated;
 482     const int qscale         = s->qscale;
 483     OPEN_READER(re, &s->gb);
 484     i = -1;
 485
 486     // special case for first coefficient, no need to add second VLC table
 487     UPDATE_CACHE(re, &s->gb);
 488     if (((int32_t) GET_CACHE(re, &s->gb)) < 0) {
 489         level = (3 * qscale) >> 1;
 490         if (GET_CACHE(re, &s->gb) & 0x40000000)
 491             level = -level;
 492         block[0] = level;
 493         i++;
 494         SKIP_BITS(re, &s->gb, 2);
 495         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF)
 496             goto end;
 497     }
 498
 499     /* now quantify & encode AC coefficients */
 500     for (;;) {
 501         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 502
 503         if (level != 0) {
 504             i += run;
 505             j = scantable[i];
 506             level = ((level * 2 + 1) * qscale) >> 1;
 507             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 508                     SHOW_SBITS(re, &s->gb, 1);
 509             SKIP_BITS(re, &s->gb, 1);
 510         } else {
 511             /* escape */
 512             run = SHOW_UBITS(re, &s->gb, 6) + 1;
 513             LAST_SKIP_BITS(re, &s->gb, 6);
 514             UPDATE_CACHE(re, &s->gb);
 515             level = SHOW_SBITS(re, &s->gb, 12);
 516             SKIP_BITS(re, &s->gb, 12);
 517
 518             i += run;
 519             j = scantable[i];
 520             if (level < 0) {
 521                 level = ((-level * 2 + 1) * qscale) >> 1;
 522                 level = -level;
 523             } else {
 524                 level = ((level * 2 + 1) * qscale) >> 1;
 525             }
 526         }
 527
 528         block[j] = level;
 529         if (((int32_t) GET_CACHE(re, &s->gb)) <= (int32_t) 0xBFFFFFFF || i > 63)
 530             break;
 531
 532         UPDATE_CACHE(re, &s->gb);
 533     }
 534 end:
 535     LAST_SKIP_BITS(re, &s->gb, 2);
 536     CLOSE_READER(re, &s->gb);
 537     s->block_last_index[n] = i;
 538     return 0;
 539 }
 540
 541 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
 542                                            int16_t *block, int n)
 543 {
 544     int level, dc, diff, i, j, run;
 545     int component;
 546     RLTable *rl;
 547     uint8_t *const scantable = s->intra_scantable.permutated;
 548     const uint16_t *quant_matrix;
 549     const int qscale = s->qscale;
 550     int mismatch;
 551
 552     /* DC coefficient */
 553     if (n < 4) {
 554         quant_matrix = s->intra_matrix;
 555         component    = 0;
 556     } else {
 557         quant_matrix = s->chroma_intra_matrix;
 558         component    = (n & 1) + 1;
 559     }
 560     diff = decode_dc(&s->gb, component);
 561     if (diff >= 0xffff)
 562         return AVERROR_INVALIDDATA;
 563     dc  = s->last_dc[component];
 564     dc += diff;
 565     s->last_dc[component] = dc;
 566     block[0] = dc << (3 - s->intra_dc_precision);
 567     ff_tlog(s->avctx, "dc=%d\n", block[0]);
 568     mismatch = block[0] ^ 1;
 569     i = 0;
 570     if (s->intra_vlc_format)
 571         rl = &ff_rl_mpeg2;
 572     else
 573         rl = &ff_rl_mpeg1;
 574
 575     {
 576         OPEN_READER(re, &s->gb);
 577         /* now quantify & encode AC coefficients */
 578         for (;;) {
 579             UPDATE_CACHE(re, &s->gb);
 580             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 581                        TEX_VLC_BITS, 2, 0);
 582
 583             if (level == 127) {
 584                 break;
 585             } else if (level != 0) {
 586                 i += run;
 587                 check_scantable_index(s, i);
 588                 j = scantable[i];
 589                 level = (level * qscale * quant_matrix[j]) >> 4;
 590                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 591                         SHOW_SBITS(re, &s->gb, 1);
 592                 LAST_SKIP_BITS(re, &s->gb, 1);
 593             } else {
 594                 /* escape */
 595                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 596                 LAST_SKIP_BITS(re, &s->gb, 6);
 597                 UPDATE_CACHE(re, &s->gb);
 598                 level = SHOW_SBITS(re, &s->gb, 12);
 599                 SKIP_BITS(re, &s->gb, 12);
 600                 i += run;
 601                 check_scantable_index(s, i);
 602                 j = scantable[i];
 603                 if (level < 0) {
 604                     level = (-level * qscale * quant_matrix[j]) >> 4;
 605                     level = -level;
 606                 } else {
 607                     level = (level * qscale * quant_matrix[j]) >> 4;
 608                 }
 609             }
 610
 611             mismatch ^= level;
 612             block[j]  = level;
 613         }
 614         CLOSE_READER(re, &s->gb);
 615     }
 616     block[63] ^= mismatch & 1;
 617
 618     s->block_last_index[n] = i;
 619     return 0;
 620 }
 621
 622 /**
 623  * Note: this function can read out of range and crash for corrupt streams.
 624  * Changing this would eat up any speed benefits it has.
 625  * Do not use "fast" flag if you need the code to be robust.
 626  */
 627 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
 628                                                 int16_t *block, int n)
 629 {
 630     int level, dc, diff, i, j, run;
 631     int component;
 632     RLTable *rl;
 633     uint8_t *const scantable = s->intra_scantable.permutated;
 634     const uint16_t *quant_matrix;
 635     const int qscale = s->qscale;
 636
 637     /* DC coefficient */
 638     if (n < 4) {
 639         quant_matrix = s->intra_matrix;
 640         component    = 0;
 641     } else {
 642         quant_matrix = s->chroma_intra_matrix;
 643         component    = (n & 1) + 1;
 644     }
 645     diff = decode_dc(&s->gb, component);
 646     if (diff >= 0xffff)
 647         return AVERROR_INVALIDDATA;
 648     dc = s->last_dc[component];
 649     dc += diff;
 650     s->last_dc[component] = dc;
 651     block[0] = dc << (3 - s->intra_dc_precision);
 652     i = 0;
 653     if (s->intra_vlc_format)
 654         rl = &ff_rl_mpeg2;
 655     else
 656         rl = &ff_rl_mpeg1;
 657
 658     {
 659         OPEN_READER(re, &s->gb);
 660         /* now quantify & encode AC coefficients */
 661         for (;;) {
 662             UPDATE_CACHE(re, &s->gb);
 663             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0],
 664                        TEX_VLC_BITS, 2, 0);
 665
 666             if (level >= 64 || i > 63) {
 667                 break;
 668             } else if (level != 0) {
 669                 i += run;
 670                 j = scantable[i];
 671                 level = (level * qscale * quant_matrix[j]) >> 4;
 672                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) -
 673                         SHOW_SBITS(re, &s->gb, 1);
 674                 LAST_SKIP_BITS(re, &s->gb, 1);
 675             } else {
 676                 /* escape */
 677                 run = SHOW_UBITS(re, &s->gb, 6) + 1;
 678                 LAST_SKIP_BITS(re, &s->gb, 6);
 679                 UPDATE_CACHE(re, &s->gb);
 680                 level = SHOW_SBITS(re, &s->gb, 12);
 681                 SKIP_BITS(re, &s->gb, 12);
 682                 i += run;
 683                 j = scantable[i];
 684                 if (level < 0) {
 685                     level = (-level * qscale * quant_matrix[j]) >> 4;
 686                     level = -level;
 687                 } else {
 688                     level = (level * qscale * quant_matrix[j]) >> 4;
 689                 }
 690             }
 691
 692             block[j] = level;
 693         }
 694         CLOSE_READER(re, &s->gb);
 695     }
 696
 697     s->block_last_index[n] = i;
 698     return 0;
 699 }
 700
 701 /******************************************/
 702 /* decoding */
 703
 704 static inline int get_dmv(MpegEncContext *s)
 705 {
 706     if (get_bits1(&s->gb))
 707         return 1 - (get_bits1(&s->gb) << 1);
 708     else
 709         return 0;
 710 }
 711
 712 static inline int get_qscale(MpegEncContext *s)
 713 {
 714     int qscale = get_bits(&s->gb, 5);
 715     if (s->q_scale_type)
 716         return ff_mpeg2_non_linear_qscale[qscale];
 717     else
 718         return qscale << 1;
 719 }
 720
 721
 722 /* motion type (for MPEG-2) */
 723 #define MT_FIELD 1
 724 #define MT_FRAME 2
 725 #define MT_16X8  2
 726 #define MT_DMV   3
 727
 728 static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
 729 {
 730     int i, j, k, cbp, val, mb_type, motion_type;
 731     const int mb_block_count = 4 + (1 << s->chroma_format);
 732     int ret;
 733
 734     ff_tlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 735
 736     av_assert2(s->mb_skipped == 0);
 737
 738     if (s->mb_skip_run-- != 0) {
 739         if (s->pict_type == AV_PICTURE_TYPE_P) {
 740             s->mb_skipped = 1;
 741             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
 742                 MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 743         } else {
 744             int mb_type;
 745
 746             if (s->mb_x)
 747                 mb_type = s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride - 1];
 748             else
 749                 // FIXME not sure if this is allowed in MPEG at all
 750                 mb_type = s->current_picture.mb_type[s->mb_width + (s->mb_y - 1) * s->mb_stride - 1];
 751             if (IS_INTRA(mb_type)) {
 752                 av_log(s->avctx, AV_LOG_ERROR, "skip with previntra\n");
 753                 return AVERROR_INVALIDDATA;
 754             }
 755             s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] =
 756                 mb_type | MB_TYPE_SKIP;
 757
 758             if ((s->mv[0][0][0] | s->mv[0][0][1] | s->mv[1][0][0] | s->mv[1][0][1]) == 0)
 759                 s->mb_skipped = 1;
 760         }
 761
 762         return 0;
 763     }
 764
 765     switch (s->pict_type) {
 766     default:
 767     case AV_PICTURE_TYPE_I:
 768         if (get_bits1(&s->gb) == 0) {
 769             if (get_bits1(&s->gb) == 0) {
 770                 av_log(s->avctx, AV_LOG_ERROR,
 771                        "invalid mb type in I Frame at %d %d\n",
 772                        s->mb_x, s->mb_y);
 773                 return AVERROR_INVALIDDATA;
 774             }
 775             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 776         } else {
 777             mb_type = MB_TYPE_INTRA;
 778         }
 779         break;
 780     case AV_PICTURE_TYPE_P:
 781         mb_type = get_vlc2(&s->gb, ff_mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 782         if (mb_type < 0) {
 783             av_log(s->avctx, AV_LOG_ERROR,
 784                    "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 785             return AVERROR_INVALIDDATA;
 786         }
 787         mb_type = ptype2mb_type[mb_type];
 788         break;
 789     case AV_PICTURE_TYPE_B:
 790         mb_type = get_vlc2(&s->gb, ff_mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 791         if (mb_type < 0) {
 792             av_log(s->avctx, AV_LOG_ERROR,
 793                    "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 794             return AVERROR_INVALIDDATA;
 795         }
 796         mb_type = btype2mb_type[mb_type];
 797         break;
 798     }
 799     ff_tlog(s->avctx, "mb_type=%x\n", mb_type);
 800 //    motion_type = 0; /* avoid warning */
 801     if (IS_INTRA(mb_type)) {
 802         s->bdsp.clear_blocks(s->block[0]);
 803
 804         if (!s->chroma_y_shift)
 805             s->bdsp.clear_blocks(s->block[6]);
 806
 807         /* compute DCT type */
 808         // FIXME: add an interlaced_dct coded var?
 809         if (s->picture_structure == PICT_FRAME &&
 810             !s->frame_pred_frame_dct)
 811             s->interlaced_dct = get_bits1(&s->gb);
 812
 813         if (IS_QUANT(mb_type))
 814             s->qscale = get_qscale(s);
 815
 816         if (s->concealment_motion_vectors) {
 817             /* just parse them */
 818             if (s->picture_structure != PICT_FRAME)
 819                 skip_bits1(&s->gb);  /* field select */
 820
 821             s->mv[0][0][0]      =
 822             s->last_mv[0][0][0] =
 823             s->last_mv[0][1][0] = mpeg_decode_motion(s, s->mpeg_f_code[0][0],
 824                                                      s->last_mv[0][0][0]);
 825             s->mv[0][0][1]      =
 826             s->last_mv[0][0][1] =
 827             s->last_mv[0][1][1] = mpeg_decode_motion(s, s->mpeg_f_code[0][1],
 828                                                      s->last_mv[0][0][1]);
 829
 830             check_marker(&s->gb, "after concealment_motion_vectors");
 831         } else {
 832             /* reset mv prediction */
 833             memset(s->last_mv, 0, sizeof(s->last_mv));
 834         }
 835         s->mb_intra = 1;
 836         // if 1, we memcpy blocks in xvmcvideo
 837         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
 838             ff_xvmc_pack_pblocks(s, -1); // inter are always full blocks
 839
 840         if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
 841             if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
 842                 for (i = 0; i < 6; i++)
 843                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 844             } else {
 845                 for (i = 0; i < mb_block_count; i++)
 846                     if ((ret = mpeg2_decode_block_intra(s, *s->pblocks[i], i)) < 0)
 847                         return ret;
 848             }
 849         } else {
 850             for (i = 0; i < 6; i++)
 851                 if ((ret = mpeg1_decode_block_intra(s, *s->pblocks[i], i)) < 0)
 852                     return ret;
 853         }
 854     } else {
 855         if (mb_type & MB_TYPE_ZERO_MV) {
 856             av_assert2(mb_type & MB_TYPE_CBP);
 857
 858             s->mv_dir = MV_DIR_FORWARD;
 859             if (s->picture_structure == PICT_FRAME) {
 860                 if (s->picture_structure == PICT_FRAME
 861                     && !s->frame_pred_frame_dct)
 862                     s->interlaced_dct = get_bits1(&s->gb);
 863                 s->mv_type = MV_TYPE_16X16;
 864             } else {
 865                 s->mv_type            = MV_TYPE_FIELD;
 866                 mb_type              |= MB_TYPE_INTERLACED;
 867                 s->field_select[0][0] = s->picture_structure - 1;
 868             }
 869
 870             if (IS_QUANT(mb_type))
 871                 s->qscale = get_qscale(s);
 872
 873             s->last_mv[0][0][0] = 0;
 874             s->last_mv[0][0][1] = 0;
 875             s->last_mv[0][1][0] = 0;
 876             s->last_mv[0][1][1] = 0;
 877             s->mv[0][0][0]      = 0;
 878             s->mv[0][0][1]      = 0;
 879         } else {
 880             av_assert2(mb_type & MB_TYPE_L0L1);
 881             // FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 882             /* get additional motion vector type */
 883             if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct) {
 884                 motion_type = MT_FRAME;
 885             } else {
 886                 motion_type = get_bits(&s->gb, 2);
 887                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 888                     s->interlaced_dct = get_bits1(&s->gb);
 889             }
 890
 891             if (IS_QUANT(mb_type))
 892                 s->qscale = get_qscale(s);
 893
 894             /* motion vectors */
 895             s->mv_dir = (mb_type >> 13) & 3;
 896             ff_tlog(s->avctx, "motion_type=%d\n", motion_type);
 897             switch (motion_type) {
 898             case MT_FRAME: /* or MT_16X8 */
 899                 if (s->picture_structure == PICT_FRAME) {
 900                     mb_type   |= MB_TYPE_16x16;
 901                     s->mv_type = MV_TYPE_16X16;
 902                     for (i = 0; i < 2; i++) {
 903                         if (USES_LIST(mb_type, i)) {
 904                             /* MT_FRAME */
 905                             s->mv[i][0][0]      =
 906                             s->last_mv[i][0][0] =
 907                             s->last_mv[i][1][0] =
 908                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 909                                                    s->last_mv[i][0][0]);
 910                             s->mv[i][0][1]      =
 911                             s->last_mv[i][0][1] =
 912                             s->last_mv[i][1][1] =
 913                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 914                                                    s->last_mv[i][0][1]);
 915                             /* full_pel: only for MPEG-1 */
 916                             if (s->full_pel[i]) {
 917                                 s->mv[i][0][0] <<= 1;
 918                                 s->mv[i][0][1] <<= 1;
 919                             }
 920                         }
 921                     }
 922                 } else {
 923                     mb_type   |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 924                     s->mv_type = MV_TYPE_16X8;
 925                     for (i = 0; i < 2; i++) {
 926                         if (USES_LIST(mb_type, i)) {
 927                             /* MT_16X8 */
 928                             for (j = 0; j < 2; j++) {
 929                                 s->field_select[i][j] = get_bits1(&s->gb);
 930                                 for (k = 0; k < 2; k++) {
 931                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 932                                                              s->last_mv[i][j][k]);
 933                                     s->last_mv[i][j][k] = val;
 934                                     s->mv[i][j][k]      = val;
 935                                 }
 936                             }
 937                         }
 938                     }
 939                 }
 940                 break;
 941             case MT_FIELD:
 942                 s->mv_type = MV_TYPE_FIELD;
 943                 if (s->picture_structure == PICT_FRAME) {
 944                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 945                     for (i = 0; i < 2; i++) {
 946                         if (USES_LIST(mb_type, i)) {
 947                             for (j = 0; j < 2; j++) {
 948                                 s->field_select[i][j] = get_bits1(&s->gb);
 949                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 950                                                          s->last_mv[i][j][0]);
 951                                 s->last_mv[i][j][0] = val;
 952                                 s->mv[i][j][0]      = val;
 953                                 ff_tlog(s->avctx, "fmx=%d\n", val);
 954                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 955                                                          s->last_mv[i][j][1] >> 1);
 956                                 s->last_mv[i][j][1] = 2 * val;
 957                                 s->mv[i][j][1]      = val;
 958                                 ff_tlog(s->avctx, "fmy=%d\n", val);
 959                             }
 960                         }
 961                     }
 962                 } else {
 963                     av_assert0(!s->progressive_sequence);
 964                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 965                     for (i = 0; i < 2; i++) {
 966                         if (USES_LIST(mb_type, i)) {
 967                             s->field_select[i][0] = get_bits1(&s->gb);
 968                             for (k = 0; k < 2; k++) {
 969                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 970                                                          s->last_mv[i][0][k]);
 971                                 s->last_mv[i][0][k] = val;
 972                                 s->last_mv[i][1][k] = val;
 973                                 s->mv[i][0][k]      = val;
 974                             }
 975                         }
 976                     }
 977                 }
 978                 break;
 979             case MT_DMV:
 980                 if (s->progressive_sequence){
 981                     av_log(s->avctx, AV_LOG_ERROR, "MT_DMV in progressive_sequence\n");
 982                     return AVERROR_INVALIDDATA;
 983                 }
 984                 s->mv_type = MV_TYPE_DMV;
 985                 for (i = 0; i < 2; i++) {
 986                     if (USES_LIST(mb_type, i)) {
 987                         int dmx, dmy, mx, my, m;
 988                         const int my_shift = s->picture_structure == PICT_FRAME;
 989
 990                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 991                                                 s->last_mv[i][0][0]);
 992                         s->last_mv[i][0][0] = mx;
 993                         s->last_mv[i][1][0] = mx;
 994                         dmx = get_dmv(s);
 995                         my  = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 996                                                  s->last_mv[i][0][1] >> my_shift);
 997                         dmy = get_dmv(s);
 998
 999
1000                         s->last_mv[i][0][1] = my << my_shift;
1001                         s->last_mv[i][1][1] = my << my_shift;
1002
1003                         s->mv[i][0][0] = mx;
1004                         s->mv[i][0][1] = my;
1005                         s->mv[i][1][0] = mx; // not used
1006                         s->mv[i][1][1] = my; // not used
1007
1008                         if (s->picture_structure == PICT_FRAME) {
1009                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
1010
1011                             // m = 1 + 2 * s->top_field_first;
1012                             m = s->top_field_first ? 1 : 3;
1013
1014                             /* top -> top pred */
1015                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1016                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
1017                             m = 4 - m;
1018                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
1019                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
1020                         } else {
1021                             mb_type |= MB_TYPE_16x16;
1022
1023                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
1024                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
1025                             if (s->picture_structure == PICT_TOP_FIELD)
1026                                 s->mv[i][2][1]--;
1027                             else
1028                                 s->mv[i][2][1]++;
1029                         }
1030                     }
1031                 }
1032                 break;
1033             default:
1034                 av_log(s->avctx, AV_LOG_ERROR,
1035                        "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
1036                 return AVERROR_INVALIDDATA;
1037             }
1038         }
1039
1040         s->mb_intra = 0;
1041         if (HAS_CBP(mb_type)) {
1042             s->bdsp.clear_blocks(s->block[0]);
1043
1044             cbp = get_vlc2(&s->gb, ff_mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
1045             if (mb_block_count > 6) {
1046                 cbp <<= mb_block_count - 6;
1047                 cbp  |= get_bits(&s->gb, mb_block_count - 6);
1048                 s->bdsp.clear_blocks(s->block[6]);
1049             }
1050             if (cbp <= 0) {
1051                 av_log(s->avctx, AV_LOG_ERROR,
1052                        "invalid cbp %d at %d %d\n", cbp, s->mb_x, s->mb_y);
1053                 return AVERROR_INVALIDDATA;
1054             }
1055
1056             // if 1, we memcpy blocks in xvmcvideo
1057             if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1058                 ff_xvmc_pack_pblocks(s, cbp);
1059
1060             if (s->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
1061                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1062                     for (i = 0; i < 6; i++) {
1063                         if (cbp & 32)
1064                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
1065                         else
1066                             s->block_last_index[i] = -1;
1067                         cbp += cbp;
1068                     }
1069                 } else {
1070                     cbp <<= 12 - mb_block_count;
1071
1072                     for (i = 0; i < mb_block_count; i++) {
1073                         if (cbp & (1 << 11)) {
1074                             if ((ret = mpeg2_decode_block_non_intra(s, *s->pblocks[i], i)) < 0)
1075                                 return ret;
1076                         } else {
1077                             s->block_last_index[i] = -1;
1078                         }
1079                         cbp += cbp;
1080                     }
1081                 }
1082             } else {
1083                 if (s->avctx->flags2 & AV_CODEC_FLAG2_FAST) {
1084                     for (i = 0; i < 6; i++) {
1085                         if (cbp & 32)
1086                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
1087                         else
1088                             s->block_last_index[i] = -1;
1089                         cbp += cbp;
1090                     }
1091                 } else {
1092                     for (i = 0; i < 6; i++) {
1093                         if (cbp & 32) {
1094                             if ((ret = mpeg1_decode_block_inter(s, *s->pblocks[i], i)) < 0)
1095                                 return ret;
1096                         } else {
1097                             s->block_last_index[i] = -1;
1098                         }
1099                         cbp += cbp;
1100                     }
1101                 }
1102             }
1103         } else {
1104             for (i = 0; i < 12; i++)
1105                 s->block_last_index[i] = -1;
1106         }
1107     }
1108
1109     s->current_picture.mb_type[s->mb_x + s->mb_y * s->mb_stride] = mb_type;
1110
1111     return 0;
1112 }
1113
1114 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1115 {
1116     Mpeg1Context *s    = avctx->priv_data;
1117     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1118
1119     ff_mpv_decode_defaults(s2);
1120
1121     if (   avctx->codec_tag != AV_RL32("VCR2")
1122         && avctx->codec_tag != AV_RL32("BW10"))
1123         avctx->coded_width = avctx->coded_height = 0; // do not trust dimensions from input
1124     ff_mpv_decode_init(s2, avctx);
1125
1126     s->mpeg_enc_ctx.avctx  = avctx;
1127
1128     /* we need some permutation to store matrices,
1129      * until the decoder sets the real permutation. */
1130     ff_mpv_idct_init(s2);
1131     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1132     ff_mpeg12_init_vlcs();
1133
1134     s2->chroma_format              = 1;
1135     s->mpeg_enc_ctx_allocated      = 0;
1136     s->mpeg_enc_ctx.picture_number = 0;
1137     s->repeat_field                = 0;
1138     s->mpeg_enc_ctx.codec_id       = avctx->codec->id;
1139     avctx->color_range             = AVCOL_RANGE_MPEG;
1140     return 0;
1141 }
1142
1143 #if HAVE_THREADS
1144 static int mpeg_decode_update_thread_context(AVCodecContext *avctx,
1145                                              const AVCodecContext *avctx_from)
1146 {
1147     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1148     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1149     int err;
1150
1151     if (avctx == avctx_from               ||
1152         !ctx_from->mpeg_enc_ctx_allocated ||
1153         !s1->context_initialized)
1154         return 0;
1155
1156     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1157     if (err)
1158         return err;
1159
1160     if (!ctx->mpeg_enc_ctx_allocated)
1161         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1162
1163     if (!(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay))
1164         s->picture_number++;
1165
1166     return 0;
1167 }
1168 #endif
1169
1170 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1171                                  const uint8_t *new_perm)
1172 {
1173     uint16_t temp_matrix[64];
1174     int i;
1175
1176     memcpy(temp_matrix, matrix, 64 * sizeof(uint16_t));
1177
1178     for (i = 0; i < 64; i++)
1179         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1180 }
1181
1182 static const enum AVPixelFormat mpeg1_hwaccel_pixfmt_list_420[] = {
1183 #if CONFIG_MPEG1_XVMC_HWACCEL
1184     AV_PIX_FMT_XVMC,
1185 #endif
1186 #if CONFIG_MPEG1_VDPAU_DECODER && FF_API_VDPAU
1187     AV_PIX_FMT_VDPAU_MPEG1,
1188 #endif
1189 #if CONFIG_MPEG1_VDPAU_HWACCEL
1190     AV_PIX_FMT_VDPAU,
1191 #endif
1192     AV_PIX_FMT_YUV420P,
1193     AV_PIX_FMT_NONE
1194 };
1195
1196 static const enum AVPixelFormat mpeg2_hwaccel_pixfmt_list_420[] = {
1197 #if CONFIG_MPEG2_XVMC_HWACCEL
1198     AV_PIX_FMT_XVMC,
1199 #endif
1200 #if CONFIG_MPEG_VDPAU_DECODER && FF_API_VDPAU
1201     AV_PIX_FMT_VDPAU_MPEG2,
1202 #endif
1203 #if CONFIG_MPEG2_VDPAU_HWACCEL
1204     AV_PIX_FMT_VDPAU,
1205 #endif
1206 #if CONFIG_MPEG2_DXVA2_HWACCEL
1207     AV_PIX_FMT_DXVA2_VLD,
1208 #endif
1209 #if CONFIG_MPEG2_D3D11VA_HWACCEL
1210     AV_PIX_FMT_D3D11VA_VLD,
1211 #endif
1212 #if CONFIG_MPEG2_VAAPI_HWACCEL
1213     AV_PIX_FMT_VAAPI,
1214 #endif
1215 #if CONFIG_MPEG2_VIDEOTOOLBOX_HWACCEL
1216     AV_PIX_FMT_VIDEOTOOLBOX,
1217 #endif
1218     AV_PIX_FMT_YUV420P,
1219     AV_PIX_FMT_NONE
1220 };
1221
1222 static const enum AVPixelFormat mpeg12_pixfmt_list_422[] = {
1223     AV_PIX_FMT_YUV422P,
1224     AV_PIX_FMT_NONE
1225 };
1226
1227 static const enum AVPixelFormat mpeg12_pixfmt_list_444[] = {
1228     AV_PIX_FMT_YUV444P,
1229     AV_PIX_FMT_NONE
1230 };
1231
1232 #if FF_API_VDPAU
1233 static inline int uses_vdpau(AVCodecContext *avctx) {
1234     return avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG1 || avctx->pix_fmt == AV_PIX_FMT_VDPAU_MPEG2;
1235 }
1236 #endif
1237
1238 static enum AVPixelFormat mpeg_get_pixelformat(AVCodecContext *avctx)
1239 {
1240     Mpeg1Context *s1  = avctx->priv_data;
1241     MpegEncContext *s = &s1->mpeg_enc_ctx;
1242     const enum AVPixelFormat *pix_fmts;
1243
1244     if (CONFIG_GRAY && (avctx->flags & AV_CODEC_FLAG_GRAY))
1245         return AV_PIX_FMT_GRAY8;
1246
1247     if (s->chroma_format < 2)
1248         pix_fmts = avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO ?
1249                                 mpeg1_hwaccel_pixfmt_list_420 :
1250                                 mpeg2_hwaccel_pixfmt_list_420;
1251     else if (s->chroma_format == 2)
1252         pix_fmts = mpeg12_pixfmt_list_422;
1253     else
1254         pix_fmts = mpeg12_pixfmt_list_444;
1255
1256     return ff_thread_get_format(avctx, pix_fmts);
1257 }
1258
1259 static void setup_hwaccel_for_pixfmt(AVCodecContext *avctx)
1260 {
1261     // until then pix_fmt may be changed right after codec init
1262     if (avctx->hwaccel
1263 #if FF_API_VDPAU
1264         || uses_vdpau(avctx)
1265 #endif
1266         )
1267         if (avctx->idct_algo == FF_IDCT_AUTO)
1268             avctx->idct_algo = FF_IDCT_SIMPLE;
1269
1270     if (avctx->hwaccel && avctx->pix_fmt == AV_PIX_FMT_XVMC) {
1271         Mpeg1Context *s1 = avctx->priv_data;
1272         MpegEncContext *s = &s1->mpeg_enc_ctx;
1273
1274         s->pack_pblocks = 1;
1275 #if FF_API_XVMC
1276 FF_DISABLE_DEPRECATION_WARNINGS
1277         avctx->xvmc_acceleration = 2;
1278 FF_ENABLE_DEPRECATION_WARNINGS
1279 #endif /* FF_API_XVMC */
1280     }
1281 }
1282
1283 /* Call this function when we know all parameters.
1284  * It may be called in different places for MPEG-1 and MPEG-2. */
1285 static int mpeg_decode_postinit(AVCodecContext *avctx)
1286 {
1287     Mpeg1Context *s1  = avctx->priv_data;
1288     MpegEncContext *s = &s1->mpeg_enc_ctx;
1289     uint8_t old_permutation[64];
1290     int ret;
1291
1292     if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1293         // MPEG-1 aspect
1294         avctx->sample_aspect_ratio = av_d2q(1.0 / ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1295     } else { // MPEG-2
1296         // MPEG-2 aspect
1297         if (s->aspect_ratio_info > 1) {
1298             AVRational dar =
1299                 av_mul_q(av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1300                                   (AVRational) { s1->pan_scan.width,
1301                                                  s1->pan_scan.height }),
1302                          (AVRational) { s->width, s->height });
1303
1304             /* We ignore the spec here and guess a bit as reality does not
1305              * match the spec, see for example res_change_ffmpeg_aspect.ts
1306              * and sequence-display-aspect.mpg.
1307              * issue1613, 621, 562 */
1308             if ((s1->pan_scan.width == 0) || (s1->pan_scan.height == 0) ||
1309                 (av_cmp_q(dar, (AVRational) { 4, 3 }) &&
1310                  av_cmp_q(dar, (AVRational) { 16, 9 }))) {
1311                 s->avctx->sample_aspect_ratio =
1312                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1313                              (AVRational) { s->width, s->height });
1314             } else {
1315                 s->avctx->sample_aspect_ratio =
1316                     av_div_q(ff_mpeg2_aspect[s->aspect_ratio_info],
1317                              (AVRational) { s1->pan_scan.width, s1->pan_scan.height });
1318 // issue1613 4/3 16/9 -> 16/9
1319 // res_change_ffmpeg_aspect.ts 4/3 225/44 ->4/3
1320 // widescreen-issue562.mpg 4/3 16/9 -> 16/9
1321 //                s->avctx->sample_aspect_ratio = av_mul_q(s->avctx->sample_aspect_ratio, (AVRational) {s->width, s->height});
1322                 ff_dlog(avctx, "aspect A %d/%d\n",
1323                         ff_mpeg2_aspect[s->aspect_ratio_info].num,
1324                         ff_mpeg2_aspect[s->aspect_ratio_info].den);
1325                 ff_dlog(avctx, "aspect B %d/%d\n", s->avctx->sample_aspect_ratio.num,
1326                         s->avctx->sample_aspect_ratio.den);
1327             }
1328         } else {
1329             s->avctx->sample_aspect_ratio =
1330                 ff_mpeg2_aspect[s->aspect_ratio_info];
1331         }
1332     } // MPEG-2
1333
1334     if (av_image_check_sar(s->width, s->height,
1335                            avctx->sample_aspect_ratio) < 0) {
1336         av_log(avctx, AV_LOG_WARNING, "ignoring invalid SAR: %u/%u\n",
1337                 avctx->sample_aspect_ratio.num,
1338                 avctx->sample_aspect_ratio.den);
1339         avctx->sample_aspect_ratio = (AVRational){ 0, 1 };
1340     }
1341
1342     if ((s1->mpeg_enc_ctx_allocated == 0)                   ||
1343         avctx->coded_width       != s->width                ||
1344         avctx->coded_height      != s->height               ||
1345         s1->save_width           != s->width                ||
1346         s1->save_height          != s->height               ||
1347         av_cmp_q(s1->save_aspect, s->avctx->sample_aspect_ratio) ||
1348         (s1->save_progressive_seq != s->progressive_sequence && FFALIGN(s->height, 16) != FFALIGN(s->height, 32)) ||
1349         0) {
1350         if (s1->mpeg_enc_ctx_allocated) {
1351             ParseContext pc = s->parse_context;
1352             s->parse_context.buffer = 0;
1353             ff_mpv_common_end(s);
1354             s->parse_context = pc;
1355             s1->mpeg_enc_ctx_allocated = 0;
1356         }
1357
1358         ret = ff_set_dimensions(avctx, s->width, s->height);
1359         if (ret < 0)
1360             return ret;
1361
1362         if (avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO && s->bit_rate) {
1363             avctx->rc_max_rate = s->bit_rate;
1364         } else if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO && s->bit_rate &&
1365                    (s->bit_rate != 0x3FFFF*400 || s->vbv_delay != 0xFFFF)) {
1366             avctx->bit_rate = s->bit_rate;
1367         }
1368         s1->save_aspect          = s->avctx->sample_aspect_ratio;
1369         s1->save_width           = s->width;
1370         s1->save_height          = s->height;
1371         s1->save_progressive_seq = s->progressive_sequence;
1372
1373         /* low_delay may be forced, in this case we will have B-frames
1374          * that behave like P-frames. */
1375         avctx->has_b_frames = !s->low_delay;
1376
1377         if (avctx->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
1378             // MPEG-1 fps
1379             avctx->framerate = ff_mpeg12_frame_rate_tab[s->frame_rate_index];
1380             avctx->ticks_per_frame     = 1;
1381
1382             avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1383         } else { // MPEG-2
1384             // MPEG-2 fps
1385             av_reduce(&s->avctx->framerate.num,
1386                       &s->avctx->framerate.den,
1387                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1388                       ff_mpeg12_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1389                       1 << 30);
1390             avctx->ticks_per_frame = 2;
1391
1392             switch (s->chroma_format) {
1393             case 1: avctx->chroma_sample_location = AVCHROMA_LOC_LEFT; break;
1394             case 2:
1395             case 3: avctx->chroma_sample_location = AVCHROMA_LOC_TOPLEFT; break;
1396             default: av_assert0(0);
1397             }
1398         } // MPEG-2
1399
1400         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1401         setup_hwaccel_for_pixfmt(avctx);
1402
1403         /* Quantization matrices may need reordering
1404          * if DCT permutation is changed. */
1405         memcpy(old_permutation, s->idsp.idct_permutation, 64 * sizeof(uint8_t));
1406
1407         ff_mpv_idct_init(s);
1408         if ((ret = ff_mpv_common_init(s)) < 0)
1409             return ret;
1410
1411         quant_matrix_rebuild(s->intra_matrix,        old_permutation, s->idsp.idct_permutation);
1412         quant_matrix_rebuild(s->inter_matrix,        old_permutation, s->idsp.idct_permutation);
1413         quant_matrix_rebuild(s->chroma_intra_matrix, old_permutation, s->idsp.idct_permutation);
1414         quant_matrix_rebuild(s->chroma_inter_matrix, old_permutation, s->idsp.idct_permutation);
1415
1416         s1->mpeg_enc_ctx_allocated = 1;
1417     }
1418     return 0;
1419 }
1420
1421 static int mpeg1_decode_picture(AVCodecContext *avctx, const uint8_t *buf,
1422                                 int buf_size)
1423 {
1424     Mpeg1Context *s1  = avctx->priv_data;
1425     MpegEncContext *s = &s1->mpeg_enc_ctx;
1426     int ref, f_code, vbv_delay;
1427
1428     init_get_bits(&s->gb, buf, buf_size * 8);
1429
1430     ref = get_bits(&s->gb, 10); /* temporal ref */
1431     s->pict_type = get_bits(&s->gb, 3);
1432     if (s->pict_type == 0 || s->pict_type > 3)
1433         return AVERROR_INVALIDDATA;
1434
1435     vbv_delay = get_bits(&s->gb, 16);
1436     s->vbv_delay = vbv_delay;
1437     if (s->pict_type == AV_PICTURE_TYPE_P ||
1438         s->pict_type == AV_PICTURE_TYPE_B) {
1439         s->full_pel[0] = get_bits1(&s->gb);
1440         f_code = get_bits(&s->gb, 3);
1441         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1442             return AVERROR_INVALIDDATA;
1443         f_code += !f_code;
1444         s->mpeg_f_code[0][0] = f_code;
1445         s->mpeg_f_code[0][1] = f_code;
1446     }
1447     if (s->pict_type == AV_PICTURE_TYPE_B) {
1448         s->full_pel[1] = get_bits1(&s->gb);
1449         f_code = get_bits(&s->gb, 3);
1450         if (f_code == 0 && (avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)))
1451             return AVERROR_INVALIDDATA;
1452         f_code += !f_code;
1453         s->mpeg_f_code[1][0] = f_code;
1454         s->mpeg_f_code[1][1] = f_code;
1455     }
1456     s->current_picture.f->pict_type = s->pict_type;
1457     s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1458
1459     if (avctx->debug & FF_DEBUG_PICT_INFO)
1460         av_log(avctx, AV_LOG_DEBUG,
1461                "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1462
1463     s->y_dc_scale = 8;
1464     s->c_dc_scale = 8;
1465     return 0;
1466 }
1467
1468 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1469 {
1470     MpegEncContext *s = &s1->mpeg_enc_ctx;
1471     int horiz_size_ext, vert_size_ext;
1472     int bit_rate_ext;
1473
1474     skip_bits(&s->gb, 1); /* profile and level esc*/
1475     s->avctx->profile       = get_bits(&s->gb, 3);
1476     s->avctx->level         = get_bits(&s->gb, 4);
1477     s->progressive_sequence = get_bits1(&s->gb);   /* progressive_sequence */
1478     s->chroma_format        = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1479
1480     if (!s->chroma_format) {
1481         s->chroma_format = 1;
1482         av_log(s->avctx, AV_LOG_WARNING, "Chroma format invalid\n");
1483     }
1484
1485     horiz_size_ext          = get_bits(&s->gb, 2);
1486     vert_size_ext           = get_bits(&s->gb, 2);
1487     s->width  |= (horiz_size_ext << 12);
1488     s->height |= (vert_size_ext  << 12);
1489     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1490     s->bit_rate += (bit_rate_ext << 18) * 400LL;
1491     check_marker(&s->gb, "after bit rate extension");
1492     s->avctx->rc_buffer_size += get_bits(&s->gb, 8) * 1024 * 16 << 10;
1493
1494     s->low_delay = get_bits1(&s->gb);
1495     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
1496         s->low_delay = 1;
1497
1498     s1->frame_rate_ext.num = get_bits(&s->gb, 2) + 1;
1499     s1->frame_rate_ext.den = get_bits(&s->gb, 5) + 1;
1500
1501     ff_dlog(s->avctx, "sequence extension\n");
1502     s->codec_id = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
1503
1504     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1505         av_log(s->avctx, AV_LOG_DEBUG,
1506                "profile: %d, level: %d ps: %d cf:%d vbv buffer: %d, bitrate:%"PRId64"\n",
1507                s->avctx->profile, s->avctx->level, s->progressive_sequence, s->chroma_format,
1508                s->avctx->rc_buffer_size, s->bit_rate);
1509 }
1510
1511 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1512 {
1513     MpegEncContext *s = &s1->mpeg_enc_ctx;
1514     int color_description, w, h;
1515
1516     skip_bits(&s->gb, 3); /* video format */
1517     color_description = get_bits1(&s->gb);
1518     if (color_description) {
1519         s->avctx->color_primaries = get_bits(&s->gb, 8);
1520         s->avctx->color_trc       = get_bits(&s->gb, 8);
1521         s->avctx->colorspace      = get_bits(&s->gb, 8);
1522     }
1523     w = get_bits(&s->gb, 14);
1524     skip_bits(&s->gb, 1); // marker
1525     h = get_bits(&s->gb, 14);
1526     // remaining 3 bits are zero padding
1527
1528     s1->pan_scan.width  = 16 * w;
1529     s1->pan_scan.height = 16 * h;
1530
1531     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1532         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1533 }
1534
1535 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1536 {
1537     MpegEncContext *s = &s1->mpeg_enc_ctx;
1538     int i, nofco;
1539
1540     nofco = 1;
1541     if (s->progressive_sequence) {
1542         if (s->repeat_first_field) {
1543             nofco++;
1544             if (s->top_field_first)
1545                 nofco++;
1546         }
1547     } else {
1548         if (s->picture_structure == PICT_FRAME) {
1549             nofco++;
1550             if (s->repeat_first_field)
1551                 nofco++;
1552         }
1553     }
1554     for (i = 0; i < nofco; i++) {
1555         s1->pan_scan.position[i][0] = get_sbits(&s->gb, 16);
1556         skip_bits(&s->gb, 1); // marker
1557         s1->pan_scan.position[i][1] = get_sbits(&s->gb, 16);
1558         skip_bits(&s->gb, 1); // marker
1559     }
1560
1561     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
1562         av_log(s->avctx, AV_LOG_DEBUG,
1563                "pde (%"PRId16",%"PRId16") (%"PRId16",%"PRId16") (%"PRId16",%"PRId16")\n",
1564                s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1565                s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1566                s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]);
1567 }
1568
1569 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64],
1570                        uint16_t matrix1[64], int intra)
1571 {
1572     int i;
1573
1574     for (i = 0; i < 64; i++) {
1575         int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
1576         int v = get_bits(&s->gb, 8);
1577         if (v == 0) {
1578             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1579             return AVERROR_INVALIDDATA;
1580         }
1581         if (intra && i == 0 && v != 8) {
1582             av_log(s->avctx, AV_LOG_DEBUG, "intra matrix specifies invalid DC quantizer %d, ignoring\n", v);
1583             v = 8; // needed by pink.mpg / issue1046
1584         }
1585         matrix0[j] = v;
1586         if (matrix1)
1587             matrix1[j] = v;
1588     }
1589     return 0;
1590 }
1591
1592 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1593 {
1594     ff_dlog(s->avctx, "matrix extension\n");
1595
1596     if (get_bits1(&s->gb))
1597         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1598     if (get_bits1(&s->gb))
1599         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1600     if (get_bits1(&s->gb))
1601         load_matrix(s, s->chroma_intra_matrix, NULL, 1);
1602     if (get_bits1(&s->gb))
1603         load_matrix(s, s->chroma_inter_matrix, NULL, 0);
1604 }
1605
1606 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1607 {
1608     MpegEncContext *s = &s1->mpeg_enc_ctx;
1609
1610     s->full_pel[0]       = s->full_pel[1] = 0;
1611     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1612     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1613     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1614     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1615     if (!s->pict_type && s1->mpeg_enc_ctx_allocated) {
1616         av_log(s->avctx, AV_LOG_ERROR,
1617                "Missing picture start code, guessing missing values\n");
1618         if (s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1] == 15) {
1619             if (s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1620                 s->pict_type = AV_PICTURE_TYPE_I;
1621             else
1622                 s->pict_type = AV_PICTURE_TYPE_P;
1623         } else
1624             s->pict_type = AV_PICTURE_TYPE_B;
1625         s->current_picture.f->pict_type = s->pict_type;
1626         s->current_picture.f->key_frame = s->pict_type == AV_PICTURE_TYPE_I;
1627     }
1628     s->mpeg_f_code[0][0] += !s->mpeg_f_code[0][0];
1629     s->mpeg_f_code[0][1] += !s->mpeg_f_code[0][1];
1630     s->mpeg_f_code[1][0] += !s->mpeg_f_code[1][0];
1631     s->mpeg_f_code[1][1] += !s->mpeg_f_code[1][1];
1632
1633     s->intra_dc_precision         = get_bits(&s->gb, 2);
1634     s->picture_structure          = get_bits(&s->gb, 2);
1635     s->top_field_first            = get_bits1(&s->gb);
1636     s->frame_pred_frame_dct       = get_bits1(&s->gb);
1637     s->concealment_motion_vectors = get_bits1(&s->gb);
1638     s->q_scale_type               = get_bits1(&s->gb);
1639     s->intra_vlc_format           = get_bits1(&s->gb);
1640     s->alternate_scan             = get_bits1(&s->gb);
1641     s->repeat_first_field         = get_bits1(&s->gb);
1642     s->chroma_420_type            = get_bits1(&s->gb);
1643     s->progressive_frame          = get_bits1(&s->gb);
1644
1645     if (s->alternate_scan) {
1646         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_alternate_vertical_scan);
1647         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_alternate_vertical_scan);
1648     } else {
1649         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable, ff_zigzag_direct);
1650         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable, ff_zigzag_direct);
1651     }
1652
1653     /* composite display not parsed */
1654     ff_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1655     ff_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1656     ff_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1657     ff_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1658     ff_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1659     ff_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1660     ff_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1661     ff_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1662     ff_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1663 }
1664
1665 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size)
1666 {
1667     AVCodecContext *avctx = s->avctx;
1668     Mpeg1Context *s1      = (Mpeg1Context *) s;
1669     int ret;
1670
1671     /* start frame decoding */
1672     if (s->first_field || s->picture_structure == PICT_FRAME) {
1673         AVFrameSideData *pan_scan;
1674
1675         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
1676             return ret;
1677
1678         ff_mpeg_er_frame_start(s);
1679
1680         /* first check if we must repeat the frame */
1681         s->current_picture_ptr->f->repeat_pict = 0;
1682         if (s->repeat_first_field) {
1683             if (s->progressive_sequence) {
1684                 if (s->top_field_first)
1685                     s->current_picture_ptr->f->repeat_pict = 4;
1686                 else
1687                     s->current_picture_ptr->f->repeat_pict = 2;
1688             } else if (s->progressive_frame) {
1689                 s->current_picture_ptr->f->repeat_pict = 1;
1690             }
1691         }
1692
1693         pan_scan = av_frame_new_side_data(s->current_picture_ptr->f,
1694                                           AV_FRAME_DATA_PANSCAN,
1695                                           sizeof(s1->pan_scan));
1696         if (!pan_scan)
1697             return AVERROR(ENOMEM);
1698         memcpy(pan_scan->data, &s1->pan_scan, sizeof(s1->pan_scan));
1699
1700         if (s1->a53_caption) {
1701             AVFrameSideData *sd = av_frame_new_side_data(
1702                 s->current_picture_ptr->f, AV_FRAME_DATA_A53_CC,
1703                 s1->a53_caption_size);
1704             if (sd)
1705                 memcpy(sd->data, s1->a53_caption, s1->a53_caption_size);
1706             av_freep(&s1->a53_caption);
1707             avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;
1708         }
1709
1710         if (s1->has_stereo3d) {
1711             AVStereo3D *stereo = av_stereo3d_create_side_data(s->current_picture_ptr->f);
1712             if (!stereo)
1713                 return AVERROR(ENOMEM);
1714
1715             *stereo = s1->stereo3d;
1716             s1->has_stereo3d = 0;
1717         }
1718
1719         if (s1->has_afd) {
1720             AVFrameSideData *sd =
1721                 av_frame_new_side_data(s->current_picture_ptr->f,
1722                                        AV_FRAME_DATA_AFD, 1);
1723             if (!sd)
1724                 return AVERROR(ENOMEM);
1725
1726             *sd->data   = s1->afd;
1727             s1->has_afd = 0;
1728         }
1729
1730         if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_FRAME))
1731             ff_thread_finish_setup(avctx);
1732     } else { // second field
1733         int i;
1734
1735         if (!s->current_picture_ptr) {
1736             av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1737             return AVERROR_INVALIDDATA;
1738         }
1739
1740         if (s->avctx->hwaccel &&
1741             (s->avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
1742             if ((ret = s->avctx->hwaccel->end_frame(s->avctx)) < 0) {
1743                 av_log(avctx, AV_LOG_ERROR,
1744                        "hardware accelerator failed to decode first field\n");
1745                 return ret;
1746             }
1747         }
1748
1749         for (i = 0; i < 4; i++) {
1750             s->current_picture.f->data[i] = s->current_picture_ptr->f->data[i];
1751             if (s->picture_structure == PICT_BOTTOM_FIELD)
1752                 s->current_picture.f->data[i] +=
1753                     s->current_picture_ptr->f->linesize[i];
1754         }
1755     }
1756
1757     if (avctx->hwaccel) {
1758         if ((ret = avctx->hwaccel->start_frame(avctx, buf, buf_size)) < 0)
1759             return ret;
1760     }
1761
1762     return 0;
1763 }
1764
1765 #define DECODE_SLICE_ERROR -1
1766 #define DECODE_SLICE_OK     0
1767
1768 /**
1769  * Decode a slice.
1770  * MpegEncContext.mb_y must be set to the MB row from the startcode.
1771  * @return DECODE_SLICE_ERROR if the slice is damaged,
1772  *         DECODE_SLICE_OK if this slice is OK
1773  */
1774 static int mpeg_decode_slice(MpegEncContext *s, int mb_y,
1775                              const uint8_t **buf, int buf_size)
1776 {
1777     AVCodecContext *avctx = s->avctx;
1778     const int lowres      = s->avctx->lowres;
1779     const int field_pic   = s->picture_structure != PICT_FRAME;
1780     int ret;
1781
1782     s->resync_mb_x =
1783     s->resync_mb_y = -1;
1784
1785     av_assert0(mb_y < s->mb_height);
1786
1787     init_get_bits(&s->gb, *buf, buf_size * 8);
1788     if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
1789         skip_bits(&s->gb, 3);
1790
1791     ff_mpeg1_clean_buffers(s);
1792     s->interlaced_dct = 0;
1793
1794     s->qscale = get_qscale(s);
1795
1796     if (s->qscale == 0) {
1797         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1798         return AVERROR_INVALIDDATA;
1799     }
1800
1801     /* extra slice info */
1802     if (skip_1stop_8data_bits(&s->gb) < 0)
1803         return AVERROR_INVALIDDATA;
1804
1805     s->mb_x = 0;
1806
1807     if (mb_y == 0 && s->codec_tag == AV_RL32("SLIF")) {
1808         skip_bits1(&s->gb);
1809     } else {
1810         while (get_bits_left(&s->gb) > 0) {
1811             int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1812                                 MBINCR_VLC_BITS, 2);
1813             if (code < 0) {
1814                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1815                 return AVERROR_INVALIDDATA;
1816             }
1817             if (code >= 33) {
1818                 if (code == 33)
1819                     s->mb_x += 33;
1820                 /* otherwise, stuffing, nothing to do */
1821             } else {
1822                 s->mb_x += code;
1823                 break;
1824             }
1825         }
1826     }
1827
1828     if (s->mb_x >= (unsigned) s->mb_width) {
1829         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1830         return AVERROR_INVALIDDATA;
1831     }
1832
1833     if (avctx->hwaccel && avctx->hwaccel->decode_slice) {
1834         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1835         int start_code = -1;
1836         buf_end = avpriv_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1837         if (buf_end < *buf + buf_size)
1838             buf_end -= 4;
1839         s->mb_y = mb_y;
1840         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1841             return DECODE_SLICE_ERROR;
1842         *buf = buf_end;
1843         return DECODE_SLICE_OK;
1844     }
1845
1846     s->resync_mb_x = s->mb_x;
1847     s->resync_mb_y = s->mb_y = mb_y;
1848     s->mb_skip_run = 0;
1849     ff_init_block_index(s);
1850
1851     if (s->mb_y == 0 && s->mb_x == 0 && (s->first_field || s->picture_structure == PICT_FRAME)) {
1852         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
1853             av_log(s->avctx, AV_LOG_DEBUG,
1854                    "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",
1855                    s->qscale,
1856                    s->mpeg_f_code[0][0], s->mpeg_f_code[0][1],
1857                    s->mpeg_f_code[1][0], s->mpeg_f_code[1][1],
1858                    s->pict_type  == AV_PICTURE_TYPE_I ? "I" :
1859                    (s->pict_type == AV_PICTURE_TYPE_P ? "P" :
1860                    (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
1861                    s->progressive_sequence ? "ps"  : "",
1862                    s->progressive_frame    ? "pf"  : "",
1863                    s->alternate_scan       ? "alt" : "",
1864                    s->top_field_first      ? "top" : "",
1865                    s->intra_dc_precision, s->picture_structure,
1866                    s->frame_pred_frame_dct, s->concealment_motion_vectors,
1867                    s->q_scale_type, s->intra_vlc_format,
1868                    s->repeat_first_field, s->chroma_420_type ? "420" : "");
1869         }
1870     }
1871
1872     for (;;) {
1873         // If 1, we memcpy blocks in xvmcvideo.
1874         if ((CONFIG_MPEG1_XVMC_HWACCEL || CONFIG_MPEG2_XVMC_HWACCEL) && s->pack_pblocks)
1875             ff_xvmc_init_block(s); // set s->block
1876
1877         if ((ret = mpeg_decode_mb(s, s->block)) < 0)
1878             return ret;
1879
1880         // Note motion_val is normally NULL unless we want to extract the MVs.
1881         if (s->current_picture.motion_val[0] && !s->encoding) {
1882             const int wrap = s->b8_stride;
1883             int xy         = s->mb_x * 2 + s->mb_y * 2 * wrap;
1884             int b8_xy      = 4 * (s->mb_x + s->mb_y * s->mb_stride);
1885             int motion_x, motion_y, dir, i;
1886
1887             for (i = 0; i < 2; i++) {
1888                 for (dir = 0; dir < 2; dir++) {
1889                     if (s->mb_intra ||
1890                         (dir == 1 && s->pict_type != AV_PICTURE_TYPE_B)) {
1891                         motion_x = motion_y = 0;
1892                     } else if (s->mv_type == MV_TYPE_16X16 ||
1893                                (s->mv_type == MV_TYPE_FIELD && field_pic)) {
1894                         motion_x = s->mv[dir][0][0];
1895                         motion_y = s->mv[dir][0][1];
1896                     } else { /* if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8)) */
1897                         motion_x = s->mv[dir][i][0];
1898                         motion_y = s->mv[dir][i][1];
1899                     }
1900
1901                     s->current_picture.motion_val[dir][xy][0]     = motion_x;
1902                     s->current_picture.motion_val[dir][xy][1]     = motion_y;
1903                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1904                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1905                     s->current_picture.ref_index [dir][b8_xy]     =
1906                     s->current_picture.ref_index [dir][b8_xy + 1] = s->field_select[dir][i];
1907                     av_assert2(s->field_select[dir][i] == 0 ||
1908                                s->field_select[dir][i] == 1);
1909                 }
1910                 xy    += wrap;
1911                 b8_xy += 2;
1912             }
1913         }
1914
1915         s->dest[0] += 16 >> lowres;
1916         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1917         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1918
1919         ff_mpv_decode_mb(s, s->block);
1920
1921         if (++s->mb_x >= s->mb_width) {
1922             const int mb_size = 16 >> s->avctx->lowres;
1923
1924             ff_mpeg_draw_horiz_band(s, mb_size * (s->mb_y >> field_pic), mb_size);
1925             ff_mpv_report_decode_progress(s);
1926
1927             s->mb_x  = 0;
1928             s->mb_y += 1 << field_pic;
1929
1930             if (s->mb_y >= s->mb_height) {
1931                 int left   = get_bits_left(&s->gb);
1932                 int is_d10 = s->chroma_format == 2 &&
1933                              s->pict_type == AV_PICTURE_TYPE_I &&
1934                              avctx->profile == 0 && avctx->level == 5 &&
1935                              s->intra_dc_precision == 2 &&
1936                              s->q_scale_type == 1 && s->alternate_scan == 0 &&
1937                              s->progressive_frame == 0
1938                              /* vbv_delay == 0xBBB || 0xE10 */;
1939
1940                 if (left >= 32 && !is_d10) {
1941                     GetBitContext gb = s->gb;
1942                     align_get_bits(&gb);
1943                     if (show_bits(&gb, 24) == 0x060E2B) {
1944                         av_log(avctx, AV_LOG_DEBUG, "Invalid MXF data found in video stream\n");
1945                         is_d10 = 1;
1946                     }
1947                 }
1948
1949                 if (left < 0 ||
1950                     (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10) ||
1951                     ((avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_AGGRESSIVE)) && left > 8)) {
1952                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n",
1953                            left, left>0 ? show_bits(&s->gb, FFMIN(left, 23)) : 0);
1954                     return AVERROR_INVALIDDATA;
1955                 } else
1956                     goto eos;
1957             }
1958             // There are some files out there which are missing the last slice
1959             // in cases where the slice is completely outside the visible
1960             // area, we detect this here instead of running into the end expecting
1961             // more data
1962             if (s->mb_y >= ((s->height + 15) >> 4) &&
1963                 !s->progressive_sequence &&
1964                 get_bits_left(&s->gb) <= 8 &&
1965                 get_bits_left(&s->gb) >= 0 &&
1966                 s->mb_skip_run == -1 &&
1967                 show_bits(&s->gb, 8) == 0)
1968                 goto eos;
1969
1970             ff_init_block_index(s);
1971         }
1972
1973         /* skip mb handling */
1974         if (s->mb_skip_run == -1) {
1975             /* read increment again */
1976             s->mb_skip_run = 0;
1977             for (;;) {
1978                 int code = get_vlc2(&s->gb, ff_mbincr_vlc.table,
1979                                     MBINCR_VLC_BITS, 2);
1980                 if (code < 0) {
1981                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1982                     return AVERROR_INVALIDDATA;
1983                 }
1984                 if (code >= 33) {
1985                     if (code == 33) {
1986                         s->mb_skip_run += 33;
1987                     } else if (code == 35) {
1988                         if (s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0) {
1989                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1990                             return AVERROR_INVALIDDATA;
1991                         }
1992                         goto eos; /* end of slice */
1993                     }
1994                     /* otherwise, stuffing, nothing to do */
1995                 } else {
1996                     s->mb_skip_run += code;
1997                     break;
1998                 }
1999             }
2000             if (s->mb_skip_run) {
2001                 int i;
2002                 if (s->pict_type == AV_PICTURE_TYPE_I) {
2003                     av_log(s->avctx, AV_LOG_ERROR,
2004                            "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
2005                     return AVERROR_INVALIDDATA;
2006                 }
2007
2008                 /* skip mb */
2009                 s->mb_intra = 0;
2010                 for (i = 0; i < 12; i++)
2011                     s->block_last_index[i] = -1;
2012                 if (s->picture_structure == PICT_FRAME)
2013                     s->mv_type = MV_TYPE_16X16;
2014                 else
2015                     s->mv_type = MV_TYPE_FIELD;
2016                 if (s->pict_type == AV_PICTURE_TYPE_P) {
2017                     /* if P type, zero motion vector is implied */
2018                     s->mv_dir             = MV_DIR_FORWARD;
2019                     s->mv[0][0][0]        = s->mv[0][0][1]      = 0;
2020                     s->last_mv[0][0][0]   = s->last_mv[0][0][1] = 0;
2021                     s->last_mv[0][1][0]   = s->last_mv[0][1][1] = 0;
2022                     s->field_select[0][0] = (s->picture_structure - 1) & 1;
2023                 } else {
2024                     /* if B type, reuse previous vectors and directions */
2025                     s->mv[0][0][0] = s->last_mv[0][0][0];
2026                     s->mv[0][0][1] = s->last_mv[0][0][1];
2027                     s->mv[1][0][0] = s->last_mv[1][0][0];
2028                     s->mv[1][0][1] = s->last_mv[1][0][1];
2029                 }
2030             }
2031         }
2032     }
2033 eos: // end of slice
2034     if (get_bits_left(&s->gb) < 0) {
2035         av_log(s, AV_LOG_ERROR, "overread %d\n", -get_bits_left(&s->gb));
2036         return AVERROR_INVALIDDATA;
2037     }
2038     *buf += (get_bits_count(&s->gb) - 1) / 8;
2039     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);
2040     return 0;
2041 }
2042
2043 static int slice_decode_thread(AVCodecContext *c, void *arg)
2044 {
2045     MpegEncContext *s   = *(void **) arg;
2046     const uint8_t *buf  = s->gb.buffer;
2047     int mb_y            = s->start_mb_y;
2048     const int field_pic = s->picture_structure != PICT_FRAME;
2049
2050     s->er.error_count = (3 * (s->end_mb_y - s->start_mb_y) * s->mb_width) >> field_pic;
2051
2052     for (;;) {
2053         uint32_t start_code;
2054         int ret;
2055
2056         ret = mpeg_decode_slice(s, mb_y, &buf, s->gb.buffer_end - buf);
2057         emms_c();
2058         ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
2059                 ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y,
2060                 s->start_mb_y, s->end_mb_y, s->er.error_count);
2061         if (ret < 0) {
2062             if (c->err_recognition & AV_EF_EXPLODE)
2063                 return ret;
2064             if (s->resync_mb_x >= 0 && s->resync_mb_y >= 0)
2065                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2066                                 s->mb_x, s->mb_y,
2067                                 ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2068         } else {
2069             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
2070                             s->mb_x - 1, s->mb_y,
2071                             ER_AC_END | ER_DC_END | ER_MV_END);
2072         }
2073
2074         if (s->mb_y == s->end_mb_y)
2075             return 0;
2076
2077         start_code = -1;
2078         buf        = avpriv_find_start_code(buf, s->gb.buffer_end, &start_code);
2079         mb_y       = start_code - SLICE_MIN_START_CODE;
2080         if (s->codec_id != AV_CODEC_ID_MPEG1VIDEO && s->mb_height > 2800/16)
2081             mb_y += (*buf&0xE0)<<2;
2082         mb_y <<= field_pic;
2083         if (s->picture_structure == PICT_BOTTOM_FIELD)
2084             mb_y++;
2085         if (mb_y < 0 || mb_y >= s->end_mb_y)
2086             return AVERROR_INVALIDDATA;
2087     }
2088 }
2089
2090 /**
2091  * Handle slice ends.
2092  * @return 1 if it seems to be the last slice
2093  */
2094 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
2095 {
2096     Mpeg1Context *s1  = avctx->priv_data;
2097     MpegEncContext *s = &s1->mpeg_enc_ctx;
2098
2099     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
2100         return 0;
2101
2102     if (s->avctx->hwaccel) {
2103         int ret = s->avctx->hwaccel->end_frame(s->avctx);
2104         if (ret < 0) {
2105             av_log(avctx, AV_LOG_ERROR,
2106                    "hardware accelerator failed to decode picture\n");
2107             return ret;
2108         }
2109     }
2110
2111     /* end of slice reached */
2112     if (/* s->mb_y << field_pic == s->mb_height && */ !s->first_field && !s1->first_slice) {
2113         /* end of image */
2114
2115         ff_er_frame_end(&s->er);
2116
2117         ff_mpv_frame_end(s);
2118
2119         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
2120             int ret = av_frame_ref(pict, s->current_picture_ptr->f);
2121             if (ret < 0)
2122                 return ret;
2123             ff_print_debug_info(s, s->current_picture_ptr, pict);
2124             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2125         } else {
2126             if (avctx->active_thread_type & FF_THREAD_FRAME)
2127                 s->picture_number++;
2128             /* latency of 1 frame for I- and P-frames */
2129             /* XXX: use another variable than picture_number */
2130             if (s->last_picture_ptr) {
2131                 int ret = av_frame_ref(pict, s->last_picture_ptr->f);
2132                 if (ret < 0)
2133                     return ret;
2134                 ff_print_debug_info(s, s->last_picture_ptr, pict);
2135                 ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG2);
2136             }
2137         }
2138
2139         return 1;
2140     } else {
2141         return 0;
2142     }
2143 }
2144
2145 static int mpeg1_decode_sequence(AVCodecContext *avctx,
2146                                  const uint8_t *buf, int buf_size)
2147 {
2148     Mpeg1Context *s1  = avctx->priv_data;
2149     MpegEncContext *s = &s1->mpeg_enc_ctx;
2150     int width, height;
2151     int i, v, j;
2152
2153     init_get_bits(&s->gb, buf, buf_size * 8);
2154
2155     width  = get_bits(&s->gb, 12);
2156     height = get_bits(&s->gb, 12);
2157     if (width == 0 || height == 0) {
2158         av_log(avctx, AV_LOG_WARNING,
2159                "Invalid horizontal or vertical size value.\n");
2160         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2161             return AVERROR_INVALIDDATA;
2162     }
2163     s->aspect_ratio_info = get_bits(&s->gb, 4);
2164     if (s->aspect_ratio_info == 0) {
2165         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
2166         if (avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
2167             return AVERROR_INVALIDDATA;
2168     }
2169     s->frame_rate_index = get_bits(&s->gb, 4);
2170     if (s->frame_rate_index == 0 || s->frame_rate_index > 13) {
2171         av_log(avctx, AV_LOG_WARNING,
2172                "frame_rate_index %d is invalid\n", s->frame_rate_index);
2173         s->frame_rate_index = 1;
2174     }
2175     s->bit_rate = get_bits(&s->gb, 18) * 400LL;
2176     if (check_marker(&s->gb, "in sequence header") == 0) {
2177         return AVERROR_INVALIDDATA;
2178     }
2179
2180     s->avctx->rc_buffer_size = get_bits(&s->gb, 10) * 1024 * 16;
2181     skip_bits(&s->gb, 1);
2182
2183     /* get matrix */
2184     if (get_bits1(&s->gb)) {
2185         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2186     } else {
2187         for (i = 0; i < 64; i++) {
2188             j = s->idsp.idct_permutation[i];
2189             v = ff_mpeg1_default_intra_matrix[i];
2190             s->intra_matrix[j]        = v;
2191             s->chroma_intra_matrix[j] = v;
2192         }
2193     }
2194     if (get_bits1(&s->gb)) {
2195         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2196     } else {
2197         for (i = 0; i < 64; i++) {
2198             int j = s->idsp.idct_permutation[i];
2199             v = ff_mpeg1_default_non_intra_matrix[i];
2200             s->inter_matrix[j]        = v;
2201             s->chroma_inter_matrix[j] = v;
2202         }
2203     }
2204
2205     if (show_bits(&s->gb, 23) != 0) {
2206         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2207         return AVERROR_INVALIDDATA;
2208     }
2209
2210     s->width  = width;
2211     s->height = height;
2212
2213     /* We set MPEG-2 parameters so that it emulates MPEG-1. */
2214     s->progressive_sequence = 1;
2215     s->progressive_frame    = 1;
2216     s->picture_structure    = PICT_FRAME;
2217     s->first_field          = 0;
2218     s->frame_pred_frame_dct = 1;
2219     s->chroma_format        = 1;
2220     s->codec_id             =
2221     s->avctx->codec_id      = AV_CODEC_ID_MPEG1VIDEO;
2222     s->out_format           = FMT_MPEG1;
2223     s->swap_uv              = 0; // AFAIK VCR2 does not have SEQ_HEADER
2224     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
2225         s->low_delay = 1;
2226
2227     if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2228         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%"PRId64", aspect_ratio_info: %d \n",
2229                s->avctx->rc_buffer_size, s->bit_rate, s->aspect_ratio_info);
2230
2231     return 0;
2232 }
2233
2234 static int vcr2_init_sequence(AVCodecContext *avctx)
2235 {
2236     Mpeg1Context *s1  = avctx->priv_data;
2237     MpegEncContext *s = &s1->mpeg_enc_ctx;
2238     int i, v, ret;
2239
2240     /* start new MPEG-1 context decoding */
2241     s->out_format = FMT_MPEG1;
2242     if (s1->mpeg_enc_ctx_allocated) {
2243         ff_mpv_common_end(s);
2244         s1->mpeg_enc_ctx_allocated = 0;
2245     }
2246     s->width            = avctx->coded_width;
2247     s->height           = avctx->coded_height;
2248     avctx->has_b_frames = 0; // true?
2249     s->low_delay        = 1;
2250
2251     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2252     setup_hwaccel_for_pixfmt(avctx);
2253
2254     ff_mpv_idct_init(s);
2255     if ((ret = ff_mpv_common_init(s)) < 0)
2256         return ret;
2257     s1->mpeg_enc_ctx_allocated = 1;
2258
2259     for (i = 0; i < 64; i++) {
2260         int j = s->idsp.idct_permutation[i];
2261         v = ff_mpeg1_default_intra_matrix[i];
2262         s->intra_matrix[j]        = v;
2263         s->chroma_intra_matrix[j] = v;
2264
2265         v = ff_mpeg1_default_non_intra_matrix[i];
2266         s->inter_matrix[j]        = v;
2267         s->chroma_inter_matrix[j] = v;
2268     }
2269
2270     s->progressive_sequence  = 1;
2271     s->progressive_frame     = 1;
2272     s->picture_structure     = PICT_FRAME;
2273     s->first_field           = 0;
2274     s->frame_pred_frame_dct  = 1;
2275     s->chroma_format         = 1;
2276     if (s->codec_tag == AV_RL32("BW10")) {
2277         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG1VIDEO;
2278     } else {
2279         s->swap_uv = 1; // in case of xvmc we need to swap uv for each MB
2280         s->codec_id              = s->avctx->codec_id = AV_CODEC_ID_MPEG2VIDEO;
2281     }
2282     s1->save_width           = s->width;
2283     s1->save_height          = s->height;
2284     s1->save_progressive_seq = s->progressive_sequence;
2285     return 0;
2286 }
2287
2288 static int mpeg_decode_a53_cc(AVCodecContext *avctx,
2289                               const uint8_t *p, int buf_size)
2290 {
2291     Mpeg1Context *s1 = avctx->priv_data;
2292
2293     if (buf_size >= 6 &&
2294         p[0] == 'G' && p[1] == 'A' && p[2] == '9' && p[3] == '4' &&
2295         p[4] == 3 && (p[5] & 0x40)) {
2296         /* extract A53 Part 4 CC data */
2297         int cc_count = p[5] & 0x1f;
2298         if (cc_count > 0 && buf_size >= 7 + cc_count * 3) {
2299             av_freep(&s1->a53_caption);
2300             s1->a53_caption_size = cc_count * 3;
2301             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2302             if (s1->a53_caption)
2303                 memcpy(s1->a53_caption, p + 7, s1->a53_caption_size);
2304         }
2305         return 1;
2306     } else if (buf_size >= 11 &&
2307                p[0] == 'C' && p[1] == 'C' && p[2] == 0x01 && p[3] == 0xf8) {
2308         /* extract DVD CC data */
2309         int cc_count = 0;
2310         int i;
2311         // There is a caption count field in the data, but it is often
2312         // incorect.  So count the number of captions present.
2313         for (i = 5; i + 6 <= buf_size && ((p[i] & 0xfe) == 0xfe); i += 6)
2314             cc_count++;
2315         // Transform the DVD format into A53 Part 4 format
2316         if (cc_count > 0) {
2317             av_freep(&s1->a53_caption);
2318             s1->a53_caption_size = cc_count * 6;
2319             s1->a53_caption      = av_malloc(s1->a53_caption_size);
2320             if (s1->a53_caption) {
2321                 uint8_t field1 = !!(p[4] & 0x80);
2322                 uint8_t *cap = s1->a53_caption;
2323                 p += 5;
2324                 for (i = 0; i < cc_count; i++) {
2325                     cap[0] = (p[0] == 0xff && field1) ? 0xfc : 0xfd;
2326                     cap[1] = p[1];
2327                     cap[2] = p[2];
2328                     cap[3] = (p[3] == 0xff && !field1) ? 0xfc : 0xfd;
2329                     cap[4] = p[4];
2330                     cap[5] = p[5];
2331                     cap += 6;
2332                     p += 6;
2333                 }
2334             }
2335         }
2336         return 1;
2337     }
2338     return 0;
2339 }
2340
2341 static void mpeg_decode_user_data(AVCodecContext *avctx,
2342                                   const uint8_t *p, int buf_size)
2343 {
2344     Mpeg1Context *s = avctx->priv_data;
2345     const uint8_t *buf_end = p + buf_size;
2346     Mpeg1Context *s1 = avctx->priv_data;
2347
2348 #if 0
2349     int i;
2350     for(i=0; !(!p[i-2] && !p[i-1] && p[i]==1) && i<buf_size; i++){
2351         av_log(avctx, AV_LOG_ERROR, "%c", p[i]);
2352     }
2353     av_log(avctx, AV_LOG_ERROR, "\n");
2354 #endif
2355
2356     if (buf_size > 29){
2357         int i;
2358         for(i=0; i<20; i++)
2359             if (!memcmp(p+i, "\0TMPGEXS\0", 9)){
2360                 s->tmpgexs= 1;
2361             }
2362     }
2363     /* we parse the DTG active format information */
2364     if (buf_end - p >= 5 &&
2365         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2366         int flags = p[4];
2367         p += 5;
2368         if (flags & 0x80) {
2369             /* skip event id */
2370             p += 2;
2371         }
2372         if (flags & 0x40) {
2373             if (buf_end - p < 1)
2374                 return;
2375 #if FF_API_AFD
2376 FF_DISABLE_DEPRECATION_WARNINGS
2377             avctx->dtg_active_format = p[0] & 0x0f;
2378 FF_ENABLE_DEPRECATION_WARNINGS
2379 #endif /* FF_API_AFD */
2380             s1->has_afd = 1;
2381             s1->afd     = p[0] & 0x0f;
2382         }
2383     } else if (buf_end - p >= 6 &&
2384                p[0] == 'J' && p[1] == 'P' && p[2] == '3' && p[3] == 'D' &&
2385                p[4] == 0x03) { // S3D_video_format_length
2386         // the 0x7F mask ignores the reserved_bit value
2387         const uint8_t S3D_video_format_type = p[5] & 0x7F;
2388
2389         if (S3D_video_format_type == 0x03 ||
2390             S3D_video_format_type == 0x04 ||
2391             S3D_video_format_type == 0x08 ||
2392             S3D_video_format_type == 0x23) {
2393
2394             s1->has_stereo3d = 1;
2395
2396             switch (S3D_video_format_type) {
2397             case 0x03:
2398                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE;
2399                 break;
2400             case 0x04:
2401                 s1->stereo3d.type = AV_STEREO3D_TOPBOTTOM;
2402                 break;
2403             case 0x08:
2404                 s1->stereo3d.type = AV_STEREO3D_2D;
2405                 break;
2406             case 0x23:
2407                 s1->stereo3d.type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
2408                 break;
2409             }
2410         }
2411     } else if (mpeg_decode_a53_cc(avctx, p, buf_size)) {
2412         return;
2413     }
2414 }
2415
2416 static void mpeg_decode_gop(AVCodecContext *avctx,
2417                             const uint8_t *buf, int buf_size)
2418 {
2419     Mpeg1Context *s1  = avctx->priv_data;
2420     MpegEncContext *s = &s1->mpeg_enc_ctx;
2421     int broken_link;
2422     int64_t tc;
2423
2424     init_get_bits(&s->gb, buf, buf_size * 8);
2425
2426     tc = s-> timecode_frame_start = get_bits(&s->gb, 25);
2427
2428 #if FF_API_PRIVATE_OPT
2429 FF_DISABLE_DEPRECATION_WARNINGS
2430     avctx->timecode_frame_start = tc;
2431 FF_ENABLE_DEPRECATION_WARNINGS
2432 #endif
2433
2434     s->closed_gop = get_bits1(&s->gb);
2435     /* broken_link indicate that after editing the
2436      * reference frames of the first B-Frames after GOP I-Frame
2437      * are missing (open gop) */
2438     broken_link = get_bits1(&s->gb);
2439
2440     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2441         char tcbuf[AV_TIMECODE_STR_SIZE];
2442         av_timecode_make_mpeg_tc_string(tcbuf, tc);
2443         av_log(s->avctx, AV_LOG_DEBUG,
2444                "GOP (%s) closed_gop=%d broken_link=%d\n",
2445                tcbuf, s->closed_gop, broken_link);
2446     }
2447 }
2448
2449 static int decode_chunks(AVCodecContext *avctx, AVFrame *picture,
2450                          int *got_output, const uint8_t *buf, int buf_size)
2451 {
2452     Mpeg1Context *s = avctx->priv_data;
2453     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2454     const uint8_t *buf_ptr = buf;
2455     const uint8_t *buf_end = buf + buf_size;
2456     int ret, input_size;
2457     int last_code = 0, skip_frame = 0;
2458     int picture_start_code_seen = 0;
2459
2460     for (;;) {
2461         /* find next start code */
2462         uint32_t start_code = -1;
2463         buf_ptr = avpriv_find_start_code(buf_ptr, buf_end, &start_code);
2464         if (start_code > 0x1ff) {
2465             if (!skip_frame) {
2466                 if (HAVE_THREADS &&
2467                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2468                     !avctx->hwaccel) {
2469                     int i;
2470                     av_assert0(avctx->thread_count > 1);
2471
2472                     avctx->execute(avctx, slice_decode_thread,
2473                                    &s2->thread_context[0], NULL,
2474                                    s->slice_count, sizeof(void *));
2475                     for (i = 0; i < s->slice_count; i++)
2476                         s2->er.error_count += s2->thread_context[i]->er.error_count;
2477                 }
2478
2479 #if FF_API_VDPAU
2480                 if ((CONFIG_MPEG_VDPAU_DECODER || CONFIG_MPEG1_VDPAU_DECODER)
2481                     && uses_vdpau(avctx))
2482                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2483 #endif
2484
2485                 ret = slice_end(avctx, picture);
2486                 if (ret < 0)
2487                     return ret;
2488                 else if (ret) {
2489                     // FIXME: merge with the stuff in mpeg_decode_slice
2490                     if (s2->last_picture_ptr || s2->low_delay)
2491                         *got_output = 1;
2492                 }
2493             }
2494             s2->pict_type = 0;
2495
2496             if (avctx->err_recognition & AV_EF_EXPLODE && s2->er.error_count)
2497                 return AVERROR_INVALIDDATA;
2498
2499             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2500         }
2501
2502         input_size = buf_end - buf_ptr;
2503
2504         if (avctx->debug & FF_DEBUG_STARTCODE)
2505             av_log(avctx, AV_LOG_DEBUG, "%3"PRIX32" at %"PTRDIFF_SPECIFIER" left %d\n",
2506                    start_code, buf_ptr - buf, input_size);
2507
2508         /* prepare data for next start code */
2509         switch (start_code) {
2510         case SEQ_START_CODE:
2511             if (last_code == 0) {
2512                 mpeg1_decode_sequence(avctx, buf_ptr, input_size);
2513                 if (buf != avctx->extradata)
2514                     s->sync = 1;
2515             } else {
2516                 av_log(avctx, AV_LOG_ERROR,
2517                        "ignoring SEQ_START_CODE after %X\n", last_code);
2518                 if (avctx->err_recognition & AV_EF_EXPLODE)
2519                     return AVERROR_INVALIDDATA;
2520             }
2521             break;
2522
2523         case PICTURE_START_CODE:
2524             if (picture_start_code_seen && s2->picture_structure == PICT_FRAME) {
2525                /* If it's a frame picture, there can't be more than one picture header.
2526                   Yet, it does happen and we need to handle it. */
2527                av_log(avctx, AV_LOG_WARNING, "ignoring extra picture following a frame-picture\n");
2528                break;
2529             }
2530             picture_start_code_seen = 1;
2531
2532             if (s2->width <= 0 || s2->height <= 0) {
2533                 av_log(avctx, AV_LOG_ERROR, "Invalid frame dimensions %dx%d.\n",
2534                        s2->width, s2->height);
2535                 return AVERROR_INVALIDDATA;
2536             }
2537
2538             if (s->tmpgexs){
2539                 s2->intra_dc_precision= 3;
2540                 s2->intra_matrix[0]= 1;
2541             }
2542             if (HAVE_THREADS && (avctx->active_thread_type & FF_THREAD_SLICE) &&
2543                 !avctx->hwaccel && s->slice_count) {
2544                 int i;
2545
2546                 avctx->execute(avctx, slice_decode_thread,
2547                                s2->thread_context, NULL,
2548                                s->slice_count, sizeof(void *));
2549                 for (i = 0; i < s->slice_count; i++)
2550                     s2->er.error_count += s2->thread_context[i]->er.error_count;
2551                 s->slice_count = 0;
2552             }
2553             if (last_code == 0 || last_code == SLICE_MIN_START_CODE) {
2554                 ret = mpeg_decode_postinit(avctx);
2555                 if (ret < 0) {
2556                     av_log(avctx, AV_LOG_ERROR,
2557                            "mpeg_decode_postinit() failure\n");
2558                     return ret;
2559                 }
2560
2561                 /* We have a complete image: we try to decompress it. */
2562                 if (mpeg1_decode_picture(avctx, buf_ptr, input_size) < 0)
2563                     s2->pict_type = 0;
2564                 s->first_slice = 1;
2565                 last_code      = PICTURE_START_CODE;
2566             } else {
2567                 av_log(avctx, AV_LOG_ERROR,
2568                        "ignoring pic after %X\n", last_code);
2569                 if (avctx->err_recognition & AV_EF_EXPLODE)
2570                     return AVERROR_INVALIDDATA;
2571             }
2572             break;
2573         case EXT_START_CODE:
2574             init_get_bits(&s2->gb, buf_ptr, input_size * 8);
2575
2576             switch (get_bits(&s2->gb, 4)) {
2577             case 0x1:
2578                 if (last_code == 0) {
2579                     mpeg_decode_sequence_extension(s);
2580                 } else {
2581                     av_log(avctx, AV_LOG_ERROR,
2582                            "ignoring seq ext after %X\n", last_code);
2583                     if (avctx->err_recognition & AV_EF_EXPLODE)
2584                         return AVERROR_INVALIDDATA;
2585                 }
2586                 break;
2587             case 0x2:
2588                 mpeg_decode_sequence_display_extension(s);
2589                 break;
2590             case 0x3:
2591                 mpeg_decode_quant_matrix_extension(s2);
2592                 break;
2593             case 0x7:
2594                 mpeg_decode_picture_display_extension(s);
2595                 break;
2596             case 0x8:
2597                 if (last_code == PICTURE_START_CODE) {
2598                     mpeg_decode_picture_coding_extension(s);
2599                 } else {
2600                     av_log(avctx, AV_LOG_ERROR,
2601                            "ignoring pic cod ext after %X\n", last_code);
2602                     if (avctx->err_recognition & AV_EF_EXPLODE)
2603                         return AVERROR_INVALIDDATA;
2604                 }
2605                 break;
2606             }
2607             break;
2608         case USER_START_CODE:
2609             mpeg_decode_user_data(avctx, buf_ptr, input_size);
2610             break;
2611         case GOP_START_CODE:
2612             if (last_code == 0) {
2613                 s2->first_field = 0;
2614                 mpeg_decode_gop(avctx, buf_ptr, input_size);
2615                 s->sync = 1;
2616             } else {
2617                 av_log(avctx, AV_LOG_ERROR,
2618                        "ignoring GOP_START_CODE after %X\n", last_code);
2619                 if (avctx->err_recognition & AV_EF_EXPLODE)
2620                     return AVERROR_INVALIDDATA;
2621             }
2622             break;
2623         default:
2624             if (start_code >= SLICE_MIN_START_CODE &&
2625                 start_code <= SLICE_MAX_START_CODE && last_code == PICTURE_START_CODE) {
2626                 if (s2->progressive_sequence && !s2->progressive_frame) {
2627                     s2->progressive_frame = 1;
2628                     av_log(s2->avctx, AV_LOG_ERROR,
2629                            "interlaced frame in progressive sequence, ignoring\n");
2630                 }
2631
2632                 if (s2->picture_structure == 0 ||
2633                     (s2->progressive_frame && s2->picture_structure != PICT_FRAME)) {
2634                     av_log(s2->avctx, AV_LOG_ERROR,
2635                            "picture_structure %d invalid, ignoring\n",
2636                            s2->picture_structure);
2637                     s2->picture_structure = PICT_FRAME;
2638                 }
2639
2640                 if (s2->progressive_sequence && !s2->frame_pred_frame_dct)
2641                     av_log(s2->avctx, AV_LOG_WARNING, "invalid frame_pred_frame_dct\n");
2642
2643                 if (s2->picture_structure == PICT_FRAME) {
2644                     s2->first_field = 0;
2645                     s2->v_edge_pos  = 16 * s2->mb_height;
2646                 } else {
2647                     s2->first_field ^= 1;
2648                     s2->v_edge_pos   = 8 * s2->mb_height;
2649                     memset(s2->mbskip_table, 0, s2->mb_stride * s2->mb_height);
2650                 }
2651             }
2652             if (start_code >= SLICE_MIN_START_CODE &&
2653                 start_code <= SLICE_MAX_START_CODE && last_code != 0) {
2654                 const int field_pic = s2->picture_structure != PICT_FRAME;
2655                 int mb_y = start_code - SLICE_MIN_START_CODE;
2656                 last_code = SLICE_MIN_START_CODE;
2657                 if (s2->codec_id != AV_CODEC_ID_MPEG1VIDEO && s2->mb_height > 2800/16)
2658                     mb_y += (*buf_ptr&0xE0)<<2;
2659
2660                 mb_y <<= field_pic;
2661                 if (s2->picture_structure == PICT_BOTTOM_FIELD)
2662                     mb_y++;
2663
2664                 if (buf_end - buf_ptr < 2) {
2665                     av_log(s2->avctx, AV_LOG_ERROR, "slice too small\n");
2666                     return AVERROR_INVALIDDATA;
2667                 }
2668
2669                 if (mb_y >= s2->mb_height) {
2670                     av_log(s2->avctx, AV_LOG_ERROR,
2671                            "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2672                     return AVERROR_INVALIDDATA;
2673                 }
2674
2675                 if (!s2->last_picture_ptr) {
2676                     /* Skip B-frames if we do not have reference frames and
2677                      * GOP is not closed. */
2678                     if (s2->pict_type == AV_PICTURE_TYPE_B) {
2679                         if (!s2->closed_gop) {
2680                             skip_frame = 1;
2681                             break;
2682                         }
2683                     }
2684                 }
2685                 if (s2->pict_type == AV_PICTURE_TYPE_I || (s2->avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
2686                     s->sync = 1;
2687                 if (!s2->next_picture_ptr) {
2688                     /* Skip P-frames if we do not have a reference frame or
2689                      * we have an invalid header. */
2690                     if (s2->pict_type == AV_PICTURE_TYPE_P && !s->sync) {
2691                         skip_frame = 1;
2692                         break;
2693                     }
2694                 }
2695                 if ((avctx->skip_frame >= AVDISCARD_NONREF &&
2696                      s2->pict_type == AV_PICTURE_TYPE_B) ||
2697                     (avctx->skip_frame >= AVDISCARD_NONKEY &&
2698                      s2->pict_type != AV_PICTURE_TYPE_I) ||
2699                     avctx->skip_frame >= AVDISCARD_ALL) {
2700                     skip_frame = 1;
2701                     break;
2702                 }
2703
2704                 if (!s->mpeg_enc_ctx_allocated)
2705                     break;
2706
2707                 if (s2->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
2708                     if (mb_y < avctx->skip_top ||
2709                         mb_y >= s2->mb_height - avctx->skip_bottom)
2710                         break;
2711                 }
2712
2713                 if (!s2->pict_type) {
2714                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2715                     if (avctx->err_recognition & AV_EF_EXPLODE)
2716                         return AVERROR_INVALIDDATA;
2717                     break;
2718                 }
2719
2720                 if (s->first_slice) {
2721                     skip_frame     = 0;
2722                     s->first_slice = 0;
2723                     if ((ret = mpeg_field_start(s2, buf, buf_size)) < 0)
2724                         return ret;
2725                 }
2726                 if (!s2->current_picture_ptr) {
2727                     av_log(avctx, AV_LOG_ERROR,
2728                            "current_picture not initialized\n");
2729                     return AVERROR_INVALIDDATA;
2730                 }
2731
2732 #if FF_API_VDPAU
2733                 if (uses_vdpau(avctx)) {
2734                     s->slice_count++;
2735                     break;
2736                 }
2737 #endif
2738
2739                 if (HAVE_THREADS &&
2740                     (avctx->active_thread_type & FF_THREAD_SLICE) &&
2741                     !avctx->hwaccel) {
2742                     int threshold = (s2->mb_height * s->slice_count +
2743                                      s2->slice_context_count / 2) /
2744                                     s2->slice_context_count;
2745                     av_assert0(avctx->thread_count > 1);
2746                     if (threshold <= mb_y) {
2747                         MpegEncContext *thread_context = s2->thread_context[s->slice_count];
2748
2749                         thread_context->start_mb_y = mb_y;
2750                         thread_context->end_mb_y   = s2->mb_height;
2751                         if (s->slice_count) {
2752                             s2->thread_context[s->slice_count - 1]->end_mb_y = mb_y;
2753                             ret = ff_update_duplicate_context(thread_context, s2);
2754                             if (ret < 0)
2755                                 return ret;
2756                         }
2757                         init_get_bits(&thread_context->gb, buf_ptr, input_size * 8);
2758                         s->slice_count++;
2759                     }
2760                     buf_ptr += 2; // FIXME add minimum number of bytes per slice
2761                 } else {
2762                     ret = mpeg_decode_slice(s2, mb_y, &buf_ptr, input_size);
2763                     emms_c();
2764
2765                     if (ret < 0) {
2766                         if (avctx->err_recognition & AV_EF_EXPLODE)
2767                             return ret;
2768                         if (s2->resync_mb_x >= 0 && s2->resync_mb_y >= 0)
2769                             ff_er_add_slice(&s2->er, s2->resync_mb_x,
2770                                             s2->resync_mb_y, s2->mb_x, s2->mb_y,
2771                                             ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
2772                     } else {
2773                         ff_er_add_slice(&s2->er, s2->resync_mb_x,
2774                                         s2->resync_mb_y, s2->mb_x - 1, s2->mb_y,
2775                                         ER_AC_END | ER_DC_END | ER_MV_END);
2776                     }
2777                 }
2778             }
2779             break;
2780         }
2781     }
2782 }
2783
2784 static int mpeg_decode_frame(AVCodecContext *avctx, void *data,
2785                              int *got_output, AVPacket *avpkt)
2786 {
2787     const uint8_t *buf = avpkt->data;
2788     int ret;
2789     int buf_size = avpkt->size;
2790     Mpeg1Context *s = avctx->priv_data;
2791     AVFrame *picture = data;
2792     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2793
2794     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2795         /* special case for last picture */
2796         if (s2->low_delay == 0 && s2->next_picture_ptr) {
2797             int ret = av_frame_ref(picture, s2->next_picture_ptr->f);
2798             if (ret < 0)
2799                 return ret;
2800
2801             s2->next_picture_ptr = NULL;
2802
2803             *got_output = 1;
2804         }
2805         return buf_size;
2806     }
2807
2808     if (s2->avctx->flags & AV_CODEC_FLAG_TRUNCATED) {
2809         int next = ff_mpeg1_find_frame_end(&s2->parse_context, buf,
2810                                            buf_size, NULL);
2811
2812         if (ff_combine_frame(&s2->parse_context, next,
2813                              (const uint8_t **) &buf, &buf_size) < 0)
2814             return buf_size;
2815     }
2816
2817     s2->codec_tag = avpriv_toupper4(avctx->codec_tag);
2818     if (s->mpeg_enc_ctx_allocated == 0 && (   s2->codec_tag == AV_RL32("VCR2")
2819                                            || s2->codec_tag == AV_RL32("BW10")
2820                                           ))
2821         vcr2_init_sequence(avctx);
2822
2823     s->slice_count = 0;
2824
2825     if (avctx->extradata && !s->extradata_decoded) {
2826         ret = decode_chunks(avctx, picture, got_output,
2827                             avctx->extradata, avctx->extradata_size);
2828         if (*got_output) {
2829             av_log(avctx, AV_LOG_ERROR, "picture in extradata\n");
2830             *got_output = 0;
2831         }
2832         s->extradata_decoded = 1;
2833         if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE)) {
2834             s2->current_picture_ptr = NULL;
2835             return ret;
2836         }
2837     }
2838
2839     ret = decode_chunks(avctx, picture, got_output, buf, buf_size);
2840     if (ret<0 || *got_output) {
2841         s2->current_picture_ptr = NULL;
2842
2843         if (s2->timecode_frame_start != -1 && *got_output) {
2844             AVFrameSideData *tcside = av_frame_new_side_data(picture,
2845                                                              AV_FRAME_DATA_GOP_TIMECODE,
2846                                                              sizeof(int64_t));
2847             if (!tcside)
2848                 return AVERROR(ENOMEM);
2849             memcpy(tcside->data, &s2->timecode_frame_start, sizeof(int64_t));
2850
2851             s2->timecode_frame_start = -1;
2852         }
2853     }
2854
2855     return ret;
2856 }
2857
2858 static void flush(AVCodecContext *avctx)
2859 {
2860     Mpeg1Context *s = avctx->priv_data;
2861
2862     s->sync       = 0;
2863
2864     ff_mpeg_flush(avctx);
2865 }
2866
2867 static av_cold int mpeg_decode_end(AVCodecContext *avctx)
2868 {
2869     Mpeg1Context *s = avctx->priv_data;
2870
2871     if (s->mpeg_enc_ctx_allocated)
2872         ff_mpv_common_end(&s->mpeg_enc_ctx);
2873     av_freep(&s->a53_caption);
2874     return 0;
2875 }
2876
2877 AVCodec ff_mpeg1video_decoder = {
2878     .name                  = "mpeg1video",
2879     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2880     .type                  = AVMEDIA_TYPE_VIDEO,
2881     .id                    = AV_CODEC_ID_MPEG1VIDEO,
2882     .priv_data_size        = sizeof(Mpeg1Context),
2883     .init                  = mpeg_decode_init,
2884     .close                 = mpeg_decode_end,
2885     .decode                = mpeg_decode_frame,
2886     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2887                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2888                              AV_CODEC_CAP_SLICE_THREADS,
2889     .flush                 = flush,
2890     .max_lowres            = 3,
2891     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2892 };
2893
2894 AVCodec ff_mpeg2video_decoder = {
2895     .name           = "mpeg2video",
2896     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2897     .type           = AVMEDIA_TYPE_VIDEO,
2898     .id             = AV_CODEC_ID_MPEG2VIDEO,
2899     .priv_data_size = sizeof(Mpeg1Context),
2900     .init           = mpeg_decode_init,
2901     .close          = mpeg_decode_end,
2902     .decode         = mpeg_decode_frame,
2903     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2904                       AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
2905                       AV_CODEC_CAP_SLICE_THREADS,
2906     .flush          = flush,
2907     .max_lowres     = 3,
2908     .profiles       = NULL_IF_CONFIG_SMALL(ff_mpeg2_video_profiles),
2909 };
2910
2911 //legacy decoder
2912 AVCodec ff_mpegvideo_decoder = {
2913     .name           = "mpegvideo",
2914     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2915     .type           = AVMEDIA_TYPE_VIDEO,
2916     .id             = AV_CODEC_ID_MPEG2VIDEO,
2917     .priv_data_size = sizeof(Mpeg1Context),
2918     .init           = mpeg_decode_init,
2919     .close          = mpeg_decode_end,
2920     .decode         = mpeg_decode_frame,
2921     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_SLICE_THREADS,
2922     .flush          = flush,
2923     .max_lowres     = 3,
2924 };
2925
2926 #if FF_API_XVMC
2927 #if CONFIG_MPEG_XVMC_DECODER
2928 FF_DISABLE_DEPRECATION_WARNINGS
2929 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx)
2930 {
2931     if (avctx->active_thread_type & FF_THREAD_SLICE)
2932         return -1;
2933     if (!(avctx->slice_flags & SLICE_FLAG_CODED_ORDER))
2934         return -1;
2935     if (!(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD)) {
2936         ff_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2937     }
2938     mpeg_decode_init(avctx);
2939
2940     avctx->pix_fmt           = AV_PIX_FMT_XVMC_MPEG2_IDCT;
2941     avctx->xvmc_acceleration = 2; // 2 - the blocks are packed!
2942
2943     return 0;
2944 }
2945
2946 AVCodec ff_mpeg_xvmc_decoder = {
2947     .name           = "mpegvideo_xvmc",
2948     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2949     .type           = AVMEDIA_TYPE_VIDEO,
2950     .id             = AV_CODEC_ID_MPEG2VIDEO_XVMC,
2951     .priv_data_size = sizeof(Mpeg1Context),
2952     .init           = mpeg_mc_decode_init,
2953     .close          = mpeg_decode_end,
2954     .decode         = mpeg_decode_frame,
2955     .capabilities   = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
2956                       AV_CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL |
2957                       AV_CODEC_CAP_DELAY,
2958     .flush          = flush,
2959 };
2960 FF_ENABLE_DEPRECATION_WARNINGS
2961 #endif
2962 #endif /* FF_API_XVMC */
2963
2964 #if CONFIG_MPEG_VDPAU_DECODER && FF_API_VDPAU
2965 AVCodec ff_mpeg_vdpau_decoder = {
2966     .name           = "mpegvideo_vdpau",
2967     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2968     .type           = AVMEDIA_TYPE_VIDEO,
2969     .id             = AV_CODEC_ID_MPEG2VIDEO,
2970     .priv_data_size = sizeof(Mpeg1Context),
2971     .init           = mpeg_decode_init,
2972     .close          = mpeg_decode_end,
2973     .decode         = mpeg_decode_frame,
2974     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2975                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2976     .flush          = flush,
2977 };
2978 #endif
2979
2980 #if CONFIG_MPEG1_VDPAU_DECODER && FF_API_VDPAU
2981 AVCodec ff_mpeg1_vdpau_decoder = {
2982     .name           = "mpeg1video_vdpau",
2983     .long_name      = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2984     .type           = AVMEDIA_TYPE_VIDEO,
2985     .id             = AV_CODEC_ID_MPEG1VIDEO,
2986     .priv_data_size = sizeof(Mpeg1Context),
2987     .init           = mpeg_decode_init,
2988     .close          = mpeg_decode_end,
2989     .decode         = mpeg_decode_frame,
2990     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_TRUNCATED |
2991                       AV_CODEC_CAP_HWACCEL_VDPAU | AV_CODEC_CAP_DELAY,
2992     .flush          = flush,
2993 };
2994 #endif