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   1 /*
   2  * MPEG-1/2 decoder
   3  * Copyright (c) 2000,2001 Fabrice Bellard
   4  * Copyright (c) 2002-2004 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 DEBUG
  29 #include "internal.h"
  30 #include "avcodec.h"
  31 #include "dsputil.h"
  32 #include "mpegvideo.h"
  33
  34 #include "mpeg12.h"
  35 #include "mpeg12data.h"
  36 #include "mpeg12decdata.h"
  37 #include "bytestream.h"
  38 #include "vdpau_internal.h"
  39 #include "xvmc_internal.h"
  40 #include "thread.h"
  41
  42 //#undef NDEBUG
  43 //#include <assert.h>
  44
  45
  46 #define MV_VLC_BITS 9
  47 #define MBINCR_VLC_BITS 9
  48 #define MB_PAT_VLC_BITS 9
  49 #define MB_PTYPE_VLC_BITS 6
  50 #define MB_BTYPE_VLC_BITS 6
  51
  52 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  53                               DCTELEM *block,
  54                               int n);
  55 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  56                               DCTELEM *block,
  57                               int n);
  58 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  59 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  60                                         DCTELEM *block,
  61                                         int n);
  62 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  63                                     DCTELEM *block,
  64                                     int n);
  65 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  66 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  67 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  68 static void exchange_uv(MpegEncContext *s);
  69
  70 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  71                                            PIX_FMT_XVMC_MPEG2_IDCT,
  72                                            PIX_FMT_XVMC_MPEG2_MC,
  73                                            PIX_FMT_NONE};
  74
  75 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  76
  77
  78 #define INIT_2D_VLC_RL(rl, static_size)\
  79 {\
  80     static RL_VLC_ELEM rl_vlc_table[static_size];\
  81     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  82              &rl.table_vlc[0][1], 4, 2,\
  83              &rl.table_vlc[0][0], 4, 2, static_size);\
  84 \
  85     rl.rl_vlc[0]= rl_vlc_table;\
  86     init_2d_vlc_rl(&rl);\
  87 }
  88
  89 static void init_2d_vlc_rl(RLTable *rl)
  90 {
  91     int i;
  92
  93     for(i=0; i<rl->vlc.table_size; i++){
  94         int code= rl->vlc.table[i][0];
  95         int len = rl->vlc.table[i][1];
  96         int level, run;
  97
  98         if(len==0){ // illegal code
  99             run= 65;
 100             level= MAX_LEVEL;
 101         }else if(len<0){ //more bits needed
 102             run= 0;
 103             level= code;
 104         }else{
 105             if(code==rl->n){ //esc
 106                 run= 65;
 107                 level= 0;
 108             }else if(code==rl->n+1){ //eob
 109                 run= 0;
 110                 level= 127;
 111             }else{
 112                 run=   rl->table_run  [code] + 1;
 113                 level= rl->table_level[code];
 114             }
 115         }
 116         rl->rl_vlc[0][i].len= len;
 117         rl->rl_vlc[0][i].level= level;
 118         rl->rl_vlc[0][i].run= run;
 119     }
 120 }
 121
 122 void ff_mpeg12_common_init(MpegEncContext *s)
 123 {
 124
 125     s->y_dc_scale_table=
 126     s->c_dc_scale_table= ff_mpeg2_dc_scale_table[s->intra_dc_precision];
 127
 128 }
 129
 130 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 131     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 132     s->last_dc[1] = s->last_dc[0];
 133     s->last_dc[2] = s->last_dc[0];
 134     memset(s->last_mv, 0, sizeof(s->last_mv));
 135 }
 136
 137
 138 /******************************************/
 139 /* decoding */
 140
 141 VLC ff_dc_lum_vlc;
 142 VLC ff_dc_chroma_vlc;
 143
 144 static VLC mv_vlc;
 145 static VLC mbincr_vlc;
 146 static VLC mb_ptype_vlc;
 147 static VLC mb_btype_vlc;
 148 static VLC mb_pat_vlc;
 149
 150 av_cold void ff_mpeg12_init_vlcs(void)
 151 {
 152     static int done = 0;
 153
 154     if (!done) {
 155         done = 1;
 156
 157         INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12,
 158                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 159                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 160         INIT_VLC_STATIC(&ff_dc_chroma_vlc,  DC_VLC_BITS, 12,
 161                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 162                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 163         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 164                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 165                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 166         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 167                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 168                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 169         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 170                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 171                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 172
 173         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 174                  &table_mb_ptype[0][1], 2, 1,
 175                  &table_mb_ptype[0][0], 2, 1, 64);
 176         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 177                  &table_mb_btype[0][1], 2, 1,
 178                  &table_mb_btype[0][0], 2, 1, 64);
 179         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 180         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 181
 182         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 183         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 184     }
 185 }
 186
 187 static inline int get_dmv(MpegEncContext *s)
 188 {
 189     if(get_bits1(&s->gb))
 190         return 1 - (get_bits1(&s->gb) << 1);
 191     else
 192         return 0;
 193 }
 194
 195 static inline int get_qscale(MpegEncContext *s)
 196 {
 197     int qscale = get_bits(&s->gb, 5);
 198     if (s->q_scale_type) {
 199         return non_linear_qscale[qscale];
 200     } else {
 201         return qscale << 1;
 202     }
 203 }
 204
 205 /* motion type (for MPEG-2) */
 206 #define MT_FIELD 1
 207 #define MT_FRAME 2
 208 #define MT_16X8  2
 209 #define MT_DMV   3
 210
 211 static int mpeg_decode_mb(MpegEncContext *s,
 212                           DCTELEM block[12][64])
 213 {
 214     int i, j, k, cbp, val, mb_type, motion_type;
 215     const int mb_block_count = 4 + (1<< s->chroma_format);
 216
 217     av_dlog(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 218
 219     assert(s->mb_skipped==0);
 220
 221     if (s->mb_skip_run-- != 0) {
 222         if (s->pict_type == FF_P_TYPE) {
 223             s->mb_skipped = 1;
 224             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 225         } else {
 226             int mb_type;
 227
 228             if(s->mb_x)
 229                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 230             else
 231                 mb_type= s->current_picture.mb_type[ s->mb_width + (s->mb_y-1)*s->mb_stride - 1]; // FIXME not sure if this is allowed in MPEG at all
 232             if(IS_INTRA(mb_type))
 233                 return -1;
 234
 235             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 236                 mb_type | MB_TYPE_SKIP;
 237 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 238
 239             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 240                 s->mb_skipped = 1;
 241         }
 242
 243         return 0;
 244     }
 245
 246     switch(s->pict_type) {
 247     default:
 248     case FF_I_TYPE:
 249         if (get_bits1(&s->gb) == 0) {
 250             if (get_bits1(&s->gb) == 0){
 251                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 252                 return -1;
 253             }
 254             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 255         } else {
 256             mb_type = MB_TYPE_INTRA;
 257         }
 258         break;
 259     case FF_P_TYPE:
 260         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 261         if (mb_type < 0){
 262             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 263             return -1;
 264         }
 265         mb_type = ptype2mb_type[ mb_type ];
 266         break;
 267     case FF_B_TYPE:
 268         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 269         if (mb_type < 0){
 270             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 271             return -1;
 272         }
 273         mb_type = btype2mb_type[ mb_type ];
 274         break;
 275     }
 276     av_dlog(s->avctx, "mb_type=%x\n", mb_type);
 277 //    motion_type = 0; /* avoid warning */
 278     if (IS_INTRA(mb_type)) {
 279         s->dsp.clear_blocks(s->block[0]);
 280
 281         if(!s->chroma_y_shift){
 282             s->dsp.clear_blocks(s->block[6]);
 283         }
 284
 285         /* compute DCT type */
 286         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 287             !s->frame_pred_frame_dct) {
 288             s->interlaced_dct = get_bits1(&s->gb);
 289         }
 290
 291         if (IS_QUANT(mb_type))
 292             s->qscale = get_qscale(s);
 293
 294         if (s->concealment_motion_vectors) {
 295             /* just parse them */
 296             if (s->picture_structure != PICT_FRAME)
 297                 skip_bits1(&s->gb); /* field select */
 298
 299             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 300                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 301             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 302                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 303
 304             skip_bits1(&s->gb); /* marker */
 305         }else
 306             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 307         s->mb_intra = 1;
 308         //if 1, we memcpy blocks in xvmcvideo
 309         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 310             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
 311             if(s->swap_uv){
 312                 exchange_uv(s);
 313             }
 314         }
 315
 316         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 317             if(s->flags2 & CODEC_FLAG2_FAST){
 318                 for(i=0;i<6;i++) {
 319                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 320                 }
 321             }else{
 322                 for(i=0;i<mb_block_count;i++) {
 323                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
 324                         return -1;
 325                 }
 326             }
 327         } else {
 328             for(i=0;i<6;i++) {
 329                 if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
 330                     return -1;
 331             }
 332         }
 333     } else {
 334         if (mb_type & MB_TYPE_ZERO_MV){
 335             assert(mb_type & MB_TYPE_CBP);
 336
 337             s->mv_dir = MV_DIR_FORWARD;
 338             if(s->picture_structure == PICT_FRAME){
 339                 if(!s->frame_pred_frame_dct)
 340                     s->interlaced_dct = get_bits1(&s->gb);
 341                 s->mv_type = MV_TYPE_16X16;
 342             }else{
 343                 s->mv_type = MV_TYPE_FIELD;
 344                 mb_type |= MB_TYPE_INTERLACED;
 345                 s->field_select[0][0]= s->picture_structure - 1;
 346             }
 347
 348             if (IS_QUANT(mb_type))
 349                 s->qscale = get_qscale(s);
 350
 351             s->last_mv[0][0][0] = 0;
 352             s->last_mv[0][0][1] = 0;
 353             s->last_mv[0][1][0] = 0;
 354             s->last_mv[0][1][1] = 0;
 355             s->mv[0][0][0] = 0;
 356             s->mv[0][0][1] = 0;
 357         }else{
 358             assert(mb_type & MB_TYPE_L0L1);
 359 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 360             /* get additional motion vector type */
 361             if (s->frame_pred_frame_dct)
 362                 motion_type = MT_FRAME;
 363             else{
 364                 motion_type = get_bits(&s->gb, 2);
 365                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 366                     s->interlaced_dct = get_bits1(&s->gb);
 367             }
 368
 369             if (IS_QUANT(mb_type))
 370                 s->qscale = get_qscale(s);
 371
 372             /* motion vectors */
 373             s->mv_dir= (mb_type>>13)&3;
 374             av_dlog(s->avctx, "motion_type=%d\n", motion_type);
 375             switch(motion_type) {
 376             case MT_FRAME: /* or MT_16X8 */
 377                 if (s->picture_structure == PICT_FRAME) {
 378                     mb_type |= MB_TYPE_16x16;
 379                     s->mv_type = MV_TYPE_16X16;
 380                     for(i=0;i<2;i++) {
 381                         if (USES_LIST(mb_type, i)) {
 382                             /* MT_FRAME */
 383                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 384                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 385                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 386                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 387                             /* full_pel: only for MPEG-1 */
 388                             if (s->full_pel[i]){
 389                                 s->mv[i][0][0] <<= 1;
 390                                 s->mv[i][0][1] <<= 1;
 391                             }
 392                         }
 393                     }
 394                 } else {
 395                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 396                     s->mv_type = MV_TYPE_16X8;
 397                     for(i=0;i<2;i++) {
 398                         if (USES_LIST(mb_type, i)) {
 399                             /* MT_16X8 */
 400                             for(j=0;j<2;j++) {
 401                                 s->field_select[i][j] = get_bits1(&s->gb);
 402                                 for(k=0;k<2;k++) {
 403                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 404                                                              s->last_mv[i][j][k]);
 405                                     s->last_mv[i][j][k] = val;
 406                                     s->mv[i][j][k] = val;
 407                                 }
 408                             }
 409                         }
 410                     }
 411                 }
 412                 break;
 413             case MT_FIELD:
 414                 s->mv_type = MV_TYPE_FIELD;
 415                 if (s->picture_structure == PICT_FRAME) {
 416                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 417                     for(i=0;i<2;i++) {
 418                         if (USES_LIST(mb_type, i)) {
 419                             for(j=0;j<2;j++) {
 420                                 s->field_select[i][j] = get_bits1(&s->gb);
 421                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 422                                                          s->last_mv[i][j][0]);
 423                                 s->last_mv[i][j][0] = val;
 424                                 s->mv[i][j][0] = val;
 425                                 av_dlog(s->avctx, "fmx=%d\n", val);
 426                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 427                                                          s->last_mv[i][j][1] >> 1);
 428                                 s->last_mv[i][j][1] = val << 1;
 429                                 s->mv[i][j][1] = val;
 430                                 av_dlog(s->avctx, "fmy=%d\n", val);
 431                             }
 432                         }
 433                     }
 434                 } else {
 435                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 436                     for(i=0;i<2;i++) {
 437                         if (USES_LIST(mb_type, i)) {
 438                             s->field_select[i][0] = get_bits1(&s->gb);
 439                             for(k=0;k<2;k++) {
 440                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 441                                                          s->last_mv[i][0][k]);
 442                                 s->last_mv[i][0][k] = val;
 443                                 s->last_mv[i][1][k] = val;
 444                                 s->mv[i][0][k] = val;
 445                             }
 446                         }
 447                     }
 448                 }
 449                 break;
 450             case MT_DMV:
 451                 s->mv_type = MV_TYPE_DMV;
 452                 for(i=0;i<2;i++) {
 453                     if (USES_LIST(mb_type, i)) {
 454                         int dmx, dmy, mx, my, m;
 455                         const int my_shift= s->picture_structure == PICT_FRAME;
 456
 457                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 458                                                 s->last_mv[i][0][0]);
 459                         s->last_mv[i][0][0] = mx;
 460                         s->last_mv[i][1][0] = mx;
 461                         dmx = get_dmv(s);
 462                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 463                                                 s->last_mv[i][0][1] >> my_shift);
 464                         dmy = get_dmv(s);
 465
 466
 467                         s->last_mv[i][0][1] = my<<my_shift;
 468                         s->last_mv[i][1][1] = my<<my_shift;
 469
 470                         s->mv[i][0][0] = mx;
 471                         s->mv[i][0][1] = my;
 472                         s->mv[i][1][0] = mx;//not used
 473                         s->mv[i][1][1] = my;//not used
 474
 475                         if (s->picture_structure == PICT_FRAME) {
 476                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 477
 478                             //m = 1 + 2 * s->top_field_first;
 479                             m = s->top_field_first ? 1 : 3;
 480
 481                             /* top -> top pred */
 482                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 483                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 484                             m = 4 - m;
 485                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 486                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 487                         } else {
 488                             mb_type |= MB_TYPE_16x16;
 489
 490                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 491                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 492                             if(s->picture_structure == PICT_TOP_FIELD)
 493                                 s->mv[i][2][1]--;
 494                             else
 495                                 s->mv[i][2][1]++;
 496                         }
 497                     }
 498                 }
 499                 break;
 500             default:
 501                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 502                 return -1;
 503             }
 504         }
 505
 506         s->mb_intra = 0;
 507         if (HAS_CBP(mb_type)) {
 508             s->dsp.clear_blocks(s->block[0]);
 509
 510             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 511             if(mb_block_count > 6){
 512                  cbp<<= mb_block_count-6;
 513                  cbp |= get_bits(&s->gb, mb_block_count-6);
 514                  s->dsp.clear_blocks(s->block[6]);
 515             }
 516             if (cbp <= 0){
 517                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 518                 return -1;
 519             }
 520
 521             //if 1, we memcpy blocks in xvmcvideo
 522             if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 523                 ff_xvmc_pack_pblocks(s,cbp);
 524                 if(s->swap_uv){
 525                     exchange_uv(s);
 526                 }
 527             }
 528
 529             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 530                 if(s->flags2 & CODEC_FLAG2_FAST){
 531                     for(i=0;i<6;i++) {
 532                         if(cbp & 32) {
 533                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
 534                         } else {
 535                             s->block_last_index[i] = -1;
 536                         }
 537                         cbp+=cbp;
 538                     }
 539                 }else{
 540                     cbp<<= 12-mb_block_count;
 541
 542                     for(i=0;i<mb_block_count;i++) {
 543                         if ( cbp & (1<<11) ) {
 544                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
 545                                 return -1;
 546                         } else {
 547                             s->block_last_index[i] = -1;
 548                         }
 549                         cbp+=cbp;
 550                     }
 551                 }
 552             } else {
 553                 if(s->flags2 & CODEC_FLAG2_FAST){
 554                     for(i=0;i<6;i++) {
 555                         if (cbp & 32) {
 556                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
 557                         } else {
 558                             s->block_last_index[i] = -1;
 559                         }
 560                         cbp+=cbp;
 561                     }
 562                 }else{
 563                     for(i=0;i<6;i++) {
 564                         if (cbp & 32) {
 565                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
 566                                 return -1;
 567                         } else {
 568                             s->block_last_index[i] = -1;
 569                         }
 570                         cbp+=cbp;
 571                     }
 572                 }
 573             }
 574         }else{
 575             for(i=0;i<12;i++)
 576                 s->block_last_index[i] = -1;
 577         }
 578     }
 579
 580     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 581
 582     return 0;
 583 }
 584
 585 /* as H.263, but only 17 codes */
 586 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 587 {
 588     int code, sign, val, l, shift;
 589
 590     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 591     if (code == 0) {
 592         return pred;
 593     }
 594     if (code < 0) {
 595         return 0xffff;
 596     }
 597
 598     sign = get_bits1(&s->gb);
 599     shift = fcode - 1;
 600     val = code;
 601     if (shift) {
 602         val = (val - 1) << shift;
 603         val |= get_bits(&s->gb, shift);
 604         val++;
 605     }
 606     if (sign)
 607         val = -val;
 608     val += pred;
 609
 610     /* modulo decoding */
 611     l= INT_BIT - 5 - shift;
 612     val = (val<<l)>>l;
 613     return val;
 614 }
 615
 616 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 617                                DCTELEM *block,
 618                                int n)
 619 {
 620     int level, dc, diff, i, j, run;
 621     int component;
 622     RLTable *rl = &ff_rl_mpeg1;
 623     uint8_t * const scantable= s->intra_scantable.permutated;
 624     const uint16_t *quant_matrix= s->intra_matrix;
 625     const int qscale= s->qscale;
 626
 627     /* DC coefficient */
 628     component = (n <= 3 ? 0 : n - 4 + 1);
 629     diff = decode_dc(&s->gb, component);
 630     if (diff >= 0xffff)
 631         return -1;
 632     dc = s->last_dc[component];
 633     dc += diff;
 634     s->last_dc[component] = dc;
 635     block[0] = dc*quant_matrix[0];
 636     av_dlog(s->avctx, "dc=%d diff=%d\n", dc, diff);
 637     i = 0;
 638     {
 639         OPEN_READER(re, &s->gb);
 640         /* now quantify & encode AC coefficients */
 641         for(;;) {
 642             UPDATE_CACHE(re, &s->gb);
 643             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 644
 645             if(level == 127){
 646                 break;
 647             } else if(level != 0) {
 648                 i += run;
 649                 j = scantable[i];
 650                 level= (level*qscale*quant_matrix[j])>>4;
 651                 level= (level-1)|1;
 652                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 653                 LAST_SKIP_BITS(re, &s->gb, 1);
 654             } else {
 655                 /* escape */
 656                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 657                 UPDATE_CACHE(re, &s->gb);
 658                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 659                 if (level == -128) {
 660                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 661                 } else if (level == 0) {
 662                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 663                 }
 664                 i += run;
 665                 j = scantable[i];
 666                 if(level<0){
 667                     level= -level;
 668                     level= (level*qscale*quant_matrix[j])>>4;
 669                     level= (level-1)|1;
 670                     level= -level;
 671                 }else{
 672                     level= (level*qscale*quant_matrix[j])>>4;
 673                     level= (level-1)|1;
 674                 }
 675             }
 676             if (i > 63){
 677                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 678                 return -1;
 679             }
 680
 681             block[j] = level;
 682         }
 683         CLOSE_READER(re, &s->gb);
 684     }
 685     s->block_last_index[n] = i;
 686    return 0;
 687 }
 688
 689 int ff_mpeg1_decode_block_intra(MpegEncContext *s,
 690                                 DCTELEM *block,
 691                                 int n)
 692 {
 693     return mpeg1_decode_block_intra(s, block, n);
 694 }
 695
 696 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 697                                DCTELEM *block,
 698                                int n)
 699 {
 700     int level, i, j, run;
 701     RLTable *rl = &ff_rl_mpeg1;
 702     uint8_t * const scantable= s->intra_scantable.permutated;
 703     const uint16_t *quant_matrix= s->inter_matrix;
 704     const int qscale= s->qscale;
 705
 706     {
 707         OPEN_READER(re, &s->gb);
 708         i = -1;
 709         // special case for first coefficient, no need to add second VLC table
 710         UPDATE_CACHE(re, &s->gb);
 711         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 712             level= (3*qscale*quant_matrix[0])>>5;
 713             level= (level-1)|1;
 714             if(GET_CACHE(re, &s->gb)&0x40000000)
 715                 level= -level;
 716             block[0] = level;
 717             i++;
 718             SKIP_BITS(re, &s->gb, 2);
 719             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 720                 goto end;
 721         }
 722         /* now quantify & encode AC coefficients */
 723         for(;;) {
 724             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 725
 726             if(level != 0) {
 727                 i += run;
 728                 j = scantable[i];
 729                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 730                 level= (level-1)|1;
 731                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 732                 SKIP_BITS(re, &s->gb, 1);
 733             } else {
 734                 /* escape */
 735                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 736                 UPDATE_CACHE(re, &s->gb);
 737                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 738                 if (level == -128) {
 739                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 740                 } else if (level == 0) {
 741                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 742                 }
 743                 i += run;
 744                 j = scantable[i];
 745                 if(level<0){
 746                     level= -level;
 747                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 748                     level= (level-1)|1;
 749                     level= -level;
 750                 }else{
 751                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 752                     level= (level-1)|1;
 753                 }
 754             }
 755             if (i > 63){
 756                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 757                 return -1;
 758             }
 759
 760             block[j] = level;
 761             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 762                 break;
 763             UPDATE_CACHE(re, &s->gb);
 764         }
 765 end:
 766         LAST_SKIP_BITS(re, &s->gb, 2);
 767         CLOSE_READER(re, &s->gb);
 768     }
 769     s->block_last_index[n] = i;
 770     return 0;
 771 }
 772
 773 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 774 {
 775     int level, i, j, run;
 776     RLTable *rl = &ff_rl_mpeg1;
 777     uint8_t * const scantable= s->intra_scantable.permutated;
 778     const int qscale= s->qscale;
 779
 780     {
 781         OPEN_READER(re, &s->gb);
 782         i = -1;
 783         // special case for first coefficient, no need to add second VLC table
 784         UPDATE_CACHE(re, &s->gb);
 785         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 786             level= (3*qscale)>>1;
 787             level= (level-1)|1;
 788             if(GET_CACHE(re, &s->gb)&0x40000000)
 789                 level= -level;
 790             block[0] = level;
 791             i++;
 792             SKIP_BITS(re, &s->gb, 2);
 793             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 794                 goto end;
 795         }
 796
 797         /* now quantify & encode AC coefficients */
 798         for(;;) {
 799             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 800
 801             if(level != 0) {
 802                 i += run;
 803                 j = scantable[i];
 804                 level= ((level*2+1)*qscale)>>1;
 805                 level= (level-1)|1;
 806                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 807                 SKIP_BITS(re, &s->gb, 1);
 808             } else {
 809                 /* escape */
 810                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 811                 UPDATE_CACHE(re, &s->gb);
 812                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 813                 if (level == -128) {
 814                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 815                 } else if (level == 0) {
 816                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 817                 }
 818                 i += run;
 819                 j = scantable[i];
 820                 if(level<0){
 821                     level= -level;
 822                     level= ((level*2+1)*qscale)>>1;
 823                     level= (level-1)|1;
 824                     level= -level;
 825                 }else{
 826                     level= ((level*2+1)*qscale)>>1;
 827                     level= (level-1)|1;
 828                 }
 829             }
 830
 831             block[j] = level;
 832             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 833                 break;
 834             UPDATE_CACHE(re, &s->gb);
 835         }
 836 end:
 837         LAST_SKIP_BITS(re, &s->gb, 2);
 838         CLOSE_READER(re, &s->gb);
 839     }
 840     s->block_last_index[n] = i;
 841     return 0;
 842 }
 843
 844
 845 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 846                                DCTELEM *block,
 847                                int n)
 848 {
 849     int level, i, j, run;
 850     RLTable *rl = &ff_rl_mpeg1;
 851     uint8_t * const scantable= s->intra_scantable.permutated;
 852     const uint16_t *quant_matrix;
 853     const int qscale= s->qscale;
 854     int mismatch;
 855
 856     mismatch = 1;
 857
 858     {
 859         OPEN_READER(re, &s->gb);
 860         i = -1;
 861         if (n < 4)
 862             quant_matrix = s->inter_matrix;
 863         else
 864             quant_matrix = s->chroma_inter_matrix;
 865
 866         // special case for first coefficient, no need to add second VLC table
 867         UPDATE_CACHE(re, &s->gb);
 868         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 869             level= (3*qscale*quant_matrix[0])>>5;
 870             if(GET_CACHE(re, &s->gb)&0x40000000)
 871                 level= -level;
 872             block[0] = level;
 873             mismatch ^= level;
 874             i++;
 875             SKIP_BITS(re, &s->gb, 2);
 876             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 877                 goto end;
 878         }
 879
 880         /* now quantify & encode AC coefficients */
 881         for(;;) {
 882             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 883
 884             if(level != 0) {
 885                 i += run;
 886                 j = scantable[i];
 887                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 888                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 889                 SKIP_BITS(re, &s->gb, 1);
 890             } else {
 891                 /* escape */
 892                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 893                 UPDATE_CACHE(re, &s->gb);
 894                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 895
 896                 i += run;
 897                 j = scantable[i];
 898                 if(level<0){
 899                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 900                     level= -level;
 901                 }else{
 902                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 903                 }
 904             }
 905             if (i > 63){
 906                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 907                 return -1;
 908             }
 909
 910             mismatch ^= level;
 911             block[j] = level;
 912             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 913                 break;
 914             UPDATE_CACHE(re, &s->gb);
 915         }
 916 end:
 917         LAST_SKIP_BITS(re, &s->gb, 2);
 918         CLOSE_READER(re, &s->gb);
 919     }
 920     block[63] ^= (mismatch & 1);
 921
 922     s->block_last_index[n] = i;
 923     return 0;
 924 }
 925
 926 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 927                                DCTELEM *block,
 928                                int n)
 929 {
 930     int level, i, j, run;
 931     RLTable *rl = &ff_rl_mpeg1;
 932     uint8_t * const scantable= s->intra_scantable.permutated;
 933     const int qscale= s->qscale;
 934     OPEN_READER(re, &s->gb);
 935     i = -1;
 936
 937     // special case for first coefficient, no need to add second VLC table
 938     UPDATE_CACHE(re, &s->gb);
 939     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 940         level= (3*qscale)>>1;
 941         if(GET_CACHE(re, &s->gb)&0x40000000)
 942             level= -level;
 943         block[0] = level;
 944         i++;
 945         SKIP_BITS(re, &s->gb, 2);
 946         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 947             goto end;
 948     }
 949
 950     /* now quantify & encode AC coefficients */
 951     for(;;) {
 952         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 953
 954         if(level != 0) {
 955             i += run;
 956             j = scantable[i];
 957             level= ((level*2+1)*qscale)>>1;
 958             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 959             SKIP_BITS(re, &s->gb, 1);
 960         } else {
 961             /* escape */
 962             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 963             UPDATE_CACHE(re, &s->gb);
 964             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 965
 966             i += run;
 967             j = scantable[i];
 968             if(level<0){
 969                 level= ((-level*2+1)*qscale)>>1;
 970                 level= -level;
 971             }else{
 972                 level= ((level*2+1)*qscale)>>1;
 973             }
 974         }
 975
 976         block[j] = level;
 977         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 978             break;
 979         UPDATE_CACHE(re, &s->gb);
 980     }
 981 end:
 982     LAST_SKIP_BITS(re, &s->gb, 2);
 983     CLOSE_READER(re, &s->gb);
 984     s->block_last_index[n] = i;
 985     return 0;
 986 }
 987
 988
 989 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
 990                                DCTELEM *block,
 991                                int n)
 992 {
 993     int level, dc, diff, i, j, run;
 994     int component;
 995     RLTable *rl;
 996     uint8_t * const scantable= s->intra_scantable.permutated;
 997     const uint16_t *quant_matrix;
 998     const int qscale= s->qscale;
 999     int mismatch;
1000
1001     /* DC coefficient */
1002     if (n < 4){
1003         quant_matrix = s->intra_matrix;
1004         component = 0;
1005     }else{
1006         quant_matrix = s->chroma_intra_matrix;
1007         component = (n&1) + 1;
1008     }
1009     diff = decode_dc(&s->gb, component);
1010     if (diff >= 0xffff)
1011         return -1;
1012     dc = s->last_dc[component];
1013     dc += diff;
1014     s->last_dc[component] = dc;
1015     block[0] = dc << (3 - s->intra_dc_precision);
1016     av_dlog(s->avctx, "dc=%d\n", block[0]);
1017     mismatch = block[0] ^ 1;
1018     i = 0;
1019     if (s->intra_vlc_format)
1020         rl = &ff_rl_mpeg2;
1021     else
1022         rl = &ff_rl_mpeg1;
1023
1024     {
1025         OPEN_READER(re, &s->gb);
1026         /* now quantify & encode AC coefficients */
1027         for(;;) {
1028             UPDATE_CACHE(re, &s->gb);
1029             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1030
1031             if(level == 127){
1032                 break;
1033             } else if(level != 0) {
1034                 i += run;
1035                 j = scantable[i];
1036                 level= (level*qscale*quant_matrix[j])>>4;
1037                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1038                 LAST_SKIP_BITS(re, &s->gb, 1);
1039             } else {
1040                 /* escape */
1041                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1042                 UPDATE_CACHE(re, &s->gb);
1043                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1044                 i += run;
1045                 j = scantable[i];
1046                 if(level<0){
1047                     level= (-level*qscale*quant_matrix[j])>>4;
1048                     level= -level;
1049                 }else{
1050                     level= (level*qscale*quant_matrix[j])>>4;
1051                 }
1052             }
1053             if (i > 63){
1054                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1055                 return -1;
1056             }
1057
1058             mismatch^= level;
1059             block[j] = level;
1060         }
1061         CLOSE_READER(re, &s->gb);
1062     }
1063     block[63]^= mismatch&1;
1064
1065     s->block_last_index[n] = i;
1066     return 0;
1067 }
1068
1069 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1070                                DCTELEM *block,
1071                                int n)
1072 {
1073     int level, dc, diff, j, run;
1074     int component;
1075     RLTable *rl;
1076     uint8_t * scantable= s->intra_scantable.permutated;
1077     const uint16_t *quant_matrix;
1078     const int qscale= s->qscale;
1079
1080     /* DC coefficient */
1081     if (n < 4){
1082         quant_matrix = s->intra_matrix;
1083         component = 0;
1084     }else{
1085         quant_matrix = s->chroma_intra_matrix;
1086         component = (n&1) + 1;
1087     }
1088     diff = decode_dc(&s->gb, component);
1089     if (diff >= 0xffff)
1090         return -1;
1091     dc = s->last_dc[component];
1092     dc += diff;
1093     s->last_dc[component] = dc;
1094     block[0] = dc << (3 - s->intra_dc_precision);
1095     if (s->intra_vlc_format)
1096         rl = &ff_rl_mpeg2;
1097     else
1098         rl = &ff_rl_mpeg1;
1099
1100     {
1101         OPEN_READER(re, &s->gb);
1102         /* now quantify & encode AC coefficients */
1103         for(;;) {
1104             UPDATE_CACHE(re, &s->gb);
1105             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1106
1107             if(level == 127){
1108                 break;
1109             } else if(level != 0) {
1110                 scantable += run;
1111                 j = *scantable;
1112                 level= (level*qscale*quant_matrix[j])>>4;
1113                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1114                 LAST_SKIP_BITS(re, &s->gb, 1);
1115             } else {
1116                 /* escape */
1117                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1118                 UPDATE_CACHE(re, &s->gb);
1119                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1120                 scantable += run;
1121                 j = *scantable;
1122                 if(level<0){
1123                     level= (-level*qscale*quant_matrix[j])>>4;
1124                     level= -level;
1125                 }else{
1126                     level= (level*qscale*quant_matrix[j])>>4;
1127                 }
1128             }
1129
1130             block[j] = level;
1131         }
1132         CLOSE_READER(re, &s->gb);
1133     }
1134
1135     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1136     return 0;
1137 }
1138
1139 typedef struct Mpeg1Context {
1140     MpegEncContext mpeg_enc_ctx;
1141     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1142     int repeat_field; /* true if we must repeat the field */
1143     AVPanScan pan_scan;              /**< some temporary storage for the panscan */
1144     int slice_count;
1145     int swap_uv;//indicate VCR2
1146     int save_aspect_info;
1147     int save_width, save_height, save_progressive_seq;
1148     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1149     int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
1150 } Mpeg1Context;
1151
1152 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1153 {
1154     Mpeg1Context *s = avctx->priv_data;
1155     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1156     int i;
1157
1158     /* we need some permutation to store matrices,
1159      * until MPV_common_init() sets the real permutation. */
1160     for(i=0;i<64;i++)
1161        s2->dsp.idct_permutation[i]=i;
1162
1163     MPV_decode_defaults(s2);
1164
1165     s->mpeg_enc_ctx.avctx= avctx;
1166     s->mpeg_enc_ctx.flags= avctx->flags;
1167     s->mpeg_enc_ctx.flags2= avctx->flags2;
1168     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1169     ff_mpeg12_init_vlcs();
1170
1171     s->mpeg_enc_ctx_allocated = 0;
1172     s->mpeg_enc_ctx.picture_number = 0;
1173     s->repeat_field = 0;
1174     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1175     avctx->color_range= AVCOL_RANGE_MPEG;
1176     if (avctx->codec->id == CODEC_ID_MPEG1VIDEO)
1177         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1178     else
1179         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
1180     return 0;
1181 }
1182
1183 static int mpeg_decode_update_thread_context(AVCodecContext *avctx, const AVCodecContext *avctx_from)
1184 {
1185     Mpeg1Context *ctx = avctx->priv_data, *ctx_from = avctx_from->priv_data;
1186     MpegEncContext *s = &ctx->mpeg_enc_ctx, *s1 = &ctx_from->mpeg_enc_ctx;
1187     int err;
1188
1189     if(avctx == avctx_from || !ctx_from->mpeg_enc_ctx_allocated || !s1->context_initialized)
1190         return 0;
1191
1192     err = ff_mpeg_update_thread_context(avctx, avctx_from);
1193     if(err) return err;
1194
1195     if(!ctx->mpeg_enc_ctx_allocated)
1196         memcpy(s + 1, s1 + 1, sizeof(Mpeg1Context) - sizeof(MpegEncContext));
1197
1198     if(!(s->pict_type == FF_B_TYPE || s->low_delay))
1199         s->picture_number++;
1200
1201     return 0;
1202 }
1203
1204 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1205                                      const uint8_t *new_perm){
1206     uint16_t temp_matrix[64];
1207     int i;
1208
1209     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1210
1211     for(i=0;i<64;i++){
1212         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1213     }
1214 }
1215
1216 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1217     Mpeg1Context *s1 = avctx->priv_data;
1218     MpegEncContext *s = &s1->mpeg_enc_ctx;
1219
1220     if(avctx->xvmc_acceleration)
1221         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1222     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1223         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1224             return PIX_FMT_VDPAU_MPEG1;
1225         else
1226             return PIX_FMT_VDPAU_MPEG2;
1227     }else{
1228         if(s->chroma_format <  2)
1229             return avctx->get_format(avctx,ff_hwaccel_pixfmt_list_420);
1230         else if(s->chroma_format == 2)
1231             return PIX_FMT_YUV422P;
1232         else
1233             return PIX_FMT_YUV444P;
1234     }
1235 }
1236
1237 /* Call this function when we know all parameters.
1238  * It may be called in different places for MPEG-1 and MPEG-2. */
1239 static int mpeg_decode_postinit(AVCodecContext *avctx){
1240     Mpeg1Context *s1 = avctx->priv_data;
1241     MpegEncContext *s = &s1->mpeg_enc_ctx;
1242     uint8_t old_permutation[64];
1243
1244     if (
1245         (s1->mpeg_enc_ctx_allocated == 0)||
1246         avctx->coded_width  != s->width ||
1247         avctx->coded_height != s->height||
1248         s1->save_width != s->width ||
1249         s1->save_height != s->height ||
1250         s1->save_aspect_info != s->aspect_ratio_info||
1251         s1->save_progressive_seq != s->progressive_sequence ||
1252         0)
1253     {
1254
1255         if (s1->mpeg_enc_ctx_allocated) {
1256             ParseContext pc= s->parse_context;
1257             s->parse_context.buffer=0;
1258             MPV_common_end(s);
1259             s->parse_context= pc;
1260         }
1261
1262         if( (s->width == 0 )||(s->height == 0))
1263             return -2;
1264
1265         avcodec_set_dimensions(avctx, s->width, s->height);
1266         avctx->bit_rate = s->bit_rate;
1267         s1->save_aspect_info = s->aspect_ratio_info;
1268         s1->save_width = s->width;
1269         s1->save_height = s->height;
1270         s1->save_progressive_seq = s->progressive_sequence;
1271
1272         /* low_delay may be forced, in this case we will have B-frames
1273          * that behave like P-frames. */
1274         avctx->has_b_frames = !(s->low_delay);
1275
1276         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1277         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1278             //MPEG-1 fps
1279             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1280             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1281             //MPEG-1 aspect
1282             avctx->sample_aspect_ratio= av_d2q(
1283                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1284             avctx->ticks_per_frame=1;
1285         }else{//MPEG-2
1286         //MPEG-2 fps
1287             av_reduce(
1288                 &s->avctx->time_base.den,
1289                 &s->avctx->time_base.num,
1290                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
1291                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1292                 1<<30);
1293             avctx->ticks_per_frame=2;
1294         //MPEG-2 aspect
1295             if(s->aspect_ratio_info > 1){
1296                 //we ignore the spec here as reality does not match the spec, see for example
1297                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1298                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1299                     s->avctx->sample_aspect_ratio=
1300                         av_div_q(
1301                          ff_mpeg2_aspect[s->aspect_ratio_info],
1302                          (AVRational){s->width, s->height}
1303                          );
1304                 }else{
1305                     s->avctx->sample_aspect_ratio=
1306                         av_div_q(
1307                          ff_mpeg2_aspect[s->aspect_ratio_info],
1308                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1309                         );
1310                 }
1311             }else{
1312                 s->avctx->sample_aspect_ratio=
1313                     ff_mpeg2_aspect[s->aspect_ratio_info];
1314             }
1315         }//MPEG-2
1316
1317         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1318         avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1319         //until then pix_fmt may be changed right after codec init
1320         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1321             avctx->hwaccel ||
1322             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1323             if( avctx->idct_algo == FF_IDCT_AUTO )
1324                 avctx->idct_algo = FF_IDCT_SIMPLE;
1325
1326         /* Quantization matrices may need reordering
1327          * if DCT permutation is changed. */
1328         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1329
1330         if (MPV_common_init(s) < 0)
1331             return -2;
1332
1333         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1334         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1335         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1336         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1337
1338         s1->mpeg_enc_ctx_allocated = 1;
1339     }
1340     return 0;
1341 }
1342
1343 static int mpeg1_decode_picture(AVCodecContext *avctx,
1344                                 const uint8_t *buf, int buf_size)
1345 {
1346     Mpeg1Context *s1 = avctx->priv_data;
1347     MpegEncContext *s = &s1->mpeg_enc_ctx;
1348     int ref, f_code, vbv_delay;
1349
1350     init_get_bits(&s->gb, buf, buf_size*8);
1351
1352     ref = get_bits(&s->gb, 10); /* temporal ref */
1353     s->pict_type = get_bits(&s->gb, 3);
1354     if(s->pict_type == 0 || s->pict_type > 3)
1355         return -1;
1356
1357     vbv_delay= get_bits(&s->gb, 16);
1358     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1359         s->full_pel[0] = get_bits1(&s->gb);
1360         f_code = get_bits(&s->gb, 3);
1361         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1362             return -1;
1363         s->mpeg_f_code[0][0] = f_code;
1364         s->mpeg_f_code[0][1] = f_code;
1365     }
1366     if (s->pict_type == FF_B_TYPE) {
1367         s->full_pel[1] = get_bits1(&s->gb);
1368         f_code = get_bits(&s->gb, 3);
1369         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1370             return -1;
1371         s->mpeg_f_code[1][0] = f_code;
1372         s->mpeg_f_code[1][1] = f_code;
1373     }
1374     s->current_picture.pict_type= s->pict_type;
1375     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1376
1377     if(avctx->debug & FF_DEBUG_PICT_INFO)
1378         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1379
1380     s->y_dc_scale = 8;
1381     s->c_dc_scale = 8;
1382     return 0;
1383 }
1384
1385 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1386 {
1387     MpegEncContext *s= &s1->mpeg_enc_ctx;
1388     int horiz_size_ext, vert_size_ext;
1389     int bit_rate_ext;
1390
1391     skip_bits(&s->gb, 1); /* profile and level esc*/
1392     s->avctx->profile= get_bits(&s->gb, 3);
1393     s->avctx->level= get_bits(&s->gb, 4);
1394     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1395     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1396     horiz_size_ext = get_bits(&s->gb, 2);
1397     vert_size_ext = get_bits(&s->gb, 2);
1398     s->width |= (horiz_size_ext << 12);
1399     s->height |= (vert_size_ext << 12);
1400     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1401     s->bit_rate += (bit_rate_ext << 18) * 400;
1402     skip_bits1(&s->gb); /* marker */
1403     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1404
1405     s->low_delay = get_bits1(&s->gb);
1406     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1407
1408     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1409     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1410
1411     av_dlog(s->avctx, "sequence extension\n");
1412     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1413     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1414
1415     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1416         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1417                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1418
1419 }
1420
1421 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1422 {
1423     MpegEncContext *s= &s1->mpeg_enc_ctx;
1424     int color_description, w, h;
1425
1426     skip_bits(&s->gb, 3); /* video format */
1427     color_description= get_bits1(&s->gb);
1428     if(color_description){
1429         s->avctx->color_primaries= get_bits(&s->gb, 8);
1430         s->avctx->color_trc      = get_bits(&s->gb, 8);
1431         s->avctx->colorspace     = get_bits(&s->gb, 8);
1432     }
1433     w= get_bits(&s->gb, 14);
1434     skip_bits(&s->gb, 1); //marker
1435     h= get_bits(&s->gb, 14);
1436     // remaining 3 bits are zero padding
1437
1438     s1->pan_scan.width= 16*w;
1439     s1->pan_scan.height=16*h;
1440
1441     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1442         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1443 }
1444
1445 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1446 {
1447     MpegEncContext *s= &s1->mpeg_enc_ctx;
1448     int i,nofco;
1449
1450     nofco = 1;
1451     if(s->progressive_sequence){
1452         if(s->repeat_first_field){
1453             nofco++;
1454             if(s->top_field_first)
1455                 nofco++;
1456         }
1457     }else{
1458         if(s->picture_structure == PICT_FRAME){
1459             nofco++;
1460             if(s->repeat_first_field)
1461                 nofco++;
1462         }
1463     }
1464     for(i=0; i<nofco; i++){
1465         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1466         skip_bits(&s->gb, 1); //marker
1467         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1468         skip_bits(&s->gb, 1); //marker
1469     }
1470
1471     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1472         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1473             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1474             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1475             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1476         );
1477 }
1478
1479 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra){
1480     int i;
1481
1482     for(i=0; i<64; i++) {
1483         int j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1484         int v = get_bits(&s->gb, 8);
1485         if(v==0){
1486             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1487             return -1;
1488         }
1489         if(intra && i==0 && v!=8){
1490             av_log(s->avctx, AV_LOG_ERROR, "intra matrix invalid, ignoring\n");
1491             v= 8; // needed by pink.mpg / issue1046
1492         }
1493         matrix0[j] = v;
1494         if(matrix1)
1495             matrix1[j] = v;
1496     }
1497     return 0;
1498 }
1499
1500 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1501 {
1502     av_dlog(s->avctx, "matrix extension\n");
1503
1504     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1505     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1506     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
1507     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
1508 }
1509
1510 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1511 {
1512     MpegEncContext *s= &s1->mpeg_enc_ctx;
1513
1514     s->full_pel[0] = s->full_pel[1] = 0;
1515     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1516     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1517     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1518     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1519     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1520         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1521         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1522             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1523                 s->pict_type= FF_I_TYPE;
1524             else
1525                 s->pict_type= FF_P_TYPE;
1526         }else
1527             s->pict_type= FF_B_TYPE;
1528         s->current_picture.pict_type= s->pict_type;
1529         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1530     }
1531     s->intra_dc_precision = get_bits(&s->gb, 2);
1532     s->picture_structure = get_bits(&s->gb, 2);
1533     s->top_field_first = get_bits1(&s->gb);
1534     s->frame_pred_frame_dct = get_bits1(&s->gb);
1535     s->concealment_motion_vectors = get_bits1(&s->gb);
1536     s->q_scale_type = get_bits1(&s->gb);
1537     s->intra_vlc_format = get_bits1(&s->gb);
1538     s->alternate_scan = get_bits1(&s->gb);
1539     s->repeat_first_field = get_bits1(&s->gb);
1540     s->chroma_420_type = get_bits1(&s->gb);
1541     s->progressive_frame = get_bits1(&s->gb);
1542
1543     if(s->progressive_sequence && !s->progressive_frame){
1544         s->progressive_frame= 1;
1545         av_log(s->avctx, AV_LOG_ERROR, "interlaced frame in progressive sequence, ignoring\n");
1546     }
1547
1548     if(s->picture_structure==0 || (s->progressive_frame && s->picture_structure!=PICT_FRAME)){
1549         av_log(s->avctx, AV_LOG_ERROR, "picture_structure %d invalid, ignoring\n", s->picture_structure);
1550         s->picture_structure= PICT_FRAME;
1551     }
1552
1553     if(s->progressive_sequence && !s->frame_pred_frame_dct){
1554         av_log(s->avctx, AV_LOG_ERROR, "invalid frame_pred_frame_dct\n");
1555         s->frame_pred_frame_dct= 1;
1556     }
1557
1558     if(s->picture_structure == PICT_FRAME){
1559         s->first_field=0;
1560         s->v_edge_pos= 16*s->mb_height;
1561     }else{
1562         s->first_field ^= 1;
1563         s->v_edge_pos=  8*s->mb_height;
1564         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1565     }
1566
1567     if(s->alternate_scan){
1568         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1569         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1570     }else{
1571         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1572         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1573     }
1574
1575     /* composite display not parsed */
1576     av_dlog(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1577     av_dlog(s->avctx, "picture_structure=%d\n", s->picture_structure);
1578     av_dlog(s->avctx, "top field first=%d\n", s->top_field_first);
1579     av_dlog(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1580     av_dlog(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1581     av_dlog(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1582     av_dlog(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1583     av_dlog(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1584     av_dlog(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1585 }
1586
1587 static void exchange_uv(MpegEncContext *s){
1588     DCTELEM (*tmp)[64];
1589
1590     tmp           = s->pblocks[4];
1591     s->pblocks[4] = s->pblocks[5];
1592     s->pblocks[5] = tmp;
1593 }
1594
1595 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size){
1596     AVCodecContext *avctx= s->avctx;
1597     Mpeg1Context *s1 = (Mpeg1Context*)s;
1598
1599     /* start frame decoding */
1600     if(s->first_field || s->picture_structure==PICT_FRAME){
1601         if(MPV_frame_start(s, avctx) < 0)
1602             return -1;
1603
1604         ff_er_frame_start(s);
1605
1606         /* first check if we must repeat the frame */
1607         s->current_picture_ptr->repeat_pict = 0;
1608         if (s->repeat_first_field) {
1609             if (s->progressive_sequence) {
1610                 if (s->top_field_first)
1611                     s->current_picture_ptr->repeat_pict = 4;
1612                 else
1613                     s->current_picture_ptr->repeat_pict = 2;
1614             } else if (s->progressive_frame) {
1615                 s->current_picture_ptr->repeat_pict = 1;
1616             }
1617         }
1618
1619         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1620
1621         if (HAVE_PTHREADS && avctx->active_thread_type&FF_THREAD_FRAME)
1622             ff_thread_finish_setup(avctx);
1623     }else{ //second field
1624             int i;
1625
1626             if(!s->current_picture_ptr){
1627                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1628                 return -1;
1629             }
1630
1631             for(i=0; i<4; i++){
1632                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1633                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1634                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1635                 }
1636             }
1637     }
1638
1639     if (avctx->hwaccel) {
1640         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
1641             return -1;
1642     }
1643
1644 // MPV_frame_start will call this function too,
1645 // but we need to call it on every field
1646     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1647         if(ff_xvmc_field_start(s,avctx) < 0)
1648             return -1;
1649
1650     return 0;
1651 }
1652
1653 #define DECODE_SLICE_ERROR -1
1654 #define DECODE_SLICE_OK 0
1655
1656 /**
1657  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1658  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1659  *         DECODE_SLICE_OK if this slice is ok<br>
1660  */
1661 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1662                              const uint8_t **buf, int buf_size)
1663 {
1664     MpegEncContext *s = &s1->mpeg_enc_ctx;
1665     AVCodecContext *avctx= s->avctx;
1666     const int field_pic= s->picture_structure != PICT_FRAME;
1667     const int lowres= s->avctx->lowres;
1668
1669     s->resync_mb_x=
1670     s->resync_mb_y= -1;
1671
1672     assert(mb_y < s->mb_height);
1673
1674     init_get_bits(&s->gb, *buf, buf_size*8);
1675
1676     ff_mpeg1_clean_buffers(s);
1677     s->interlaced_dct = 0;
1678
1679     s->qscale = get_qscale(s);
1680
1681     if(s->qscale == 0){
1682         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1683         return -1;
1684     }
1685
1686     /* extra slice info */
1687     while (get_bits1(&s->gb) != 0) {
1688         skip_bits(&s->gb, 8);
1689     }
1690
1691     s->mb_x=0;
1692
1693     if(mb_y==0 && s->codec_tag == AV_RL32("SLIF")){
1694         skip_bits1(&s->gb);
1695     }else{
1696         for(;;) {
1697             int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1698             if (code < 0){
1699                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1700                 return -1;
1701             }
1702             if (code >= 33) {
1703                 if (code == 33) {
1704                     s->mb_x += 33;
1705                 }
1706                 /* otherwise, stuffing, nothing to do */
1707             } else {
1708                 s->mb_x += code;
1709                 break;
1710             }
1711         }
1712     }
1713
1714     if(s->mb_x >= (unsigned)s->mb_width){
1715         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1716         return -1;
1717     }
1718
1719     if (avctx->hwaccel) {
1720         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1721         int start_code = -1;
1722         buf_end = ff_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1723         if (buf_end < *buf + buf_size)
1724             buf_end -= 4;
1725         s->mb_y = mb_y;
1726         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1727             return DECODE_SLICE_ERROR;
1728         *buf = buf_end;
1729         return DECODE_SLICE_OK;
1730     }
1731
1732     s->resync_mb_x= s->mb_x;
1733     s->resync_mb_y= s->mb_y= mb_y;
1734     s->mb_skip_run= 0;
1735     ff_init_block_index(s);
1736
1737     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1738         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1739              av_log(s->avctx, AV_LOG_DEBUG, "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",
1740                  s->qscale, s->mpeg_f_code[0][0],s->mpeg_f_code[0][1],s->mpeg_f_code[1][0],s->mpeg_f_code[1][1],
1741                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1742                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1743                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1744                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1745         }
1746     }
1747
1748     for(;;) {
1749         //If 1, we memcpy blocks in xvmcvideo.
1750         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1751             ff_xvmc_init_block(s);//set s->block
1752
1753         if(mpeg_decode_mb(s, s->block) < 0)
1754             return -1;
1755
1756         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1757             const int wrap = s->b8_stride;
1758             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1759             int b8_xy= 4*(s->mb_x + s->mb_y*s->mb_stride);
1760             int motion_x, motion_y, dir, i;
1761
1762             for(i=0; i<2; i++){
1763                 for(dir=0; dir<2; dir++){
1764                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1765                         motion_x = motion_y = 0;
1766                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1767                         motion_x = s->mv[dir][0][0];
1768                         motion_y = s->mv[dir][0][1];
1769                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1770                         motion_x = s->mv[dir][i][0];
1771                         motion_y = s->mv[dir][i][1];
1772                     }
1773
1774                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1775                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1776                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1777                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1778                     s->current_picture.ref_index [dir][b8_xy    ]=
1779                     s->current_picture.ref_index [dir][b8_xy + 1]= s->field_select[dir][i];
1780                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1781                 }
1782                 xy += wrap;
1783                 b8_xy +=2;
1784             }
1785         }
1786
1787         s->dest[0] += 16 >> lowres;
1788         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1789         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1790
1791         MPV_decode_mb(s, s->block);
1792
1793         if (++s->mb_x >= s->mb_width) {
1794             const int mb_size= 16>>s->avctx->lowres;
1795
1796             ff_draw_horiz_band(s, mb_size*(s->mb_y>>field_pic), mb_size);
1797             MPV_report_decode_progress(s);
1798
1799             s->mb_x = 0;
1800             s->mb_y += 1<<field_pic;
1801
1802             if(s->mb_y >= s->mb_height){
1803                 int left= get_bits_left(&s->gb);
1804                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1805                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1806                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1807
1808                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1809                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1810                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1811                     return -1;
1812                 }else
1813                     goto eos;
1814             }
1815
1816             ff_init_block_index(s);
1817         }
1818
1819         /* skip mb handling */
1820         if (s->mb_skip_run == -1) {
1821             /* read increment again */
1822             s->mb_skip_run = 0;
1823             for(;;) {
1824                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1825                 if (code < 0){
1826                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1827                     return -1;
1828                 }
1829                 if (code >= 33) {
1830                     if (code == 33) {
1831                         s->mb_skip_run += 33;
1832                     }else if(code == 35){
1833                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1834                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1835                             return -1;
1836                         }
1837                         goto eos; /* end of slice */
1838                     }
1839                     /* otherwise, stuffing, nothing to do */
1840                 } else {
1841                     s->mb_skip_run += code;
1842                     break;
1843                 }
1844             }
1845             if(s->mb_skip_run){
1846                 int i;
1847                 if(s->pict_type == FF_I_TYPE){
1848                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1849                     return -1;
1850                 }
1851
1852                 /* skip mb */
1853                 s->mb_intra = 0;
1854                 for(i=0;i<12;i++)
1855                     s->block_last_index[i] = -1;
1856                 if(s->picture_structure == PICT_FRAME)
1857                     s->mv_type = MV_TYPE_16X16;
1858                 else
1859                     s->mv_type = MV_TYPE_FIELD;
1860                 if (s->pict_type == FF_P_TYPE) {
1861                     /* if P type, zero motion vector is implied */
1862                     s->mv_dir = MV_DIR_FORWARD;
1863                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1864                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1865                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1866                     s->field_select[0][0]= (s->picture_structure - 1) & 1;
1867                 } else {
1868                     /* if B type, reuse previous vectors and directions */
1869                     s->mv[0][0][0] = s->last_mv[0][0][0];
1870                     s->mv[0][0][1] = s->last_mv[0][0][1];
1871                     s->mv[1][0][0] = s->last_mv[1][0][0];
1872                     s->mv[1][0][1] = s->last_mv[1][0][1];
1873                 }
1874             }
1875         }
1876     }
1877 eos: // end of slice
1878     *buf += (get_bits_count(&s->gb)-1)/8;
1879 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1880     return 0;
1881 }
1882
1883 static int slice_decode_thread(AVCodecContext *c, void *arg){
1884     MpegEncContext *s= *(void**)arg;
1885     const uint8_t *buf= s->gb.buffer;
1886     int mb_y= s->start_mb_y;
1887     const int field_pic= s->picture_structure != PICT_FRAME;
1888
1889     s->error_count= (3*(s->end_mb_y - s->start_mb_y)*s->mb_width) >> field_pic;
1890
1891     for(;;){
1892         uint32_t start_code;
1893         int ret;
1894
1895         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1896         emms_c();
1897 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1898 //ret, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, s->start_mb_y, s->end_mb_y, s->error_count);
1899         if(ret < 0){
1900             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1901                 ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
1902         }else{
1903             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
1904         }
1905
1906         if(s->mb_y == s->end_mb_y)
1907             return 0;
1908
1909         start_code= -1;
1910         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1911         mb_y= start_code - SLICE_MIN_START_CODE;
1912         if(mb_y < 0 || mb_y >= s->end_mb_y)
1913             return -1;
1914     }
1915
1916     return 0; //not reached
1917 }
1918
1919 /**
1920  * Handle slice ends.
1921  * @return 1 if it seems to be the last slice
1922  */
1923 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1924 {
1925     Mpeg1Context *s1 = avctx->priv_data;
1926     MpegEncContext *s = &s1->mpeg_enc_ctx;
1927
1928     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1929         return 0;
1930
1931     if (s->avctx->hwaccel) {
1932         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1933             av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
1934     }
1935
1936     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1937         ff_xvmc_field_end(s);
1938
1939     /* end of slice reached */
1940     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1941         /* end of image */
1942
1943         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1944
1945         ff_er_frame_end(s);
1946
1947         MPV_frame_end(s);
1948
1949         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1950             *pict= *(AVFrame*)s->current_picture_ptr;
1951             ff_print_debug_info(s, pict);
1952         } else {
1953             if (avctx->active_thread_type&FF_THREAD_FRAME)
1954                 s->picture_number++;
1955             /* latency of 1 frame for I- and P-frames */
1956             /* XXX: use another variable than picture_number */
1957             if (s->last_picture_ptr != NULL) {
1958                 *pict= *(AVFrame*)s->last_picture_ptr;
1959                  ff_print_debug_info(s, pict);
1960             }
1961         }
1962
1963         return 1;
1964     } else {
1965         return 0;
1966     }
1967 }
1968
1969 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1970                                  const uint8_t *buf, int buf_size)
1971 {
1972     Mpeg1Context *s1 = avctx->priv_data;
1973     MpegEncContext *s = &s1->mpeg_enc_ctx;
1974     int width,height;
1975     int i, v, j;
1976
1977     init_get_bits(&s->gb, buf, buf_size*8);
1978
1979     width = get_bits(&s->gb, 12);
1980     height = get_bits(&s->gb, 12);
1981     if (width <= 0 || height <= 0)
1982         return -1;
1983     s->aspect_ratio_info= get_bits(&s->gb, 4);
1984     if (s->aspect_ratio_info == 0) {
1985         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1986         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1987             return -1;
1988     }
1989     s->frame_rate_index = get_bits(&s->gb, 4);
1990     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1991         return -1;
1992     s->bit_rate = get_bits(&s->gb, 18) * 400;
1993     if (get_bits1(&s->gb) == 0) /* marker */
1994         return -1;
1995     s->width = width;
1996     s->height = height;
1997
1998     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1999     skip_bits(&s->gb, 1);
2000
2001     /* get matrix */
2002     if (get_bits1(&s->gb)) {
2003         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2004     } else {
2005         for(i=0;i<64;i++) {
2006             j = s->dsp.idct_permutation[i];
2007             v = ff_mpeg1_default_intra_matrix[i];
2008             s->intra_matrix[j] = v;
2009             s->chroma_intra_matrix[j] = v;
2010         }
2011     }
2012     if (get_bits1(&s->gb)) {
2013         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2014     } else {
2015         for(i=0;i<64;i++) {
2016             int j= s->dsp.idct_permutation[i];
2017             v = ff_mpeg1_default_non_intra_matrix[i];
2018             s->inter_matrix[j] = v;
2019             s->chroma_inter_matrix[j] = v;
2020         }
2021     }
2022
2023     if(show_bits(&s->gb, 23) != 0){
2024         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2025         return -1;
2026     }
2027
2028     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2029     s->progressive_sequence = 1;
2030     s->progressive_frame = 1;
2031     s->picture_structure = PICT_FRAME;
2032     s->frame_pred_frame_dct = 1;
2033     s->chroma_format = 1;
2034     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2035     avctx->sub_id = 1; /* indicates MPEG-1 */
2036     s->out_format = FMT_MPEG1;
2037     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2038     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2039
2040     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2041         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2042                s->avctx->rc_buffer_size, s->bit_rate);
2043
2044     return 0;
2045 }
2046
2047 static int vcr2_init_sequence(AVCodecContext *avctx)
2048 {
2049     Mpeg1Context *s1 = avctx->priv_data;
2050     MpegEncContext *s = &s1->mpeg_enc_ctx;
2051     int i, v;
2052
2053     /* start new MPEG-1 context decoding */
2054     s->out_format = FMT_MPEG1;
2055     if (s1->mpeg_enc_ctx_allocated) {
2056         MPV_common_end(s);
2057     }
2058     s->width  = avctx->coded_width;
2059     s->height = avctx->coded_height;
2060     avctx->has_b_frames= 0; //true?
2061     s->low_delay= 1;
2062
2063     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2064     avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
2065
2066     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel ||
2067         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2068         if( avctx->idct_algo == FF_IDCT_AUTO )
2069             avctx->idct_algo = FF_IDCT_SIMPLE;
2070
2071     if (MPV_common_init(s) < 0)
2072         return -1;
2073     exchange_uv(s);//common init reset pblocks, so we swap them here
2074     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2075     s1->mpeg_enc_ctx_allocated = 1;
2076
2077     for(i=0;i<64;i++) {
2078         int j= s->dsp.idct_permutation[i];
2079         v = ff_mpeg1_default_intra_matrix[i];
2080         s->intra_matrix[j] = v;
2081         s->chroma_intra_matrix[j] = v;
2082
2083         v = ff_mpeg1_default_non_intra_matrix[i];
2084         s->inter_matrix[j] = v;
2085         s->chroma_inter_matrix[j] = v;
2086     }
2087
2088     s->progressive_sequence = 1;
2089     s->progressive_frame = 1;
2090     s->picture_structure = PICT_FRAME;
2091     s->frame_pred_frame_dct = 1;
2092     s->chroma_format = 1;
2093     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2094     avctx->sub_id = 2; /* indicates MPEG-2 */
2095     s1->save_width           = s->width;
2096     s1->save_height          = s->height;
2097     s1->save_progressive_seq = s->progressive_sequence;
2098     return 0;
2099 }
2100
2101
2102 static void mpeg_decode_user_data(AVCodecContext *avctx,
2103                                   const uint8_t *p, int buf_size)
2104 {
2105     const uint8_t *buf_end = p+buf_size;
2106
2107     /* we parse the DTG active format information */
2108     if (buf_end - p >= 5 &&
2109         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2110         int flags = p[4];
2111         p += 5;
2112         if (flags & 0x80) {
2113             /* skip event id */
2114             p += 2;
2115         }
2116         if (flags & 0x40) {
2117             if (buf_end - p < 1)
2118                 return;
2119             avctx->dtg_active_format = p[0] & 0x0f;
2120         }
2121     }
2122 }
2123
2124 static void mpeg_decode_gop(AVCodecContext *avctx,
2125                             const uint8_t *buf, int buf_size){
2126     Mpeg1Context *s1 = avctx->priv_data;
2127     MpegEncContext *s = &s1->mpeg_enc_ctx;
2128
2129     int drop_frame_flag;
2130     int time_code_hours, time_code_minutes;
2131     int time_code_seconds, time_code_pictures;
2132     int broken_link;
2133
2134     init_get_bits(&s->gb, buf, buf_size*8);
2135
2136     drop_frame_flag = get_bits1(&s->gb);
2137
2138     time_code_hours=get_bits(&s->gb,5);
2139     time_code_minutes = get_bits(&s->gb,6);
2140     skip_bits1(&s->gb);//marker bit
2141     time_code_seconds = get_bits(&s->gb,6);
2142     time_code_pictures = get_bits(&s->gb,6);
2143
2144     s->closed_gop = get_bits1(&s->gb);
2145     /*broken_link indicate that after editing the
2146       reference frames of the first B-Frames after GOP I-Frame
2147       are missing (open gop)*/
2148     broken_link = get_bits1(&s->gb);
2149
2150     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2151         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2152             time_code_hours, time_code_minutes, time_code_seconds,
2153             time_code_pictures, s->closed_gop, broken_link);
2154 }
2155 /**
2156  * Find the end of the current frame in the bitstream.
2157  * @return the position of the first byte of the next frame, or -1
2158  */
2159 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
2160 {
2161     int i;
2162     uint32_t state= pc->state;
2163
2164     /* EOF considered as end of frame */
2165     if (buf_size == 0)
2166         return 0;
2167
2168 /*
2169  0  frame start         -> 1/4
2170  1  first_SEQEXT        -> 0/2
2171  2  first field start   -> 3/0
2172  3  second_SEQEXT       -> 2/0
2173  4  searching end
2174 */
2175
2176     for(i=0; i<buf_size; i++){
2177         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2178         if(pc->frame_start_found&1){
2179             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2180                 pc->frame_start_found--;
2181             else if(state == EXT_START_CODE+2){
2182                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2183                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2184             }
2185             state++;
2186         }else{
2187             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2188             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2189                 i++;
2190                 pc->frame_start_found=4;
2191             }
2192             if(state == SEQ_END_CODE){
2193                 pc->state=-1;
2194                 return i+1;
2195             }
2196             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2197                 pc->frame_start_found= 0;
2198             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2199                 pc->frame_start_found++;
2200             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2201                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2202                     pc->frame_start_found=0;
2203                     pc->state=-1;
2204                     return i-3;
2205                 }
2206             }
2207             if(pc->frame_start_found == 0 && s && state == PICTURE_START_CODE){
2208                 ff_fetch_timestamp(s, i-3, 1);
2209             }
2210         }
2211     }
2212     pc->state= state;
2213     return END_NOT_FOUND;
2214 }
2215
2216 static int decode_chunks(AVCodecContext *avctx,
2217                              AVFrame *picture, int *data_size,
2218                              const uint8_t *buf, int buf_size);
2219
2220 /* handle buffering and image synchronisation */
2221 static int mpeg_decode_frame(AVCodecContext *avctx,
2222                              void *data, int *data_size,
2223                              AVPacket *avpkt)
2224 {
2225     const uint8_t *buf = avpkt->data;
2226     int buf_size = avpkt->size;
2227     Mpeg1Context *s = avctx->priv_data;
2228     AVFrame *picture = data;
2229     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2230     av_dlog(avctx, "fill_buffer\n");
2231
2232     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2233         /* special case for last picture */
2234         if (s2->low_delay==0 && s2->next_picture_ptr) {
2235             *picture= *(AVFrame*)s2->next_picture_ptr;
2236             s2->next_picture_ptr= NULL;
2237
2238             *data_size = sizeof(AVFrame);
2239         }
2240         return buf_size;
2241     }
2242
2243     if(s2->flags&CODEC_FLAG_TRUNCATED){
2244         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
2245
2246         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2247             return buf_size;
2248     }
2249
2250 #if 0
2251     if (s->repeat_field % 2 == 1) {
2252         s->repeat_field++;
2253         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2254         //        s2->picture_number, s->repeat_field);
2255         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2256             *data_size = sizeof(AVPicture);
2257             goto the_end;
2258         }
2259     }
2260 #endif
2261
2262     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2263         vcr2_init_sequence(avctx);
2264
2265     s->slice_count= 0;
2266
2267     if(avctx->extradata && !avctx->frame_number)
2268         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2269
2270     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2271 }
2272
2273 static int decode_chunks(AVCodecContext *avctx,
2274                              AVFrame *picture, int *data_size,
2275                              const uint8_t *buf, int buf_size)
2276 {
2277     Mpeg1Context *s = avctx->priv_data;
2278     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2279     const uint8_t *buf_ptr = buf;
2280     const uint8_t *buf_end = buf + buf_size;
2281     int ret, input_size;
2282     int last_code= 0;
2283
2284     for(;;) {
2285         /* find next start code */
2286         uint32_t start_code = -1;
2287         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2288         if (start_code > 0x1ff){
2289             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2290                 if(HAVE_THREADS && avctx->active_thread_type&FF_THREAD_SLICE){
2291                     int i;
2292
2293                     avctx->execute(avctx, slice_decode_thread,  &s2->thread_context[0], NULL, s->slice_count, sizeof(void*));
2294                     for(i=0; i<s->slice_count; i++)
2295                         s2->error_count += s2->thread_context[i]->error_count;
2296                 }
2297
2298                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2299                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2300
2301                 if (slice_end(avctx, picture)) {
2302                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2303                         *data_size = sizeof(AVPicture);
2304                 }
2305             }
2306             s2->pict_type= 0;
2307             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2308         }
2309
2310         input_size = buf_end - buf_ptr;
2311
2312         if(avctx->debug & FF_DEBUG_STARTCODE){
2313             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2314         }
2315
2316         /* prepare data for next start code */
2317         switch(start_code) {
2318         case SEQ_START_CODE:
2319             if(last_code == 0){
2320             mpeg1_decode_sequence(avctx, buf_ptr,
2321                                     input_size);
2322                 s->sync=1;
2323             }else{
2324                 av_log(avctx, AV_LOG_ERROR, "ignoring SEQ_START_CODE after %X\n", last_code);
2325             }
2326             break;
2327
2328         case PICTURE_START_CODE:
2329             if(last_code == 0 || last_code == SLICE_MIN_START_CODE){
2330             if(mpeg_decode_postinit(avctx) < 0){
2331                 av_log(avctx, AV_LOG_ERROR, "mpeg_decode_postinit() failure\n");
2332                 return -1;
2333             }
2334
2335             /* we have a complete image: we try to decompress it */
2336             if(mpeg1_decode_picture(avctx,
2337                                     buf_ptr, input_size) < 0)
2338                 s2->pict_type=0;
2339                 s2->first_slice = 1;
2340             last_code= PICTURE_START_CODE;
2341             }else{
2342                 av_log(avctx, AV_LOG_ERROR, "ignoring pic after %X\n", last_code);
2343             }
2344             break;
2345         case EXT_START_CODE:
2346             init_get_bits(&s2->gb, buf_ptr, input_size*8);
2347
2348             switch(get_bits(&s2->gb, 4)) {
2349             case 0x1:
2350                 if(last_code == 0){
2351                 mpeg_decode_sequence_extension(s);
2352                 }else{
2353                     av_log(avctx, AV_LOG_ERROR, "ignoring seq ext after %X\n", last_code);
2354                 }
2355                 break;
2356             case 0x2:
2357                 mpeg_decode_sequence_display_extension(s);
2358                 break;
2359             case 0x3:
2360                 mpeg_decode_quant_matrix_extension(s2);
2361                 break;
2362             case 0x7:
2363                 mpeg_decode_picture_display_extension(s);
2364                 break;
2365             case 0x8:
2366                 if(last_code == PICTURE_START_CODE){
2367                 mpeg_decode_picture_coding_extension(s);
2368                 }else{
2369                     av_log(avctx, AV_LOG_ERROR, "ignoring pic cod ext after %X\n", last_code);
2370                 }
2371                 break;
2372             }
2373             break;
2374         case USER_START_CODE:
2375             mpeg_decode_user_data(avctx,
2376                                     buf_ptr, input_size);
2377             break;
2378         case GOP_START_CODE:
2379             if(last_code == 0){
2380             s2->first_field=0;
2381             mpeg_decode_gop(avctx,
2382                                     buf_ptr, input_size);
2383                 s->sync=1;
2384             }else{
2385                 av_log(avctx, AV_LOG_ERROR, "ignoring GOP_START_CODE after %X\n", last_code);
2386             }
2387             break;
2388         default:
2389             if (start_code >= SLICE_MIN_START_CODE &&
2390                 start_code <= SLICE_MAX_START_CODE && last_code!=0) {
2391                 const int field_pic= s2->picture_structure != PICT_FRAME;
2392                 int mb_y= (start_code - SLICE_MIN_START_CODE) << field_pic;
2393                 last_code= SLICE_MIN_START_CODE;
2394
2395                 if(s2->picture_structure == PICT_BOTTOM_FIELD)
2396                     mb_y++;
2397
2398                 if (mb_y >= s2->mb_height){
2399                     av_log(s2->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2400                     return -1;
2401                 }
2402
2403                 if(s2->last_picture_ptr==NULL){
2404                 /* Skip B-frames if we do not have reference frames and gop is not closed */
2405                     if(s2->pict_type==FF_B_TYPE){
2406                         if(!s2->closed_gop)
2407                             break;
2408                     }
2409                 }
2410                 if(s2->pict_type==FF_I_TYPE)
2411                     s->sync=1;
2412                 if(s2->next_picture_ptr==NULL){
2413                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2414                     if(s2->pict_type==FF_P_TYPE && !s->sync) break;
2415                 }
2416                 /* Skip B-frames if we are in a hurry. */
2417                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2418                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2419                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2420                     || avctx->skip_frame >= AVDISCARD_ALL)
2421                     break;
2422                 /* Skip everything if we are in a hurry>=5. */
2423                 if(avctx->hurry_up>=5) break;
2424
2425                 if (!s->mpeg_enc_ctx_allocated) break;
2426
2427                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2428                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2429                         break;
2430                 }
2431
2432                 if(!s2->pict_type){
2433                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2434                     break;
2435                 }
2436
2437                 if(s2->first_slice){
2438                     s2->first_slice=0;
2439                     if(mpeg_field_start(s2, buf, buf_size) < 0)
2440                         return -1;
2441                 }
2442                 if(!s2->current_picture_ptr){
2443                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2444                     return -1;
2445                 }
2446
2447                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2448                     s->slice_count++;
2449                     break;
2450                 }
2451
2452                 if(HAVE_THREADS && avctx->active_thread_type&FF_THREAD_SLICE){
2453                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2454                     if(threshold <= mb_y){
2455                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2456
2457                         thread_context->start_mb_y= mb_y;
2458                         thread_context->end_mb_y  = s2->mb_height;
2459                         if(s->slice_count){
2460                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2461                             ff_update_duplicate_context(thread_context, s2);
2462                         }
2463                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2464                         s->slice_count++;
2465                     }
2466                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2467                 }else{
2468                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2469                     emms_c();
2470
2471                     if(ret < 0){
2472                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2473                             ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
2474                     }else{
2475                         ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x-1, s2->mb_y, AC_END|DC_END|MV_END);
2476                     }
2477                 }
2478             }
2479             break;
2480         }
2481     }
2482 }
2483
2484 static void flush(AVCodecContext *avctx){
2485     Mpeg1Context *s = avctx->priv_data;
2486
2487     s->sync=0;
2488
2489     ff_mpeg_flush(avctx);
2490 }
2491
2492 static int mpeg_decode_end(AVCodecContext *avctx)
2493 {
2494     Mpeg1Context *s = avctx->priv_data;
2495
2496     if (s->mpeg_enc_ctx_allocated)
2497         MPV_common_end(&s->mpeg_enc_ctx);
2498     return 0;
2499 }
2500
2501 static const AVProfile mpeg2_video_profiles[] = {
2502     { FF_PROFILE_MPEG2_422,          "4:2:2"              },
2503     { FF_PROFILE_MPEG2_HIGH,         "High"               },
2504     { FF_PROFILE_MPEG2_SS,           "Spatially Scalable" },
2505     { FF_PROFILE_MPEG2_SNR_SCALABLE, "SNR Scalable"       },
2506     { FF_PROFILE_MPEG2_MAIN,         "Main"               },
2507     { FF_PROFILE_MPEG2_SIMPLE,       "Simple"             },
2508     { FF_PROFILE_RESERVED,           "Reserved"           },
2509     { FF_PROFILE_RESERVED,           "Reserved"           },
2510 };
2511
2512
2513 AVCodec ff_mpeg1video_decoder = {
2514     "mpeg1video",
2515     AVMEDIA_TYPE_VIDEO,
2516     CODEC_ID_MPEG1VIDEO,
2517     sizeof(Mpeg1Context),
2518     mpeg_decode_init,
2519     NULL,
2520     mpeg_decode_end,
2521     mpeg_decode_frame,
2522     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2523     .flush= flush,
2524     .max_lowres= 3,
2525     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2526     .update_thread_context= ONLY_IF_THREADS_ENABLED(mpeg_decode_update_thread_context)
2527 };
2528
2529 AVCodec ff_mpeg2video_decoder = {
2530     "mpeg2video",
2531     AVMEDIA_TYPE_VIDEO,
2532     CODEC_ID_MPEG2VIDEO,
2533     sizeof(Mpeg1Context),
2534     mpeg_decode_init,
2535     NULL,
2536     mpeg_decode_end,
2537     mpeg_decode_frame,
2538     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2539     .flush= flush,
2540     .max_lowres= 3,
2541     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2542     .profiles = NULL_IF_CONFIG_SMALL(mpeg2_video_profiles),
2543 };
2544
2545 //legacy decoder
2546 AVCodec ff_mpegvideo_decoder = {
2547     "mpegvideo",
2548     AVMEDIA_TYPE_VIDEO,
2549     CODEC_ID_MPEG2VIDEO,
2550     sizeof(Mpeg1Context),
2551     mpeg_decode_init,
2552     NULL,
2553     mpeg_decode_end,
2554     mpeg_decode_frame,
2555     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2556     .flush= flush,
2557     .max_lowres= 3,
2558     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2559 };
2560
2561 #if CONFIG_MPEG_XVMC_DECODER
2562 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2563     if( avctx->active_thread_type & FF_THREAD_SLICE )
2564         return -1;
2565     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2566         return -1;
2567     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2568         av_dlog(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2569     }
2570     mpeg_decode_init(avctx);
2571
2572     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2573     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2574
2575     return 0;
2576 }
2577
2578 AVCodec ff_mpeg_xvmc_decoder = {
2579     "mpegvideo_xvmc",
2580     AVMEDIA_TYPE_VIDEO,
2581     CODEC_ID_MPEG2VIDEO_XVMC,
2582     sizeof(Mpeg1Context),
2583     mpeg_mc_decode_init,
2584     NULL,
2585     mpeg_decode_end,
2586     mpeg_decode_frame,
2587     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2588     .flush= flush,
2589     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2590 };
2591
2592 #endif
2593
2594 #if CONFIG_MPEG_VDPAU_DECODER
2595 AVCodec ff_mpeg_vdpau_decoder = {
2596     "mpegvideo_vdpau",
2597     AVMEDIA_TYPE_VIDEO,
2598     CODEC_ID_MPEG2VIDEO,
2599     sizeof(Mpeg1Context),
2600     mpeg_decode_init,
2601     NULL,
2602     mpeg_decode_end,
2603     mpeg_decode_frame,
2604     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2605     .flush= flush,
2606     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2607 };
2608 #endif
2609
2610 #if CONFIG_MPEG1_VDPAU_DECODER
2611 AVCodec ff_mpeg1_vdpau_decoder = {
2612     "mpeg1video_vdpau",
2613     AVMEDIA_TYPE_VIDEO,
2614     CODEC_ID_MPEG1VIDEO,
2615     sizeof(Mpeg1Context),
2616     mpeg_decode_init,
2617     NULL,
2618     mpeg_decode_end,
2619     mpeg_decode_frame,
2620     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2621     .flush= flush,
2622     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2623 };
2624 #endif
2625