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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 libavcodec/mpeg12.c
  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
  41 //#undef NDEBUG
  42 //#include <assert.h>
  43
  44
  45 #define MV_VLC_BITS 9
  46 #define MBINCR_VLC_BITS 9
  47 #define MB_PAT_VLC_BITS 9
  48 #define MB_PTYPE_VLC_BITS 6
  49 #define MB_BTYPE_VLC_BITS 6
  50
  51 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  52                               DCTELEM *block,
  53                               int n);
  54 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  55                               DCTELEM *block,
  56                               int n);
  57 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  58 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  59                                         DCTELEM *block,
  60                                         int n);
  61 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  62                                     DCTELEM *block,
  63                                     int n);
  64 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  65 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  66 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  67 static void exchange_uv(MpegEncContext *s);
  68
  69 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  70                                            PIX_FMT_XVMC_MPEG2_IDCT,
  71                                            PIX_FMT_XVMC_MPEG2_MC,
  72                                            PIX_FMT_NONE};
  73
  74 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  75
  76
  77 #define INIT_2D_VLC_RL(rl, static_size)\
  78 {\
  79     static RL_VLC_ELEM rl_vlc_table[static_size];\
  80     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  81              &rl.table_vlc[0][1], 4, 2,\
  82              &rl.table_vlc[0][0], 4, 2, static_size);\
  83 \
  84     rl.rl_vlc[0]= rl_vlc_table;\
  85     init_2d_vlc_rl(&rl);\
  86 }
  87
  88 static void init_2d_vlc_rl(RLTable *rl)
  89 {
  90     int i;
  91
  92     for(i=0; i<rl->vlc.table_size; i++){
  93         int code= rl->vlc.table[i][0];
  94         int len = rl->vlc.table[i][1];
  95         int level, run;
  96
  97         if(len==0){ // illegal code
  98             run= 65;
  99             level= MAX_LEVEL;
 100         }else if(len<0){ //more bits needed
 101             run= 0;
 102             level= code;
 103         }else{
 104             if(code==rl->n){ //esc
 105                 run= 65;
 106                 level= 0;
 107             }else if(code==rl->n+1){ //eob
 108                 run= 0;
 109                 level= 127;
 110             }else{
 111                 run=   rl->table_run  [code] + 1;
 112                 level= rl->table_level[code];
 113             }
 114         }
 115         rl->rl_vlc[0][i].len= len;
 116         rl->rl_vlc[0][i].level= level;
 117         rl->rl_vlc[0][i].run= run;
 118     }
 119 }
 120
 121 void ff_mpeg12_common_init(MpegEncContext *s)
 122 {
 123
 124     s->y_dc_scale_table=
 125     s->c_dc_scale_table= ff_mpeg2_dc_scale_table[s->intra_dc_precision];
 126
 127 }
 128
 129 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 130     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 131     s->last_dc[1] = s->last_dc[0];
 132     s->last_dc[2] = s->last_dc[0];
 133     memset(s->last_mv, 0, sizeof(s->last_mv));
 134 }
 135
 136
 137 /******************************************/
 138 /* decoding */
 139
 140 static VLC mv_vlc;
 141 static VLC mbincr_vlc;
 142 static VLC mb_ptype_vlc;
 143 static VLC mb_btype_vlc;
 144 static VLC mb_pat_vlc;
 145
 146 av_cold void ff_mpeg12_init_vlcs(void)
 147 {
 148     static int done = 0;
 149
 150     if (!done) {
 151         done = 1;
 152
 153         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
 154                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 155                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 156         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 157                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 158                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 159         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 160                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 161                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 162         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 163                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 164                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 165         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 166                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 167                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 168
 169         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 170                  &table_mb_ptype[0][1], 2, 1,
 171                  &table_mb_ptype[0][0], 2, 1, 64);
 172         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 173                  &table_mb_btype[0][1], 2, 1,
 174                  &table_mb_btype[0][0], 2, 1, 64);
 175         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 176         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 177
 178         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 179         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 180     }
 181 }
 182
 183 static inline int get_dmv(MpegEncContext *s)
 184 {
 185     if(get_bits1(&s->gb))
 186         return 1 - (get_bits1(&s->gb) << 1);
 187     else
 188         return 0;
 189 }
 190
 191 static inline int get_qscale(MpegEncContext *s)
 192 {
 193     int qscale = get_bits(&s->gb, 5);
 194     if (s->q_scale_type) {
 195         return non_linear_qscale[qscale];
 196     } else {
 197         return qscale << 1;
 198     }
 199 }
 200
 201 /* motion type (for MPEG-2) */
 202 #define MT_FIELD 1
 203 #define MT_FRAME 2
 204 #define MT_16X8  2
 205 #define MT_DMV   3
 206
 207 static int mpeg_decode_mb(MpegEncContext *s,
 208                           DCTELEM block[12][64])
 209 {
 210     int i, j, k, cbp, val, mb_type, motion_type;
 211     const int mb_block_count = 4 + (1<< s->chroma_format);
 212
 213     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 214
 215     assert(s->mb_skipped==0);
 216
 217     if (s->mb_skip_run-- != 0) {
 218         if (s->pict_type == FF_P_TYPE) {
 219             s->mb_skipped = 1;
 220             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 221         } else {
 222             int mb_type;
 223
 224             if(s->mb_x)
 225                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 226             else
 227                 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
 228             if(IS_INTRA(mb_type))
 229                 return -1;
 230
 231             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 232                 mb_type | MB_TYPE_SKIP;
 233 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 234
 235             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 236                 s->mb_skipped = 1;
 237         }
 238
 239         return 0;
 240     }
 241
 242     switch(s->pict_type) {
 243     default:
 244     case FF_I_TYPE:
 245         if (get_bits1(&s->gb) == 0) {
 246             if (get_bits1(&s->gb) == 0){
 247                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 248                 return -1;
 249             }
 250             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 251         } else {
 252             mb_type = MB_TYPE_INTRA;
 253         }
 254         break;
 255     case FF_P_TYPE:
 256         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 257         if (mb_type < 0){
 258             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 259             return -1;
 260         }
 261         mb_type = ptype2mb_type[ mb_type ];
 262         break;
 263     case FF_B_TYPE:
 264         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 265         if (mb_type < 0){
 266             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 267             return -1;
 268         }
 269         mb_type = btype2mb_type[ mb_type ];
 270         break;
 271     }
 272     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 273 //    motion_type = 0; /* avoid warning */
 274     if (IS_INTRA(mb_type)) {
 275         s->dsp.clear_blocks(s->block[0]);
 276
 277         if(!s->chroma_y_shift){
 278             s->dsp.clear_blocks(s->block[6]);
 279         }
 280
 281         /* compute DCT type */
 282         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 283             !s->frame_pred_frame_dct) {
 284             s->interlaced_dct = get_bits1(&s->gb);
 285         }
 286
 287         if (IS_QUANT(mb_type))
 288             s->qscale = get_qscale(s);
 289
 290         if (s->concealment_motion_vectors) {
 291             /* just parse them */
 292             if (s->picture_structure != PICT_FRAME)
 293                 skip_bits1(&s->gb); /* field select */
 294
 295             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 296                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 297             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 298                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 299
 300             skip_bits1(&s->gb); /* marker */
 301         }else
 302             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 303         s->mb_intra = 1;
 304         //if 1, we memcpy blocks in xvmcvideo
 305         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 306             ff_xvmc_pack_pblocks(s,-1);//inter are always full blocks
 307             if(s->swap_uv){
 308                 exchange_uv(s);
 309             }
 310         }
 311
 312         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 313             if(s->flags2 & CODEC_FLAG2_FAST){
 314                 for(i=0;i<6;i++) {
 315                     mpeg2_fast_decode_block_intra(s, *s->pblocks[i], i);
 316                 }
 317             }else{
 318                 for(i=0;i<mb_block_count;i++) {
 319                     if (mpeg2_decode_block_intra(s, *s->pblocks[i], i) < 0)
 320                         return -1;
 321                 }
 322             }
 323         } else {
 324             for(i=0;i<6;i++) {
 325                 if (mpeg1_decode_block_intra(s, *s->pblocks[i], i) < 0)
 326                     return -1;
 327             }
 328         }
 329     } else {
 330         if (mb_type & MB_TYPE_ZERO_MV){
 331             assert(mb_type & MB_TYPE_CBP);
 332
 333             s->mv_dir = MV_DIR_FORWARD;
 334             if(s->picture_structure == PICT_FRAME){
 335                 if(!s->frame_pred_frame_dct)
 336                     s->interlaced_dct = get_bits1(&s->gb);
 337                 s->mv_type = MV_TYPE_16X16;
 338             }else{
 339                 s->mv_type = MV_TYPE_FIELD;
 340                 mb_type |= MB_TYPE_INTERLACED;
 341                 s->field_select[0][0]= s->picture_structure - 1;
 342             }
 343
 344             if (IS_QUANT(mb_type))
 345                 s->qscale = get_qscale(s);
 346
 347             s->last_mv[0][0][0] = 0;
 348             s->last_mv[0][0][1] = 0;
 349             s->last_mv[0][1][0] = 0;
 350             s->last_mv[0][1][1] = 0;
 351             s->mv[0][0][0] = 0;
 352             s->mv[0][0][1] = 0;
 353         }else{
 354             assert(mb_type & MB_TYPE_L0L1);
 355 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 356             /* get additional motion vector type */
 357             if (s->frame_pred_frame_dct)
 358                 motion_type = MT_FRAME;
 359             else{
 360                 motion_type = get_bits(&s->gb, 2);
 361                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 362                     s->interlaced_dct = get_bits1(&s->gb);
 363             }
 364
 365             if (IS_QUANT(mb_type))
 366                 s->qscale = get_qscale(s);
 367
 368             /* motion vectors */
 369             s->mv_dir= (mb_type>>13)&3;
 370             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 371             switch(motion_type) {
 372             case MT_FRAME: /* or MT_16X8 */
 373                 if (s->picture_structure == PICT_FRAME) {
 374                     mb_type |= MB_TYPE_16x16;
 375                     s->mv_type = MV_TYPE_16X16;
 376                     for(i=0;i<2;i++) {
 377                         if (USES_LIST(mb_type, i)) {
 378                             /* MT_FRAME */
 379                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 380                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 381                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 382                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 383                             /* full_pel: only for MPEG-1 */
 384                             if (s->full_pel[i]){
 385                                 s->mv[i][0][0] <<= 1;
 386                                 s->mv[i][0][1] <<= 1;
 387                             }
 388                         }
 389                     }
 390                 } else {
 391                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 392                     s->mv_type = MV_TYPE_16X8;
 393                     for(i=0;i<2;i++) {
 394                         if (USES_LIST(mb_type, i)) {
 395                             /* MT_16X8 */
 396                             for(j=0;j<2;j++) {
 397                                 s->field_select[i][j] = get_bits1(&s->gb);
 398                                 for(k=0;k<2;k++) {
 399                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 400                                                              s->last_mv[i][j][k]);
 401                                     s->last_mv[i][j][k] = val;
 402                                     s->mv[i][j][k] = val;
 403                                 }
 404                             }
 405                         }
 406                     }
 407                 }
 408                 break;
 409             case MT_FIELD:
 410                 s->mv_type = MV_TYPE_FIELD;
 411                 if (s->picture_structure == PICT_FRAME) {
 412                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 413                     for(i=0;i<2;i++) {
 414                         if (USES_LIST(mb_type, i)) {
 415                             for(j=0;j<2;j++) {
 416                                 s->field_select[i][j] = get_bits1(&s->gb);
 417                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 418                                                          s->last_mv[i][j][0]);
 419                                 s->last_mv[i][j][0] = val;
 420                                 s->mv[i][j][0] = val;
 421                                 dprintf(s->avctx, "fmx=%d\n", val);
 422                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 423                                                          s->last_mv[i][j][1] >> 1);
 424                                 s->last_mv[i][j][1] = val << 1;
 425                                 s->mv[i][j][1] = val;
 426                                 dprintf(s->avctx, "fmy=%d\n", val);
 427                             }
 428                         }
 429                     }
 430                 } else {
 431                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 432                     for(i=0;i<2;i++) {
 433                         if (USES_LIST(mb_type, i)) {
 434                             s->field_select[i][0] = get_bits1(&s->gb);
 435                             for(k=0;k<2;k++) {
 436                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 437                                                          s->last_mv[i][0][k]);
 438                                 s->last_mv[i][0][k] = val;
 439                                 s->last_mv[i][1][k] = val;
 440                                 s->mv[i][0][k] = val;
 441                             }
 442                         }
 443                     }
 444                 }
 445                 break;
 446             case MT_DMV:
 447                 s->mv_type = MV_TYPE_DMV;
 448                 for(i=0;i<2;i++) {
 449                     if (USES_LIST(mb_type, i)) {
 450                         int dmx, dmy, mx, my, m;
 451                         const int my_shift= s->picture_structure == PICT_FRAME;
 452
 453                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 454                                                 s->last_mv[i][0][0]);
 455                         s->last_mv[i][0][0] = mx;
 456                         s->last_mv[i][1][0] = mx;
 457                         dmx = get_dmv(s);
 458                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 459                                                 s->last_mv[i][0][1] >> my_shift);
 460                         dmy = get_dmv(s);
 461
 462
 463                         s->last_mv[i][0][1] = my<<my_shift;
 464                         s->last_mv[i][1][1] = my<<my_shift;
 465
 466                         s->mv[i][0][0] = mx;
 467                         s->mv[i][0][1] = my;
 468                         s->mv[i][1][0] = mx;//not used
 469                         s->mv[i][1][1] = my;//not used
 470
 471                         if (s->picture_structure == PICT_FRAME) {
 472                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 473
 474                             //m = 1 + 2 * s->top_field_first;
 475                             m = s->top_field_first ? 1 : 3;
 476
 477                             /* top -> top pred */
 478                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 479                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 480                             m = 4 - m;
 481                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 482                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 483                         } else {
 484                             mb_type |= MB_TYPE_16x16;
 485
 486                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 487                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 488                             if(s->picture_structure == PICT_TOP_FIELD)
 489                                 s->mv[i][2][1]--;
 490                             else
 491                                 s->mv[i][2][1]++;
 492                         }
 493                     }
 494                 }
 495                 break;
 496             default:
 497                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 498                 return -1;
 499             }
 500         }
 501
 502         s->mb_intra = 0;
 503         if (HAS_CBP(mb_type)) {
 504             s->dsp.clear_blocks(s->block[0]);
 505
 506             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 507             if(mb_block_count > 6){
 508                  cbp<<= mb_block_count-6;
 509                  cbp |= get_bits(&s->gb, mb_block_count-6);
 510                  s->dsp.clear_blocks(s->block[6]);
 511             }
 512             if (cbp <= 0){
 513                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 514                 return -1;
 515             }
 516
 517             //if 1, we memcpy blocks in xvmcvideo
 518             if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1){
 519                 ff_xvmc_pack_pblocks(s,cbp);
 520                 if(s->swap_uv){
 521                     exchange_uv(s);
 522                 }
 523             }
 524
 525             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 526                 if(s->flags2 & CODEC_FLAG2_FAST){
 527                     for(i=0;i<6;i++) {
 528                         if(cbp & 32) {
 529                             mpeg2_fast_decode_block_non_intra(s, *s->pblocks[i], i);
 530                         } else {
 531                             s->block_last_index[i] = -1;
 532                         }
 533                         cbp+=cbp;
 534                     }
 535                 }else{
 536                     cbp<<= 12-mb_block_count;
 537
 538                     for(i=0;i<mb_block_count;i++) {
 539                         if ( cbp & (1<<11) ) {
 540                             if (mpeg2_decode_block_non_intra(s, *s->pblocks[i], i) < 0)
 541                                 return -1;
 542                         } else {
 543                             s->block_last_index[i] = -1;
 544                         }
 545                         cbp+=cbp;
 546                     }
 547                 }
 548             } else {
 549                 if(s->flags2 & CODEC_FLAG2_FAST){
 550                     for(i=0;i<6;i++) {
 551                         if (cbp & 32) {
 552                             mpeg1_fast_decode_block_inter(s, *s->pblocks[i], i);
 553                         } else {
 554                             s->block_last_index[i] = -1;
 555                         }
 556                         cbp+=cbp;
 557                     }
 558                 }else{
 559                     for(i=0;i<6;i++) {
 560                         if (cbp & 32) {
 561                             if (mpeg1_decode_block_inter(s, *s->pblocks[i], i) < 0)
 562                                 return -1;
 563                         } else {
 564                             s->block_last_index[i] = -1;
 565                         }
 566                         cbp+=cbp;
 567                     }
 568                 }
 569             }
 570         }else{
 571             for(i=0;i<12;i++)
 572                 s->block_last_index[i] = -1;
 573         }
 574     }
 575
 576     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 577
 578     return 0;
 579 }
 580
 581 /* as H.263, but only 17 codes */
 582 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 583 {
 584     int code, sign, val, l, shift;
 585
 586     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 587     if (code == 0) {
 588         return pred;
 589     }
 590     if (code < 0) {
 591         return 0xffff;
 592     }
 593
 594     sign = get_bits1(&s->gb);
 595     shift = fcode - 1;
 596     val = code;
 597     if (shift) {
 598         val = (val - 1) << shift;
 599         val |= get_bits(&s->gb, shift);
 600         val++;
 601     }
 602     if (sign)
 603         val = -val;
 604     val += pred;
 605
 606     /* modulo decoding */
 607     l= INT_BIT - 5 - shift;
 608     val = (val<<l)>>l;
 609     return val;
 610 }
 611
 612 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 613                                DCTELEM *block,
 614                                int n)
 615 {
 616     int level, dc, diff, i, j, run;
 617     int component;
 618     RLTable *rl = &ff_rl_mpeg1;
 619     uint8_t * const scantable= s->intra_scantable.permutated;
 620     const uint16_t *quant_matrix= s->intra_matrix;
 621     const int qscale= s->qscale;
 622
 623     /* DC coefficient */
 624     component = (n <= 3 ? 0 : n - 4 + 1);
 625     diff = decode_dc(&s->gb, component);
 626     if (diff >= 0xffff)
 627         return -1;
 628     dc = s->last_dc[component];
 629     dc += diff;
 630     s->last_dc[component] = dc;
 631     block[0] = dc*quant_matrix[0];
 632     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 633     i = 0;
 634     {
 635         OPEN_READER(re, &s->gb);
 636         /* now quantify & encode AC coefficients */
 637         for(;;) {
 638             UPDATE_CACHE(re, &s->gb);
 639             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 640
 641             if(level == 127){
 642                 break;
 643             } else if(level != 0) {
 644                 i += run;
 645                 j = scantable[i];
 646                 level= (level*qscale*quant_matrix[j])>>4;
 647                 level= (level-1)|1;
 648                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 649                 LAST_SKIP_BITS(re, &s->gb, 1);
 650             } else {
 651                 /* escape */
 652                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 653                 UPDATE_CACHE(re, &s->gb);
 654                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 655                 if (level == -128) {
 656                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 657                 } else if (level == 0) {
 658                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 659                 }
 660                 i += run;
 661                 j = scantable[i];
 662                 if(level<0){
 663                     level= -level;
 664                     level= (level*qscale*quant_matrix[j])>>4;
 665                     level= (level-1)|1;
 666                     level= -level;
 667                 }else{
 668                     level= (level*qscale*quant_matrix[j])>>4;
 669                     level= (level-1)|1;
 670                 }
 671             }
 672             if (i > 63){
 673                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 674                 return -1;
 675             }
 676
 677             block[j] = level;
 678         }
 679         CLOSE_READER(re, &s->gb);
 680     }
 681     s->block_last_index[n] = i;
 682    return 0;
 683 }
 684
 685 int ff_mpeg1_decode_block_intra(MpegEncContext *s,
 686                                 DCTELEM *block,
 687                                 int n)
 688 {
 689     return mpeg1_decode_block_intra(s, block, n);
 690 }
 691
 692 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 693                                DCTELEM *block,
 694                                int n)
 695 {
 696     int level, i, j, run;
 697     RLTable *rl = &ff_rl_mpeg1;
 698     uint8_t * const scantable= s->intra_scantable.permutated;
 699     const uint16_t *quant_matrix= s->inter_matrix;
 700     const int qscale= s->qscale;
 701
 702     {
 703         OPEN_READER(re, &s->gb);
 704         i = -1;
 705         // special case for first coefficient, no need to add second VLC table
 706         UPDATE_CACHE(re, &s->gb);
 707         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 708             level= (3*qscale*quant_matrix[0])>>5;
 709             level= (level-1)|1;
 710             if(GET_CACHE(re, &s->gb)&0x40000000)
 711                 level= -level;
 712             block[0] = level;
 713             i++;
 714             SKIP_BITS(re, &s->gb, 2);
 715             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 716                 goto end;
 717         }
 718 #if MIN_CACHE_BITS < 19
 719         UPDATE_CACHE(re, &s->gb);
 720 #endif
 721         /* now quantify & encode AC coefficients */
 722         for(;;) {
 723             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 724
 725             if(level != 0) {
 726                 i += run;
 727                 j = scantable[i];
 728                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 729                 level= (level-1)|1;
 730                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 731                 SKIP_BITS(re, &s->gb, 1);
 732             } else {
 733                 /* escape */
 734                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 735                 UPDATE_CACHE(re, &s->gb);
 736                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 737                 if (level == -128) {
 738                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 739                 } else if (level == 0) {
 740                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 741                 }
 742                 i += run;
 743                 j = scantable[i];
 744                 if(level<0){
 745                     level= -level;
 746                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 747                     level= (level-1)|1;
 748                     level= -level;
 749                 }else{
 750                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 751                     level= (level-1)|1;
 752                 }
 753             }
 754             if (i > 63){
 755                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 756                 return -1;
 757             }
 758
 759             block[j] = level;
 760 #if MIN_CACHE_BITS < 19
 761             UPDATE_CACHE(re, &s->gb);
 762 #endif
 763             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 764                 break;
 765 #if MIN_CACHE_BITS >= 19
 766             UPDATE_CACHE(re, &s->gb);
 767 #endif
 768         }
 769 end:
 770         LAST_SKIP_BITS(re, &s->gb, 2);
 771         CLOSE_READER(re, &s->gb);
 772     }
 773     s->block_last_index[n] = i;
 774     return 0;
 775 }
 776
 777 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 778 {
 779     int level, i, j, run;
 780     RLTable *rl = &ff_rl_mpeg1;
 781     uint8_t * const scantable= s->intra_scantable.permutated;
 782     const int qscale= s->qscale;
 783
 784     {
 785         OPEN_READER(re, &s->gb);
 786         i = -1;
 787         // special case for first coefficient, no need to add second VLC table
 788         UPDATE_CACHE(re, &s->gb);
 789         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 790             level= (3*qscale)>>1;
 791             level= (level-1)|1;
 792             if(GET_CACHE(re, &s->gb)&0x40000000)
 793                 level= -level;
 794             block[0] = level;
 795             i++;
 796             SKIP_BITS(re, &s->gb, 2);
 797             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 798                 goto end;
 799         }
 800 #if MIN_CACHE_BITS < 19
 801         UPDATE_CACHE(re, &s->gb);
 802 #endif
 803
 804         /* now quantify & encode AC coefficients */
 805         for(;;) {
 806             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 807
 808             if(level != 0) {
 809                 i += run;
 810                 j = scantable[i];
 811                 level= ((level*2+1)*qscale)>>1;
 812                 level= (level-1)|1;
 813                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 814                 SKIP_BITS(re, &s->gb, 1);
 815             } else {
 816                 /* escape */
 817                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 818                 UPDATE_CACHE(re, &s->gb);
 819                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 820                 if (level == -128) {
 821                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 822                 } else if (level == 0) {
 823                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 824                 }
 825                 i += run;
 826                 j = scantable[i];
 827                 if(level<0){
 828                     level= -level;
 829                     level= ((level*2+1)*qscale)>>1;
 830                     level= (level-1)|1;
 831                     level= -level;
 832                 }else{
 833                     level= ((level*2+1)*qscale)>>1;
 834                     level= (level-1)|1;
 835                 }
 836             }
 837
 838             block[j] = level;
 839 #if MIN_CACHE_BITS < 19
 840             UPDATE_CACHE(re, &s->gb);
 841 #endif
 842             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 843                 break;
 844 #if MIN_CACHE_BITS >= 19
 845             UPDATE_CACHE(re, &s->gb);
 846 #endif
 847         }
 848 end:
 849         LAST_SKIP_BITS(re, &s->gb, 2);
 850         CLOSE_READER(re, &s->gb);
 851     }
 852     s->block_last_index[n] = i;
 853     return 0;
 854 }
 855
 856
 857 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 858                                DCTELEM *block,
 859                                int n)
 860 {
 861     int level, i, j, run;
 862     RLTable *rl = &ff_rl_mpeg1;
 863     uint8_t * const scantable= s->intra_scantable.permutated;
 864     const uint16_t *quant_matrix;
 865     const int qscale= s->qscale;
 866     int mismatch;
 867
 868     mismatch = 1;
 869
 870     {
 871         OPEN_READER(re, &s->gb);
 872         i = -1;
 873         if (n < 4)
 874             quant_matrix = s->inter_matrix;
 875         else
 876             quant_matrix = s->chroma_inter_matrix;
 877
 878         // special case for first coefficient, no need to add second VLC table
 879         UPDATE_CACHE(re, &s->gb);
 880         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 881             level= (3*qscale*quant_matrix[0])>>5;
 882             if(GET_CACHE(re, &s->gb)&0x40000000)
 883                 level= -level;
 884             block[0] = level;
 885             mismatch ^= level;
 886             i++;
 887             SKIP_BITS(re, &s->gb, 2);
 888             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 889                 goto end;
 890         }
 891 #if MIN_CACHE_BITS < 19
 892         UPDATE_CACHE(re, &s->gb);
 893 #endif
 894
 895         /* now quantify & encode AC coefficients */
 896         for(;;) {
 897             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 898
 899             if(level != 0) {
 900                 i += run;
 901                 j = scantable[i];
 902                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 903                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 904                 SKIP_BITS(re, &s->gb, 1);
 905             } else {
 906                 /* escape */
 907                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 908                 UPDATE_CACHE(re, &s->gb);
 909                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 910
 911                 i += run;
 912                 j = scantable[i];
 913                 if(level<0){
 914                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 915                     level= -level;
 916                 }else{
 917                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 918                 }
 919             }
 920             if (i > 63){
 921                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 922                 return -1;
 923             }
 924
 925             mismatch ^= level;
 926             block[j] = level;
 927 #if MIN_CACHE_BITS < 19
 928             UPDATE_CACHE(re, &s->gb);
 929 #endif
 930             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 931                 break;
 932 #if MIN_CACHE_BITS >= 19
 933             UPDATE_CACHE(re, &s->gb);
 934 #endif
 935         }
 936 end:
 937         LAST_SKIP_BITS(re, &s->gb, 2);
 938         CLOSE_READER(re, &s->gb);
 939     }
 940     block[63] ^= (mismatch & 1);
 941
 942     s->block_last_index[n] = i;
 943     return 0;
 944 }
 945
 946 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 947                                DCTELEM *block,
 948                                int n)
 949 {
 950     int level, i, j, run;
 951     RLTable *rl = &ff_rl_mpeg1;
 952     uint8_t * const scantable= s->intra_scantable.permutated;
 953     const int qscale= s->qscale;
 954     OPEN_READER(re, &s->gb);
 955     i = -1;
 956
 957     // special case for first coefficient, no need to add second VLC table
 958     UPDATE_CACHE(re, &s->gb);
 959     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 960         level= (3*qscale)>>1;
 961         if(GET_CACHE(re, &s->gb)&0x40000000)
 962             level= -level;
 963         block[0] = level;
 964         i++;
 965         SKIP_BITS(re, &s->gb, 2);
 966         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 967             goto end;
 968     }
 969 #if MIN_CACHE_BITS < 19
 970     UPDATE_CACHE(re, &s->gb);
 971 #endif
 972
 973     /* now quantify & encode AC coefficients */
 974     for(;;) {
 975         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 976
 977         if(level != 0) {
 978             i += run;
 979             j = scantable[i];
 980             level= ((level*2+1)*qscale)>>1;
 981             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 982             SKIP_BITS(re, &s->gb, 1);
 983         } else {
 984             /* escape */
 985             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 986             UPDATE_CACHE(re, &s->gb);
 987             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 988
 989             i += run;
 990             j = scantable[i];
 991             if(level<0){
 992                 level= ((-level*2+1)*qscale)>>1;
 993                 level= -level;
 994             }else{
 995                 level= ((level*2+1)*qscale)>>1;
 996             }
 997         }
 998
 999         block[j] = level;
1000 #if MIN_CACHE_BITS < 19
1001         UPDATE_CACHE(re, &s->gb);
1002 #endif
1003         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
1004             break;
1005 #if MIN_CACHE_BITS >=19
1006         UPDATE_CACHE(re, &s->gb);
1007 #endif
1008     }
1009 end:
1010     LAST_SKIP_BITS(re, &s->gb, 2);
1011     CLOSE_READER(re, &s->gb);
1012     s->block_last_index[n] = i;
1013     return 0;
1014 }
1015
1016
1017 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1018                                DCTELEM *block,
1019                                int n)
1020 {
1021     int level, dc, diff, i, j, run;
1022     int component;
1023     RLTable *rl;
1024     uint8_t * const scantable= s->intra_scantable.permutated;
1025     const uint16_t *quant_matrix;
1026     const int qscale= s->qscale;
1027     int mismatch;
1028
1029     /* DC coefficient */
1030     if (n < 4){
1031         quant_matrix = s->intra_matrix;
1032         component = 0;
1033     }else{
1034         quant_matrix = s->chroma_intra_matrix;
1035         component = (n&1) + 1;
1036     }
1037     diff = decode_dc(&s->gb, component);
1038     if (diff >= 0xffff)
1039         return -1;
1040     dc = s->last_dc[component];
1041     dc += diff;
1042     s->last_dc[component] = dc;
1043     block[0] = dc << (3 - s->intra_dc_precision);
1044     dprintf(s->avctx, "dc=%d\n", block[0]);
1045     mismatch = block[0] ^ 1;
1046     i = 0;
1047     if (s->intra_vlc_format)
1048         rl = &ff_rl_mpeg2;
1049     else
1050         rl = &ff_rl_mpeg1;
1051
1052     {
1053         OPEN_READER(re, &s->gb);
1054         /* now quantify & encode AC coefficients */
1055         for(;;) {
1056             UPDATE_CACHE(re, &s->gb);
1057             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1058
1059             if(level == 127){
1060                 break;
1061             } else if(level != 0) {
1062                 i += run;
1063                 j = scantable[i];
1064                 level= (level*qscale*quant_matrix[j])>>4;
1065                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1066                 LAST_SKIP_BITS(re, &s->gb, 1);
1067             } else {
1068                 /* escape */
1069                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1070                 UPDATE_CACHE(re, &s->gb);
1071                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1072                 i += run;
1073                 j = scantable[i];
1074                 if(level<0){
1075                     level= (-level*qscale*quant_matrix[j])>>4;
1076                     level= -level;
1077                 }else{
1078                     level= (level*qscale*quant_matrix[j])>>4;
1079                 }
1080             }
1081             if (i > 63){
1082                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1083                 return -1;
1084             }
1085
1086             mismatch^= level;
1087             block[j] = level;
1088         }
1089         CLOSE_READER(re, &s->gb);
1090     }
1091     block[63]^= mismatch&1;
1092
1093     s->block_last_index[n] = i;
1094     return 0;
1095 }
1096
1097 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1098                                DCTELEM *block,
1099                                int n)
1100 {
1101     int level, dc, diff, j, run;
1102     int component;
1103     RLTable *rl;
1104     uint8_t * scantable= s->intra_scantable.permutated;
1105     const uint16_t *quant_matrix;
1106     const int qscale= s->qscale;
1107
1108     /* DC coefficient */
1109     if (n < 4){
1110         quant_matrix = s->intra_matrix;
1111         component = 0;
1112     }else{
1113         quant_matrix = s->chroma_intra_matrix;
1114         component = (n&1) + 1;
1115     }
1116     diff = decode_dc(&s->gb, component);
1117     if (diff >= 0xffff)
1118         return -1;
1119     dc = s->last_dc[component];
1120     dc += diff;
1121     s->last_dc[component] = dc;
1122     block[0] = dc << (3 - s->intra_dc_precision);
1123     if (s->intra_vlc_format)
1124         rl = &ff_rl_mpeg2;
1125     else
1126         rl = &ff_rl_mpeg1;
1127
1128     {
1129         OPEN_READER(re, &s->gb);
1130         /* now quantify & encode AC coefficients */
1131         for(;;) {
1132             UPDATE_CACHE(re, &s->gb);
1133             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1134
1135             if(level == 127){
1136                 break;
1137             } else if(level != 0) {
1138                 scantable += run;
1139                 j = *scantable;
1140                 level= (level*qscale*quant_matrix[j])>>4;
1141                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1142                 LAST_SKIP_BITS(re, &s->gb, 1);
1143             } else {
1144                 /* escape */
1145                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1146                 UPDATE_CACHE(re, &s->gb);
1147                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1148                 scantable += run;
1149                 j = *scantable;
1150                 if(level<0){
1151                     level= (-level*qscale*quant_matrix[j])>>4;
1152                     level= -level;
1153                 }else{
1154                     level= (level*qscale*quant_matrix[j])>>4;
1155                 }
1156             }
1157
1158             block[j] = level;
1159         }
1160         CLOSE_READER(re, &s->gb);
1161     }
1162
1163     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1164     return 0;
1165 }
1166
1167 typedef struct Mpeg1Context {
1168     MpegEncContext mpeg_enc_ctx;
1169     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1170     int repeat_field; /* true if we must repeat the field */
1171     AVPanScan pan_scan; /** some temporary storage for the panscan */
1172     int slice_count;
1173     int swap_uv;//indicate VCR2
1174     int save_aspect_info;
1175     int save_width, save_height, save_progressive_seq;
1176     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1177     int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
1178 } Mpeg1Context;
1179
1180 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1181 {
1182     Mpeg1Context *s = avctx->priv_data;
1183     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1184     int i;
1185
1186     /* we need some permutation to store matrices,
1187      * until MPV_common_init() sets the real permutation. */
1188     for(i=0;i<64;i++)
1189        s2->dsp.idct_permutation[i]=i;
1190
1191     MPV_decode_defaults(s2);
1192
1193     s->mpeg_enc_ctx.avctx= avctx;
1194     s->mpeg_enc_ctx.flags= avctx->flags;
1195     s->mpeg_enc_ctx.flags2= avctx->flags2;
1196     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1197     ff_mpeg12_init_vlcs();
1198
1199     s->mpeg_enc_ctx_allocated = 0;
1200     s->mpeg_enc_ctx.picture_number = 0;
1201     s->repeat_field = 0;
1202     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1203     avctx->color_range= AVCOL_RANGE_MPEG;
1204     if (avctx->codec->id == CODEC_ID_MPEG1VIDEO)
1205         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
1206     else
1207         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
1208     return 0;
1209 }
1210
1211 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1212                                      const uint8_t *new_perm){
1213     uint16_t temp_matrix[64];
1214     int i;
1215
1216     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1217
1218     for(i=0;i<64;i++){
1219         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1220     }
1221 }
1222
1223 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1224     Mpeg1Context *s1 = avctx->priv_data;
1225     MpegEncContext *s = &s1->mpeg_enc_ctx;
1226
1227     if(avctx->xvmc_acceleration)
1228         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1229     else if(avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU){
1230         if(avctx->codec_id == CODEC_ID_MPEG1VIDEO)
1231             return PIX_FMT_VDPAU_MPEG1;
1232         else
1233             return PIX_FMT_VDPAU_MPEG2;
1234     }else{
1235         if(s->chroma_format <  2)
1236             return avctx->get_format(avctx,ff_hwaccel_pixfmt_list_420);
1237         else if(s->chroma_format == 2)
1238             return PIX_FMT_YUV422P;
1239         else
1240             return PIX_FMT_YUV444P;
1241     }
1242 }
1243
1244 /* Call this function when we know all parameters.
1245  * It may be called in different places for MPEG-1 and MPEG-2. */
1246 static int mpeg_decode_postinit(AVCodecContext *avctx){
1247     Mpeg1Context *s1 = avctx->priv_data;
1248     MpegEncContext *s = &s1->mpeg_enc_ctx;
1249     uint8_t old_permutation[64];
1250
1251     if (
1252         (s1->mpeg_enc_ctx_allocated == 0)||
1253         avctx->coded_width  != s->width ||
1254         avctx->coded_height != s->height||
1255         s1->save_width != s->width ||
1256         s1->save_height != s->height ||
1257         s1->save_aspect_info != s->aspect_ratio_info||
1258         s1->save_progressive_seq != s->progressive_sequence ||
1259         0)
1260     {
1261
1262         if (s1->mpeg_enc_ctx_allocated) {
1263             ParseContext pc= s->parse_context;
1264             s->parse_context.buffer=0;
1265             MPV_common_end(s);
1266             s->parse_context= pc;
1267         }
1268
1269         if( (s->width == 0 )||(s->height == 0))
1270             return -2;
1271
1272         avcodec_set_dimensions(avctx, s->width, s->height);
1273         avctx->bit_rate = s->bit_rate;
1274         s1->save_aspect_info = s->aspect_ratio_info;
1275         s1->save_width = s->width;
1276         s1->save_height = s->height;
1277         s1->save_progressive_seq = s->progressive_sequence;
1278
1279         /* low_delay may be forced, in this case we will have B-frames
1280          * that behave like P-frames. */
1281         avctx->has_b_frames = !(s->low_delay);
1282
1283         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1284         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1285             //MPEG-1 fps
1286             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1287             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1288             //MPEG-1 aspect
1289             avctx->sample_aspect_ratio= av_d2q(
1290                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1291             avctx->ticks_per_frame=1;
1292         }else{//MPEG-2
1293         //MPEG-2 fps
1294             av_reduce(
1295                 &s->avctx->time_base.den,
1296                 &s->avctx->time_base.num,
1297                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num*2,
1298                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1299                 1<<30);
1300             avctx->ticks_per_frame=2;
1301         //MPEG-2 aspect
1302             if(s->aspect_ratio_info > 1){
1303                 //we ignore the spec here as reality does not match the spec, see for example
1304                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1305                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1306                     s->avctx->sample_aspect_ratio=
1307                         av_div_q(
1308                          ff_mpeg2_aspect[s->aspect_ratio_info],
1309                          (AVRational){s->width, s->height}
1310                          );
1311                 }else{
1312                     s->avctx->sample_aspect_ratio=
1313                         av_div_q(
1314                          ff_mpeg2_aspect[s->aspect_ratio_info],
1315                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1316                         );
1317                 }
1318             }else{
1319                 s->avctx->sample_aspect_ratio=
1320                     ff_mpeg2_aspect[s->aspect_ratio_info];
1321             }
1322         }//MPEG-2
1323
1324         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1325         avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
1326         //until then pix_fmt may be changed right after codec init
1327         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT ||
1328             avctx->hwaccel ||
1329             s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
1330             if( avctx->idct_algo == FF_IDCT_AUTO )
1331                 avctx->idct_algo = FF_IDCT_SIMPLE;
1332
1333         /* Quantization matrices may need reordering
1334          * if DCT permutation is changed. */
1335         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1336
1337         if (MPV_common_init(s) < 0)
1338             return -2;
1339
1340         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1341         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1342         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1343         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1344
1345         s1->mpeg_enc_ctx_allocated = 1;
1346     }
1347     return 0;
1348 }
1349
1350 static int mpeg1_decode_picture(AVCodecContext *avctx,
1351                                 const uint8_t *buf, int buf_size)
1352 {
1353     Mpeg1Context *s1 = avctx->priv_data;
1354     MpegEncContext *s = &s1->mpeg_enc_ctx;
1355     int ref, f_code, vbv_delay;
1356
1357     init_get_bits(&s->gb, buf, buf_size*8);
1358
1359     ref = get_bits(&s->gb, 10); /* temporal ref */
1360     s->pict_type = get_bits(&s->gb, 3);
1361     if(s->pict_type == 0 || s->pict_type > 3)
1362         return -1;
1363
1364     vbv_delay= get_bits(&s->gb, 16);
1365     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1366         s->full_pel[0] = get_bits1(&s->gb);
1367         f_code = get_bits(&s->gb, 3);
1368         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1369             return -1;
1370         s->mpeg_f_code[0][0] = f_code;
1371         s->mpeg_f_code[0][1] = f_code;
1372     }
1373     if (s->pict_type == FF_B_TYPE) {
1374         s->full_pel[1] = get_bits1(&s->gb);
1375         f_code = get_bits(&s->gb, 3);
1376         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1377             return -1;
1378         s->mpeg_f_code[1][0] = f_code;
1379         s->mpeg_f_code[1][1] = f_code;
1380     }
1381     s->current_picture.pict_type= s->pict_type;
1382     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1383
1384     if(avctx->debug & FF_DEBUG_PICT_INFO)
1385         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1386
1387     s->y_dc_scale = 8;
1388     s->c_dc_scale = 8;
1389     return 0;
1390 }
1391
1392 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1393 {
1394     MpegEncContext *s= &s1->mpeg_enc_ctx;
1395     int horiz_size_ext, vert_size_ext;
1396     int bit_rate_ext;
1397
1398     skip_bits(&s->gb, 1); /* profile and level esc*/
1399     s->avctx->profile= get_bits(&s->gb, 3);
1400     s->avctx->level= get_bits(&s->gb, 4);
1401     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1402     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1403     horiz_size_ext = get_bits(&s->gb, 2);
1404     vert_size_ext = get_bits(&s->gb, 2);
1405     s->width |= (horiz_size_ext << 12);
1406     s->height |= (vert_size_ext << 12);
1407     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1408     s->bit_rate += (bit_rate_ext << 18) * 400;
1409     skip_bits1(&s->gb); /* marker */
1410     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1411
1412     s->low_delay = get_bits1(&s->gb);
1413     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1414
1415     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1416     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1417
1418     dprintf(s->avctx, "sequence extension\n");
1419     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1420     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1421
1422     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1423         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1424                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1425
1426 }
1427
1428 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1429 {
1430     MpegEncContext *s= &s1->mpeg_enc_ctx;
1431     int color_description, w, h;
1432
1433     skip_bits(&s->gb, 3); /* video format */
1434     color_description= get_bits1(&s->gb);
1435     if(color_description){
1436         s->avctx->color_primaries= get_bits(&s->gb, 8);
1437         s->avctx->color_trc      = get_bits(&s->gb, 8);
1438         s->avctx->colorspace     = get_bits(&s->gb, 8);
1439     }
1440     w= get_bits(&s->gb, 14);
1441     skip_bits(&s->gb, 1); //marker
1442     h= get_bits(&s->gb, 14);
1443     skip_bits(&s->gb, 1); //marker
1444
1445     s1->pan_scan.width= 16*w;
1446     s1->pan_scan.height=16*h;
1447
1448     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1449         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1450 }
1451
1452 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1453 {
1454     MpegEncContext *s= &s1->mpeg_enc_ctx;
1455     int i,nofco;
1456
1457     nofco = 1;
1458     if(s->progressive_sequence){
1459         if(s->repeat_first_field){
1460             nofco++;
1461             if(s->top_field_first)
1462                 nofco++;
1463         }
1464     }else{
1465         if(s->picture_structure == PICT_FRAME){
1466             nofco++;
1467             if(s->repeat_first_field)
1468                 nofco++;
1469         }
1470     }
1471     for(i=0; i<nofco; i++){
1472         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1473         skip_bits(&s->gb, 1); //marker
1474         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1475         skip_bits(&s->gb, 1); //marker
1476     }
1477
1478     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1479         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1480             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1481             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1482             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1483         );
1484 }
1485
1486 static int load_matrix(MpegEncContext *s, uint16_t matrix0[64], uint16_t matrix1[64], int intra){
1487     int i;
1488
1489     for(i=0; i<64; i++) {
1490         int j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1491         int v = get_bits(&s->gb, 8);
1492         if(v==0){
1493             av_log(s->avctx, AV_LOG_ERROR, "matrix damaged\n");
1494             return -1;
1495         }
1496         if(intra && i==0 && v!=8){
1497             av_log(s->avctx, AV_LOG_ERROR, "intra matrix invalid, ignoring\n");
1498             v= 8; // needed by pink.mpg / issue1046
1499         }
1500         matrix0[j] = v;
1501         if(matrix1)
1502             matrix1[j] = v;
1503     }
1504     return 0;
1505 }
1506
1507 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1508 {
1509     dprintf(s->avctx, "matrix extension\n");
1510
1511     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
1512     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
1513     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_intra_matrix, NULL           , 1);
1514     if(get_bits1(&s->gb)) load_matrix(s, s->chroma_inter_matrix, NULL           , 0);
1515 }
1516
1517 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1518 {
1519     MpegEncContext *s= &s1->mpeg_enc_ctx;
1520
1521     s->full_pel[0] = s->full_pel[1] = 0;
1522     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1523     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1524     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1525     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1526     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1527         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1528         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1529             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1530                 s->pict_type= FF_I_TYPE;
1531             else
1532                 s->pict_type= FF_P_TYPE;
1533         }else
1534             s->pict_type= FF_B_TYPE;
1535         s->current_picture.pict_type= s->pict_type;
1536         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1537     }
1538     s->intra_dc_precision = get_bits(&s->gb, 2);
1539     s->picture_structure = get_bits(&s->gb, 2);
1540     s->top_field_first = get_bits1(&s->gb);
1541     s->frame_pred_frame_dct = get_bits1(&s->gb);
1542     s->concealment_motion_vectors = get_bits1(&s->gb);
1543     s->q_scale_type = get_bits1(&s->gb);
1544     s->intra_vlc_format = get_bits1(&s->gb);
1545     s->alternate_scan = get_bits1(&s->gb);
1546     s->repeat_first_field = get_bits1(&s->gb);
1547     s->chroma_420_type = get_bits1(&s->gb);
1548     s->progressive_frame = get_bits1(&s->gb);
1549
1550     if(s->progressive_sequence && !s->progressive_frame){
1551         s->progressive_frame= 1;
1552         av_log(s->avctx, AV_LOG_ERROR, "interlaced frame in progressive sequence, ignoring\n");
1553     }
1554
1555     if(s->picture_structure==0 || (s->progressive_frame && s->picture_structure!=PICT_FRAME)){
1556         av_log(s->avctx, AV_LOG_ERROR, "picture_structure %d invalid, ignoring\n", s->picture_structure);
1557         s->picture_structure= PICT_FRAME;
1558     }
1559
1560     if(s->progressive_sequence && !s->frame_pred_frame_dct){
1561         av_log(s->avctx, AV_LOG_ERROR, "invalid frame_pred_frame_dct\n");
1562         s->frame_pred_frame_dct= 1;
1563     }
1564
1565     if(s->picture_structure == PICT_FRAME){
1566         s->first_field=0;
1567         s->v_edge_pos= 16*s->mb_height;
1568     }else{
1569         s->first_field ^= 1;
1570         s->v_edge_pos=  8*s->mb_height;
1571         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1572     }
1573
1574     if(s->alternate_scan){
1575         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1576         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1577     }else{
1578         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1579         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1580     }
1581
1582     /* composite display not parsed */
1583     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1584     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1585     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1586     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1587     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1588     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1589     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1590     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1591     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1592 }
1593
1594 static void exchange_uv(MpegEncContext *s){
1595     DCTELEM (*tmp)[64];
1596
1597     tmp           = s->pblocks[4];
1598     s->pblocks[4] = s->pblocks[5];
1599     s->pblocks[5] = tmp;
1600 }
1601
1602 static int mpeg_field_start(MpegEncContext *s, const uint8_t *buf, int buf_size){
1603     AVCodecContext *avctx= s->avctx;
1604     Mpeg1Context *s1 = (Mpeg1Context*)s;
1605
1606     /* start frame decoding */
1607     if(s->first_field || s->picture_structure==PICT_FRAME){
1608         if(MPV_frame_start(s, avctx) < 0)
1609             return -1;
1610
1611         ff_er_frame_start(s);
1612
1613         /* first check if we must repeat the frame */
1614         s->current_picture_ptr->repeat_pict = 0;
1615         if (s->repeat_first_field) {
1616             if (s->progressive_sequence) {
1617                 if (s->top_field_first)
1618                     s->current_picture_ptr->repeat_pict = 4;
1619                 else
1620                     s->current_picture_ptr->repeat_pict = 2;
1621             } else if (s->progressive_frame) {
1622                 s->current_picture_ptr->repeat_pict = 1;
1623             }
1624         }
1625
1626         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1627     }else{ //second field
1628             int i;
1629
1630             if(!s->current_picture_ptr){
1631                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1632                 return -1;
1633             }
1634
1635             for(i=0; i<4; i++){
1636                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1637                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1638                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1639                 }
1640             }
1641     }
1642
1643     if (avctx->hwaccel) {
1644         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
1645             return -1;
1646     }
1647
1648 // MPV_frame_start will call this function too,
1649 // but we need to call it on every field
1650     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1651         if(ff_xvmc_field_start(s,avctx) < 0)
1652             return -1;
1653
1654     return 0;
1655 }
1656
1657 #define DECODE_SLICE_ERROR -1
1658 #define DECODE_SLICE_OK 0
1659
1660 /**
1661  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1662  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1663  *         DECODE_SLICE_OK if this slice is ok<br>
1664  */
1665 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1666                              const uint8_t **buf, int buf_size)
1667 {
1668     MpegEncContext *s = &s1->mpeg_enc_ctx;
1669     AVCodecContext *avctx= s->avctx;
1670     const int field_pic= s->picture_structure != PICT_FRAME;
1671     const int lowres= s->avctx->lowres;
1672
1673     s->resync_mb_x=
1674     s->resync_mb_y= -1;
1675
1676     assert(mb_y < s->mb_height);
1677
1678     init_get_bits(&s->gb, *buf, buf_size*8);
1679
1680     ff_mpeg1_clean_buffers(s);
1681     s->interlaced_dct = 0;
1682
1683     s->qscale = get_qscale(s);
1684
1685     if(s->qscale == 0){
1686         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1687         return -1;
1688     }
1689
1690     /* extra slice info */
1691     while (get_bits1(&s->gb) != 0) {
1692         skip_bits(&s->gb, 8);
1693     }
1694
1695     s->mb_x=0;
1696
1697     if(mb_y==0 && s->codec_tag == AV_RL32("SLIF")){
1698         skip_bits1(&s->gb);
1699     }else{
1700         for(;;) {
1701             int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1702             if (code < 0){
1703                 av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1704                 return -1;
1705             }
1706             if (code >= 33) {
1707                 if (code == 33) {
1708                     s->mb_x += 33;
1709                 }
1710                 /* otherwise, stuffing, nothing to do */
1711             } else {
1712                 s->mb_x += code;
1713                 break;
1714             }
1715         }
1716     }
1717
1718     if(s->mb_x >= (unsigned)s->mb_width){
1719         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1720         return -1;
1721     }
1722
1723     if (avctx->hwaccel) {
1724         const uint8_t *buf_end, *buf_start = *buf - 4; /* include start_code */
1725         int start_code = -1;
1726         buf_end = ff_find_start_code(buf_start + 2, *buf + buf_size, &start_code);
1727         if (buf_end < *buf + buf_size)
1728             buf_end -= 4;
1729         s->mb_y = mb_y;
1730         if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_end - buf_start) < 0)
1731             return DECODE_SLICE_ERROR;
1732         *buf = buf_end;
1733         return DECODE_SLICE_OK;
1734     }
1735
1736     s->resync_mb_x= s->mb_x;
1737     s->resync_mb_y= s->mb_y= mb_y;
1738     s->mb_skip_run= 0;
1739     ff_init_block_index(s);
1740
1741     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1742         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1743              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",
1744                  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],
1745                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1746                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1747                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1748                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1749         }
1750     }
1751
1752     for(;;) {
1753         //If 1, we memcpy blocks in xvmcvideo.
1754         if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration > 1)
1755             ff_xvmc_init_block(s);//set s->block
1756
1757         if(mpeg_decode_mb(s, s->block) < 0)
1758             return -1;
1759
1760         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1761             const int wrap = s->b8_stride;
1762             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1763             int b8_xy= 4*(s->mb_x + s->mb_y*s->mb_stride);
1764             int motion_x, motion_y, dir, i;
1765
1766             for(i=0; i<2; i++){
1767                 for(dir=0; dir<2; dir++){
1768                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1769                         motion_x = motion_y = 0;
1770                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1771                         motion_x = s->mv[dir][0][0];
1772                         motion_y = s->mv[dir][0][1];
1773                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1774                         motion_x = s->mv[dir][i][0];
1775                         motion_y = s->mv[dir][i][1];
1776                     }
1777
1778                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1779                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1780                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1781                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1782                     s->current_picture.ref_index [dir][b8_xy    ]=
1783                     s->current_picture.ref_index [dir][b8_xy + 1]= s->field_select[dir][i];
1784                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1785                 }
1786                 xy += wrap;
1787                 b8_xy +=2;
1788             }
1789         }
1790
1791         s->dest[0] += 16 >> lowres;
1792         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1793         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1794
1795         MPV_decode_mb(s, s->block);
1796
1797         if (++s->mb_x >= s->mb_width) {
1798             const int mb_size= 16>>s->avctx->lowres;
1799
1800             ff_draw_horiz_band(s, mb_size*(s->mb_y>>field_pic), mb_size);
1801
1802             s->mb_x = 0;
1803             s->mb_y += 1<<field_pic;
1804
1805             if(s->mb_y >= s->mb_height){
1806                 int left= get_bits_left(&s->gb);
1807                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1808                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1809                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1810
1811                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1812                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1813                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1814                     return -1;
1815                 }else
1816                     goto eos;
1817             }
1818
1819             ff_init_block_index(s);
1820         }
1821
1822         /* skip mb handling */
1823         if (s->mb_skip_run == -1) {
1824             /* read increment again */
1825             s->mb_skip_run = 0;
1826             for(;;) {
1827                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1828                 if (code < 0){
1829                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1830                     return -1;
1831                 }
1832                 if (code >= 33) {
1833                     if (code == 33) {
1834                         s->mb_skip_run += 33;
1835                     }else if(code == 35){
1836                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1837                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1838                             return -1;
1839                         }
1840                         goto eos; /* end of slice */
1841                     }
1842                     /* otherwise, stuffing, nothing to do */
1843                 } else {
1844                     s->mb_skip_run += code;
1845                     break;
1846                 }
1847             }
1848             if(s->mb_skip_run){
1849                 int i;
1850                 if(s->pict_type == FF_I_TYPE){
1851                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1852                     return -1;
1853                 }
1854
1855                 /* skip mb */
1856                 s->mb_intra = 0;
1857                 for(i=0;i<12;i++)
1858                     s->block_last_index[i] = -1;
1859                 if(s->picture_structure == PICT_FRAME)
1860                     s->mv_type = MV_TYPE_16X16;
1861                 else
1862                     s->mv_type = MV_TYPE_FIELD;
1863                 if (s->pict_type == FF_P_TYPE) {
1864                     /* if P type, zero motion vector is implied */
1865                     s->mv_dir = MV_DIR_FORWARD;
1866                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1867                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1868                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1869                     s->field_select[0][0]= (s->picture_structure - 1) & 1;
1870                 } else {
1871                     /* if B type, reuse previous vectors and directions */
1872                     s->mv[0][0][0] = s->last_mv[0][0][0];
1873                     s->mv[0][0][1] = s->last_mv[0][0][1];
1874                     s->mv[1][0][0] = s->last_mv[1][0][0];
1875                     s->mv[1][0][1] = s->last_mv[1][0][1];
1876                 }
1877             }
1878         }
1879     }
1880 eos: // end of slice
1881     *buf += (get_bits_count(&s->gb)-1)/8;
1882 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1883     return 0;
1884 }
1885
1886 static int slice_decode_thread(AVCodecContext *c, void *arg){
1887     MpegEncContext *s= *(void**)arg;
1888     const uint8_t *buf= s->gb.buffer;
1889     int mb_y= s->start_mb_y;
1890     const int field_pic= s->picture_structure != PICT_FRAME;
1891
1892     s->error_count= (3*(s->end_mb_y - s->start_mb_y)*s->mb_width) >> field_pic;
1893
1894     for(;;){
1895         uint32_t start_code;
1896         int ret;
1897
1898         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1899         emms_c();
1900 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1901 //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);
1902         if(ret < 0){
1903             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1904                 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);
1905         }else{
1906             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);
1907         }
1908
1909         if(s->mb_y == s->end_mb_y)
1910             return 0;
1911
1912         start_code= -1;
1913         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1914         mb_y= start_code - SLICE_MIN_START_CODE;
1915         if(mb_y < 0 || mb_y >= s->end_mb_y)
1916             return -1;
1917     }
1918
1919     return 0; //not reached
1920 }
1921
1922 /**
1923  * Handles slice ends.
1924  * @return 1 if it seems to be the last slice
1925  */
1926 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1927 {
1928     Mpeg1Context *s1 = avctx->priv_data;
1929     MpegEncContext *s = &s1->mpeg_enc_ctx;
1930
1931     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1932         return 0;
1933
1934     if (s->avctx->hwaccel) {
1935         if (s->avctx->hwaccel->end_frame(s->avctx) < 0)
1936             av_log(avctx, AV_LOG_ERROR, "hardware accelerator failed to decode picture\n");
1937     }
1938
1939     if(CONFIG_MPEG_XVMC_DECODER && s->avctx->xvmc_acceleration)
1940         ff_xvmc_field_end(s);
1941
1942     /* end of slice reached */
1943     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1944         /* end of image */
1945
1946         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1947
1948         ff_er_frame_end(s);
1949
1950         MPV_frame_end(s);
1951
1952         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1953             *pict= *(AVFrame*)s->current_picture_ptr;
1954             ff_print_debug_info(s, pict);
1955         } else {
1956             s->picture_number++;
1957             /* latency of 1 frame for I- and P-frames */
1958             /* XXX: use another variable than picture_number */
1959             if (s->last_picture_ptr != NULL) {
1960                 *pict= *(AVFrame*)s->last_picture_ptr;
1961                  ff_print_debug_info(s, pict);
1962             }
1963         }
1964
1965         return 1;
1966     } else {
1967         return 0;
1968     }
1969 }
1970
1971 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1972                                  const uint8_t *buf, int buf_size)
1973 {
1974     Mpeg1Context *s1 = avctx->priv_data;
1975     MpegEncContext *s = &s1->mpeg_enc_ctx;
1976     int width,height;
1977     int i, v, j;
1978
1979     init_get_bits(&s->gb, buf, buf_size*8);
1980
1981     width = get_bits(&s->gb, 12);
1982     height = get_bits(&s->gb, 12);
1983     if (width <= 0 || height <= 0)
1984         return -1;
1985     s->aspect_ratio_info= get_bits(&s->gb, 4);
1986     if (s->aspect_ratio_info == 0) {
1987         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1988         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1989             return -1;
1990     }
1991     s->frame_rate_index = get_bits(&s->gb, 4);
1992     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1993         return -1;
1994     s->bit_rate = get_bits(&s->gb, 18) * 400;
1995     if (get_bits1(&s->gb) == 0) /* marker */
1996         return -1;
1997     s->width = width;
1998     s->height = height;
1999
2000     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
2001     skip_bits(&s->gb, 1);
2002
2003     /* get matrix */
2004     if (get_bits1(&s->gb)) {
2005         load_matrix(s, s->chroma_intra_matrix, s->intra_matrix, 1);
2006     } else {
2007         for(i=0;i<64;i++) {
2008             j = s->dsp.idct_permutation[i];
2009             v = ff_mpeg1_default_intra_matrix[i];
2010             s->intra_matrix[j] = v;
2011             s->chroma_intra_matrix[j] = v;
2012         }
2013     }
2014     if (get_bits1(&s->gb)) {
2015         load_matrix(s, s->chroma_inter_matrix, s->inter_matrix, 0);
2016     } else {
2017         for(i=0;i<64;i++) {
2018             int j= s->dsp.idct_permutation[i];
2019             v = ff_mpeg1_default_non_intra_matrix[i];
2020             s->inter_matrix[j] = v;
2021             s->chroma_inter_matrix[j] = v;
2022         }
2023     }
2024
2025     if(show_bits(&s->gb, 23) != 0){
2026         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2027         return -1;
2028     }
2029
2030     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2031     s->progressive_sequence = 1;
2032     s->progressive_frame = 1;
2033     s->picture_structure = PICT_FRAME;
2034     s->frame_pred_frame_dct = 1;
2035     s->chroma_format = 1;
2036     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2037     avctx->sub_id = 1; /* indicates MPEG-1 */
2038     s->out_format = FMT_MPEG1;
2039     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2040     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2041
2042     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2043         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2044                s->avctx->rc_buffer_size, s->bit_rate);
2045
2046     return 0;
2047 }
2048
2049 static int vcr2_init_sequence(AVCodecContext *avctx)
2050 {
2051     Mpeg1Context *s1 = avctx->priv_data;
2052     MpegEncContext *s = &s1->mpeg_enc_ctx;
2053     int i, v;
2054
2055     /* start new MPEG-1 context decoding */
2056     s->out_format = FMT_MPEG1;
2057     if (s1->mpeg_enc_ctx_allocated) {
2058         MPV_common_end(s);
2059     }
2060     s->width  = avctx->coded_width;
2061     s->height = avctx->coded_height;
2062     avctx->has_b_frames= 0; //true?
2063     s->low_delay= 1;
2064
2065     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2066     avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
2067
2068     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT || avctx->hwaccel ||
2069         s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU )
2070         if( avctx->idct_algo == FF_IDCT_AUTO )
2071             avctx->idct_algo = FF_IDCT_SIMPLE;
2072
2073     if (MPV_common_init(s) < 0)
2074         return -1;
2075     exchange_uv(s);//common init reset pblocks, so we swap them here
2076     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2077     s1->mpeg_enc_ctx_allocated = 1;
2078
2079     for(i=0;i<64;i++) {
2080         int j= s->dsp.idct_permutation[i];
2081         v = ff_mpeg1_default_intra_matrix[i];
2082         s->intra_matrix[j] = v;
2083         s->chroma_intra_matrix[j] = v;
2084
2085         v = ff_mpeg1_default_non_intra_matrix[i];
2086         s->inter_matrix[j] = v;
2087         s->chroma_inter_matrix[j] = v;
2088     }
2089
2090     s->progressive_sequence = 1;
2091     s->progressive_frame = 1;
2092     s->picture_structure = PICT_FRAME;
2093     s->frame_pred_frame_dct = 1;
2094     s->chroma_format = 1;
2095     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2096     avctx->sub_id = 2; /* indicates MPEG-2 */
2097     s1->save_width           = s->width;
2098     s1->save_height          = s->height;
2099     s1->save_progressive_seq = s->progressive_sequence;
2100     return 0;
2101 }
2102
2103
2104 static void mpeg_decode_user_data(AVCodecContext *avctx,
2105                                   const uint8_t *p, int buf_size)
2106 {
2107     const uint8_t *buf_end = p+buf_size;
2108
2109     /* we parse the DTG active format information */
2110     if (buf_end - p >= 5 &&
2111         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2112         int flags = p[4];
2113         p += 5;
2114         if (flags & 0x80) {
2115             /* skip event id */
2116             p += 2;
2117         }
2118         if (flags & 0x40) {
2119             if (buf_end - p < 1)
2120                 return;
2121             avctx->dtg_active_format = p[0] & 0x0f;
2122         }
2123     }
2124 }
2125
2126 static void mpeg_decode_gop(AVCodecContext *avctx,
2127                             const uint8_t *buf, int buf_size){
2128     Mpeg1Context *s1 = avctx->priv_data;
2129     MpegEncContext *s = &s1->mpeg_enc_ctx;
2130
2131     int drop_frame_flag;
2132     int time_code_hours, time_code_minutes;
2133     int time_code_seconds, time_code_pictures;
2134     int broken_link;
2135
2136     init_get_bits(&s->gb, buf, buf_size*8);
2137
2138     drop_frame_flag = get_bits1(&s->gb);
2139
2140     time_code_hours=get_bits(&s->gb,5);
2141     time_code_minutes = get_bits(&s->gb,6);
2142     skip_bits1(&s->gb);//marker bit
2143     time_code_seconds = get_bits(&s->gb,6);
2144     time_code_pictures = get_bits(&s->gb,6);
2145
2146     s->closed_gop = get_bits1(&s->gb);
2147     /*broken_link indicate that after editing the
2148       reference frames of the first B-Frames after GOP I-Frame
2149       are missing (open gop)*/
2150     broken_link = get_bits1(&s->gb);
2151
2152     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2153         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2154             time_code_hours, time_code_minutes, time_code_seconds,
2155             time_code_pictures, s->closed_gop, broken_link);
2156 }
2157 /**
2158  * Finds the end of the current frame in the bitstream.
2159  * @return the position of the first byte of the next frame, or -1
2160  */
2161 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s)
2162 {
2163     int i;
2164     uint32_t state= pc->state;
2165
2166     /* EOF considered as end of frame */
2167     if (buf_size == 0)
2168         return 0;
2169
2170 /*
2171  0  frame start         -> 1/4
2172  1  first_SEQEXT        -> 0/2
2173  2  first field start   -> 3/0
2174  3  second_SEQEXT       -> 2/0
2175  4  searching end
2176 */
2177
2178     for(i=0; i<buf_size; i++){
2179         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2180         if(pc->frame_start_found&1){
2181             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2182                 pc->frame_start_found--;
2183             else if(state == EXT_START_CODE+2){
2184                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2185                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2186             }
2187             state++;
2188         }else{
2189             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2190             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2191                 i++;
2192                 pc->frame_start_found=4;
2193             }
2194             if(state == SEQ_END_CODE){
2195                 pc->state=-1;
2196                 return i+1;
2197             }
2198             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2199                 pc->frame_start_found= 0;
2200             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2201                 pc->frame_start_found++;
2202             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2203                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2204                     pc->frame_start_found=0;
2205                     pc->state=-1;
2206                     return i-3;
2207                 }
2208             }
2209             if(pc->frame_start_found == 0 && s && state == PICTURE_START_CODE){
2210                 ff_fetch_timestamp(s, i-3, 1);
2211             }
2212         }
2213     }
2214     pc->state= state;
2215     return END_NOT_FOUND;
2216 }
2217
2218 static int decode_chunks(AVCodecContext *avctx,
2219                              AVFrame *picture, int *data_size,
2220                              const uint8_t *buf, int buf_size);
2221
2222 /* handle buffering and image synchronisation */
2223 static int mpeg_decode_frame(AVCodecContext *avctx,
2224                              void *data, int *data_size,
2225                              AVPacket *avpkt)
2226 {
2227     const uint8_t *buf = avpkt->data;
2228     int buf_size = avpkt->size;
2229     Mpeg1Context *s = avctx->priv_data;
2230     AVFrame *picture = data;
2231     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2232     dprintf(avctx, "fill_buffer\n");
2233
2234     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2235         /* special case for last picture */
2236         if (s2->low_delay==0 && s2->next_picture_ptr) {
2237             *picture= *(AVFrame*)s2->next_picture_ptr;
2238             s2->next_picture_ptr= NULL;
2239
2240             *data_size = sizeof(AVFrame);
2241         }
2242         return buf_size;
2243     }
2244
2245     if(s2->flags&CODEC_FLAG_TRUNCATED){
2246         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size, NULL);
2247
2248         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2249             return buf_size;
2250     }
2251
2252 #if 0
2253     if (s->repeat_field % 2 == 1) {
2254         s->repeat_field++;
2255         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2256         //        s2->picture_number, s->repeat_field);
2257         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2258             *data_size = sizeof(AVPicture);
2259             goto the_end;
2260         }
2261     }
2262 #endif
2263
2264     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == AV_RL32("VCR2"))
2265         vcr2_init_sequence(avctx);
2266
2267     s->slice_count= 0;
2268
2269     if(avctx->extradata && !avctx->frame_number)
2270         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2271
2272     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2273 }
2274
2275 static int decode_chunks(AVCodecContext *avctx,
2276                              AVFrame *picture, int *data_size,
2277                              const uint8_t *buf, int buf_size)
2278 {
2279     Mpeg1Context *s = avctx->priv_data;
2280     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2281     const uint8_t *buf_ptr = buf;
2282     const uint8_t *buf_end = buf + buf_size;
2283     int ret, input_size;
2284     int last_code= 0;
2285
2286     for(;;) {
2287         /* find next start code */
2288         uint32_t start_code = -1;
2289         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2290         if (start_code > 0x1ff){
2291             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2292                 if(avctx->thread_count > 1){
2293                     int i;
2294
2295                     avctx->execute(avctx, slice_decode_thread,  &s2->thread_context[0], NULL, s->slice_count, sizeof(void*));
2296                     for(i=0; i<s->slice_count; i++)
2297                         s2->error_count += s2->thread_context[i]->error_count;
2298                 }
2299
2300                 if (CONFIG_MPEG_VDPAU_DECODER && avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
2301                     ff_vdpau_mpeg_picture_complete(s2, buf, buf_size, s->slice_count);
2302
2303                 if (slice_end(avctx, picture)) {
2304                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2305                         *data_size = sizeof(AVPicture);
2306                 }
2307             }
2308             s2->pict_type= 0;
2309             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2310         }
2311
2312         input_size = buf_end - buf_ptr;
2313
2314         if(avctx->debug & FF_DEBUG_STARTCODE){
2315             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2316         }
2317
2318         /* prepare data for next start code */
2319         switch(start_code) {
2320         case SEQ_START_CODE:
2321             if(last_code == 0){
2322             mpeg1_decode_sequence(avctx, buf_ptr,
2323                                     input_size);
2324                 s->sync=1;
2325             }else{
2326                 av_log(avctx, AV_LOG_ERROR, "ignoring SEQ_START_CODE after %X\n", last_code);
2327             }
2328             break;
2329
2330         case PICTURE_START_CODE:
2331             if(last_code == 0 || last_code == SLICE_MIN_START_CODE){
2332             if(mpeg_decode_postinit(avctx) < 0){
2333                 av_log(avctx, AV_LOG_ERROR, "mpeg_decode_postinit() failure\n");
2334                 return -1;
2335             }
2336
2337             /* we have a complete image: we try to decompress it */
2338             if(mpeg1_decode_picture(avctx,
2339                                     buf_ptr, input_size) < 0)
2340                 s2->pict_type=0;
2341                 s2->first_slice = 1;
2342             last_code= PICTURE_START_CODE;
2343             }else{
2344                 av_log(avctx, AV_LOG_ERROR, "ignoring pic after %X\n", last_code);
2345             }
2346             break;
2347         case EXT_START_CODE:
2348             init_get_bits(&s2->gb, buf_ptr, input_size*8);
2349
2350             switch(get_bits(&s2->gb, 4)) {
2351             case 0x1:
2352                 if(last_code == 0){
2353                 mpeg_decode_sequence_extension(s);
2354                 }else{
2355                     av_log(avctx, AV_LOG_ERROR, "ignoring seq ext after %X\n", last_code);
2356                 }
2357                 break;
2358             case 0x2:
2359                 mpeg_decode_sequence_display_extension(s);
2360                 break;
2361             case 0x3:
2362                 mpeg_decode_quant_matrix_extension(s2);
2363                 break;
2364             case 0x7:
2365                 mpeg_decode_picture_display_extension(s);
2366                 break;
2367             case 0x8:
2368                 if(last_code == PICTURE_START_CODE){
2369                 mpeg_decode_picture_coding_extension(s);
2370                 }else{
2371                     av_log(avctx, AV_LOG_ERROR, "ignoring pic cod ext after %X\n", last_code);
2372                 }
2373                 break;
2374             }
2375             break;
2376         case USER_START_CODE:
2377             mpeg_decode_user_data(avctx,
2378                                     buf_ptr, input_size);
2379             break;
2380         case GOP_START_CODE:
2381             if(last_code == 0){
2382             s2->first_field=0;
2383             mpeg_decode_gop(avctx,
2384                                     buf_ptr, input_size);
2385                 s->sync=1;
2386             }else{
2387                 av_log(avctx, AV_LOG_ERROR, "ignoring GOP_START_CODE after %X\n", last_code);
2388             }
2389             break;
2390         default:
2391             if (start_code >= SLICE_MIN_START_CODE &&
2392                 start_code <= SLICE_MAX_START_CODE && last_code!=0) {
2393                 const int field_pic= s2->picture_structure != PICT_FRAME;
2394                 int mb_y= (start_code - SLICE_MIN_START_CODE) << field_pic;
2395                 last_code= SLICE_MIN_START_CODE;
2396
2397                 if(s2->picture_structure == PICT_BOTTOM_FIELD)
2398                     mb_y++;
2399
2400                 if (mb_y >= s2->mb_height){
2401                     av_log(s2->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s2->mb_height);
2402                     return -1;
2403                 }
2404
2405                 if(s2->last_picture_ptr==NULL){
2406                 /* Skip B-frames if we do not have reference frames and gop is not closed */
2407                     if(s2->pict_type==FF_B_TYPE){
2408                         if(!s2->closed_gop)
2409                             break;
2410                     }
2411                 }
2412                 if(s2->pict_type==FF_I_TYPE)
2413                     s->sync=1;
2414                 if(s2->next_picture_ptr==NULL){
2415                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2416                     if(s2->pict_type==FF_P_TYPE && !s->sync) break;
2417                 }
2418                 /* Skip B-frames if we are in a hurry. */
2419                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2420                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2421                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2422                     || avctx->skip_frame >= AVDISCARD_ALL)
2423                     break;
2424                 /* Skip everything if we are in a hurry>=5. */
2425                 if(avctx->hurry_up>=5) break;
2426
2427                 if (!s->mpeg_enc_ctx_allocated) break;
2428
2429                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2430                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2431                         break;
2432                 }
2433
2434                 if(!s2->pict_type){
2435                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2436                     break;
2437                 }
2438
2439                 if(s2->first_slice){
2440                     s2->first_slice=0;
2441                     if(mpeg_field_start(s2, buf, buf_size) < 0)
2442                         return -1;
2443                 }
2444                 if(!s2->current_picture_ptr){
2445                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2446                     return -1;
2447                 }
2448
2449                 if (avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
2450                     s->slice_count++;
2451                     break;
2452                 }
2453
2454                 if(avctx->thread_count > 1){
2455                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2456                     if(threshold <= mb_y){
2457                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2458
2459                         thread_context->start_mb_y= mb_y;
2460                         thread_context->end_mb_y  = s2->mb_height;
2461                         if(s->slice_count){
2462                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2463                             ff_update_duplicate_context(thread_context, s2);
2464                         }
2465                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2466                         s->slice_count++;
2467                     }
2468                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2469                 }else{
2470                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2471                     emms_c();
2472
2473                     if(ret < 0){
2474                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2475                             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);
2476                     }else{
2477                         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);
2478                     }
2479                 }
2480             }
2481             break;
2482         }
2483     }
2484 }
2485
2486 static void flush(AVCodecContext *avctx){
2487     Mpeg1Context *s = avctx->priv_data;
2488
2489     s->sync=0;
2490
2491     ff_mpeg_flush(avctx);
2492 }
2493
2494 static int mpeg_decode_end(AVCodecContext *avctx)
2495 {
2496     Mpeg1Context *s = avctx->priv_data;
2497
2498     if (s->mpeg_enc_ctx_allocated)
2499         MPV_common_end(&s->mpeg_enc_ctx);
2500     return 0;
2501 }
2502
2503 AVCodec mpeg1video_decoder = {
2504     "mpeg1video",
2505     CODEC_TYPE_VIDEO,
2506     CODEC_ID_MPEG1VIDEO,
2507     sizeof(Mpeg1Context),
2508     mpeg_decode_init,
2509     NULL,
2510     mpeg_decode_end,
2511     mpeg_decode_frame,
2512     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2513     .flush= flush,
2514     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2515 };
2516
2517 AVCodec mpeg2video_decoder = {
2518     "mpeg2video",
2519     CODEC_TYPE_VIDEO,
2520     CODEC_ID_MPEG2VIDEO,
2521     sizeof(Mpeg1Context),
2522     mpeg_decode_init,
2523     NULL,
2524     mpeg_decode_end,
2525     mpeg_decode_frame,
2526     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2527     .flush= flush,
2528     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2529 };
2530
2531 //legacy decoder
2532 AVCodec mpegvideo_decoder = {
2533     "mpegvideo",
2534     CODEC_TYPE_VIDEO,
2535     CODEC_ID_MPEG2VIDEO,
2536     sizeof(Mpeg1Context),
2537     mpeg_decode_init,
2538     NULL,
2539     mpeg_decode_end,
2540     mpeg_decode_frame,
2541     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2542     .flush= flush,
2543     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2544 };
2545
2546 #if CONFIG_MPEG_XVMC_DECODER
2547 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2548     if( avctx->thread_count > 1)
2549         return -1;
2550     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2551         return -1;
2552     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2553         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2554     }
2555     mpeg_decode_init(avctx);
2556
2557     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2558     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2559
2560     return 0;
2561 }
2562
2563 AVCodec mpeg_xvmc_decoder = {
2564     "mpegvideo_xvmc",
2565     CODEC_TYPE_VIDEO,
2566     CODEC_ID_MPEG2VIDEO_XVMC,
2567     sizeof(Mpeg1Context),
2568     mpeg_mc_decode_init,
2569     NULL,
2570     mpeg_decode_end,
2571     mpeg_decode_frame,
2572     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2573     .flush= flush,
2574     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video XvMC (X-Video Motion Compensation)"),
2575 };
2576
2577 #endif
2578
2579 #if CONFIG_MPEG_VDPAU_DECODER
2580 AVCodec mpeg_vdpau_decoder = {
2581     "mpegvideo_vdpau",
2582     CODEC_TYPE_VIDEO,
2583     CODEC_ID_MPEG2VIDEO,
2584     sizeof(Mpeg1Context),
2585     mpeg_decode_init,
2586     NULL,
2587     mpeg_decode_end,
2588     mpeg_decode_frame,
2589     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2590     .flush= flush,
2591     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1/2 video (VDPAU acceleration)"),
2592 };
2593 #endif
2594
2595 #if CONFIG_MPEG1_VDPAU_DECODER
2596 AVCodec mpeg1_vdpau_decoder = {
2597     "mpeg1video_vdpau",
2598     CODEC_TYPE_VIDEO,
2599     CODEC_ID_MPEG1VIDEO,
2600     sizeof(Mpeg1Context),
2601     mpeg_decode_init,
2602     NULL,
2603     mpeg_decode_end,
2604     mpeg_decode_frame,
2605     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_HWACCEL_VDPAU | CODEC_CAP_DELAY,
2606     .flush= flush,
2607     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video (VDPAU acceleration)"),
2608 };
2609 #endif
2610