libavcodec/mpeg12.c

   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 mpeg12.c
  25  * MPEG-1/2 decoder
  26  */
  27
  28 //#define DEBUG
  29 #include "avcodec.h"
  30 #include "dsputil.h"
  31 #include "mpegvideo.h"
  32
  33 #include "mpeg12.h"
  34 #include "mpeg12data.h"
  35 #include "mpeg12decdata.h"
  36 #include "bytestream.h"
  37
  38 //#undef NDEBUG
  39 //#include <assert.h>
  40
  41
  42 #define MV_VLC_BITS 9
  43 #define MBINCR_VLC_BITS 9
  44 #define MB_PAT_VLC_BITS 9
  45 #define MB_PTYPE_VLC_BITS 6
  46 #define MB_BTYPE_VLC_BITS 6
  47
  48 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  49                               DCTELEM *block,
  50                               int n);
  51 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  52                               DCTELEM *block,
  53                               int n);
  54 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  55 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  56                                         DCTELEM *block,
  57                                         int n);
  58 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  59                                     DCTELEM *block,
  60                                     int n);
  61 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  62 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  63 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  64 static void exchange_uv(MpegEncContext *s);
  65
  66 extern int XVMC_field_start(MpegEncContext *s, AVCodecContext *avctx);
  67 extern int XVMC_field_end(MpegEncContext *s);
  68 extern void XVMC_pack_pblocks(MpegEncContext *s,int cbp);
  69 extern void XVMC_init_block(MpegEncContext *s);//set s->block
  70
  71 static const enum PixelFormat pixfmt_yuv_420[]= {PIX_FMT_YUV420P,PIX_FMT_NONE};
  72 static const enum PixelFormat pixfmt_yuv_422[]= {PIX_FMT_YUV422P,PIX_FMT_NONE};
  73 static const enum PixelFormat pixfmt_yuv_444[]= {PIX_FMT_YUV444P,PIX_FMT_NONE};
  74 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  75                                            PIX_FMT_XVMC_MPEG2_IDCT,
  76                                            PIX_FMT_XVMC_MPEG2_MC,
  77                                            PIX_FMT_NONE};
  78
  79 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  80
  81
  82 #define INIT_2D_VLC_RL(rl, static_size)\
  83 {\
  84     static RL_VLC_ELEM rl_vlc_table[static_size];\
  85     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  86              &rl.table_vlc[0][1], 4, 2,\
  87              &rl.table_vlc[0][0], 4, 2, static_size);\
  88 \
  89     rl.rl_vlc[0]= rl_vlc_table;\
  90     init_2d_vlc_rl(&rl);\
  91 }
  92
  93 static void init_2d_vlc_rl(RLTable *rl)
  94 {
  95     int i;
  96
  97     for(i=0; i<rl->vlc.table_size; i++){
  98         int code= rl->vlc.table[i][0];
  99         int len = rl->vlc.table[i][1];
 100         int level, run;
 101
 102         if(len==0){ // illegal code
 103             run= 65;
 104             level= MAX_LEVEL;
 105         }else if(len<0){ //more bits needed
 106             run= 0;
 107             level= code;
 108         }else{
 109             if(code==rl->n){ //esc
 110                 run= 65;
 111                 level= 0;
 112             }else if(code==rl->n+1){ //eob
 113                 run= 0;
 114                 level= 127;
 115             }else{
 116                 run=   rl->table_run  [code] + 1;
 117                 level= rl->table_level[code];
 118             }
 119         }
 120         rl->rl_vlc[0][i].len= len;
 121         rl->rl_vlc[0][i].level= level;
 122         rl->rl_vlc[0][i].run= run;
 123     }
 124 }
 125
 126 void ff_mpeg12_common_init(MpegEncContext *s)
 127 {
 128
 129     s->y_dc_scale_table=
 130     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
 131
 132 }
 133
 134 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 135     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 136     s->last_dc[1] = s->last_dc[0];
 137     s->last_dc[2] = s->last_dc[0];
 138     memset(s->last_mv, 0, sizeof(s->last_mv));
 139 }
 140
 141
 142 /******************************************/
 143 /* decoding */
 144
 145 static VLC mv_vlc;
 146 static VLC mbincr_vlc;
 147 static VLC mb_ptype_vlc;
 148 static VLC mb_btype_vlc;
 149 static VLC mb_pat_vlc;
 150
 151 av_cold void ff_init_vlcs(void)
 152 {
 153     static int done = 0;
 154
 155     if (!done) {
 156         done = 1;
 157
 158         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
 159                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 160                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 161         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 162                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 163                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 164         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 165                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 166                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 167         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 168                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 169                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 170         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 171                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 172                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 173
 174         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 175                  &table_mb_ptype[0][1], 2, 1,
 176                  &table_mb_ptype[0][0], 2, 1, 64);
 177         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 178                  &table_mb_btype[0][1], 2, 1,
 179                  &table_mb_btype[0][0], 2, 1, 64);
 180         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 181         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 182
 183         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 184         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 185     }
 186 }
 187
 188 static inline int get_dmv(MpegEncContext *s)
 189 {
 190     if(get_bits1(&s->gb))
 191         return 1 - (get_bits1(&s->gb) << 1);
 192     else
 193         return 0;
 194 }
 195
 196 static inline int get_qscale(MpegEncContext *s)
 197 {
 198     int qscale = get_bits(&s->gb, 5);
 199     if (s->q_scale_type) {
 200         return non_linear_qscale[qscale];
 201     } else {
 202         return qscale << 1;
 203     }
 204 }
 205
 206 /* motion type (for MPEG-2) */
 207 #define MT_FIELD 1
 208 #define MT_FRAME 2
 209 #define MT_16X8  2
 210 #define MT_DMV   3
 211
 212 static int mpeg_decode_mb(MpegEncContext *s,
 213                           DCTELEM block[12][64])
 214 {
 215     int i, j, k, cbp, val, mb_type, motion_type;
 216     const int mb_block_count = 4 + (1<< s->chroma_format);
 217
 218     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 219
 220     assert(s->mb_skipped==0);
 221
 222     if (s->mb_skip_run-- != 0) {
 223         if (s->pict_type == FF_P_TYPE) {
 224             s->mb_skipped = 1;
 225             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 226         } else {
 227             int mb_type;
 228
 229             if(s->mb_x)
 230                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 231             else
 232                 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
 233             if(IS_INTRA(mb_type))
 234                 return -1;
 235
 236             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 237                 mb_type | MB_TYPE_SKIP;
 238 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 239
 240             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 241                 s->mb_skipped = 1;
 242         }
 243
 244         return 0;
 245     }
 246
 247     switch(s->pict_type) {
 248     default:
 249     case FF_I_TYPE:
 250         if (get_bits1(&s->gb) == 0) {
 251             if (get_bits1(&s->gb) == 0){
 252                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 253                 return -1;
 254             }
 255             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 256         } else {
 257             mb_type = MB_TYPE_INTRA;
 258         }
 259         break;
 260     case FF_P_TYPE:
 261         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 262         if (mb_type < 0){
 263             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 264             return -1;
 265         }
 266         mb_type = ptype2mb_type[ mb_type ];
 267         break;
 268     case FF_B_TYPE:
 269         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 270         if (mb_type < 0){
 271             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 272             return -1;
 273         }
 274         mb_type = btype2mb_type[ mb_type ];
 275         break;
 276     }
 277     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 278 //    motion_type = 0; /* avoid warning */
 279     if (IS_INTRA(mb_type)) {
 280         s->dsp.clear_blocks(s->block[0]);
 281
 282         if(!s->chroma_y_shift){
 283             s->dsp.clear_blocks(s->block[6]);
 284         }
 285
 286         /* compute DCT type */
 287         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 288             !s->frame_pred_frame_dct) {
 289             s->interlaced_dct = get_bits1(&s->gb);
 290         }
 291
 292         if (IS_QUANT(mb_type))
 293             s->qscale = get_qscale(s);
 294
 295         if (s->concealment_motion_vectors) {
 296             /* just parse them */
 297             if (s->picture_structure != PICT_FRAME)
 298                 skip_bits1(&s->gb); /* field select */
 299
 300             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 301                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 302             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 303                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 304
 305             skip_bits1(&s->gb); /* marker */
 306         }else
 307             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 308         s->mb_intra = 1;
 309 #ifdef HAVE_XVMC
 310         //if 1, we memcpy blocks in xvmcvideo
 311         if(s->avctx->xvmc_acceleration > 1){
 312             XVMC_pack_pblocks(s,-1);//inter are always full blocks
 313             if(s->swap_uv){
 314                 exchange_uv(s);
 315             }
 316         }
 317 #endif
 318
 319         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 320             if(s->flags2 & CODEC_FLAG2_FAST){
 321                 for(i=0;i<6;i++) {
 322                     mpeg2_fast_decode_block_intra(s, s->pblocks[i], i);
 323                 }
 324             }else{
 325                 for(i=0;i<mb_block_count;i++) {
 326                     if (mpeg2_decode_block_intra(s, s->pblocks[i], i) < 0)
 327                         return -1;
 328                 }
 329             }
 330         } else {
 331             for(i=0;i<6;i++) {
 332                 if (mpeg1_decode_block_intra(s, s->pblocks[i], i) < 0)
 333                     return -1;
 334             }
 335         }
 336     } else {
 337         if (mb_type & MB_TYPE_ZERO_MV){
 338             assert(mb_type & MB_TYPE_CBP);
 339
 340             s->mv_dir = MV_DIR_FORWARD;
 341             if(s->picture_structure == PICT_FRAME){
 342                 if(!s->frame_pred_frame_dct)
 343                     s->interlaced_dct = get_bits1(&s->gb);
 344                 s->mv_type = MV_TYPE_16X16;
 345             }else{
 346                 s->mv_type = MV_TYPE_FIELD;
 347                 mb_type |= MB_TYPE_INTERLACED;
 348                 s->field_select[0][0]= s->picture_structure - 1;
 349             }
 350
 351             if (IS_QUANT(mb_type))
 352                 s->qscale = get_qscale(s);
 353
 354             s->last_mv[0][0][0] = 0;
 355             s->last_mv[0][0][1] = 0;
 356             s->last_mv[0][1][0] = 0;
 357             s->last_mv[0][1][1] = 0;
 358             s->mv[0][0][0] = 0;
 359             s->mv[0][0][1] = 0;
 360         }else{
 361             assert(mb_type & MB_TYPE_L0L1);
 362 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 363             /* get additional motion vector type */
 364             if (s->frame_pred_frame_dct)
 365                 motion_type = MT_FRAME;
 366             else{
 367                 motion_type = get_bits(&s->gb, 2);
 368                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 369                     s->interlaced_dct = get_bits1(&s->gb);
 370             }
 371
 372             if (IS_QUANT(mb_type))
 373                 s->qscale = get_qscale(s);
 374
 375             /* motion vectors */
 376             s->mv_dir= (mb_type>>13)&3;
 377             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 378             switch(motion_type) {
 379             case MT_FRAME: /* or MT_16X8 */
 380                 if (s->picture_structure == PICT_FRAME) {
 381                     mb_type |= MB_TYPE_16x16;
 382                     s->mv_type = MV_TYPE_16X16;
 383                     for(i=0;i<2;i++) {
 384                         if (USES_LIST(mb_type, i)) {
 385                             /* MT_FRAME */
 386                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 387                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 388                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 389                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 390                             /* full_pel: only for MPEG-1 */
 391                             if (s->full_pel[i]){
 392                                 s->mv[i][0][0] <<= 1;
 393                                 s->mv[i][0][1] <<= 1;
 394                             }
 395                         }
 396                     }
 397                 } else {
 398                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 399                     s->mv_type = MV_TYPE_16X8;
 400                     for(i=0;i<2;i++) {
 401                         if (USES_LIST(mb_type, i)) {
 402                             /* MT_16X8 */
 403                             for(j=0;j<2;j++) {
 404                                 s->field_select[i][j] = get_bits1(&s->gb);
 405                                 for(k=0;k<2;k++) {
 406                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 407                                                              s->last_mv[i][j][k]);
 408                                     s->last_mv[i][j][k] = val;
 409                                     s->mv[i][j][k] = val;
 410                                 }
 411                             }
 412                         }
 413                     }
 414                 }
 415                 break;
 416             case MT_FIELD:
 417                 s->mv_type = MV_TYPE_FIELD;
 418                 if (s->picture_structure == PICT_FRAME) {
 419                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 420                     for(i=0;i<2;i++) {
 421                         if (USES_LIST(mb_type, i)) {
 422                             for(j=0;j<2;j++) {
 423                                 s->field_select[i][j] = get_bits1(&s->gb);
 424                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 425                                                          s->last_mv[i][j][0]);
 426                                 s->last_mv[i][j][0] = val;
 427                                 s->mv[i][j][0] = val;
 428                                 dprintf(s->avctx, "fmx=%d\n", val);
 429                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 430                                                          s->last_mv[i][j][1] >> 1);
 431                                 s->last_mv[i][j][1] = val << 1;
 432                                 s->mv[i][j][1] = val;
 433                                 dprintf(s->avctx, "fmy=%d\n", val);
 434                             }
 435                         }
 436                     }
 437                 } else {
 438                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 439                     for(i=0;i<2;i++) {
 440                         if (USES_LIST(mb_type, i)) {
 441                             s->field_select[i][0] = get_bits1(&s->gb);
 442                             for(k=0;k<2;k++) {
 443                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 444                                                          s->last_mv[i][0][k]);
 445                                 s->last_mv[i][0][k] = val;
 446                                 s->last_mv[i][1][k] = val;
 447                                 s->mv[i][0][k] = val;
 448                             }
 449                         }
 450                     }
 451                 }
 452                 break;
 453             case MT_DMV:
 454                 s->mv_type = MV_TYPE_DMV;
 455                 for(i=0;i<2;i++) {
 456                     if (USES_LIST(mb_type, i)) {
 457                         int dmx, dmy, mx, my, m;
 458                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 459                                                 s->last_mv[i][0][0]);
 460                         s->last_mv[i][0][0] = mx;
 461                         s->last_mv[i][1][0] = mx;
 462                         dmx = get_dmv(s);
 463                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 464                                                 s->last_mv[i][0][1] >> 1);
 465                         dmy = get_dmv(s);
 466
 467
 468                         s->last_mv[i][0][1] = my<<1;
 469                         s->last_mv[i][1][1] = my<<1;
 470
 471                         s->mv[i][0][0] = mx;
 472                         s->mv[i][0][1] = my;
 473                         s->mv[i][1][0] = mx;//not used
 474                         s->mv[i][1][1] = my;//not used
 475
 476                         if (s->picture_structure == PICT_FRAME) {
 477                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 478
 479                             //m = 1 + 2 * s->top_field_first;
 480                             m = s->top_field_first ? 1 : 3;
 481
 482                             /* top -> top pred */
 483                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 484                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 485                             m = 4 - m;
 486                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 487                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 488                         } else {
 489                             mb_type |= MB_TYPE_16x16;
 490
 491                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 492                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 493                             if(s->picture_structure == PICT_TOP_FIELD)
 494                                 s->mv[i][2][1]--;
 495                             else
 496                                 s->mv[i][2][1]++;
 497                         }
 498                     }
 499                 }
 500                 break;
 501             default:
 502                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 503                 return -1;
 504             }
 505         }
 506
 507         s->mb_intra = 0;
 508         if (HAS_CBP(mb_type)) {
 509             s->dsp.clear_blocks(s->block[0]);
 510
 511             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 512             if(mb_block_count > 6){
 513                  cbp<<= mb_block_count-6;
 514                  cbp |= get_bits(&s->gb, mb_block_count-6);
 515                  s->dsp.clear_blocks(s->block[6]);
 516             }
 517             if (cbp <= 0){
 518                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 519                 return -1;
 520             }
 521
 522 #ifdef HAVE_XVMC
 523             //if 1, we memcpy blocks in xvmcvideo
 524             if(s->avctx->xvmc_acceleration > 1){
 525                 XVMC_pack_pblocks(s,cbp);
 526                 if(s->swap_uv){
 527                     exchange_uv(s);
 528                 }
 529             }
 530 #endif
 531
 532             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 533                 if(s->flags2 & CODEC_FLAG2_FAST){
 534                     for(i=0;i<6;i++) {
 535                         if(cbp & 32) {
 536                             mpeg2_fast_decode_block_non_intra(s, s->pblocks[i], i);
 537                         } else {
 538                             s->block_last_index[i] = -1;
 539                         }
 540                         cbp+=cbp;
 541                     }
 542                 }else{
 543                     cbp<<= 12-mb_block_count;
 544
 545                     for(i=0;i<mb_block_count;i++) {
 546                         if ( cbp & (1<<11) ) {
 547                             if (mpeg2_decode_block_non_intra(s, s->pblocks[i], i) < 0)
 548                                 return -1;
 549                         } else {
 550                             s->block_last_index[i] = -1;
 551                         }
 552                         cbp+=cbp;
 553                     }
 554                 }
 555             } else {
 556                 if(s->flags2 & CODEC_FLAG2_FAST){
 557                     for(i=0;i<6;i++) {
 558                         if (cbp & 32) {
 559                             mpeg1_fast_decode_block_inter(s, s->pblocks[i], i);
 560                         } else {
 561                             s->block_last_index[i] = -1;
 562                         }
 563                         cbp+=cbp;
 564                     }
 565                 }else{
 566                     for(i=0;i<6;i++) {
 567                         if (cbp & 32) {
 568                             if (mpeg1_decode_block_inter(s, s->pblocks[i], i) < 0)
 569                                 return -1;
 570                         } else {
 571                             s->block_last_index[i] = -1;
 572                         }
 573                         cbp+=cbp;
 574                     }
 575                 }
 576             }
 577         }else{
 578             for(i=0;i<12;i++)
 579                 s->block_last_index[i] = -1;
 580         }
 581     }
 582
 583     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 584
 585     return 0;
 586 }
 587
 588 /* as H.263, but only 17 codes */
 589 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 590 {
 591     int code, sign, val, l, shift;
 592
 593     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 594     if (code == 0) {
 595         return pred;
 596     }
 597     if (code < 0) {
 598         return 0xffff;
 599     }
 600
 601     sign = get_bits1(&s->gb);
 602     shift = fcode - 1;
 603     val = code;
 604     if (shift) {
 605         val = (val - 1) << shift;
 606         val |= get_bits(&s->gb, shift);
 607         val++;
 608     }
 609     if (sign)
 610         val = -val;
 611     val += pred;
 612
 613     /* modulo decoding */
 614     l= INT_BIT - 5 - shift;
 615     val = (val<<l)>>l;
 616     return val;
 617 }
 618
 619 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 620                                DCTELEM *block,
 621                                int n)
 622 {
 623     int level, dc, diff, i, j, run;
 624     int component;
 625     RLTable *rl = &ff_rl_mpeg1;
 626     uint8_t * const scantable= s->intra_scantable.permutated;
 627     const uint16_t *quant_matrix= s->intra_matrix;
 628     const int qscale= s->qscale;
 629
 630     /* DC coefficient */
 631     component = (n <= 3 ? 0 : n - 4 + 1);
 632     diff = decode_dc(&s->gb, component);
 633     if (diff >= 0xffff)
 634         return -1;
 635     dc = s->last_dc[component];
 636     dc += diff;
 637     s->last_dc[component] = dc;
 638     block[0] = dc<<3;
 639     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 640     i = 0;
 641     {
 642         OPEN_READER(re, &s->gb);
 643         /* now quantify & encode AC coefficients */
 644         for(;;) {
 645             UPDATE_CACHE(re, &s->gb);
 646             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 647
 648             if(level == 127){
 649                 break;
 650             } else if(level != 0) {
 651                 i += run;
 652                 j = scantable[i];
 653                 level= (level*qscale*quant_matrix[j])>>4;
 654                 level= (level-1)|1;
 655                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 656                 LAST_SKIP_BITS(re, &s->gb, 1);
 657             } else {
 658                 /* escape */
 659                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 660                 UPDATE_CACHE(re, &s->gb);
 661                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 662                 if (level == -128) {
 663                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 664                 } else if (level == 0) {
 665                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 666                 }
 667                 i += run;
 668                 j = scantable[i];
 669                 if(level<0){
 670                     level= -level;
 671                     level= (level*qscale*quant_matrix[j])>>4;
 672                     level= (level-1)|1;
 673                     level= -level;
 674                 }else{
 675                     level= (level*qscale*quant_matrix[j])>>4;
 676                     level= (level-1)|1;
 677                 }
 678             }
 679             if (i > 63){
 680                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 681                 return -1;
 682             }
 683
 684             block[j] = level;
 685         }
 686         CLOSE_READER(re, &s->gb);
 687     }
 688     s->block_last_index[n] = i;
 689    return 0;
 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;
1176     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1177
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_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     return 0;
1204 }
1205
1206 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1207                                      const uint8_t *new_perm){
1208     uint16_t temp_matrix[64];
1209     int i;
1210
1211     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1212
1213     for(i=0;i<64;i++){
1214         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1215     }
1216 }
1217
1218 /* Call this function when we know all parameters.
1219  * It may be called in different places for MPEG-1 and MPEG-2. */
1220 static int mpeg_decode_postinit(AVCodecContext *avctx){
1221     Mpeg1Context *s1 = avctx->priv_data;
1222     MpegEncContext *s = &s1->mpeg_enc_ctx;
1223     uint8_t old_permutation[64];
1224
1225     if (
1226         (s1->mpeg_enc_ctx_allocated == 0)||
1227         avctx->coded_width  != s->width ||
1228         avctx->coded_height != s->height||
1229         s1->save_width != s->width ||
1230         s1->save_height != s->height ||
1231         s1->save_aspect_info != s->aspect_ratio_info||
1232         0)
1233     {
1234
1235         if (s1->mpeg_enc_ctx_allocated) {
1236             ParseContext pc= s->parse_context;
1237             s->parse_context.buffer=0;
1238             MPV_common_end(s);
1239             s->parse_context= pc;
1240         }
1241
1242         if( (s->width == 0 )||(s->height == 0))
1243             return -2;
1244
1245         avcodec_set_dimensions(avctx, s->width, s->height);
1246         avctx->bit_rate = s->bit_rate;
1247         s1->save_aspect_info = s->aspect_ratio_info;
1248         s1->save_width = s->width;
1249         s1->save_height = s->height;
1250
1251         /* low_delay may be forced, in this case we will have B-frames
1252          * that behave like P-frames. */
1253         avctx->has_b_frames = !(s->low_delay);
1254
1255         if(avctx->sub_id==1){//s->codec_id==avctx->codec_id==CODEC_ID
1256             //MPEG-1 fps
1257             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1258             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1259             //MPEG-1 aspect
1260             avctx->sample_aspect_ratio= av_d2q(
1261                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1262
1263         }else{//MPEG-2
1264         //MPEG-2 fps
1265             av_reduce(
1266                 &s->avctx->time_base.den,
1267                 &s->avctx->time_base.num,
1268                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1269                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1270                 1<<30);
1271         //MPEG-2 aspect
1272             if(s->aspect_ratio_info > 1){
1273                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) ){
1274                     s->avctx->sample_aspect_ratio=
1275                         av_div_q(
1276                          ff_mpeg2_aspect[s->aspect_ratio_info],
1277                          (AVRational){s->width, s->height}
1278                          );
1279                 }else{
1280                     s->avctx->sample_aspect_ratio=
1281                         av_div_q(
1282                          ff_mpeg2_aspect[s->aspect_ratio_info],
1283                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1284                         );
1285                 }
1286             }else{
1287                 s->avctx->sample_aspect_ratio=
1288                     ff_mpeg2_aspect[s->aspect_ratio_info];
1289             }
1290         }//MPEG-2
1291
1292         if(avctx->xvmc_acceleration){
1293             avctx->pix_fmt = avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1294         }else{
1295             if(s->chroma_format <  2){
1296                 avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_420);
1297             }else
1298             if(s->chroma_format == 2){
1299                 avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_422);
1300             }else
1301             if(s->chroma_format >  2){
1302                 avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_444);
1303             }
1304         }
1305         //until then pix_fmt may be changed right after codec init
1306         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
1307             if( avctx->idct_algo == FF_IDCT_AUTO )
1308                 avctx->idct_algo = FF_IDCT_SIMPLE;
1309
1310         /* Quantization matrices may need reordering
1311          * if DCT permutation is changed. */
1312         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1313
1314         if (MPV_common_init(s) < 0)
1315             return -2;
1316
1317         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1318         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1319         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1320         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1321
1322         s1->mpeg_enc_ctx_allocated = 1;
1323     }
1324     return 0;
1325 }
1326
1327 static int mpeg1_decode_picture(AVCodecContext *avctx,
1328                                 const uint8_t *buf, int buf_size)
1329 {
1330     Mpeg1Context *s1 = avctx->priv_data;
1331     MpegEncContext *s = &s1->mpeg_enc_ctx;
1332     int ref, f_code, vbv_delay;
1333
1334     if(mpeg_decode_postinit(s->avctx) < 0)
1335        return -2;
1336
1337     init_get_bits(&s->gb, buf, buf_size*8);
1338
1339     ref = get_bits(&s->gb, 10); /* temporal ref */
1340     s->pict_type = get_bits(&s->gb, 3);
1341     if(s->pict_type == 0 || s->pict_type > 3)
1342         return -1;
1343
1344     vbv_delay= get_bits(&s->gb, 16);
1345     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1346         s->full_pel[0] = get_bits1(&s->gb);
1347         f_code = get_bits(&s->gb, 3);
1348         if (f_code == 0 && avctx->error_resilience >= FF_ER_COMPLIANT)
1349             return -1;
1350         s->mpeg_f_code[0][0] = f_code;
1351         s->mpeg_f_code[0][1] = f_code;
1352     }
1353     if (s->pict_type == FF_B_TYPE) {
1354         s->full_pel[1] = get_bits1(&s->gb);
1355         f_code = get_bits(&s->gb, 3);
1356         if (f_code == 0 && avctx->error_resilience >= FF_ER_COMPLIANT)
1357             return -1;
1358         s->mpeg_f_code[1][0] = f_code;
1359         s->mpeg_f_code[1][1] = f_code;
1360     }
1361     s->current_picture.pict_type= s->pict_type;
1362     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1363
1364     if(avctx->debug & FF_DEBUG_PICT_INFO)
1365         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1366
1367     s->y_dc_scale = 8;
1368     s->c_dc_scale = 8;
1369     s->first_slice = 1;
1370     return 0;
1371 }
1372
1373 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1374 {
1375     MpegEncContext *s= &s1->mpeg_enc_ctx;
1376     int horiz_size_ext, vert_size_ext;
1377     int bit_rate_ext;
1378
1379     skip_bits(&s->gb, 1); /* profile and level esc*/
1380     s->avctx->profile= get_bits(&s->gb, 3);
1381     s->avctx->level= get_bits(&s->gb, 4);
1382     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1383     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1384     horiz_size_ext = get_bits(&s->gb, 2);
1385     vert_size_ext = get_bits(&s->gb, 2);
1386     s->width |= (horiz_size_ext << 12);
1387     s->height |= (vert_size_ext << 12);
1388     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1389     s->bit_rate += (bit_rate_ext << 18) * 400;
1390     skip_bits1(&s->gb); /* marker */
1391     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1392
1393     s->low_delay = get_bits1(&s->gb);
1394     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1395
1396     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1397     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1398
1399     dprintf(s->avctx, "sequence extension\n");
1400     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1401     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1402
1403     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1404         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1405                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1406
1407 }
1408
1409 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1410 {
1411     MpegEncContext *s= &s1->mpeg_enc_ctx;
1412     int color_description, w, h;
1413
1414     skip_bits(&s->gb, 3); /* video format */
1415     color_description= get_bits1(&s->gb);
1416     if(color_description){
1417         skip_bits(&s->gb, 8); /* color primaries */
1418         skip_bits(&s->gb, 8); /* transfer_characteristics */
1419         skip_bits(&s->gb, 8); /* matrix_coefficients */
1420     }
1421     w= get_bits(&s->gb, 14);
1422     skip_bits(&s->gb, 1); //marker
1423     h= get_bits(&s->gb, 14);
1424     skip_bits(&s->gb, 1); //marker
1425
1426     s1->pan_scan.width= 16*w;
1427     s1->pan_scan.height=16*h;
1428
1429     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1430         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1431 }
1432
1433 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1434 {
1435     MpegEncContext *s= &s1->mpeg_enc_ctx;
1436     int i,nofco;
1437
1438     nofco = 1;
1439     if(s->progressive_sequence){
1440         if(s->repeat_first_field){
1441             nofco++;
1442             if(s->top_field_first)
1443                 nofco++;
1444         }
1445     }else{
1446         if(s->picture_structure == PICT_FRAME){
1447             nofco++;
1448             if(s->repeat_first_field)
1449                 nofco++;
1450         }
1451     }
1452     for(i=0; i<nofco; i++){
1453         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1454         skip_bits(&s->gb, 1); //marker
1455         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1456         skip_bits(&s->gb, 1); //marker
1457     }
1458
1459     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1460         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1461             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1462             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1463             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1464         );
1465 }
1466
1467 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1468 {
1469     int i, v, j;
1470
1471     dprintf(s->avctx, "matrix extension\n");
1472
1473     if (get_bits1(&s->gb)) {
1474         for(i=0;i<64;i++) {
1475             v = get_bits(&s->gb, 8);
1476             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1477             s->intra_matrix[j] = v;
1478             s->chroma_intra_matrix[j] = v;
1479         }
1480     }
1481     if (get_bits1(&s->gb)) {
1482         for(i=0;i<64;i++) {
1483             v = get_bits(&s->gb, 8);
1484             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1485             s->inter_matrix[j] = v;
1486             s->chroma_inter_matrix[j] = v;
1487         }
1488     }
1489     if (get_bits1(&s->gb)) {
1490         for(i=0;i<64;i++) {
1491             v = get_bits(&s->gb, 8);
1492             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1493             s->chroma_intra_matrix[j] = v;
1494         }
1495     }
1496     if (get_bits1(&s->gb)) {
1497         for(i=0;i<64;i++) {
1498             v = get_bits(&s->gb, 8);
1499             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1500             s->chroma_inter_matrix[j] = v;
1501         }
1502     }
1503 }
1504
1505 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1506 {
1507     s->full_pel[0] = s->full_pel[1] = 0;
1508     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1509     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1510     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1511     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1512     s->intra_dc_precision = get_bits(&s->gb, 2);
1513     s->picture_structure = get_bits(&s->gb, 2);
1514     s->top_field_first = get_bits1(&s->gb);
1515     s->frame_pred_frame_dct = get_bits1(&s->gb);
1516     s->concealment_motion_vectors = get_bits1(&s->gb);
1517     s->q_scale_type = get_bits1(&s->gb);
1518     s->intra_vlc_format = get_bits1(&s->gb);
1519     s->alternate_scan = get_bits1(&s->gb);
1520     s->repeat_first_field = get_bits1(&s->gb);
1521     s->chroma_420_type = get_bits1(&s->gb);
1522     s->progressive_frame = get_bits1(&s->gb);
1523
1524     if(s->picture_structure == PICT_FRAME){
1525         s->first_field=0;
1526         s->v_edge_pos= 16*s->mb_height;
1527     }else{
1528         s->first_field ^= 1;
1529         s->v_edge_pos=  8*s->mb_height;
1530         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1531     }
1532
1533     if(s->alternate_scan){
1534         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1535         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1536     }else{
1537         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1538         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1539     }
1540
1541     /* composite display not parsed */
1542     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1543     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1544     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1545     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1546     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1547     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1548     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1549     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1550     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1551 }
1552
1553 static void mpeg_decode_extension(AVCodecContext *avctx,
1554                                   const uint8_t *buf, int buf_size)
1555 {
1556     Mpeg1Context *s1 = avctx->priv_data;
1557     MpegEncContext *s = &s1->mpeg_enc_ctx;
1558     int ext_type;
1559
1560     init_get_bits(&s->gb, buf, buf_size*8);
1561
1562     ext_type = get_bits(&s->gb, 4);
1563     switch(ext_type) {
1564     case 0x1:
1565         mpeg_decode_sequence_extension(s1);
1566         break;
1567     case 0x2:
1568         mpeg_decode_sequence_display_extension(s1);
1569         break;
1570     case 0x3:
1571         mpeg_decode_quant_matrix_extension(s);
1572         break;
1573     case 0x7:
1574         mpeg_decode_picture_display_extension(s1);
1575         break;
1576     case 0x8:
1577         mpeg_decode_picture_coding_extension(s);
1578         break;
1579     }
1580 }
1581
1582 static void exchange_uv(MpegEncContext *s){
1583     short * tmp = s->pblocks[4];
1584     s->pblocks[4] = s->pblocks[5];
1585     s->pblocks[5] = tmp;
1586 }
1587
1588 static int mpeg_field_start(MpegEncContext *s){
1589     AVCodecContext *avctx= s->avctx;
1590     Mpeg1Context *s1 = (Mpeg1Context*)s;
1591
1592     /* start frame decoding */
1593     if(s->first_field || s->picture_structure==PICT_FRAME){
1594         if(MPV_frame_start(s, avctx) < 0)
1595             return -1;
1596
1597         ff_er_frame_start(s);
1598
1599         /* first check if we must repeat the frame */
1600         s->current_picture_ptr->repeat_pict = 0;
1601         if (s->repeat_first_field) {
1602             if (s->progressive_sequence) {
1603                 if (s->top_field_first)
1604                     s->current_picture_ptr->repeat_pict = 4;
1605                 else
1606                     s->current_picture_ptr->repeat_pict = 2;
1607             } else if (s->progressive_frame) {
1608                 s->current_picture_ptr->repeat_pict = 1;
1609             }
1610         }
1611
1612         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1613     }else{ //second field
1614             int i;
1615
1616             if(!s->current_picture_ptr){
1617                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1618                 return -1;
1619             }
1620
1621             for(i=0; i<4; i++){
1622                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1623                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1624                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1625                 }
1626             }
1627     }
1628 #ifdef HAVE_XVMC
1629 // MPV_frame_start will call this function too,
1630 // but we need to call it on every field
1631     if(s->avctx->xvmc_acceleration)
1632          XVMC_field_start(s,avctx);
1633 #endif
1634
1635     return 0;
1636 }
1637
1638 #define DECODE_SLICE_ERROR -1
1639 #define DECODE_SLICE_OK 0
1640
1641 /**
1642  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1643  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1644  *         DECODE_SLICE_OK if this slice is ok<br>
1645  */
1646 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1647                              const uint8_t **buf, int buf_size)
1648 {
1649     MpegEncContext *s = &s1->mpeg_enc_ctx;
1650     AVCodecContext *avctx= s->avctx;
1651     const int field_pic= s->picture_structure != PICT_FRAME;
1652     const int lowres= s->avctx->lowres;
1653
1654     s->resync_mb_x=
1655     s->resync_mb_y= -1;
1656
1657     if (mb_y<<field_pic >= s->mb_height){
1658         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1659         return -1;
1660     }
1661
1662     init_get_bits(&s->gb, *buf, buf_size*8);
1663
1664     ff_mpeg1_clean_buffers(s);
1665     s->interlaced_dct = 0;
1666
1667     s->qscale = get_qscale(s);
1668
1669     if(s->qscale == 0){
1670         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1671         return -1;
1672     }
1673
1674     /* extra slice info */
1675     while (get_bits1(&s->gb) != 0) {
1676         skip_bits(&s->gb, 8);
1677     }
1678
1679     s->mb_x=0;
1680
1681     for(;;) {
1682         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1683         if (code < 0){
1684             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1685             return -1;
1686         }
1687         if (code >= 33) {
1688             if (code == 33) {
1689                 s->mb_x += 33;
1690             }
1691             /* otherwise, stuffing, nothing to do */
1692         } else {
1693             s->mb_x += code;
1694             break;
1695         }
1696     }
1697     if(s->mb_x >= (unsigned)s->mb_width){
1698         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1699         return -1;
1700     }
1701
1702     s->resync_mb_x= s->mb_x;
1703     s->resync_mb_y= s->mb_y= mb_y;
1704     s->mb_skip_run= 0;
1705     ff_init_block_index(s);
1706
1707     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1708         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1709              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",
1710                  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],
1711                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1712                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1713                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1714                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1715         }
1716     }
1717
1718     for(;;) {
1719 #ifdef HAVE_XVMC
1720         //If 1, we memcpy blocks in xvmcvideo.
1721         if(s->avctx->xvmc_acceleration > 1)
1722             XVMC_init_block(s);//set s->block
1723 #endif
1724
1725         if(mpeg_decode_mb(s, s->block) < 0)
1726             return -1;
1727
1728         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1729             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1730             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1731             int motion_x, motion_y, dir, i;
1732             if(field_pic && !s->first_field)
1733                 xy += wrap/2;
1734
1735             for(i=0; i<2; i++){
1736                 for(dir=0; dir<2; dir++){
1737                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1738                         motion_x = motion_y = 0;
1739                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1740                         motion_x = s->mv[dir][0][0];
1741                         motion_y = s->mv[dir][0][1];
1742                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1743                         motion_x = s->mv[dir][i][0];
1744                         motion_y = s->mv[dir][i][1];
1745                     }
1746
1747                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1748                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1749                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1750                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1751                     s->current_picture.ref_index [dir][xy    ]=
1752                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1753                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1754                 }
1755                 xy += wrap;
1756             }
1757         }
1758
1759         s->dest[0] += 16 >> lowres;
1760         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1761         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1762
1763         MPV_decode_mb(s, s->block);
1764
1765         if (++s->mb_x >= s->mb_width) {
1766             const int mb_size= 16>>s->avctx->lowres;
1767
1768             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1769
1770             s->mb_x = 0;
1771             s->mb_y++;
1772
1773             if(s->mb_y<<field_pic >= s->mb_height){
1774                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1775                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1776                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1777                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1778
1779                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1780                    || (avctx->error_resilience >= FF_ER_AGGRESSIVE && left>8)){
1781                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1782                     return -1;
1783                 }else
1784                     goto eos;
1785             }
1786
1787             ff_init_block_index(s);
1788         }
1789
1790         /* skip mb handling */
1791         if (s->mb_skip_run == -1) {
1792             /* read increment again */
1793             s->mb_skip_run = 0;
1794             for(;;) {
1795                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1796                 if (code < 0){
1797                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1798                     return -1;
1799                 }
1800                 if (code >= 33) {
1801                     if (code == 33) {
1802                         s->mb_skip_run += 33;
1803                     }else if(code == 35){
1804                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1805                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1806                             return -1;
1807                         }
1808                         goto eos; /* end of slice */
1809                     }
1810                     /* otherwise, stuffing, nothing to do */
1811                 } else {
1812                     s->mb_skip_run += code;
1813                     break;
1814                 }
1815             }
1816             if(s->mb_skip_run){
1817                 int i;
1818                 if(s->pict_type == FF_I_TYPE){
1819                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1820                     return -1;
1821                 }
1822
1823                 /* skip mb */
1824                 s->mb_intra = 0;
1825                 for(i=0;i<12;i++)
1826                     s->block_last_index[i] = -1;
1827                 if(s->picture_structure == PICT_FRAME)
1828                     s->mv_type = MV_TYPE_16X16;
1829                 else
1830                     s->mv_type = MV_TYPE_FIELD;
1831                 if (s->pict_type == FF_P_TYPE) {
1832                     /* if P type, zero motion vector is implied */
1833                     s->mv_dir = MV_DIR_FORWARD;
1834                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1835                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1836                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1837                     s->field_select[0][0]= s->picture_structure - 1;
1838                 } else {
1839                     /* if B type, reuse previous vectors and directions */
1840                     s->mv[0][0][0] = s->last_mv[0][0][0];
1841                     s->mv[0][0][1] = s->last_mv[0][0][1];
1842                     s->mv[1][0][0] = s->last_mv[1][0][0];
1843                     s->mv[1][0][1] = s->last_mv[1][0][1];
1844                 }
1845             }
1846         }
1847     }
1848 eos: // end of slice
1849     *buf += (get_bits_count(&s->gb)-1)/8;
1850 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1851     return 0;
1852 }
1853
1854 static int slice_decode_thread(AVCodecContext *c, void *arg){
1855     MpegEncContext *s= arg;
1856     const uint8_t *buf= s->gb.buffer;
1857     int mb_y= s->start_mb_y;
1858
1859     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1860
1861     for(;;){
1862         uint32_t start_code;
1863         int ret;
1864
1865         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1866         emms_c();
1867 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1868 //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);
1869         if(ret < 0){
1870             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1871                 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);
1872         }else{
1873             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);
1874         }
1875
1876         if(s->mb_y == s->end_mb_y)
1877             return 0;
1878
1879         start_code= -1;
1880         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1881         mb_y= start_code - SLICE_MIN_START_CODE;
1882         if(mb_y < 0 || mb_y >= s->end_mb_y)
1883             return -1;
1884     }
1885
1886     return 0; //not reached
1887 }
1888
1889 /**
1890  * Handles slice ends.
1891  * @return 1 if it seems to be the last slice
1892  */
1893 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1894 {
1895     Mpeg1Context *s1 = avctx->priv_data;
1896     MpegEncContext *s = &s1->mpeg_enc_ctx;
1897
1898     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1899         return 0;
1900
1901 #ifdef HAVE_XVMC
1902     if(s->avctx->xvmc_acceleration)
1903         XVMC_field_end(s);
1904 #endif
1905     /* end of slice reached */
1906     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1907         /* end of image */
1908
1909         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1910
1911         ff_er_frame_end(s);
1912
1913         MPV_frame_end(s);
1914
1915         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1916             *pict= *(AVFrame*)s->current_picture_ptr;
1917             ff_print_debug_info(s, pict);
1918         } else {
1919             s->picture_number++;
1920             /* latency of 1 frame for I- and P-frames */
1921             /* XXX: use another variable than picture_number */
1922             if (s->last_picture_ptr != NULL) {
1923                 *pict= *(AVFrame*)s->last_picture_ptr;
1924                  ff_print_debug_info(s, pict);
1925             }
1926         }
1927
1928         return 1;
1929     } else {
1930         return 0;
1931     }
1932 }
1933
1934 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1935                                  const uint8_t *buf, int buf_size)
1936 {
1937     Mpeg1Context *s1 = avctx->priv_data;
1938     MpegEncContext *s = &s1->mpeg_enc_ctx;
1939     int width,height;
1940     int i, v, j;
1941
1942     init_get_bits(&s->gb, buf, buf_size*8);
1943
1944     width = get_bits(&s->gb, 12);
1945     height = get_bits(&s->gb, 12);
1946     if (width <= 0 || height <= 0)
1947         return -1;
1948     s->aspect_ratio_info= get_bits(&s->gb, 4);
1949     if (s->aspect_ratio_info == 0) {
1950         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1951         if (avctx->error_resilience >= FF_ER_COMPLIANT)
1952             return -1;
1953     }
1954     s->frame_rate_index = get_bits(&s->gb, 4);
1955     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1956         return -1;
1957     s->bit_rate = get_bits(&s->gb, 18) * 400;
1958     if (get_bits1(&s->gb) == 0) /* marker */
1959         return -1;
1960     s->width = width;
1961     s->height = height;
1962
1963     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1964     skip_bits(&s->gb, 1);
1965
1966     /* get matrix */
1967     if (get_bits1(&s->gb)) {
1968         for(i=0;i<64;i++) {
1969             v = get_bits(&s->gb, 8);
1970             if(v==0){
1971                 av_log(s->avctx, AV_LOG_ERROR, "intra matrix damaged\n");
1972                 return -1;
1973             }
1974             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1975             s->intra_matrix[j] = v;
1976             s->chroma_intra_matrix[j] = v;
1977         }
1978 #ifdef DEBUG
1979         dprintf(s->avctx, "intra matrix present\n");
1980         for(i=0;i<64;i++)
1981             dprintf(s->avctx, " %d", s->intra_matrix[s->dsp.idct_permutation[i]]);
1982         dprintf(s->avctx, "\n");
1983 #endif
1984     } else {
1985         for(i=0;i<64;i++) {
1986             j = s->dsp.idct_permutation[i];
1987             v = ff_mpeg1_default_intra_matrix[i];
1988             s->intra_matrix[j] = v;
1989             s->chroma_intra_matrix[j] = v;
1990         }
1991     }
1992     if (get_bits1(&s->gb)) {
1993         for(i=0;i<64;i++) {
1994             v = get_bits(&s->gb, 8);
1995             if(v==0){
1996                 av_log(s->avctx, AV_LOG_ERROR, "inter matrix damaged\n");
1997                 return -1;
1998             }
1999             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
2000             s->inter_matrix[j] = v;
2001             s->chroma_inter_matrix[j] = v;
2002         }
2003 #ifdef DEBUG
2004         dprintf(s->avctx, "non-intra matrix present\n");
2005         for(i=0;i<64;i++)
2006             dprintf(s->avctx, " %d", s->inter_matrix[s->dsp.idct_permutation[i]]);
2007         dprintf(s->avctx, "\n");
2008 #endif
2009     } else {
2010         for(i=0;i<64;i++) {
2011             int j= s->dsp.idct_permutation[i];
2012             v = ff_mpeg1_default_non_intra_matrix[i];
2013             s->inter_matrix[j] = v;
2014             s->chroma_inter_matrix[j] = v;
2015         }
2016     }
2017
2018     if(show_bits(&s->gb, 23) != 0){
2019         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2020         return -1;
2021     }
2022
2023     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2024     s->progressive_sequence = 1;
2025     s->progressive_frame = 1;
2026     s->picture_structure = PICT_FRAME;
2027     s->frame_pred_frame_dct = 1;
2028     s->chroma_format = 1;
2029     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2030     avctx->sub_id = 1; /* indicates MPEG-1 */
2031     s->out_format = FMT_MPEG1;
2032     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2033     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2034
2035     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2036         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2037                s->avctx->rc_buffer_size, s->bit_rate);
2038
2039     return 0;
2040 }
2041
2042 static int vcr2_init_sequence(AVCodecContext *avctx)
2043 {
2044     Mpeg1Context *s1 = avctx->priv_data;
2045     MpegEncContext *s = &s1->mpeg_enc_ctx;
2046     int i, v;
2047
2048     /* start new MPEG-1 context decoding */
2049     s->out_format = FMT_MPEG1;
2050     if (s1->mpeg_enc_ctx_allocated) {
2051         MPV_common_end(s);
2052     }
2053     s->width  = avctx->coded_width;
2054     s->height = avctx->coded_height;
2055     avctx->has_b_frames= 0; //true?
2056     s->low_delay= 1;
2057
2058     if(avctx->xvmc_acceleration){
2059         avctx->pix_fmt = avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
2060     }else{
2061         avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_420);
2062     }
2063
2064     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
2065         if( avctx->idct_algo == FF_IDCT_AUTO )
2066             avctx->idct_algo = FF_IDCT_SIMPLE;
2067
2068     if (MPV_common_init(s) < 0)
2069         return -1;
2070     exchange_uv(s);//common init reset pblocks, so we swap them here
2071     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2072     s1->mpeg_enc_ctx_allocated = 1;
2073
2074     for(i=0;i<64;i++) {
2075         int j= s->dsp.idct_permutation[i];
2076         v = ff_mpeg1_default_intra_matrix[i];
2077         s->intra_matrix[j] = v;
2078         s->chroma_intra_matrix[j] = v;
2079
2080         v = ff_mpeg1_default_non_intra_matrix[i];
2081         s->inter_matrix[j] = v;
2082         s->chroma_inter_matrix[j] = v;
2083     }
2084
2085     s->progressive_sequence = 1;
2086     s->progressive_frame = 1;
2087     s->picture_structure = PICT_FRAME;
2088     s->frame_pred_frame_dct = 1;
2089     s->chroma_format = 1;
2090     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2091     avctx->sub_id = 2; /* indicates MPEG-2 */
2092     return 0;
2093 }
2094
2095
2096 static void mpeg_decode_user_data(AVCodecContext *avctx,
2097                                   const uint8_t *buf, int buf_size)
2098 {
2099     const uint8_t *p;
2100     int len, flags;
2101     p = buf;
2102     len = buf_size;
2103
2104     /* we parse the DTG active format information */
2105     if (len >= 5 &&
2106         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2107         flags = p[4];
2108         p += 5;
2109         len -= 5;
2110         if (flags & 0x80) {
2111             /* skip event id */
2112             if (len < 2)
2113                 return;
2114             p += 2;
2115             len -= 2;
2116         }
2117         if (flags & 0x40) {
2118             if (len < 1)
2119                 return;
2120             avctx->dtg_active_format = p[0] & 0x0f;
2121         }
2122     }
2123 }
2124
2125 static void mpeg_decode_gop(AVCodecContext *avctx,
2126                             const uint8_t *buf, int buf_size){
2127     Mpeg1Context *s1 = avctx->priv_data;
2128     MpegEncContext *s = &s1->mpeg_enc_ctx;
2129
2130     int drop_frame_flag;
2131     int time_code_hours, time_code_minutes;
2132     int time_code_seconds, time_code_pictures;
2133     int closed_gop, broken_link;
2134
2135     init_get_bits(&s->gb, buf, buf_size*8);
2136
2137     drop_frame_flag = get_bits1(&s->gb);
2138
2139     time_code_hours=get_bits(&s->gb,5);
2140     time_code_minutes = get_bits(&s->gb,6);
2141     skip_bits1(&s->gb);//marker bit
2142     time_code_seconds = get_bits(&s->gb,6);
2143     time_code_pictures = get_bits(&s->gb,6);
2144
2145     closed_gop  = get_bits1(&s->gb);
2146     /*broken_link indicate that after editing the
2147       reference frames of the first B-Frames after GOP I-Frame
2148       are missing (open gop)*/
2149     broken_link = get_bits1(&s->gb);
2150
2151     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2152         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2153             time_code_hours, time_code_minutes, time_code_seconds,
2154             time_code_pictures, closed_gop, broken_link);
2155 }
2156 /**
2157  * Finds the end of the current frame in the bitstream.
2158  * @return the position of the first byte of the next frame, or -1
2159  */
2160 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
2161 {
2162     int i;
2163     uint32_t state= pc->state;
2164
2165     /* EOF considered as end of frame */
2166     if (buf_size == 0)
2167         return 0;
2168
2169 /*
2170  0  frame start         -> 1/4
2171  1  first_SEQEXT        -> 0/2
2172  2  first field start   -> 3/0
2173  3  second_SEQEXT       -> 2/0
2174  4  searching end
2175 */
2176
2177     for(i=0; i<buf_size; i++){
2178         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2179         if(pc->frame_start_found&1){
2180             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2181                 pc->frame_start_found--;
2182             else if(state == EXT_START_CODE+2){
2183                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2184                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2185             }
2186             state++;
2187         }else{
2188             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2189             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2190                 i++;
2191                 pc->frame_start_found=4;
2192             }
2193             if(state == SEQ_END_CODE){
2194                 pc->state=-1;
2195                 return i+1;
2196             }
2197             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2198                 pc->frame_start_found= 0;
2199             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2200                 pc->frame_start_found++;
2201             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2202                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2203                     pc->frame_start_found=0;
2204                     pc->state=-1;
2205                     return i-3;
2206                 }
2207             }
2208         }
2209     }
2210     pc->state= state;
2211     return END_NOT_FOUND;
2212 }
2213
2214 static int decode_chunks(AVCodecContext *avctx,
2215                              AVFrame *picture, int *data_size,
2216                              const uint8_t *buf, int buf_size);
2217
2218 /* handle buffering and image synchronisation */
2219 static int mpeg_decode_frame(AVCodecContext *avctx,
2220                              void *data, int *data_size,
2221                              const uint8_t *buf, int buf_size)
2222 {
2223     Mpeg1Context *s = avctx->priv_data;
2224     AVFrame *picture = data;
2225     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2226     dprintf(avctx, "fill_buffer\n");
2227
2228     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2229         /* special case for last picture */
2230         if (s2->low_delay==0 && s2->next_picture_ptr) {
2231             *picture= *(AVFrame*)s2->next_picture_ptr;
2232             s2->next_picture_ptr= NULL;
2233
2234             *data_size = sizeof(AVFrame);
2235         }
2236         return buf_size;
2237     }
2238
2239     if(s2->flags&CODEC_FLAG_TRUNCATED){
2240         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size);
2241
2242         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2243             return buf_size;
2244     }
2245
2246 #if 0
2247     if (s->repeat_field % 2 == 1) {
2248         s->repeat_field++;
2249         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2250         //        s2->picture_number, s->repeat_field);
2251         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2252             *data_size = sizeof(AVPicture);
2253             goto the_end;
2254         }
2255     }
2256 #endif
2257
2258     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == ff_get_fourcc("VCR2"))
2259         vcr2_init_sequence(avctx);
2260
2261     s->slice_count= 0;
2262
2263     if(avctx->extradata && !avctx->frame_number)
2264         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2265
2266     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2267 }
2268
2269 static int decode_chunks(AVCodecContext *avctx,
2270                              AVFrame *picture, int *data_size,
2271                              const uint8_t *buf, int buf_size)
2272 {
2273     Mpeg1Context *s = avctx->priv_data;
2274     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2275     const uint8_t *buf_ptr = buf;
2276     const uint8_t *buf_end = buf + buf_size;
2277     int ret, input_size;
2278
2279     for(;;) {
2280         /* find next start code */
2281         uint32_t start_code = -1;
2282         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2283         if (start_code > 0x1ff){
2284             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2285                 if(avctx->thread_count > 1){
2286                     int i;
2287
2288                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count);
2289                     for(i=0; i<s->slice_count; i++)
2290                         s2->error_count += s2->thread_context[i]->error_count;
2291                 }
2292                 if (slice_end(avctx, picture)) {
2293                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2294                         *data_size = sizeof(AVPicture);
2295                 }
2296             }
2297             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2298         }
2299
2300         input_size = buf_end - buf_ptr;
2301
2302         if(avctx->debug & FF_DEBUG_STARTCODE){
2303             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2304         }
2305
2306         /* prepare data for next start code */
2307         switch(start_code) {
2308         case SEQ_START_CODE:
2309             mpeg1_decode_sequence(avctx, buf_ptr,
2310                                     input_size);
2311             break;
2312
2313         case PICTURE_START_CODE:
2314             /* we have a complete image: we try to decompress it */
2315             mpeg1_decode_picture(avctx,
2316                                     buf_ptr, input_size);
2317             break;
2318         case EXT_START_CODE:
2319             mpeg_decode_extension(avctx,
2320                                     buf_ptr, input_size);
2321             break;
2322         case USER_START_CODE:
2323             mpeg_decode_user_data(avctx,
2324                                     buf_ptr, input_size);
2325             break;
2326         case GOP_START_CODE:
2327             s2->first_field=0;
2328             mpeg_decode_gop(avctx,
2329                                     buf_ptr, input_size);
2330             break;
2331         default:
2332             if (start_code >= SLICE_MIN_START_CODE &&
2333                 start_code <= SLICE_MAX_START_CODE) {
2334                 int mb_y= start_code - SLICE_MIN_START_CODE;
2335
2336                 if(s2->last_picture_ptr==NULL){
2337                 /* Skip B-frames if we do not have reference frames. */
2338                     if(s2->pict_type==FF_B_TYPE) break;
2339                 }
2340                 if(s2->next_picture_ptr==NULL){
2341                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2342                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2343                 }
2344                 /* Skip B-frames if we are in a hurry. */
2345                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2346                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2347                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2348                     || avctx->skip_frame >= AVDISCARD_ALL)
2349                     break;
2350                 /* Skip everything if we are in a hurry>=5. */
2351                 if(avctx->hurry_up>=5) break;
2352
2353                 if (!s->mpeg_enc_ctx_allocated) break;
2354
2355                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2356                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2357                         break;
2358                 }
2359
2360                 if(s2->first_slice){
2361                     s2->first_slice=0;
2362                             if(mpeg_field_start(s2) < 0)
2363                         return -1;
2364                     }
2365                 if(!s2->current_picture_ptr){
2366                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2367                     return -1;
2368                 }
2369
2370                 if(avctx->thread_count > 1){
2371                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2372                     if(threshold <= mb_y){
2373                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2374
2375                         thread_context->start_mb_y= mb_y;
2376                         thread_context->end_mb_y  = s2->mb_height;
2377                         if(s->slice_count){
2378                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2379                             ff_update_duplicate_context(thread_context, s2);
2380                         }
2381                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2382                         s->slice_count++;
2383                     }
2384                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2385                 }else{
2386                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2387                     emms_c();
2388
2389                     if(ret < 0){
2390                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2391                             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);
2392                     }else{
2393                         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);
2394                     }
2395                 }
2396             }
2397             break;
2398         }
2399     }
2400 }
2401
2402 static int mpeg_decode_end(AVCodecContext *avctx)
2403 {
2404     Mpeg1Context *s = avctx->priv_data;
2405
2406     if (s->mpeg_enc_ctx_allocated)
2407         MPV_common_end(&s->mpeg_enc_ctx);
2408     return 0;
2409 }
2410
2411 AVCodec mpeg1video_decoder = {
2412     "mpeg1video",
2413     CODEC_TYPE_VIDEO,
2414     CODEC_ID_MPEG1VIDEO,
2415     sizeof(Mpeg1Context),
2416     mpeg_decode_init,
2417     NULL,
2418     mpeg_decode_end,
2419     mpeg_decode_frame,
2420     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2421     .flush= ff_mpeg_flush,
2422     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2423 };
2424
2425 AVCodec mpeg2video_decoder = {
2426     "mpeg2video",
2427     CODEC_TYPE_VIDEO,
2428     CODEC_ID_MPEG2VIDEO,
2429     sizeof(Mpeg1Context),
2430     mpeg_decode_init,
2431     NULL,
2432     mpeg_decode_end,
2433     mpeg_decode_frame,
2434     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2435     .flush= ff_mpeg_flush,
2436     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2437 };
2438
2439 //legacy decoder
2440 AVCodec mpegvideo_decoder = {
2441     "mpegvideo",
2442     CODEC_TYPE_VIDEO,
2443     CODEC_ID_MPEG2VIDEO,
2444     sizeof(Mpeg1Context),
2445     mpeg_decode_init,
2446     NULL,
2447     mpeg_decode_end,
2448     mpeg_decode_frame,
2449     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2450     .flush= ff_mpeg_flush,
2451     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2452 };
2453
2454 #ifdef HAVE_XVMC
2455 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2456     Mpeg1Context *s;
2457
2458     if( avctx->thread_count > 1)
2459         return -1;
2460     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2461         return -1;
2462     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2463         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2464     }
2465     mpeg_decode_init(avctx);
2466     s = avctx->priv_data;
2467
2468     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2469     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2470
2471     return 0;
2472 }
2473
2474 AVCodec mpeg_xvmc_decoder = {
2475     "mpegvideo_xvmc",
2476     CODEC_TYPE_VIDEO,
2477     CODEC_ID_MPEG2VIDEO_XVMC,
2478     sizeof(Mpeg1Context),
2479     mpeg_mc_decode_init,
2480     NULL,
2481     mpeg_decode_end,
2482     mpeg_decode_frame,
2483     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2484     .flush= ff_mpeg_flush,
2485     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video XvMC (X-Video Motion Compensation)"),
2486 };
2487
2488 #endif