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 int XVMC_field_start(MpegEncContext *s, AVCodecContext *avctx);
  67 int XVMC_field_end(MpegEncContext *s);
  68 void XVMC_pack_pblocks(MpegEncContext *s,int cbp);
  69 void XVMC_init_block(MpegEncContext *s);//set s->block
  70
  71 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  72                                            PIX_FMT_XVMC_MPEG2_IDCT,
  73                                            PIX_FMT_XVMC_MPEG2_MC,
  74                                            PIX_FMT_NONE};
  75
  76 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  77
  78
  79 #define INIT_2D_VLC_RL(rl, static_size)\
  80 {\
  81     static RL_VLC_ELEM rl_vlc_table[static_size];\
  82     INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\
  83              &rl.table_vlc[0][1], 4, 2,\
  84              &rl.table_vlc[0][0], 4, 2, static_size);\
  85 \
  86     rl.rl_vlc[0]= rl_vlc_table;\
  87     init_2d_vlc_rl(&rl);\
  88 }
  89
  90 static void init_2d_vlc_rl(RLTable *rl)
  91 {
  92     int i;
  93
  94     for(i=0; i<rl->vlc.table_size; i++){
  95         int code= rl->vlc.table[i][0];
  96         int len = rl->vlc.table[i][1];
  97         int level, run;
  98
  99         if(len==0){ // illegal code
 100             run= 65;
 101             level= MAX_LEVEL;
 102         }else if(len<0){ //more bits needed
 103             run= 0;
 104             level= code;
 105         }else{
 106             if(code==rl->n){ //esc
 107                 run= 65;
 108                 level= 0;
 109             }else if(code==rl->n+1){ //eob
 110                 run= 0;
 111                 level= 127;
 112             }else{
 113                 run=   rl->table_run  [code] + 1;
 114                 level= rl->table_level[code];
 115             }
 116         }
 117         rl->rl_vlc[0][i].len= len;
 118         rl->rl_vlc[0][i].level= level;
 119         rl->rl_vlc[0][i].run= run;
 120     }
 121 }
 122
 123 void ff_mpeg12_common_init(MpegEncContext *s)
 124 {
 125
 126     s->y_dc_scale_table=
 127     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
 128
 129 }
 130
 131 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 132     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 133     s->last_dc[1] = s->last_dc[0];
 134     s->last_dc[2] = s->last_dc[0];
 135     memset(s->last_mv, 0, sizeof(s->last_mv));
 136 }
 137
 138
 139 /******************************************/
 140 /* decoding */
 141
 142 static VLC mv_vlc;
 143 static VLC mbincr_vlc;
 144 static VLC mb_ptype_vlc;
 145 static VLC mb_btype_vlc;
 146 static VLC mb_pat_vlc;
 147
 148 av_cold void ff_mpeg12_init_vlcs(void)
 149 {
 150     static int done = 0;
 151
 152     if (!done) {
 153         done = 1;
 154
 155         INIT_VLC_STATIC(&dc_lum_vlc, DC_VLC_BITS, 12,
 156                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 157                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 512);
 158         INIT_VLC_STATIC(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 159                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 160                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514);
 161         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 17,
 162                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 163                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518);
 164         INIT_VLC_STATIC(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 165                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 166                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538);
 167         INIT_VLC_STATIC(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 168                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 169                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 512);
 170
 171         INIT_VLC_STATIC(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 172                  &table_mb_ptype[0][1], 2, 1,
 173                  &table_mb_ptype[0][0], 2, 1, 64);
 174         INIT_VLC_STATIC(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 175                  &table_mb_btype[0][1], 2, 1,
 176                  &table_mb_btype[0][0], 2, 1, 64);
 177         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 178         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 179
 180         INIT_2D_VLC_RL(ff_rl_mpeg1, 680);
 181         INIT_2D_VLC_RL(ff_rl_mpeg2, 674);
 182     }
 183 }
 184
 185 static inline int get_dmv(MpegEncContext *s)
 186 {
 187     if(get_bits1(&s->gb))
 188         return 1 - (get_bits1(&s->gb) << 1);
 189     else
 190         return 0;
 191 }
 192
 193 static inline int get_qscale(MpegEncContext *s)
 194 {
 195     int qscale = get_bits(&s->gb, 5);
 196     if (s->q_scale_type) {
 197         return non_linear_qscale[qscale];
 198     } else {
 199         return qscale << 1;
 200     }
 201 }
 202
 203 /* motion type (for MPEG-2) */
 204 #define MT_FIELD 1
 205 #define MT_FRAME 2
 206 #define MT_16X8  2
 207 #define MT_DMV   3
 208
 209 static int mpeg_decode_mb(MpegEncContext *s,
 210                           DCTELEM block[12][64])
 211 {
 212     int i, j, k, cbp, val, mb_type, motion_type;
 213     const int mb_block_count = 4 + (1<< s->chroma_format);
 214
 215     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 216
 217     assert(s->mb_skipped==0);
 218
 219     if (s->mb_skip_run-- != 0) {
 220         if (s->pict_type == FF_P_TYPE) {
 221             s->mb_skipped = 1;
 222             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 223         } else {
 224             int mb_type;
 225
 226             if(s->mb_x)
 227                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 228             else
 229                 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
 230             if(IS_INTRA(mb_type))
 231                 return -1;
 232
 233             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 234                 mb_type | MB_TYPE_SKIP;
 235 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 236
 237             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 238                 s->mb_skipped = 1;
 239         }
 240
 241         return 0;
 242     }
 243
 244     switch(s->pict_type) {
 245     default:
 246     case FF_I_TYPE:
 247         if (get_bits1(&s->gb) == 0) {
 248             if (get_bits1(&s->gb) == 0){
 249                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 250                 return -1;
 251             }
 252             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 253         } else {
 254             mb_type = MB_TYPE_INTRA;
 255         }
 256         break;
 257     case FF_P_TYPE:
 258         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 259         if (mb_type < 0){
 260             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 261             return -1;
 262         }
 263         mb_type = ptype2mb_type[ mb_type ];
 264         break;
 265     case FF_B_TYPE:
 266         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 267         if (mb_type < 0){
 268             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 269             return -1;
 270         }
 271         mb_type = btype2mb_type[ mb_type ];
 272         break;
 273     }
 274     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 275 //    motion_type = 0; /* avoid warning */
 276     if (IS_INTRA(mb_type)) {
 277         s->dsp.clear_blocks(s->block[0]);
 278
 279         if(!s->chroma_y_shift){
 280             s->dsp.clear_blocks(s->block[6]);
 281         }
 282
 283         /* compute DCT type */
 284         if (s->picture_structure == PICT_FRAME && //FIXME add an interlaced_dct coded var?
 285             !s->frame_pred_frame_dct) {
 286             s->interlaced_dct = get_bits1(&s->gb);
 287         }
 288
 289         if (IS_QUANT(mb_type))
 290             s->qscale = get_qscale(s);
 291
 292         if (s->concealment_motion_vectors) {
 293             /* just parse them */
 294             if (s->picture_structure != PICT_FRAME)
 295                 skip_bits1(&s->gb); /* field select */
 296
 297             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 298                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 299             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 300                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 301
 302             skip_bits1(&s->gb); /* marker */
 303         }else
 304             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 305         s->mb_intra = 1;
 306 #if CONFIG_XVMC
 307         //if 1, we memcpy blocks in xvmcvideo
 308         if(s->avctx->xvmc_acceleration > 1){
 309             XVMC_pack_pblocks(s,-1);//inter are always full blocks
 310             if(s->swap_uv){
 311                 exchange_uv(s);
 312             }
 313         }
 314 #endif
 315
 316         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 317             if(s->flags2 & CODEC_FLAG2_FAST){
 318                 for(i=0;i<6;i++) {
 319                     mpeg2_fast_decode_block_intra(s, s->pblocks[i], i);
 320                 }
 321             }else{
 322                 for(i=0;i<mb_block_count;i++) {
 323                     if (mpeg2_decode_block_intra(s, s->pblocks[i], i) < 0)
 324                         return -1;
 325                 }
 326             }
 327         } else {
 328             for(i=0;i<6;i++) {
 329                 if (mpeg1_decode_block_intra(s, s->pblocks[i], i) < 0)
 330                     return -1;
 331             }
 332         }
 333     } else {
 334         if (mb_type & MB_TYPE_ZERO_MV){
 335             assert(mb_type & MB_TYPE_CBP);
 336
 337             s->mv_dir = MV_DIR_FORWARD;
 338             if(s->picture_structure == PICT_FRAME){
 339                 if(!s->frame_pred_frame_dct)
 340                     s->interlaced_dct = get_bits1(&s->gb);
 341                 s->mv_type = MV_TYPE_16X16;
 342             }else{
 343                 s->mv_type = MV_TYPE_FIELD;
 344                 mb_type |= MB_TYPE_INTERLACED;
 345                 s->field_select[0][0]= s->picture_structure - 1;
 346             }
 347
 348             if (IS_QUANT(mb_type))
 349                 s->qscale = get_qscale(s);
 350
 351             s->last_mv[0][0][0] = 0;
 352             s->last_mv[0][0][1] = 0;
 353             s->last_mv[0][1][0] = 0;
 354             s->last_mv[0][1][1] = 0;
 355             s->mv[0][0][0] = 0;
 356             s->mv[0][0][1] = 0;
 357         }else{
 358             assert(mb_type & MB_TYPE_L0L1);
 359 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 360             /* get additional motion vector type */
 361             if (s->frame_pred_frame_dct)
 362                 motion_type = MT_FRAME;
 363             else{
 364                 motion_type = get_bits(&s->gb, 2);
 365                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 366                     s->interlaced_dct = get_bits1(&s->gb);
 367             }
 368
 369             if (IS_QUANT(mb_type))
 370                 s->qscale = get_qscale(s);
 371
 372             /* motion vectors */
 373             s->mv_dir= (mb_type>>13)&3;
 374             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 375             switch(motion_type) {
 376             case MT_FRAME: /* or MT_16X8 */
 377                 if (s->picture_structure == PICT_FRAME) {
 378                     mb_type |= MB_TYPE_16x16;
 379                     s->mv_type = MV_TYPE_16X16;
 380                     for(i=0;i<2;i++) {
 381                         if (USES_LIST(mb_type, i)) {
 382                             /* MT_FRAME */
 383                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 384                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 385                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 386                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 387                             /* full_pel: only for MPEG-1 */
 388                             if (s->full_pel[i]){
 389                                 s->mv[i][0][0] <<= 1;
 390                                 s->mv[i][0][1] <<= 1;
 391                             }
 392                         }
 393                     }
 394                 } else {
 395                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 396                     s->mv_type = MV_TYPE_16X8;
 397                     for(i=0;i<2;i++) {
 398                         if (USES_LIST(mb_type, i)) {
 399                             /* MT_16X8 */
 400                             for(j=0;j<2;j++) {
 401                                 s->field_select[i][j] = get_bits1(&s->gb);
 402                                 for(k=0;k<2;k++) {
 403                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 404                                                              s->last_mv[i][j][k]);
 405                                     s->last_mv[i][j][k] = val;
 406                                     s->mv[i][j][k] = val;
 407                                 }
 408                             }
 409                         }
 410                     }
 411                 }
 412                 break;
 413             case MT_FIELD:
 414                 s->mv_type = MV_TYPE_FIELD;
 415                 if (s->picture_structure == PICT_FRAME) {
 416                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 417                     for(i=0;i<2;i++) {
 418                         if (USES_LIST(mb_type, i)) {
 419                             for(j=0;j<2;j++) {
 420                                 s->field_select[i][j] = get_bits1(&s->gb);
 421                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 422                                                          s->last_mv[i][j][0]);
 423                                 s->last_mv[i][j][0] = val;
 424                                 s->mv[i][j][0] = val;
 425                                 dprintf(s->avctx, "fmx=%d\n", val);
 426                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 427                                                          s->last_mv[i][j][1] >> 1);
 428                                 s->last_mv[i][j][1] = val << 1;
 429                                 s->mv[i][j][1] = val;
 430                                 dprintf(s->avctx, "fmy=%d\n", val);
 431                             }
 432                         }
 433                     }
 434                 } else {
 435                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 436                     for(i=0;i<2;i++) {
 437                         if (USES_LIST(mb_type, i)) {
 438                             s->field_select[i][0] = get_bits1(&s->gb);
 439                             for(k=0;k<2;k++) {
 440                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 441                                                          s->last_mv[i][0][k]);
 442                                 s->last_mv[i][0][k] = val;
 443                                 s->last_mv[i][1][k] = val;
 444                                 s->mv[i][0][k] = val;
 445                             }
 446                         }
 447                     }
 448                 }
 449                 break;
 450             case MT_DMV:
 451                 s->mv_type = MV_TYPE_DMV;
 452                 for(i=0;i<2;i++) {
 453                     if (USES_LIST(mb_type, i)) {
 454                         int dmx, dmy, mx, my, m;
 455                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 456                                                 s->last_mv[i][0][0]);
 457                         s->last_mv[i][0][0] = mx;
 458                         s->last_mv[i][1][0] = mx;
 459                         dmx = get_dmv(s);
 460                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 461                                                 s->last_mv[i][0][1] >> 1);
 462                         dmy = get_dmv(s);
 463
 464
 465                         s->last_mv[i][0][1] = my<<1;
 466                         s->last_mv[i][1][1] = my<<1;
 467
 468                         s->mv[i][0][0] = mx;
 469                         s->mv[i][0][1] = my;
 470                         s->mv[i][1][0] = mx;//not used
 471                         s->mv[i][1][1] = my;//not used
 472
 473                         if (s->picture_structure == PICT_FRAME) {
 474                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 475
 476                             //m = 1 + 2 * s->top_field_first;
 477                             m = s->top_field_first ? 1 : 3;
 478
 479                             /* top -> top pred */
 480                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 481                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 482                             m = 4 - m;
 483                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 484                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 485                         } else {
 486                             mb_type |= MB_TYPE_16x16;
 487
 488                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 489                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 490                             if(s->picture_structure == PICT_TOP_FIELD)
 491                                 s->mv[i][2][1]--;
 492                             else
 493                                 s->mv[i][2][1]++;
 494                         }
 495                     }
 496                 }
 497                 break;
 498             default:
 499                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 500                 return -1;
 501             }
 502         }
 503
 504         s->mb_intra = 0;
 505         if (HAS_CBP(mb_type)) {
 506             s->dsp.clear_blocks(s->block[0]);
 507
 508             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 509             if(mb_block_count > 6){
 510                  cbp<<= mb_block_count-6;
 511                  cbp |= get_bits(&s->gb, mb_block_count-6);
 512                  s->dsp.clear_blocks(s->block[6]);
 513             }
 514             if (cbp <= 0){
 515                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 516                 return -1;
 517             }
 518
 519 #if CONFIG_XVMC
 520             //if 1, we memcpy blocks in xvmcvideo
 521             if(s->avctx->xvmc_acceleration > 1){
 522                 XVMC_pack_pblocks(s,cbp);
 523                 if(s->swap_uv){
 524                     exchange_uv(s);
 525                 }
 526             }
 527 #endif
 528
 529             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 530                 if(s->flags2 & CODEC_FLAG2_FAST){
 531                     for(i=0;i<6;i++) {
 532                         if(cbp & 32) {
 533                             mpeg2_fast_decode_block_non_intra(s, s->pblocks[i], i);
 534                         } else {
 535                             s->block_last_index[i] = -1;
 536                         }
 537                         cbp+=cbp;
 538                     }
 539                 }else{
 540                     cbp<<= 12-mb_block_count;
 541
 542                     for(i=0;i<mb_block_count;i++) {
 543                         if ( cbp & (1<<11) ) {
 544                             if (mpeg2_decode_block_non_intra(s, s->pblocks[i], i) < 0)
 545                                 return -1;
 546                         } else {
 547                             s->block_last_index[i] = -1;
 548                         }
 549                         cbp+=cbp;
 550                     }
 551                 }
 552             } else {
 553                 if(s->flags2 & CODEC_FLAG2_FAST){
 554                     for(i=0;i<6;i++) {
 555                         if (cbp & 32) {
 556                             mpeg1_fast_decode_block_inter(s, s->pblocks[i], i);
 557                         } else {
 558                             s->block_last_index[i] = -1;
 559                         }
 560                         cbp+=cbp;
 561                     }
 562                 }else{
 563                     for(i=0;i<6;i++) {
 564                         if (cbp & 32) {
 565                             if (mpeg1_decode_block_inter(s, s->pblocks[i], i) < 0)
 566                                 return -1;
 567                         } else {
 568                             s->block_last_index[i] = -1;
 569                         }
 570                         cbp+=cbp;
 571                     }
 572                 }
 573             }
 574         }else{
 575             for(i=0;i<12;i++)
 576                 s->block_last_index[i] = -1;
 577         }
 578     }
 579
 580     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 581
 582     return 0;
 583 }
 584
 585 /* as H.263, but only 17 codes */
 586 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 587 {
 588     int code, sign, val, l, shift;
 589
 590     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 591     if (code == 0) {
 592         return pred;
 593     }
 594     if (code < 0) {
 595         return 0xffff;
 596     }
 597
 598     sign = get_bits1(&s->gb);
 599     shift = fcode - 1;
 600     val = code;
 601     if (shift) {
 602         val = (val - 1) << shift;
 603         val |= get_bits(&s->gb, shift);
 604         val++;
 605     }
 606     if (sign)
 607         val = -val;
 608     val += pred;
 609
 610     /* modulo decoding */
 611     l= INT_BIT - 5 - shift;
 612     val = (val<<l)>>l;
 613     return val;
 614 }
 615
 616 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 617                                DCTELEM *block,
 618                                int n)
 619 {
 620     int level, dc, diff, i, j, run;
 621     int component;
 622     RLTable *rl = &ff_rl_mpeg1;
 623     uint8_t * const scantable= s->intra_scantable.permutated;
 624     const uint16_t *quant_matrix= s->intra_matrix;
 625     const int qscale= s->qscale;
 626
 627     /* DC coefficient */
 628     component = (n <= 3 ? 0 : n - 4 + 1);
 629     diff = decode_dc(&s->gb, component);
 630     if (diff >= 0xffff)
 631         return -1;
 632     dc = s->last_dc[component];
 633     dc += diff;
 634     s->last_dc[component] = dc;
 635     block[0] = dc<<3;
 636     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 637     i = 0;
 638     {
 639         OPEN_READER(re, &s->gb);
 640         /* now quantify & encode AC coefficients */
 641         for(;;) {
 642             UPDATE_CACHE(re, &s->gb);
 643             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 644
 645             if(level == 127){
 646                 break;
 647             } else if(level != 0) {
 648                 i += run;
 649                 j = scantable[i];
 650                 level= (level*qscale*quant_matrix[j])>>4;
 651                 level= (level-1)|1;
 652                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 653                 LAST_SKIP_BITS(re, &s->gb, 1);
 654             } else {
 655                 /* escape */
 656                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 657                 UPDATE_CACHE(re, &s->gb);
 658                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 659                 if (level == -128) {
 660                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 661                 } else if (level == 0) {
 662                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 663                 }
 664                 i += run;
 665                 j = scantable[i];
 666                 if(level<0){
 667                     level= -level;
 668                     level= (level*qscale*quant_matrix[j])>>4;
 669                     level= (level-1)|1;
 670                     level= -level;
 671                 }else{
 672                     level= (level*qscale*quant_matrix[j])>>4;
 673                     level= (level-1)|1;
 674                 }
 675             }
 676             if (i > 63){
 677                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 678                 return -1;
 679             }
 680
 681             block[j] = level;
 682         }
 683         CLOSE_READER(re, &s->gb);
 684     }
 685     s->block_last_index[n] = i;
 686    return 0;
 687 }
 688
 689 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 690                                DCTELEM *block,
 691                                int n)
 692 {
 693     int level, i, j, run;
 694     RLTable *rl = &ff_rl_mpeg1;
 695     uint8_t * const scantable= s->intra_scantable.permutated;
 696     const uint16_t *quant_matrix= s->inter_matrix;
 697     const int qscale= s->qscale;
 698
 699     {
 700         OPEN_READER(re, &s->gb);
 701         i = -1;
 702         // special case for first coefficient, no need to add second VLC table
 703         UPDATE_CACHE(re, &s->gb);
 704         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 705             level= (3*qscale*quant_matrix[0])>>5;
 706             level= (level-1)|1;
 707             if(GET_CACHE(re, &s->gb)&0x40000000)
 708                 level= -level;
 709             block[0] = level;
 710             i++;
 711             SKIP_BITS(re, &s->gb, 2);
 712             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 713                 goto end;
 714         }
 715 #if MIN_CACHE_BITS < 19
 716         UPDATE_CACHE(re, &s->gb);
 717 #endif
 718         /* now quantify & encode AC coefficients */
 719         for(;;) {
 720             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 721
 722             if(level != 0) {
 723                 i += run;
 724                 j = scantable[i];
 725                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 726                 level= (level-1)|1;
 727                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 728                 SKIP_BITS(re, &s->gb, 1);
 729             } else {
 730                 /* escape */
 731                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 732                 UPDATE_CACHE(re, &s->gb);
 733                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 734                 if (level == -128) {
 735                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 736                 } else if (level == 0) {
 737                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 738                 }
 739                 i += run;
 740                 j = scantable[i];
 741                 if(level<0){
 742                     level= -level;
 743                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 744                     level= (level-1)|1;
 745                     level= -level;
 746                 }else{
 747                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 748                     level= (level-1)|1;
 749                 }
 750             }
 751             if (i > 63){
 752                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 753                 return -1;
 754             }
 755
 756             block[j] = level;
 757 #if MIN_CACHE_BITS < 19
 758             UPDATE_CACHE(re, &s->gb);
 759 #endif
 760             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 761                 break;
 762 #if MIN_CACHE_BITS >= 19
 763             UPDATE_CACHE(re, &s->gb);
 764 #endif
 765         }
 766 end:
 767         LAST_SKIP_BITS(re, &s->gb, 2);
 768         CLOSE_READER(re, &s->gb);
 769     }
 770     s->block_last_index[n] = i;
 771     return 0;
 772 }
 773
 774 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 775 {
 776     int level, i, j, run;
 777     RLTable *rl = &ff_rl_mpeg1;
 778     uint8_t * const scantable= s->intra_scantable.permutated;
 779     const int qscale= s->qscale;
 780
 781     {
 782         OPEN_READER(re, &s->gb);
 783         i = -1;
 784         // special case for first coefficient, no need to add second VLC table
 785         UPDATE_CACHE(re, &s->gb);
 786         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 787             level= (3*qscale)>>1;
 788             level= (level-1)|1;
 789             if(GET_CACHE(re, &s->gb)&0x40000000)
 790                 level= -level;
 791             block[0] = level;
 792             i++;
 793             SKIP_BITS(re, &s->gb, 2);
 794             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 795                 goto end;
 796         }
 797 #if MIN_CACHE_BITS < 19
 798         UPDATE_CACHE(re, &s->gb);
 799 #endif
 800
 801         /* now quantify & encode AC coefficients */
 802         for(;;) {
 803             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 804
 805             if(level != 0) {
 806                 i += run;
 807                 j = scantable[i];
 808                 level= ((level*2+1)*qscale)>>1;
 809                 level= (level-1)|1;
 810                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 811                 SKIP_BITS(re, &s->gb, 1);
 812             } else {
 813                 /* escape */
 814                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 815                 UPDATE_CACHE(re, &s->gb);
 816                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 817                 if (level == -128) {
 818                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 819                 } else if (level == 0) {
 820                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 821                 }
 822                 i += run;
 823                 j = scantable[i];
 824                 if(level<0){
 825                     level= -level;
 826                     level= ((level*2+1)*qscale)>>1;
 827                     level= (level-1)|1;
 828                     level= -level;
 829                 }else{
 830                     level= ((level*2+1)*qscale)>>1;
 831                     level= (level-1)|1;
 832                 }
 833             }
 834
 835             block[j] = level;
 836 #if MIN_CACHE_BITS < 19
 837             UPDATE_CACHE(re, &s->gb);
 838 #endif
 839             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 840                 break;
 841 #if MIN_CACHE_BITS >= 19
 842             UPDATE_CACHE(re, &s->gb);
 843 #endif
 844         }
 845 end:
 846         LAST_SKIP_BITS(re, &s->gb, 2);
 847         CLOSE_READER(re, &s->gb);
 848     }
 849     s->block_last_index[n] = i;
 850     return 0;
 851 }
 852
 853
 854 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 855                                DCTELEM *block,
 856                                int n)
 857 {
 858     int level, i, j, run;
 859     RLTable *rl = &ff_rl_mpeg1;
 860     uint8_t * const scantable= s->intra_scantable.permutated;
 861     const uint16_t *quant_matrix;
 862     const int qscale= s->qscale;
 863     int mismatch;
 864
 865     mismatch = 1;
 866
 867     {
 868         OPEN_READER(re, &s->gb);
 869         i = -1;
 870         if (n < 4)
 871             quant_matrix = s->inter_matrix;
 872         else
 873             quant_matrix = s->chroma_inter_matrix;
 874
 875         // special case for first coefficient, no need to add second VLC table
 876         UPDATE_CACHE(re, &s->gb);
 877         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 878             level= (3*qscale*quant_matrix[0])>>5;
 879             if(GET_CACHE(re, &s->gb)&0x40000000)
 880                 level= -level;
 881             block[0] = level;
 882             mismatch ^= level;
 883             i++;
 884             SKIP_BITS(re, &s->gb, 2);
 885             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 886                 goto end;
 887         }
 888 #if MIN_CACHE_BITS < 19
 889         UPDATE_CACHE(re, &s->gb);
 890 #endif
 891
 892         /* now quantify & encode AC coefficients */
 893         for(;;) {
 894             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 895
 896             if(level != 0) {
 897                 i += run;
 898                 j = scantable[i];
 899                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 900                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 901                 SKIP_BITS(re, &s->gb, 1);
 902             } else {
 903                 /* escape */
 904                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 905                 UPDATE_CACHE(re, &s->gb);
 906                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 907
 908                 i += run;
 909                 j = scantable[i];
 910                 if(level<0){
 911                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 912                     level= -level;
 913                 }else{
 914                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 915                 }
 916             }
 917             if (i > 63){
 918                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 919                 return -1;
 920             }
 921
 922             mismatch ^= level;
 923             block[j] = level;
 924 #if MIN_CACHE_BITS < 19
 925             UPDATE_CACHE(re, &s->gb);
 926 #endif
 927             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 928                 break;
 929 #if MIN_CACHE_BITS >= 19
 930             UPDATE_CACHE(re, &s->gb);
 931 #endif
 932         }
 933 end:
 934         LAST_SKIP_BITS(re, &s->gb, 2);
 935         CLOSE_READER(re, &s->gb);
 936     }
 937     block[63] ^= (mismatch & 1);
 938
 939     s->block_last_index[n] = i;
 940     return 0;
 941 }
 942
 943 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 944                                DCTELEM *block,
 945                                int n)
 946 {
 947     int level, i, j, run;
 948     RLTable *rl = &ff_rl_mpeg1;
 949     uint8_t * const scantable= s->intra_scantable.permutated;
 950     const int qscale= s->qscale;
 951     OPEN_READER(re, &s->gb);
 952     i = -1;
 953
 954     // special case for first coefficient, no need to add second VLC table
 955     UPDATE_CACHE(re, &s->gb);
 956     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 957         level= (3*qscale)>>1;
 958         if(GET_CACHE(re, &s->gb)&0x40000000)
 959             level= -level;
 960         block[0] = level;
 961         i++;
 962         SKIP_BITS(re, &s->gb, 2);
 963         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 964             goto end;
 965     }
 966 #if MIN_CACHE_BITS < 19
 967     UPDATE_CACHE(re, &s->gb);
 968 #endif
 969
 970     /* now quantify & encode AC coefficients */
 971     for(;;) {
 972         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 973
 974         if(level != 0) {
 975             i += run;
 976             j = scantable[i];
 977             level= ((level*2+1)*qscale)>>1;
 978             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 979             SKIP_BITS(re, &s->gb, 1);
 980         } else {
 981             /* escape */
 982             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 983             UPDATE_CACHE(re, &s->gb);
 984             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 985
 986             i += run;
 987             j = scantable[i];
 988             if(level<0){
 989                 level= ((-level*2+1)*qscale)>>1;
 990                 level= -level;
 991             }else{
 992                 level= ((level*2+1)*qscale)>>1;
 993             }
 994         }
 995
 996         block[j] = level;
 997 #if MIN_CACHE_BITS < 19
 998         UPDATE_CACHE(re, &s->gb);
 999 #endif
1000         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
1001             break;
1002 #if MIN_CACHE_BITS >=19
1003         UPDATE_CACHE(re, &s->gb);
1004 #endif
1005     }
1006 end:
1007     LAST_SKIP_BITS(re, &s->gb, 2);
1008     CLOSE_READER(re, &s->gb);
1009     s->block_last_index[n] = i;
1010     return 0;
1011 }
1012
1013
1014 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1015                                DCTELEM *block,
1016                                int n)
1017 {
1018     int level, dc, diff, i, j, run;
1019     int component;
1020     RLTable *rl;
1021     uint8_t * const scantable= s->intra_scantable.permutated;
1022     const uint16_t *quant_matrix;
1023     const int qscale= s->qscale;
1024     int mismatch;
1025
1026     /* DC coefficient */
1027     if (n < 4){
1028         quant_matrix = s->intra_matrix;
1029         component = 0;
1030     }else{
1031         quant_matrix = s->chroma_intra_matrix;
1032         component = (n&1) + 1;
1033     }
1034     diff = decode_dc(&s->gb, component);
1035     if (diff >= 0xffff)
1036         return -1;
1037     dc = s->last_dc[component];
1038     dc += diff;
1039     s->last_dc[component] = dc;
1040     block[0] = dc << (3 - s->intra_dc_precision);
1041     dprintf(s->avctx, "dc=%d\n", block[0]);
1042     mismatch = block[0] ^ 1;
1043     i = 0;
1044     if (s->intra_vlc_format)
1045         rl = &ff_rl_mpeg2;
1046     else
1047         rl = &ff_rl_mpeg1;
1048
1049     {
1050         OPEN_READER(re, &s->gb);
1051         /* now quantify & encode AC coefficients */
1052         for(;;) {
1053             UPDATE_CACHE(re, &s->gb);
1054             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1055
1056             if(level == 127){
1057                 break;
1058             } else if(level != 0) {
1059                 i += run;
1060                 j = scantable[i];
1061                 level= (level*qscale*quant_matrix[j])>>4;
1062                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1063                 LAST_SKIP_BITS(re, &s->gb, 1);
1064             } else {
1065                 /* escape */
1066                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1067                 UPDATE_CACHE(re, &s->gb);
1068                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1069                 i += run;
1070                 j = scantable[i];
1071                 if(level<0){
1072                     level= (-level*qscale*quant_matrix[j])>>4;
1073                     level= -level;
1074                 }else{
1075                     level= (level*qscale*quant_matrix[j])>>4;
1076                 }
1077             }
1078             if (i > 63){
1079                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1080                 return -1;
1081             }
1082
1083             mismatch^= level;
1084             block[j] = level;
1085         }
1086         CLOSE_READER(re, &s->gb);
1087     }
1088     block[63]^= mismatch&1;
1089
1090     s->block_last_index[n] = i;
1091     return 0;
1092 }
1093
1094 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1095                                DCTELEM *block,
1096                                int n)
1097 {
1098     int level, dc, diff, j, run;
1099     int component;
1100     RLTable *rl;
1101     uint8_t * scantable= s->intra_scantable.permutated;
1102     const uint16_t *quant_matrix;
1103     const int qscale= s->qscale;
1104
1105     /* DC coefficient */
1106     if (n < 4){
1107         quant_matrix = s->intra_matrix;
1108         component = 0;
1109     }else{
1110         quant_matrix = s->chroma_intra_matrix;
1111         component = (n&1) + 1;
1112     }
1113     diff = decode_dc(&s->gb, component);
1114     if (diff >= 0xffff)
1115         return -1;
1116     dc = s->last_dc[component];
1117     dc += diff;
1118     s->last_dc[component] = dc;
1119     block[0] = dc << (3 - s->intra_dc_precision);
1120     if (s->intra_vlc_format)
1121         rl = &ff_rl_mpeg2;
1122     else
1123         rl = &ff_rl_mpeg1;
1124
1125     {
1126         OPEN_READER(re, &s->gb);
1127         /* now quantify & encode AC coefficients */
1128         for(;;) {
1129             UPDATE_CACHE(re, &s->gb);
1130             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1131
1132             if(level == 127){
1133                 break;
1134             } else if(level != 0) {
1135                 scantable += run;
1136                 j = *scantable;
1137                 level= (level*qscale*quant_matrix[j])>>4;
1138                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1139                 LAST_SKIP_BITS(re, &s->gb, 1);
1140             } else {
1141                 /* escape */
1142                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1143                 UPDATE_CACHE(re, &s->gb);
1144                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1145                 scantable += run;
1146                 j = *scantable;
1147                 if(level<0){
1148                     level= (-level*qscale*quant_matrix[j])>>4;
1149                     level= -level;
1150                 }else{
1151                     level= (level*qscale*quant_matrix[j])>>4;
1152                 }
1153             }
1154
1155             block[j] = level;
1156         }
1157         CLOSE_READER(re, &s->gb);
1158     }
1159
1160     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1161     return 0;
1162 }
1163
1164 typedef struct Mpeg1Context {
1165     MpegEncContext mpeg_enc_ctx;
1166     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1167     int repeat_field; /* true if we must repeat the field */
1168     AVPanScan pan_scan; /** some temporary storage for the panscan */
1169     int slice_count;
1170     int swap_uv;//indicate VCR2
1171     int save_aspect_info;
1172     int save_width, save_height;
1173     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1174
1175 } Mpeg1Context;
1176
1177 static av_cold int mpeg_decode_init(AVCodecContext *avctx)
1178 {
1179     Mpeg1Context *s = avctx->priv_data;
1180     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1181     int i;
1182
1183     /* we need some permutation to store matrices,
1184      * until MPV_common_init() sets the real permutation. */
1185     for(i=0;i<64;i++)
1186        s2->dsp.idct_permutation[i]=i;
1187
1188     MPV_decode_defaults(s2);
1189
1190     s->mpeg_enc_ctx.avctx= avctx;
1191     s->mpeg_enc_ctx.flags= avctx->flags;
1192     s->mpeg_enc_ctx.flags2= avctx->flags2;
1193     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1194     ff_mpeg12_init_vlcs();
1195
1196     s->mpeg_enc_ctx_allocated = 0;
1197     s->mpeg_enc_ctx.picture_number = 0;
1198     s->repeat_field = 0;
1199     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1200     return 0;
1201 }
1202
1203 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1204                                      const uint8_t *new_perm){
1205     uint16_t temp_matrix[64];
1206     int i;
1207
1208     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1209
1210     for(i=0;i<64;i++){
1211         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1212     }
1213 }
1214
1215 static enum PixelFormat mpeg_get_pixelformat(AVCodecContext *avctx){
1216     Mpeg1Context *s1 = avctx->priv_data;
1217     MpegEncContext *s = &s1->mpeg_enc_ctx;
1218
1219     if(avctx->xvmc_acceleration)
1220         return avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1221     else{
1222         if(s->chroma_format <  2)
1223             return PIX_FMT_YUV420P;
1224         else if(s->chroma_format == 2)
1225             return PIX_FMT_YUV422P;
1226         else
1227             return PIX_FMT_YUV444P;
1228     }
1229 }
1230
1231 /* Call this function when we know all parameters.
1232  * It may be called in different places for MPEG-1 and MPEG-2. */
1233 static int mpeg_decode_postinit(AVCodecContext *avctx){
1234     Mpeg1Context *s1 = avctx->priv_data;
1235     MpegEncContext *s = &s1->mpeg_enc_ctx;
1236     uint8_t old_permutation[64];
1237
1238     if (
1239         (s1->mpeg_enc_ctx_allocated == 0)||
1240         avctx->coded_width  != s->width ||
1241         avctx->coded_height != s->height||
1242         s1->save_width != s->width ||
1243         s1->save_height != s->height ||
1244         s1->save_aspect_info != s->aspect_ratio_info||
1245         0)
1246     {
1247
1248         if (s1->mpeg_enc_ctx_allocated) {
1249             ParseContext pc= s->parse_context;
1250             s->parse_context.buffer=0;
1251             MPV_common_end(s);
1252             s->parse_context= pc;
1253         }
1254
1255         if( (s->width == 0 )||(s->height == 0))
1256             return -2;
1257
1258         avcodec_set_dimensions(avctx, s->width, s->height);
1259         avctx->bit_rate = s->bit_rate;
1260         s1->save_aspect_info = s->aspect_ratio_info;
1261         s1->save_width = s->width;
1262         s1->save_height = s->height;
1263
1264         /* low_delay may be forced, in this case we will have B-frames
1265          * that behave like P-frames. */
1266         avctx->has_b_frames = !(s->low_delay);
1267
1268         assert((avctx->sub_id==1) == (avctx->codec_id==CODEC_ID_MPEG1VIDEO));
1269         if(avctx->codec_id==CODEC_ID_MPEG1VIDEO){
1270             //MPEG-1 fps
1271             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1272             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1273             //MPEG-1 aspect
1274             avctx->sample_aspect_ratio= av_d2q(
1275                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1276
1277         }else{//MPEG-2
1278         //MPEG-2 fps
1279             av_reduce(
1280                 &s->avctx->time_base.den,
1281                 &s->avctx->time_base.num,
1282                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1283                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1284                 1<<30);
1285         //MPEG-2 aspect
1286             if(s->aspect_ratio_info > 1){
1287                 //we ignore the spec here as reality does not match the spec, see for example
1288                 // res_change_ffmpeg_aspect.ts and sequence-display-aspect.mpg
1289                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) || 1){
1290                     s->avctx->sample_aspect_ratio=
1291                         av_div_q(
1292                          ff_mpeg2_aspect[s->aspect_ratio_info],
1293                          (AVRational){s->width, s->height}
1294                          );
1295                 }else{
1296                     s->avctx->sample_aspect_ratio=
1297                         av_div_q(
1298                          ff_mpeg2_aspect[s->aspect_ratio_info],
1299                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1300                         );
1301                 }
1302             }else{
1303                 s->avctx->sample_aspect_ratio=
1304                     ff_mpeg2_aspect[s->aspect_ratio_info];
1305             }
1306         }//MPEG-2
1307
1308         avctx->pix_fmt = mpeg_get_pixelformat(avctx);
1309         //until then pix_fmt may be changed right after codec init
1310         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
1311             if( avctx->idct_algo == FF_IDCT_AUTO )
1312                 avctx->idct_algo = FF_IDCT_SIMPLE;
1313
1314         /* Quantization matrices may need reordering
1315          * if DCT permutation is changed. */
1316         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1317
1318         if (MPV_common_init(s) < 0)
1319             return -2;
1320
1321         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1322         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1323         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1324         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1325
1326         s1->mpeg_enc_ctx_allocated = 1;
1327     }
1328     return 0;
1329 }
1330
1331 static int mpeg1_decode_picture(AVCodecContext *avctx,
1332                                 const uint8_t *buf, int buf_size)
1333 {
1334     Mpeg1Context *s1 = avctx->priv_data;
1335     MpegEncContext *s = &s1->mpeg_enc_ctx;
1336     int ref, f_code, vbv_delay;
1337
1338     if(mpeg_decode_postinit(s->avctx) < 0)
1339        return -2;
1340
1341     init_get_bits(&s->gb, buf, buf_size*8);
1342
1343     ref = get_bits(&s->gb, 10); /* temporal ref */
1344     s->pict_type = get_bits(&s->gb, 3);
1345     if(s->pict_type == 0 || s->pict_type > 3)
1346         return -1;
1347
1348     vbv_delay= get_bits(&s->gb, 16);
1349     if (s->pict_type == FF_P_TYPE || s->pict_type == FF_B_TYPE) {
1350         s->full_pel[0] = get_bits1(&s->gb);
1351         f_code = get_bits(&s->gb, 3);
1352         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1353             return -1;
1354         s->mpeg_f_code[0][0] = f_code;
1355         s->mpeg_f_code[0][1] = f_code;
1356     }
1357     if (s->pict_type == FF_B_TYPE) {
1358         s->full_pel[1] = get_bits1(&s->gb);
1359         f_code = get_bits(&s->gb, 3);
1360         if (f_code == 0 && avctx->error_recognition >= FF_ER_COMPLIANT)
1361             return -1;
1362         s->mpeg_f_code[1][0] = f_code;
1363         s->mpeg_f_code[1][1] = f_code;
1364     }
1365     s->current_picture.pict_type= s->pict_type;
1366     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1367
1368     if(avctx->debug & FF_DEBUG_PICT_INFO)
1369         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1370
1371     s->y_dc_scale = 8;
1372     s->c_dc_scale = 8;
1373     s->first_slice = 1;
1374     return 0;
1375 }
1376
1377 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1378 {
1379     MpegEncContext *s= &s1->mpeg_enc_ctx;
1380     int horiz_size_ext, vert_size_ext;
1381     int bit_rate_ext;
1382
1383     skip_bits(&s->gb, 1); /* profile and level esc*/
1384     s->avctx->profile= get_bits(&s->gb, 3);
1385     s->avctx->level= get_bits(&s->gb, 4);
1386     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1387     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1388     horiz_size_ext = get_bits(&s->gb, 2);
1389     vert_size_ext = get_bits(&s->gb, 2);
1390     s->width |= (horiz_size_ext << 12);
1391     s->height |= (vert_size_ext << 12);
1392     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1393     s->bit_rate += (bit_rate_ext << 18) * 400;
1394     skip_bits1(&s->gb); /* marker */
1395     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1396
1397     s->low_delay = get_bits1(&s->gb);
1398     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1399
1400     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1401     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1402
1403     dprintf(s->avctx, "sequence extension\n");
1404     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1405     s->avctx->sub_id = 2; /* indicates MPEG-2 found */
1406
1407     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1408         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1409                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1410
1411 }
1412
1413 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1414 {
1415     MpegEncContext *s= &s1->mpeg_enc_ctx;
1416     int color_description, w, h;
1417
1418     skip_bits(&s->gb, 3); /* video format */
1419     color_description= get_bits1(&s->gb);
1420     if(color_description){
1421         skip_bits(&s->gb, 8); /* color primaries */
1422         skip_bits(&s->gb, 8); /* transfer_characteristics */
1423         skip_bits(&s->gb, 8); /* matrix_coefficients */
1424     }
1425     w= get_bits(&s->gb, 14);
1426     skip_bits(&s->gb, 1); //marker
1427     h= get_bits(&s->gb, 14);
1428     skip_bits(&s->gb, 1); //marker
1429
1430     s1->pan_scan.width= 16*w;
1431     s1->pan_scan.height=16*h;
1432
1433     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1434         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1435 }
1436
1437 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1438 {
1439     MpegEncContext *s= &s1->mpeg_enc_ctx;
1440     int i,nofco;
1441
1442     nofco = 1;
1443     if(s->progressive_sequence){
1444         if(s->repeat_first_field){
1445             nofco++;
1446             if(s->top_field_first)
1447                 nofco++;
1448         }
1449     }else{
1450         if(s->picture_structure == PICT_FRAME){
1451             nofco++;
1452             if(s->repeat_first_field)
1453                 nofco++;
1454         }
1455     }
1456     for(i=0; i<nofco; i++){
1457         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1458         skip_bits(&s->gb, 1); //marker
1459         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1460         skip_bits(&s->gb, 1); //marker
1461     }
1462
1463     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1464         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1465             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1466             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1467             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1468         );
1469 }
1470
1471 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1472 {
1473     int i, v, j;
1474
1475     dprintf(s->avctx, "matrix extension\n");
1476
1477     if (get_bits1(&s->gb)) {
1478         for(i=0;i<64;i++) {
1479             v = get_bits(&s->gb, 8);
1480             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1481             s->intra_matrix[j] = v;
1482             s->chroma_intra_matrix[j] = v;
1483         }
1484     }
1485     if (get_bits1(&s->gb)) {
1486         for(i=0;i<64;i++) {
1487             v = get_bits(&s->gb, 8);
1488             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1489             s->inter_matrix[j] = v;
1490             s->chroma_inter_matrix[j] = v;
1491         }
1492     }
1493     if (get_bits1(&s->gb)) {
1494         for(i=0;i<64;i++) {
1495             v = get_bits(&s->gb, 8);
1496             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1497             s->chroma_intra_matrix[j] = v;
1498         }
1499     }
1500     if (get_bits1(&s->gb)) {
1501         for(i=0;i<64;i++) {
1502             v = get_bits(&s->gb, 8);
1503             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1504             s->chroma_inter_matrix[j] = v;
1505         }
1506     }
1507 }
1508
1509 static void mpeg_decode_picture_coding_extension(Mpeg1Context *s1)
1510 {
1511     MpegEncContext *s= &s1->mpeg_enc_ctx;
1512
1513     s->full_pel[0] = s->full_pel[1] = 0;
1514     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1515     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1516     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1517     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1518     if(!s->pict_type && s1->mpeg_enc_ctx_allocated){
1519         av_log(s->avctx, AV_LOG_ERROR, "Missing picture start code, guessing missing values\n");
1520         if(s->mpeg_f_code[1][0] == 15 && s->mpeg_f_code[1][1]==15){
1521             if(s->mpeg_f_code[0][0] == 15 && s->mpeg_f_code[0][1] == 15)
1522                 s->pict_type= FF_I_TYPE;
1523             else
1524                 s->pict_type= FF_P_TYPE;
1525         }else
1526             s->pict_type= FF_B_TYPE;
1527         s->current_picture.pict_type= s->pict_type;
1528         s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
1529         s->first_slice= 1;
1530     }
1531     s->intra_dc_precision = get_bits(&s->gb, 2);
1532     s->picture_structure = get_bits(&s->gb, 2);
1533     s->top_field_first = get_bits1(&s->gb);
1534     s->frame_pred_frame_dct = get_bits1(&s->gb);
1535     s->concealment_motion_vectors = get_bits1(&s->gb);
1536     s->q_scale_type = get_bits1(&s->gb);
1537     s->intra_vlc_format = get_bits1(&s->gb);
1538     s->alternate_scan = get_bits1(&s->gb);
1539     s->repeat_first_field = get_bits1(&s->gb);
1540     s->chroma_420_type = get_bits1(&s->gb);
1541     s->progressive_frame = get_bits1(&s->gb);
1542
1543     if(s->picture_structure == PICT_FRAME){
1544         s->first_field=0;
1545         s->v_edge_pos= 16*s->mb_height;
1546     }else{
1547         s->first_field ^= 1;
1548         s->v_edge_pos=  8*s->mb_height;
1549         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1550     }
1551
1552     if(s->alternate_scan){
1553         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1554         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1555     }else{
1556         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1557         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1558     }
1559
1560     /* composite display not parsed */
1561     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1562     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1563     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1564     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1565     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1566     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1567     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1568     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1569     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1570 }
1571
1572 static void mpeg_decode_extension(AVCodecContext *avctx,
1573                                   const uint8_t *buf, int buf_size)
1574 {
1575     Mpeg1Context *s1 = avctx->priv_data;
1576     MpegEncContext *s = &s1->mpeg_enc_ctx;
1577     int ext_type;
1578
1579     init_get_bits(&s->gb, buf, buf_size*8);
1580
1581     ext_type = get_bits(&s->gb, 4);
1582     switch(ext_type) {
1583     case 0x1:
1584         mpeg_decode_sequence_extension(s1);
1585         break;
1586     case 0x2:
1587         mpeg_decode_sequence_display_extension(s1);
1588         break;
1589     case 0x3:
1590         mpeg_decode_quant_matrix_extension(s);
1591         break;
1592     case 0x7:
1593         mpeg_decode_picture_display_extension(s1);
1594         break;
1595     case 0x8:
1596         mpeg_decode_picture_coding_extension(s1);
1597         break;
1598     }
1599 }
1600
1601 static void exchange_uv(MpegEncContext *s){
1602     short * tmp = s->pblocks[4];
1603     s->pblocks[4] = s->pblocks[5];
1604     s->pblocks[5] = tmp;
1605 }
1606
1607 static int mpeg_field_start(MpegEncContext *s){
1608     AVCodecContext *avctx= s->avctx;
1609     Mpeg1Context *s1 = (Mpeg1Context*)s;
1610
1611     /* start frame decoding */
1612     if(s->first_field || s->picture_structure==PICT_FRAME){
1613         if(MPV_frame_start(s, avctx) < 0)
1614             return -1;
1615
1616         ff_er_frame_start(s);
1617
1618         /* first check if we must repeat the frame */
1619         s->current_picture_ptr->repeat_pict = 0;
1620         if (s->repeat_first_field) {
1621             if (s->progressive_sequence) {
1622                 if (s->top_field_first)
1623                     s->current_picture_ptr->repeat_pict = 4;
1624                 else
1625                     s->current_picture_ptr->repeat_pict = 2;
1626             } else if (s->progressive_frame) {
1627                 s->current_picture_ptr->repeat_pict = 1;
1628             }
1629         }
1630
1631         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1632     }else{ //second field
1633             int i;
1634
1635             if(!s->current_picture_ptr){
1636                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1637                 return -1;
1638             }
1639
1640             for(i=0; i<4; i++){
1641                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1642                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1643                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1644                 }
1645             }
1646     }
1647 #if CONFIG_XVMC
1648 // MPV_frame_start will call this function too,
1649 // but we need to call it on every field
1650     if(s->avctx->xvmc_acceleration)
1651          XVMC_field_start(s,avctx);
1652 #endif
1653
1654     return 0;
1655 }
1656
1657 #define DECODE_SLICE_ERROR -1
1658 #define DECODE_SLICE_OK 0
1659
1660 /**
1661  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1662  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1663  *         DECODE_SLICE_OK if this slice is ok<br>
1664  */
1665 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1666                              const uint8_t **buf, int buf_size)
1667 {
1668     MpegEncContext *s = &s1->mpeg_enc_ctx;
1669     AVCodecContext *avctx= s->avctx;
1670     const int field_pic= s->picture_structure != PICT_FRAME;
1671     const int lowres= s->avctx->lowres;
1672
1673     s->resync_mb_x=
1674     s->resync_mb_y= -1;
1675
1676     if (mb_y<<field_pic >= s->mb_height){
1677         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1678         return -1;
1679     }
1680
1681     init_get_bits(&s->gb, *buf, buf_size*8);
1682
1683     ff_mpeg1_clean_buffers(s);
1684     s->interlaced_dct = 0;
1685
1686     s->qscale = get_qscale(s);
1687
1688     if(s->qscale == 0){
1689         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1690         return -1;
1691     }
1692
1693     /* extra slice info */
1694     while (get_bits1(&s->gb) != 0) {
1695         skip_bits(&s->gb, 8);
1696     }
1697
1698     s->mb_x=0;
1699
1700     for(;;) {
1701         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1702         if (code < 0){
1703             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1704             return -1;
1705         }
1706         if (code >= 33) {
1707             if (code == 33) {
1708                 s->mb_x += 33;
1709             }
1710             /* otherwise, stuffing, nothing to do */
1711         } else {
1712             s->mb_x += code;
1713             break;
1714         }
1715     }
1716     if(s->mb_x >= (unsigned)s->mb_width){
1717         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1718         return -1;
1719     }
1720
1721     s->resync_mb_x= s->mb_x;
1722     s->resync_mb_y= s->mb_y= mb_y;
1723     s->mb_skip_run= 0;
1724     ff_init_block_index(s);
1725
1726     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1727         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1728              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",
1729                  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],
1730                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
1731                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1732                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1733                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1734         }
1735     }
1736
1737     for(;;) {
1738 #if CONFIG_XVMC
1739         //If 1, we memcpy blocks in xvmcvideo.
1740         if(s->avctx->xvmc_acceleration > 1)
1741             XVMC_init_block(s);//set s->block
1742 #endif
1743
1744         if(mpeg_decode_mb(s, s->block) < 0)
1745             return -1;
1746
1747         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1748             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1749             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1750             int motion_x, motion_y, dir, i;
1751             if(field_pic && !s->first_field)
1752                 xy += wrap/2;
1753
1754             for(i=0; i<2; i++){
1755                 for(dir=0; dir<2; dir++){
1756                     if (s->mb_intra || (dir==1 && s->pict_type != FF_B_TYPE)) {
1757                         motion_x = motion_y = 0;
1758                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1759                         motion_x = s->mv[dir][0][0];
1760                         motion_y = s->mv[dir][0][1];
1761                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1762                         motion_x = s->mv[dir][i][0];
1763                         motion_y = s->mv[dir][i][1];
1764                     }
1765
1766                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1767                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1768                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1769                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1770                     s->current_picture.ref_index [dir][xy    ]=
1771                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1772                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1773                 }
1774                 xy += wrap;
1775             }
1776         }
1777
1778         s->dest[0] += 16 >> lowres;
1779         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1780         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1781
1782         MPV_decode_mb(s, s->block);
1783
1784         if (++s->mb_x >= s->mb_width) {
1785             const int mb_size= 16>>s->avctx->lowres;
1786
1787             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1788
1789             s->mb_x = 0;
1790             s->mb_y++;
1791
1792             if(s->mb_y<<field_pic >= s->mb_height){
1793                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1794                 int is_d10= s->chroma_format==2 && s->pict_type==FF_I_TYPE && avctx->profile==0 && avctx->level==5
1795                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1796                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1797
1798                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1799                    || (avctx->error_recognition >= FF_ER_AGGRESSIVE && left>8)){
1800                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1801                     return -1;
1802                 }else
1803                     goto eos;
1804             }
1805
1806             ff_init_block_index(s);
1807         }
1808
1809         /* skip mb handling */
1810         if (s->mb_skip_run == -1) {
1811             /* read increment again */
1812             s->mb_skip_run = 0;
1813             for(;;) {
1814                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1815                 if (code < 0){
1816                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1817                     return -1;
1818                 }
1819                 if (code >= 33) {
1820                     if (code == 33) {
1821                         s->mb_skip_run += 33;
1822                     }else if(code == 35){
1823                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1824                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1825                             return -1;
1826                         }
1827                         goto eos; /* end of slice */
1828                     }
1829                     /* otherwise, stuffing, nothing to do */
1830                 } else {
1831                     s->mb_skip_run += code;
1832                     break;
1833                 }
1834             }
1835             if(s->mb_skip_run){
1836                 int i;
1837                 if(s->pict_type == FF_I_TYPE){
1838                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1839                     return -1;
1840                 }
1841
1842                 /* skip mb */
1843                 s->mb_intra = 0;
1844                 for(i=0;i<12;i++)
1845                     s->block_last_index[i] = -1;
1846                 if(s->picture_structure == PICT_FRAME)
1847                     s->mv_type = MV_TYPE_16X16;
1848                 else
1849                     s->mv_type = MV_TYPE_FIELD;
1850                 if (s->pict_type == FF_P_TYPE) {
1851                     /* if P type, zero motion vector is implied */
1852                     s->mv_dir = MV_DIR_FORWARD;
1853                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1854                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1855                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1856                     s->field_select[0][0]= s->picture_structure - 1;
1857                 } else {
1858                     /* if B type, reuse previous vectors and directions */
1859                     s->mv[0][0][0] = s->last_mv[0][0][0];
1860                     s->mv[0][0][1] = s->last_mv[0][0][1];
1861                     s->mv[1][0][0] = s->last_mv[1][0][0];
1862                     s->mv[1][0][1] = s->last_mv[1][0][1];
1863                 }
1864             }
1865         }
1866     }
1867 eos: // end of slice
1868     *buf += (get_bits_count(&s->gb)-1)/8;
1869 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1870     return 0;
1871 }
1872
1873 static int slice_decode_thread(AVCodecContext *c, void *arg){
1874     MpegEncContext *s= *(void**)arg;
1875     const uint8_t *buf= s->gb.buffer;
1876     int mb_y= s->start_mb_y;
1877
1878     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1879
1880     for(;;){
1881         uint32_t start_code;
1882         int ret;
1883
1884         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1885         emms_c();
1886 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1887 //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);
1888         if(ret < 0){
1889             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1890                 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);
1891         }else{
1892             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);
1893         }
1894
1895         if(s->mb_y == s->end_mb_y)
1896             return 0;
1897
1898         start_code= -1;
1899         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1900         mb_y= start_code - SLICE_MIN_START_CODE;
1901         if(mb_y < 0 || mb_y >= s->end_mb_y)
1902             return -1;
1903     }
1904
1905     return 0; //not reached
1906 }
1907
1908 /**
1909  * Handles slice ends.
1910  * @return 1 if it seems to be the last slice
1911  */
1912 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1913 {
1914     Mpeg1Context *s1 = avctx->priv_data;
1915     MpegEncContext *s = &s1->mpeg_enc_ctx;
1916
1917     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1918         return 0;
1919
1920 #if CONFIG_XVMC
1921     if(s->avctx->xvmc_acceleration)
1922         XVMC_field_end(s);
1923 #endif
1924     /* end of slice reached */
1925     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1926         /* end of image */
1927
1928         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1929
1930         ff_er_frame_end(s);
1931
1932         MPV_frame_end(s);
1933
1934         if (s->pict_type == FF_B_TYPE || s->low_delay) {
1935             *pict= *(AVFrame*)s->current_picture_ptr;
1936             ff_print_debug_info(s, pict);
1937         } else {
1938             s->picture_number++;
1939             /* latency of 1 frame for I- and P-frames */
1940             /* XXX: use another variable than picture_number */
1941             if (s->last_picture_ptr != NULL) {
1942                 *pict= *(AVFrame*)s->last_picture_ptr;
1943                  ff_print_debug_info(s, pict);
1944             }
1945         }
1946
1947         return 1;
1948     } else {
1949         return 0;
1950     }
1951 }
1952
1953 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1954                                  const uint8_t *buf, int buf_size)
1955 {
1956     Mpeg1Context *s1 = avctx->priv_data;
1957     MpegEncContext *s = &s1->mpeg_enc_ctx;
1958     int width,height;
1959     int i, v, j;
1960
1961     init_get_bits(&s->gb, buf, buf_size*8);
1962
1963     width = get_bits(&s->gb, 12);
1964     height = get_bits(&s->gb, 12);
1965     if (width <= 0 || height <= 0)
1966         return -1;
1967     s->aspect_ratio_info= get_bits(&s->gb, 4);
1968     if (s->aspect_ratio_info == 0) {
1969         av_log(avctx, AV_LOG_ERROR, "aspect ratio has forbidden 0 value\n");
1970         if (avctx->error_recognition >= FF_ER_COMPLIANT)
1971             return -1;
1972     }
1973     s->frame_rate_index = get_bits(&s->gb, 4);
1974     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1975         return -1;
1976     s->bit_rate = get_bits(&s->gb, 18) * 400;
1977     if (get_bits1(&s->gb) == 0) /* marker */
1978         return -1;
1979     s->width = width;
1980     s->height = height;
1981
1982     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1983     skip_bits(&s->gb, 1);
1984
1985     /* get matrix */
1986     if (get_bits1(&s->gb)) {
1987         for(i=0;i<64;i++) {
1988             v = get_bits(&s->gb, 8);
1989             if(v==0){
1990                 av_log(s->avctx, AV_LOG_ERROR, "intra matrix damaged\n");
1991                 return -1;
1992             }
1993             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1994             s->intra_matrix[j] = v;
1995             s->chroma_intra_matrix[j] = v;
1996         }
1997 #ifdef DEBUG
1998         dprintf(s->avctx, "intra matrix present\n");
1999         for(i=0;i<64;i++)
2000             dprintf(s->avctx, " %d", s->intra_matrix[s->dsp.idct_permutation[i]]);
2001         dprintf(s->avctx, "\n");
2002 #endif
2003     } else {
2004         for(i=0;i<64;i++) {
2005             j = s->dsp.idct_permutation[i];
2006             v = ff_mpeg1_default_intra_matrix[i];
2007             s->intra_matrix[j] = v;
2008             s->chroma_intra_matrix[j] = v;
2009         }
2010     }
2011     if (get_bits1(&s->gb)) {
2012         for(i=0;i<64;i++) {
2013             v = get_bits(&s->gb, 8);
2014             if(v==0){
2015                 av_log(s->avctx, AV_LOG_ERROR, "inter matrix damaged\n");
2016                 return -1;
2017             }
2018             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
2019             s->inter_matrix[j] = v;
2020             s->chroma_inter_matrix[j] = v;
2021         }
2022 #ifdef DEBUG
2023         dprintf(s->avctx, "non-intra matrix present\n");
2024         for(i=0;i<64;i++)
2025             dprintf(s->avctx, " %d", s->inter_matrix[s->dsp.idct_permutation[i]]);
2026         dprintf(s->avctx, "\n");
2027 #endif
2028     } else {
2029         for(i=0;i<64;i++) {
2030             int j= s->dsp.idct_permutation[i];
2031             v = ff_mpeg1_default_non_intra_matrix[i];
2032             s->inter_matrix[j] = v;
2033             s->chroma_inter_matrix[j] = v;
2034         }
2035     }
2036
2037     if(show_bits(&s->gb, 23) != 0){
2038         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2039         return -1;
2040     }
2041
2042     /* we set MPEG-2 parameters so that it emulates MPEG-1 */
2043     s->progressive_sequence = 1;
2044     s->progressive_frame = 1;
2045     s->picture_structure = PICT_FRAME;
2046     s->frame_pred_frame_dct = 1;
2047     s->chroma_format = 1;
2048     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2049     avctx->sub_id = 1; /* indicates MPEG-1 */
2050     s->out_format = FMT_MPEG1;
2051     s->swap_uv = 0;//AFAIK VCR2 does not have SEQ_HEADER
2052     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2053
2054     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2055         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2056                s->avctx->rc_buffer_size, s->bit_rate);
2057
2058     return 0;
2059 }
2060
2061 static int vcr2_init_sequence(AVCodecContext *avctx)
2062 {
2063     Mpeg1Context *s1 = avctx->priv_data;
2064     MpegEncContext *s = &s1->mpeg_enc_ctx;
2065     int i, v;
2066
2067     /* start new MPEG-1 context decoding */
2068     s->out_format = FMT_MPEG1;
2069     if (s1->mpeg_enc_ctx_allocated) {
2070         MPV_common_end(s);
2071     }
2072     s->width  = avctx->coded_width;
2073     s->height = avctx->coded_height;
2074     avctx->has_b_frames= 0; //true?
2075     s->low_delay= 1;
2076
2077     avctx->pix_fmt = mpeg_get_pixelformat(avctx);
2078
2079     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
2080         if( avctx->idct_algo == FF_IDCT_AUTO )
2081             avctx->idct_algo = FF_IDCT_SIMPLE;
2082
2083     if (MPV_common_init(s) < 0)
2084         return -1;
2085     exchange_uv(s);//common init reset pblocks, so we swap them here
2086     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2087     s1->mpeg_enc_ctx_allocated = 1;
2088
2089     for(i=0;i<64;i++) {
2090         int j= s->dsp.idct_permutation[i];
2091         v = ff_mpeg1_default_intra_matrix[i];
2092         s->intra_matrix[j] = v;
2093         s->chroma_intra_matrix[j] = v;
2094
2095         v = ff_mpeg1_default_non_intra_matrix[i];
2096         s->inter_matrix[j] = v;
2097         s->chroma_inter_matrix[j] = v;
2098     }
2099
2100     s->progressive_sequence = 1;
2101     s->progressive_frame = 1;
2102     s->picture_structure = PICT_FRAME;
2103     s->frame_pred_frame_dct = 1;
2104     s->chroma_format = 1;
2105     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2106     avctx->sub_id = 2; /* indicates MPEG-2 */
2107     return 0;
2108 }
2109
2110
2111 static void mpeg_decode_user_data(AVCodecContext *avctx,
2112                                   const uint8_t *buf, int buf_size)
2113 {
2114     const uint8_t *p;
2115     int len, flags;
2116     p = buf;
2117     len = buf_size;
2118
2119     /* we parse the DTG active format information */
2120     if (len >= 5 &&
2121         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2122         flags = p[4];
2123         p += 5;
2124         len -= 5;
2125         if (flags & 0x80) {
2126             /* skip event id */
2127             if (len < 2)
2128                 return;
2129             p += 2;
2130             len -= 2;
2131         }
2132         if (flags & 0x40) {
2133             if (len < 1)
2134                 return;
2135             avctx->dtg_active_format = p[0] & 0x0f;
2136         }
2137     }
2138 }
2139
2140 static void mpeg_decode_gop(AVCodecContext *avctx,
2141                             const uint8_t *buf, int buf_size){
2142     Mpeg1Context *s1 = avctx->priv_data;
2143     MpegEncContext *s = &s1->mpeg_enc_ctx;
2144
2145     int drop_frame_flag;
2146     int time_code_hours, time_code_minutes;
2147     int time_code_seconds, time_code_pictures;
2148     int closed_gop, broken_link;
2149
2150     init_get_bits(&s->gb, buf, buf_size*8);
2151
2152     drop_frame_flag = get_bits1(&s->gb);
2153
2154     time_code_hours=get_bits(&s->gb,5);
2155     time_code_minutes = get_bits(&s->gb,6);
2156     skip_bits1(&s->gb);//marker bit
2157     time_code_seconds = get_bits(&s->gb,6);
2158     time_code_pictures = get_bits(&s->gb,6);
2159
2160     closed_gop  = get_bits1(&s->gb);
2161     /*broken_link indicate that after editing the
2162       reference frames of the first B-Frames after GOP I-Frame
2163       are missing (open gop)*/
2164     broken_link = get_bits1(&s->gb);
2165
2166     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2167         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) closed_gop=%d broken_link=%d\n",
2168             time_code_hours, time_code_minutes, time_code_seconds,
2169             time_code_pictures, closed_gop, broken_link);
2170 }
2171 /**
2172  * Finds the end of the current frame in the bitstream.
2173  * @return the position of the first byte of the next frame, or -1
2174  */
2175 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
2176 {
2177     int i;
2178     uint32_t state= pc->state;
2179
2180     /* EOF considered as end of frame */
2181     if (buf_size == 0)
2182         return 0;
2183
2184 /*
2185  0  frame start         -> 1/4
2186  1  first_SEQEXT        -> 0/2
2187  2  first field start   -> 3/0
2188  3  second_SEQEXT       -> 2/0
2189  4  searching end
2190 */
2191
2192     for(i=0; i<buf_size; i++){
2193         assert(pc->frame_start_found>=0 && pc->frame_start_found<=4);
2194         if(pc->frame_start_found&1){
2195             if(state == EXT_START_CODE && (buf[i]&0xF0) != 0x80)
2196                 pc->frame_start_found--;
2197             else if(state == EXT_START_CODE+2){
2198                 if((buf[i]&3) == 3) pc->frame_start_found= 0;
2199                 else                pc->frame_start_found= (pc->frame_start_found+1)&3;
2200             }
2201             state++;
2202         }else{
2203             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2204             if(pc->frame_start_found==0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2205                 i++;
2206                 pc->frame_start_found=4;
2207             }
2208             if(state == SEQ_END_CODE){
2209                 pc->state=-1;
2210                 return i+1;
2211             }
2212             if(pc->frame_start_found==2 && state == SEQ_START_CODE)
2213                 pc->frame_start_found= 0;
2214             if(pc->frame_start_found<4 && state == EXT_START_CODE)
2215                 pc->frame_start_found++;
2216             if(pc->frame_start_found == 4 && (state&0xFFFFFF00) == 0x100){
2217                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2218                     pc->frame_start_found=0;
2219                     pc->state=-1;
2220                     return i-3;
2221                 }
2222             }
2223         }
2224     }
2225     pc->state= state;
2226     return END_NOT_FOUND;
2227 }
2228
2229 static int decode_chunks(AVCodecContext *avctx,
2230                              AVFrame *picture, int *data_size,
2231                              const uint8_t *buf, int buf_size);
2232
2233 /* handle buffering and image synchronisation */
2234 static int mpeg_decode_frame(AVCodecContext *avctx,
2235                              void *data, int *data_size,
2236                              const uint8_t *buf, int buf_size)
2237 {
2238     Mpeg1Context *s = avctx->priv_data;
2239     AVFrame *picture = data;
2240     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2241     dprintf(avctx, "fill_buffer\n");
2242
2243     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2244         /* special case for last picture */
2245         if (s2->low_delay==0 && s2->next_picture_ptr) {
2246             *picture= *(AVFrame*)s2->next_picture_ptr;
2247             s2->next_picture_ptr= NULL;
2248
2249             *data_size = sizeof(AVFrame);
2250         }
2251         return buf_size;
2252     }
2253
2254     if(s2->flags&CODEC_FLAG_TRUNCATED){
2255         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size);
2256
2257         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2258             return buf_size;
2259     }
2260
2261 #if 0
2262     if (s->repeat_field % 2 == 1) {
2263         s->repeat_field++;
2264         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2265         //        s2->picture_number, s->repeat_field);
2266         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2267             *data_size = sizeof(AVPicture);
2268             goto the_end;
2269         }
2270     }
2271 #endif
2272
2273     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == ff_get_fourcc("VCR2"))
2274         vcr2_init_sequence(avctx);
2275
2276     s->slice_count= 0;
2277
2278     if(avctx->extradata && !avctx->frame_number)
2279         decode_chunks(avctx, picture, data_size, avctx->extradata, avctx->extradata_size);
2280
2281     return decode_chunks(avctx, picture, data_size, buf, buf_size);
2282 }
2283
2284 static int decode_chunks(AVCodecContext *avctx,
2285                              AVFrame *picture, int *data_size,
2286                              const uint8_t *buf, int buf_size)
2287 {
2288     Mpeg1Context *s = avctx->priv_data;
2289     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2290     const uint8_t *buf_ptr = buf;
2291     const uint8_t *buf_end = buf + buf_size;
2292     int ret, input_size;
2293
2294     for(;;) {
2295         /* find next start code */
2296         uint32_t start_code = -1;
2297         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2298         if (start_code > 0x1ff){
2299             if(s2->pict_type != FF_B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2300                 if(avctx->thread_count > 1){
2301                     int i;
2302
2303                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count, sizeof(void*));
2304                     for(i=0; i<s->slice_count; i++)
2305                         s2->error_count += s2->thread_context[i]->error_count;
2306                 }
2307                 if (slice_end(avctx, picture)) {
2308                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2309                         *data_size = sizeof(AVPicture);
2310                 }
2311             }
2312             s2->pict_type= 0;
2313             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2314         }
2315
2316         input_size = buf_end - buf_ptr;
2317
2318         if(avctx->debug & FF_DEBUG_STARTCODE){
2319             av_log(avctx, AV_LOG_DEBUG, "%3X at %td left %d\n", start_code, buf_ptr-buf, input_size);
2320         }
2321
2322         /* prepare data for next start code */
2323         switch(start_code) {
2324         case SEQ_START_CODE:
2325             mpeg1_decode_sequence(avctx, buf_ptr,
2326                                     input_size);
2327             break;
2328
2329         case PICTURE_START_CODE:
2330             /* we have a complete image: we try to decompress it */
2331             if(mpeg1_decode_picture(avctx,
2332                                     buf_ptr, input_size) < 0)
2333                 s2->pict_type=0;
2334             break;
2335         case EXT_START_CODE:
2336             mpeg_decode_extension(avctx,
2337                                     buf_ptr, input_size);
2338             break;
2339         case USER_START_CODE:
2340             mpeg_decode_user_data(avctx,
2341                                     buf_ptr, input_size);
2342             break;
2343         case GOP_START_CODE:
2344             s2->first_field=0;
2345             mpeg_decode_gop(avctx,
2346                                     buf_ptr, input_size);
2347             break;
2348         default:
2349             if (start_code >= SLICE_MIN_START_CODE &&
2350                 start_code <= SLICE_MAX_START_CODE) {
2351                 int mb_y= start_code - SLICE_MIN_START_CODE;
2352
2353                 if(s2->last_picture_ptr==NULL){
2354                 /* Skip B-frames if we do not have reference frames. */
2355                     if(s2->pict_type==FF_B_TYPE) break;
2356                 }
2357                 if(s2->next_picture_ptr==NULL){
2358                 /* Skip P-frames if we do not have a reference frame or we have an invalid header. */
2359                     if(s2->pict_type==FF_P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2360                 }
2361                 /* Skip B-frames if we are in a hurry. */
2362                 if(avctx->hurry_up && s2->pict_type==FF_B_TYPE) break;
2363                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==FF_B_TYPE)
2364                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=FF_I_TYPE)
2365                     || avctx->skip_frame >= AVDISCARD_ALL)
2366                     break;
2367                 /* Skip everything if we are in a hurry>=5. */
2368                 if(avctx->hurry_up>=5) break;
2369
2370                 if (!s->mpeg_enc_ctx_allocated) break;
2371
2372                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2373                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2374                         break;
2375                 }
2376
2377                 if(!s2->pict_type){
2378                     av_log(avctx, AV_LOG_ERROR, "Missing picture start code\n");
2379                     break;
2380                 }
2381
2382                 if(s2->first_slice){
2383                     s2->first_slice=0;
2384                             if(mpeg_field_start(s2) < 0)
2385                         return -1;
2386                     }
2387                 if(!s2->current_picture_ptr){
2388                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2389                     return -1;
2390                 }
2391
2392                 if(avctx->thread_count > 1){
2393                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2394                     if(threshold <= mb_y){
2395                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2396
2397                         thread_context->start_mb_y= mb_y;
2398                         thread_context->end_mb_y  = s2->mb_height;
2399                         if(s->slice_count){
2400                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2401                             ff_update_duplicate_context(thread_context, s2);
2402                         }
2403                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2404                         s->slice_count++;
2405                     }
2406                     buf_ptr += 2; //FIXME add minimum number of bytes per slice
2407                 }else{
2408                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2409                     emms_c();
2410
2411                     if(ret < 0){
2412                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2413                             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);
2414                     }else{
2415                         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);
2416                     }
2417                 }
2418             }
2419             break;
2420         }
2421     }
2422 }
2423
2424 static int mpeg_decode_end(AVCodecContext *avctx)
2425 {
2426     Mpeg1Context *s = avctx->priv_data;
2427
2428     if (s->mpeg_enc_ctx_allocated)
2429         MPV_common_end(&s->mpeg_enc_ctx);
2430     return 0;
2431 }
2432
2433 AVCodec mpeg1video_decoder = {
2434     "mpeg1video",
2435     CODEC_TYPE_VIDEO,
2436     CODEC_ID_MPEG1VIDEO,
2437     sizeof(Mpeg1Context),
2438     mpeg_decode_init,
2439     NULL,
2440     mpeg_decode_end,
2441     mpeg_decode_frame,
2442     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2443     .flush= ff_mpeg_flush,
2444     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2445 };
2446
2447 AVCodec mpeg2video_decoder = {
2448     "mpeg2video",
2449     CODEC_TYPE_VIDEO,
2450     CODEC_ID_MPEG2VIDEO,
2451     sizeof(Mpeg1Context),
2452     mpeg_decode_init,
2453     NULL,
2454     mpeg_decode_end,
2455     mpeg_decode_frame,
2456     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2457     .flush= ff_mpeg_flush,
2458     .long_name= NULL_IF_CONFIG_SMALL("MPEG-2 video"),
2459 };
2460
2461 //legacy decoder
2462 AVCodec mpegvideo_decoder = {
2463     "mpegvideo",
2464     CODEC_TYPE_VIDEO,
2465     CODEC_ID_MPEG2VIDEO,
2466     sizeof(Mpeg1Context),
2467     mpeg_decode_init,
2468     NULL,
2469     mpeg_decode_end,
2470     mpeg_decode_frame,
2471     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2472     .flush= ff_mpeg_flush,
2473     .long_name= NULL_IF_CONFIG_SMALL("MPEG-1 video"),
2474 };
2475
2476 #if CONFIG_XVMC
2477 static av_cold int mpeg_mc_decode_init(AVCodecContext *avctx){
2478     Mpeg1Context *s;
2479
2480     if( avctx->thread_count > 1)
2481         return -1;
2482     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2483         return -1;
2484     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2485         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2486     }
2487     mpeg_decode_init(avctx);
2488     s = avctx->priv_data;
2489
2490     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2491     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2492
2493     return 0;
2494 }
2495
2496 AVCodec mpeg_xvmc_decoder = {
2497     "mpegvideo_xvmc",
2498     CODEC_TYPE_VIDEO,
2499     CODEC_ID_MPEG2VIDEO_XVMC,
2500     sizeof(Mpeg1Context),
2501     mpeg_mc_decode_init,
2502     NULL,
2503     mpeg_decode_end,
2504     mpeg_decode_frame,
2505     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2506     .flush= ff_mpeg_flush,
2507     .long_name = NULL_IF_CONFIG_SMALL("MPEG-1 video XvMC (X-Video Motion Compensation)"),
2508 };
2509
2510 #endif