libavcodec/mpeg12.c

   1 /*
   2  * MPEG1/2 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  * MPEG1/2 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 DC_VLC_BITS 9
  43 #define MV_VLC_BITS 9
  44 #define MBINCR_VLC_BITS 9
  45 #define MB_PAT_VLC_BITS 9
  46 #define MB_PTYPE_VLC_BITS 6
  47 #define MB_BTYPE_VLC_BITS 6
  48 #define TEX_VLC_BITS 9
  49
  50 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
  51                               DCTELEM *block,
  52                               int n);
  53 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
  54                               DCTELEM *block,
  55                               int n);
  56 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n);
  57 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
  58                                         DCTELEM *block,
  59                                         int n);
  60 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
  61                                     DCTELEM *block,
  62                                     int n);
  63 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s, DCTELEM *block, int n);
  64 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  65 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
  66 static void exchange_uv(MpegEncContext *s);
  67
  68 extern int XVMC_field_start(MpegEncContext *s, AVCodecContext *avctx);
  69 extern int XVMC_field_end(MpegEncContext *s);
  70 extern void XVMC_pack_pblocks(MpegEncContext *s,int cbp);
  71 extern void XVMC_init_block(MpegEncContext *s);//set s->block
  72
  73 static const enum PixelFormat pixfmt_yuv_420[]= {PIX_FMT_YUV420P,-1};
  74 static const enum PixelFormat pixfmt_yuv_422[]= {PIX_FMT_YUV422P,-1};
  75 static const enum PixelFormat pixfmt_yuv_444[]= {PIX_FMT_YUV444P,-1};
  76 static const enum PixelFormat pixfmt_xvmc_mpg2_420[] = {
  77                                            PIX_FMT_XVMC_MPEG2_IDCT,
  78                                            PIX_FMT_XVMC_MPEG2_MC,
  79                                            -1};
  80
  81 uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  82
  83 static void init_2d_vlc_rl(RLTable *rl, int use_static)
  84 {
  85     int i;
  86
  87     init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2,
  88              &rl->table_vlc[0][1], 4, 2,
  89              &rl->table_vlc[0][0], 4, 2, use_static);
  90
  91     if(use_static)
  92         rl->rl_vlc[0]= av_mallocz_static(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
  93     else
  94         rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
  95
  96     for(i=0; i<rl->vlc.table_size; i++){
  97         int code= rl->vlc.table[i][0];
  98         int len = rl->vlc.table[i][1];
  99         int level, run;
 100
 101         if(len==0){ // illegal code
 102             run= 65;
 103             level= MAX_LEVEL;
 104         }else if(len<0){ //more bits needed
 105             run= 0;
 106             level= code;
 107         }else{
 108             if(code==rl->n){ //esc
 109                 run= 65;
 110                 level= 0;
 111             }else if(code==rl->n+1){ //eob
 112                 run= 0;
 113                 level= 127;
 114             }else{
 115                 run=   rl->table_run  [code] + 1;
 116                 level= rl->table_level[code];
 117             }
 118         }
 119         rl->rl_vlc[0][i].len= len;
 120         rl->rl_vlc[0][i].level= level;
 121         rl->rl_vlc[0][i].run= run;
 122     }
 123 }
 124
 125 void ff_mpeg12_common_init(MpegEncContext *s)
 126 {
 127
 128     s->y_dc_scale_table=
 129     s->c_dc_scale_table= mpeg2_dc_scale_table[s->intra_dc_precision];
 130
 131 }
 132
 133 void ff_mpeg1_clean_buffers(MpegEncContext *s){
 134     s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
 135     s->last_dc[1] = s->last_dc[0];
 136     s->last_dc[2] = s->last_dc[0];
 137     memset(s->last_mv, 0, sizeof(s->last_mv));
 138 }
 139
 140
 141 /******************************************/
 142 /* decoding */
 143
 144 static VLC dc_lum_vlc;
 145 static VLC dc_chroma_vlc;
 146 static VLC mv_vlc;
 147 static VLC mbincr_vlc;
 148 static VLC mb_ptype_vlc;
 149 static VLC mb_btype_vlc;
 150 static VLC mb_pat_vlc;
 151
 152 static void init_vlcs(void)
 153 {
 154     static int done = 0;
 155
 156     if (!done) {
 157         done = 1;
 158
 159         init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12,
 160                  ff_mpeg12_vlc_dc_lum_bits, 1, 1,
 161                  ff_mpeg12_vlc_dc_lum_code, 2, 2, 1);
 162         init_vlc(&dc_chroma_vlc,  DC_VLC_BITS, 12,
 163                  ff_mpeg12_vlc_dc_chroma_bits, 1, 1,
 164                  ff_mpeg12_vlc_dc_chroma_code, 2, 2, 1);
 165         init_vlc(&mv_vlc, MV_VLC_BITS, 17,
 166                  &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1,
 167                  &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 1);
 168         init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 36,
 169                  &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1,
 170                  &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 1);
 171         init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 64,
 172                  &ff_mpeg12_mbPatTable[0][1], 2, 1,
 173                  &ff_mpeg12_mbPatTable[0][0], 2, 1, 1);
 174
 175         init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
 176                  &table_mb_ptype[0][1], 2, 1,
 177                  &table_mb_ptype[0][0], 2, 1, 1);
 178         init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
 179                  &table_mb_btype[0][1], 2, 1,
 180                  &table_mb_btype[0][0], 2, 1, 1);
 181         init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]);
 182         init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]);
 183
 184         init_2d_vlc_rl(&ff_rl_mpeg1, 1);
 185         init_2d_vlc_rl(&ff_rl_mpeg2, 1);
 186     }
 187 }
 188
 189 static inline int get_dmv(MpegEncContext *s)
 190 {
 191     if(get_bits1(&s->gb))
 192         return 1 - (get_bits1(&s->gb) << 1);
 193     else
 194         return 0;
 195 }
 196
 197 static inline int get_qscale(MpegEncContext *s)
 198 {
 199     int qscale = get_bits(&s->gb, 5);
 200     if (s->q_scale_type) {
 201         return non_linear_qscale[qscale];
 202     } else {
 203         return qscale << 1;
 204     }
 205 }
 206
 207 /* motion type (for mpeg2) */
 208 #define MT_FIELD 1
 209 #define MT_FRAME 2
 210 #define MT_16X8  2
 211 #define MT_DMV   3
 212
 213 static int mpeg_decode_mb(MpegEncContext *s,
 214                           DCTELEM block[12][64])
 215 {
 216     int i, j, k, cbp, val, mb_type, motion_type;
 217     const int mb_block_count = 4 + (1<< s->chroma_format);
 218
 219     dprintf(s->avctx, "decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
 220
 221     assert(s->mb_skipped==0);
 222
 223     if (s->mb_skip_run-- != 0) {
 224         if (s->pict_type == P_TYPE) {
 225             s->mb_skipped = 1;
 226             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
 227         } else {
 228             int mb_type;
 229
 230             if(s->mb_x)
 231                 mb_type= s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1];
 232             else
 233                 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,
 234             if(IS_INTRA(mb_type))
 235                 return -1;
 236
 237             s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
 238                 mb_type | MB_TYPE_SKIP;
 239 //            assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
 240
 241             if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
 242                 s->mb_skipped = 1;
 243         }
 244
 245         return 0;
 246     }
 247
 248     switch(s->pict_type) {
 249     default:
 250     case I_TYPE:
 251         if (get_bits1(&s->gb) == 0) {
 252             if (get_bits1(&s->gb) == 0){
 253                 av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in I Frame at %d %d\n", s->mb_x, s->mb_y);
 254                 return -1;
 255             }
 256             mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
 257         } else {
 258             mb_type = MB_TYPE_INTRA;
 259         }
 260         break;
 261     case P_TYPE:
 262         mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
 263         if (mb_type < 0){
 264             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
 265             return -1;
 266         }
 267         mb_type = ptype2mb_type[ mb_type ];
 268         break;
 269     case B_TYPE:
 270         mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
 271         if (mb_type < 0){
 272             av_log(s->avctx, AV_LOG_ERROR, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
 273             return -1;
 274         }
 275         mb_type = btype2mb_type[ mb_type ];
 276         break;
 277     }
 278     dprintf(s->avctx, "mb_type=%x\n", mb_type);
 279 //    motion_type = 0; /* avoid warning */
 280     if (IS_INTRA(mb_type)) {
 281         s->dsp.clear_blocks(s->block[0]);
 282
 283         if(!s->chroma_y_shift){
 284             s->dsp.clear_blocks(s->block[6]);
 285         }
 286
 287         /* compute dct type */
 288         if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
 289             !s->frame_pred_frame_dct) {
 290             s->interlaced_dct = get_bits1(&s->gb);
 291         }
 292
 293         if (IS_QUANT(mb_type))
 294             s->qscale = get_qscale(s);
 295
 296         if (s->concealment_motion_vectors) {
 297             /* just parse them */
 298             if (s->picture_structure != PICT_FRAME)
 299                 skip_bits1(&s->gb); /* field select */
 300
 301             s->mv[0][0][0]= s->last_mv[0][0][0]= s->last_mv[0][1][0] =
 302                 mpeg_decode_motion(s, s->mpeg_f_code[0][0], s->last_mv[0][0][0]);
 303             s->mv[0][0][1]= s->last_mv[0][0][1]= s->last_mv[0][1][1] =
 304                 mpeg_decode_motion(s, s->mpeg_f_code[0][1], s->last_mv[0][0][1]);
 305
 306             skip_bits1(&s->gb); /* marker */
 307         }else
 308             memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
 309         s->mb_intra = 1;
 310 #ifdef HAVE_XVMC
 311         //one 1 we memcpy blocks in xvmcvideo
 312         if(s->avctx->xvmc_acceleration > 1){
 313             XVMC_pack_pblocks(s,-1);//inter are always full blocks
 314             if(s->swap_uv){
 315                 exchange_uv(s);
 316             }
 317         }
 318 #endif
 319
 320         if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 321             if(s->flags2 & CODEC_FLAG2_FAST){
 322                 for(i=0;i<6;i++) {
 323                     mpeg2_fast_decode_block_intra(s, s->pblocks[i], i);
 324                 }
 325             }else{
 326                 for(i=0;i<mb_block_count;i++) {
 327                     if (mpeg2_decode_block_intra(s, s->pblocks[i], i) < 0)
 328                         return -1;
 329                 }
 330             }
 331         } else {
 332             for(i=0;i<6;i++) {
 333                 if (mpeg1_decode_block_intra(s, s->pblocks[i], i) < 0)
 334                     return -1;
 335             }
 336         }
 337     } else {
 338         if (mb_type & MB_TYPE_ZERO_MV){
 339             assert(mb_type & MB_TYPE_CBP);
 340
 341             s->mv_dir = MV_DIR_FORWARD;
 342             if(s->picture_structure == PICT_FRAME){
 343                 if(!s->frame_pred_frame_dct)
 344                     s->interlaced_dct = get_bits1(&s->gb);
 345                 s->mv_type = MV_TYPE_16X16;
 346             }else{
 347                 s->mv_type = MV_TYPE_FIELD;
 348                 mb_type |= MB_TYPE_INTERLACED;
 349                 s->field_select[0][0]= s->picture_structure - 1;
 350             }
 351
 352             if (IS_QUANT(mb_type))
 353                 s->qscale = get_qscale(s);
 354
 355             s->last_mv[0][0][0] = 0;
 356             s->last_mv[0][0][1] = 0;
 357             s->last_mv[0][1][0] = 0;
 358             s->last_mv[0][1][1] = 0;
 359             s->mv[0][0][0] = 0;
 360             s->mv[0][0][1] = 0;
 361         }else{
 362             assert(mb_type & MB_TYPE_L0L1);
 363 //FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
 364             /* get additional motion vector type */
 365             if (s->frame_pred_frame_dct)
 366                 motion_type = MT_FRAME;
 367             else{
 368                 motion_type = get_bits(&s->gb, 2);
 369                 if (s->picture_structure == PICT_FRAME && HAS_CBP(mb_type))
 370                     s->interlaced_dct = get_bits1(&s->gb);
 371             }
 372
 373             if (IS_QUANT(mb_type))
 374                 s->qscale = get_qscale(s);
 375
 376             /* motion vectors */
 377             s->mv_dir= (mb_type>>13)&3;
 378             dprintf(s->avctx, "motion_type=%d\n", motion_type);
 379             switch(motion_type) {
 380             case MT_FRAME: /* or MT_16X8 */
 381                 if (s->picture_structure == PICT_FRAME) {
 382                     mb_type |= MB_TYPE_16x16;
 383                     s->mv_type = MV_TYPE_16X16;
 384                     for(i=0;i<2;i++) {
 385                         if (USES_LIST(mb_type, i)) {
 386                             /* MT_FRAME */
 387                             s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
 388                                 mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
 389                             s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
 390                                 mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
 391                             /* full_pel: only for mpeg1 */
 392                             if (s->full_pel[i]){
 393                                 s->mv[i][0][0] <<= 1;
 394                                 s->mv[i][0][1] <<= 1;
 395                             }
 396                         }
 397                     }
 398                 } else {
 399                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 400                     s->mv_type = MV_TYPE_16X8;
 401                     for(i=0;i<2;i++) {
 402                         if (USES_LIST(mb_type, i)) {
 403                             /* MT_16X8 */
 404                             for(j=0;j<2;j++) {
 405                                 s->field_select[i][j] = get_bits1(&s->gb);
 406                                 for(k=0;k<2;k++) {
 407                                     val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 408                                                              s->last_mv[i][j][k]);
 409                                     s->last_mv[i][j][k] = val;
 410                                     s->mv[i][j][k] = val;
 411                                 }
 412                             }
 413                         }
 414                     }
 415                 }
 416                 break;
 417             case MT_FIELD:
 418                 s->mv_type = MV_TYPE_FIELD;
 419                 if (s->picture_structure == PICT_FRAME) {
 420                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
 421                     for(i=0;i<2;i++) {
 422                         if (USES_LIST(mb_type, i)) {
 423                             for(j=0;j<2;j++) {
 424                                 s->field_select[i][j] = get_bits1(&s->gb);
 425                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 426                                                          s->last_mv[i][j][0]);
 427                                 s->last_mv[i][j][0] = val;
 428                                 s->mv[i][j][0] = val;
 429                                 dprintf(s->avctx, "fmx=%d\n", val);
 430                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 431                                                          s->last_mv[i][j][1] >> 1);
 432                                 s->last_mv[i][j][1] = val << 1;
 433                                 s->mv[i][j][1] = val;
 434                                 dprintf(s->avctx, "fmy=%d\n", val);
 435                             }
 436                         }
 437                     }
 438                 } else {
 439                     mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 440                     for(i=0;i<2;i++) {
 441                         if (USES_LIST(mb_type, i)) {
 442                             s->field_select[i][0] = get_bits1(&s->gb);
 443                             for(k=0;k<2;k++) {
 444                                 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
 445                                                          s->last_mv[i][0][k]);
 446                                 s->last_mv[i][0][k] = val;
 447                                 s->last_mv[i][1][k] = val;
 448                                 s->mv[i][0][k] = val;
 449                             }
 450                         }
 451                     }
 452                 }
 453                 break;
 454             case MT_DMV:
 455                 s->mv_type = MV_TYPE_DMV;
 456                 for(i=0;i<2;i++) {
 457                     if (USES_LIST(mb_type, i)) {
 458                         int dmx, dmy, mx, my, m;
 459                         mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
 460                                                 s->last_mv[i][0][0]);
 461                         s->last_mv[i][0][0] = mx;
 462                         s->last_mv[i][1][0] = mx;
 463                         dmx = get_dmv(s);
 464                         my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
 465                                                 s->last_mv[i][0][1] >> 1);
 466                         dmy = get_dmv(s);
 467
 468
 469                         s->last_mv[i][0][1] = my<<1;
 470                         s->last_mv[i][1][1] = my<<1;
 471
 472                         s->mv[i][0][0] = mx;
 473                         s->mv[i][0][1] = my;
 474                         s->mv[i][1][0] = mx;//not used
 475                         s->mv[i][1][1] = my;//not used
 476
 477                         if (s->picture_structure == PICT_FRAME) {
 478                             mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
 479
 480                             //m = 1 + 2 * s->top_field_first;
 481                             m = s->top_field_first ? 1 : 3;
 482
 483                             /* top -> top pred */
 484                             s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 485                             s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
 486                             m = 4 - m;
 487                             s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
 488                             s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
 489                         } else {
 490                             mb_type |= MB_TYPE_16x16;
 491
 492                             s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
 493                             s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
 494                             if(s->picture_structure == PICT_TOP_FIELD)
 495                                 s->mv[i][2][1]--;
 496                             else
 497                                 s->mv[i][2][1]++;
 498                         }
 499                     }
 500                 }
 501                 break;
 502             default:
 503                 av_log(s->avctx, AV_LOG_ERROR, "00 motion_type at %d %d\n", s->mb_x, s->mb_y);
 504                 return -1;
 505             }
 506         }
 507
 508         s->mb_intra = 0;
 509         if (HAS_CBP(mb_type)) {
 510             s->dsp.clear_blocks(s->block[0]);
 511
 512             cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
 513             if(mb_block_count > 6){
 514                  cbp<<= mb_block_count-6;
 515                  cbp |= get_bits(&s->gb, mb_block_count-6);
 516                  s->dsp.clear_blocks(s->block[6]);
 517             }
 518             if (cbp <= 0){
 519                 av_log(s->avctx, AV_LOG_ERROR, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
 520                 return -1;
 521             }
 522
 523 #ifdef HAVE_XVMC
 524             //on 1 we memcpy blocks in xvmcvideo
 525             if(s->avctx->xvmc_acceleration > 1){
 526                 XVMC_pack_pblocks(s,cbp);
 527                 if(s->swap_uv){
 528                     exchange_uv(s);
 529                 }
 530             }
 531 #endif
 532
 533             if (s->codec_id == CODEC_ID_MPEG2VIDEO) {
 534                 if(s->flags2 & CODEC_FLAG2_FAST){
 535                     for(i=0;i<6;i++) {
 536                         if(cbp & 32) {
 537                             mpeg2_fast_decode_block_non_intra(s, s->pblocks[i], i);
 538                         } else {
 539                             s->block_last_index[i] = -1;
 540                         }
 541                         cbp+=cbp;
 542                     }
 543                 }else{
 544                     cbp<<= 12-mb_block_count;
 545
 546                     for(i=0;i<mb_block_count;i++) {
 547                         if ( cbp & (1<<11) ) {
 548                             if (mpeg2_decode_block_non_intra(s, s->pblocks[i], i) < 0)
 549                                 return -1;
 550                         } else {
 551                             s->block_last_index[i] = -1;
 552                         }
 553                         cbp+=cbp;
 554                     }
 555                 }
 556             } else {
 557                 if(s->flags2 & CODEC_FLAG2_FAST){
 558                     for(i=0;i<6;i++) {
 559                         if (cbp & 32) {
 560                             mpeg1_fast_decode_block_inter(s, s->pblocks[i], i);
 561                         } else {
 562                             s->block_last_index[i] = -1;
 563                         }
 564                         cbp+=cbp;
 565                     }
 566                 }else{
 567                     for(i=0;i<6;i++) {
 568                         if (cbp & 32) {
 569                             if (mpeg1_decode_block_inter(s, s->pblocks[i], i) < 0)
 570                                 return -1;
 571                         } else {
 572                             s->block_last_index[i] = -1;
 573                         }
 574                         cbp+=cbp;
 575                     }
 576                 }
 577             }
 578         }else{
 579             for(i=0;i<12;i++)
 580                 s->block_last_index[i] = -1;
 581         }
 582     }
 583
 584     s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
 585
 586     return 0;
 587 }
 588
 589 /* as h263, but only 17 codes */
 590 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 591 {
 592     int code, sign, val, l, shift;
 593
 594     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
 595     if (code == 0) {
 596         return pred;
 597     }
 598     if (code < 0) {
 599         return 0xffff;
 600     }
 601
 602     sign = get_bits1(&s->gb);
 603     shift = fcode - 1;
 604     val = code;
 605     if (shift) {
 606         val = (val - 1) << shift;
 607         val |= get_bits(&s->gb, shift);
 608         val++;
 609     }
 610     if (sign)
 611         val = -val;
 612     val += pred;
 613
 614     /* modulo decoding */
 615     l= INT_BIT - 5 - shift;
 616     val = (val<<l)>>l;
 617     return val;
 618 }
 619
 620 static inline int decode_dc(GetBitContext *gb, int component)
 621 {
 622     int code, diff;
 623
 624     if (component == 0) {
 625         code = get_vlc2(gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
 626     } else {
 627         code = get_vlc2(gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
 628     }
 629     if (code < 0){
 630         av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
 631         return 0xffff;
 632     }
 633     if (code == 0) {
 634         diff = 0;
 635     } else {
 636         diff = get_xbits(gb, code);
 637     }
 638     return diff;
 639 }
 640
 641 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
 642                                DCTELEM *block,
 643                                int n)
 644 {
 645     int level, dc, diff, i, j, run;
 646     int component;
 647     RLTable *rl = &ff_rl_mpeg1;
 648     uint8_t * const scantable= s->intra_scantable.permutated;
 649     const uint16_t *quant_matrix= s->intra_matrix;
 650     const int qscale= s->qscale;
 651
 652     /* DC coef */
 653     component = (n <= 3 ? 0 : n - 4 + 1);
 654     diff = decode_dc(&s->gb, component);
 655     if (diff >= 0xffff)
 656         return -1;
 657     dc = s->last_dc[component];
 658     dc += diff;
 659     s->last_dc[component] = dc;
 660     block[0] = dc<<3;
 661     dprintf(s->avctx, "dc=%d diff=%d\n", dc, diff);
 662     i = 0;
 663     {
 664         OPEN_READER(re, &s->gb);
 665         /* now quantify & encode AC coefs */
 666         for(;;) {
 667             UPDATE_CACHE(re, &s->gb);
 668             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 669
 670             if(level == 127){
 671                 break;
 672             } else if(level != 0) {
 673                 i += run;
 674                 j = scantable[i];
 675                 level= (level*qscale*quant_matrix[j])>>4;
 676                 level= (level-1)|1;
 677                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 678                 LAST_SKIP_BITS(re, &s->gb, 1);
 679             } else {
 680                 /* escape */
 681                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 682                 UPDATE_CACHE(re, &s->gb);
 683                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 684                 if (level == -128) {
 685                     level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
 686                 } else if (level == 0) {
 687                     level = SHOW_UBITS(re, &s->gb, 8)      ; LAST_SKIP_BITS(re, &s->gb, 8);
 688                 }
 689                 i += run;
 690                 j = scantable[i];
 691                 if(level<0){
 692                     level= -level;
 693                     level= (level*qscale*quant_matrix[j])>>4;
 694                     level= (level-1)|1;
 695                     level= -level;
 696                 }else{
 697                     level= (level*qscale*quant_matrix[j])>>4;
 698                     level= (level-1)|1;
 699                 }
 700             }
 701             if (i > 63){
 702                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 703                 return -1;
 704             }
 705
 706             block[j] = level;
 707         }
 708         CLOSE_READER(re, &s->gb);
 709     }
 710     s->block_last_index[n] = i;
 711    return 0;
 712 }
 713
 714 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
 715                                DCTELEM *block,
 716                                int n)
 717 {
 718     int level, i, j, run;
 719     RLTable *rl = &ff_rl_mpeg1;
 720     uint8_t * const scantable= s->intra_scantable.permutated;
 721     const uint16_t *quant_matrix= s->inter_matrix;
 722     const int qscale= s->qscale;
 723
 724     {
 725         OPEN_READER(re, &s->gb);
 726         i = -1;
 727         /* special case for the first coef. no need to add a second vlc table */
 728         UPDATE_CACHE(re, &s->gb);
 729         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 730             level= (3*qscale*quant_matrix[0])>>5;
 731             level= (level-1)|1;
 732             if(GET_CACHE(re, &s->gb)&0x40000000)
 733                 level= -level;
 734             block[0] = level;
 735             i++;
 736             SKIP_BITS(re, &s->gb, 2);
 737             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 738                 goto end;
 739         }
 740 #if MIN_CACHE_BITS < 19
 741         UPDATE_CACHE(re, &s->gb);
 742 #endif
 743         /* now quantify & encode AC coefs */
 744         for(;;) {
 745             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 746
 747             if(level != 0) {
 748                 i += run;
 749                 j = scantable[i];
 750                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 751                 level= (level-1)|1;
 752                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 753                 SKIP_BITS(re, &s->gb, 1);
 754             } else {
 755                 /* escape */
 756                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 757                 UPDATE_CACHE(re, &s->gb);
 758                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 759                 if (level == -128) {
 760                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 761                 } else if (level == 0) {
 762                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 763                 }
 764                 i += run;
 765                 j = scantable[i];
 766                 if(level<0){
 767                     level= -level;
 768                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 769                     level= (level-1)|1;
 770                     level= -level;
 771                 }else{
 772                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 773                     level= (level-1)|1;
 774                 }
 775             }
 776             if (i > 63){
 777                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 778                 return -1;
 779             }
 780
 781             block[j] = level;
 782 #if MIN_CACHE_BITS < 19
 783             UPDATE_CACHE(re, &s->gb);
 784 #endif
 785             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 786                 break;
 787 #if MIN_CACHE_BITS >= 19
 788             UPDATE_CACHE(re, &s->gb);
 789 #endif
 790         }
 791 end:
 792         LAST_SKIP_BITS(re, &s->gb, 2);
 793         CLOSE_READER(re, &s->gb);
 794     }
 795     s->block_last_index[n] = i;
 796     return 0;
 797 }
 798
 799 static inline int mpeg1_fast_decode_block_inter(MpegEncContext *s, DCTELEM *block, int n)
 800 {
 801     int level, i, j, run;
 802     RLTable *rl = &ff_rl_mpeg1;
 803     uint8_t * const scantable= s->intra_scantable.permutated;
 804     const int qscale= s->qscale;
 805
 806     {
 807         OPEN_READER(re, &s->gb);
 808         i = -1;
 809         /* special case for the first coef. no need to add a second vlc table */
 810         UPDATE_CACHE(re, &s->gb);
 811         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 812             level= (3*qscale)>>1;
 813             level= (level-1)|1;
 814             if(GET_CACHE(re, &s->gb)&0x40000000)
 815                 level= -level;
 816             block[0] = level;
 817             i++;
 818             SKIP_BITS(re, &s->gb, 2);
 819             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 820                 goto end;
 821         }
 822 #if MIN_CACHE_BITS < 19
 823         UPDATE_CACHE(re, &s->gb);
 824 #endif
 825
 826         /* now quantify & encode AC coefs */
 827         for(;;) {
 828             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 829
 830             if(level != 0) {
 831                 i += run;
 832                 j = scantable[i];
 833                 level= ((level*2+1)*qscale)>>1;
 834                 level= (level-1)|1;
 835                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 836                 SKIP_BITS(re, &s->gb, 1);
 837             } else {
 838                 /* escape */
 839                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 840                 UPDATE_CACHE(re, &s->gb);
 841                 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
 842                 if (level == -128) {
 843                     level = SHOW_UBITS(re, &s->gb, 8) - 256; SKIP_BITS(re, &s->gb, 8);
 844                 } else if (level == 0) {
 845                     level = SHOW_UBITS(re, &s->gb, 8)      ; SKIP_BITS(re, &s->gb, 8);
 846                 }
 847                 i += run;
 848                 j = scantable[i];
 849                 if(level<0){
 850                     level= -level;
 851                     level= ((level*2+1)*qscale)>>1;
 852                     level= (level-1)|1;
 853                     level= -level;
 854                 }else{
 855                     level= ((level*2+1)*qscale)>>1;
 856                     level= (level-1)|1;
 857                 }
 858             }
 859
 860             block[j] = level;
 861 #if MIN_CACHE_BITS < 19
 862             UPDATE_CACHE(re, &s->gb);
 863 #endif
 864             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 865                 break;
 866 #if MIN_CACHE_BITS >= 19
 867             UPDATE_CACHE(re, &s->gb);
 868 #endif
 869         }
 870 end:
 871         LAST_SKIP_BITS(re, &s->gb, 2);
 872         CLOSE_READER(re, &s->gb);
 873     }
 874     s->block_last_index[n] = i;
 875     return 0;
 876 }
 877
 878
 879 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
 880                                DCTELEM *block,
 881                                int n)
 882 {
 883     int level, i, j, run;
 884     RLTable *rl = &ff_rl_mpeg1;
 885     uint8_t * const scantable= s->intra_scantable.permutated;
 886     const uint16_t *quant_matrix;
 887     const int qscale= s->qscale;
 888     int mismatch;
 889
 890     mismatch = 1;
 891
 892     {
 893         OPEN_READER(re, &s->gb);
 894         i = -1;
 895         if (n < 4)
 896             quant_matrix = s->inter_matrix;
 897         else
 898             quant_matrix = s->chroma_inter_matrix;
 899
 900         /* special case for the first coef. no need to add a second vlc table */
 901         UPDATE_CACHE(re, &s->gb);
 902         if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 903             level= (3*qscale*quant_matrix[0])>>5;
 904             if(GET_CACHE(re, &s->gb)&0x40000000)
 905                 level= -level;
 906             block[0] = level;
 907             mismatch ^= level;
 908             i++;
 909             SKIP_BITS(re, &s->gb, 2);
 910             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 911                 goto end;
 912         }
 913 #if MIN_CACHE_BITS < 19
 914         UPDATE_CACHE(re, &s->gb);
 915 #endif
 916
 917         /* now quantify & encode AC coefs */
 918         for(;;) {
 919             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 920
 921             if(level != 0) {
 922                 i += run;
 923                 j = scantable[i];
 924                 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 925                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
 926                 SKIP_BITS(re, &s->gb, 1);
 927             } else {
 928                 /* escape */
 929                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
 930                 UPDATE_CACHE(re, &s->gb);
 931                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
 932
 933                 i += run;
 934                 j = scantable[i];
 935                 if(level<0){
 936                     level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
 937                     level= -level;
 938                 }else{
 939                     level= ((level*2+1)*qscale*quant_matrix[j])>>5;
 940                 }
 941             }
 942             if (i > 63){
 943                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
 944                 return -1;
 945             }
 946
 947             mismatch ^= level;
 948             block[j] = level;
 949 #if MIN_CACHE_BITS < 19
 950             UPDATE_CACHE(re, &s->gb);
 951 #endif
 952             if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 953                 break;
 954 #if MIN_CACHE_BITS >= 19
 955             UPDATE_CACHE(re, &s->gb);
 956 #endif
 957         }
 958 end:
 959         LAST_SKIP_BITS(re, &s->gb, 2);
 960         CLOSE_READER(re, &s->gb);
 961     }
 962     block[63] ^= (mismatch & 1);
 963
 964     s->block_last_index[n] = i;
 965     return 0;
 966 }
 967
 968 static inline int mpeg2_fast_decode_block_non_intra(MpegEncContext *s,
 969                                DCTELEM *block,
 970                                int n)
 971 {
 972     int level, i, j, run;
 973     RLTable *rl = &ff_rl_mpeg1;
 974     uint8_t * const scantable= s->intra_scantable.permutated;
 975     const int qscale= s->qscale;
 976     OPEN_READER(re, &s->gb);
 977     i = -1;
 978
 979     /* special case for the first coef. no need to add a second vlc table */
 980     UPDATE_CACHE(re, &s->gb);
 981     if (((int32_t)GET_CACHE(re, &s->gb)) < 0) {
 982         level= (3*qscale)>>1;
 983         if(GET_CACHE(re, &s->gb)&0x40000000)
 984             level= -level;
 985         block[0] = level;
 986         i++;
 987         SKIP_BITS(re, &s->gb, 2);
 988         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
 989             goto end;
 990     }
 991 #if MIN_CACHE_BITS < 19
 992     UPDATE_CACHE(re, &s->gb);
 993 #endif
 994
 995     /* now quantify & encode AC coefs */
 996     for(;;) {
 997         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
 998
 999         if(level != 0) {
1000             i += run;
1001             j = scantable[i];
1002             level= ((level*2+1)*qscale)>>1;
1003             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1004             SKIP_BITS(re, &s->gb, 1);
1005         } else {
1006             /* escape */
1007             run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1008             UPDATE_CACHE(re, &s->gb);
1009             level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1010
1011             i += run;
1012             j = scantable[i];
1013             if(level<0){
1014                 level= ((-level*2+1)*qscale)>>1;
1015                 level= -level;
1016             }else{
1017                 level= ((level*2+1)*qscale)>>1;
1018             }
1019         }
1020
1021         block[j] = level;
1022 #if MIN_CACHE_BITS < 19
1023         UPDATE_CACHE(re, &s->gb);
1024 #endif
1025         if(((int32_t)GET_CACHE(re, &s->gb)) <= (int32_t)0xBFFFFFFF)
1026             break;
1027 #if MIN_CACHE_BITS >=19
1028         UPDATE_CACHE(re, &s->gb);
1029 #endif
1030     }
1031 end:
1032     LAST_SKIP_BITS(re, &s->gb, 2);
1033     CLOSE_READER(re, &s->gb);
1034     s->block_last_index[n] = i;
1035     return 0;
1036 }
1037
1038
1039 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1040                                DCTELEM *block,
1041                                int n)
1042 {
1043     int level, dc, diff, i, j, run;
1044     int component;
1045     RLTable *rl;
1046     uint8_t * const scantable= s->intra_scantable.permutated;
1047     const uint16_t *quant_matrix;
1048     const int qscale= s->qscale;
1049     int mismatch;
1050
1051     /* DC coef */
1052     if (n < 4){
1053         quant_matrix = s->intra_matrix;
1054         component = 0;
1055     }else{
1056         quant_matrix = s->chroma_intra_matrix;
1057         component = (n&1) + 1;
1058     }
1059     diff = decode_dc(&s->gb, component);
1060     if (diff >= 0xffff)
1061         return -1;
1062     dc = s->last_dc[component];
1063     dc += diff;
1064     s->last_dc[component] = dc;
1065     block[0] = dc << (3 - s->intra_dc_precision);
1066     dprintf(s->avctx, "dc=%d\n", block[0]);
1067     mismatch = block[0] ^ 1;
1068     i = 0;
1069     if (s->intra_vlc_format)
1070         rl = &ff_rl_mpeg2;
1071     else
1072         rl = &ff_rl_mpeg1;
1073
1074     {
1075         OPEN_READER(re, &s->gb);
1076         /* now quantify & encode AC coefs */
1077         for(;;) {
1078             UPDATE_CACHE(re, &s->gb);
1079             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1080
1081             if(level == 127){
1082                 break;
1083             } else if(level != 0) {
1084                 i += run;
1085                 j = scantable[i];
1086                 level= (level*qscale*quant_matrix[j])>>4;
1087                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1088                 LAST_SKIP_BITS(re, &s->gb, 1);
1089             } else {
1090                 /* escape */
1091                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1092                 UPDATE_CACHE(re, &s->gb);
1093                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1094                 i += run;
1095                 j = scantable[i];
1096                 if(level<0){
1097                     level= (-level*qscale*quant_matrix[j])>>4;
1098                     level= -level;
1099                 }else{
1100                     level= (level*qscale*quant_matrix[j])>>4;
1101                 }
1102             }
1103             if (i > 63){
1104                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1105                 return -1;
1106             }
1107
1108             mismatch^= level;
1109             block[j] = level;
1110         }
1111         CLOSE_READER(re, &s->gb);
1112     }
1113     block[63]^= mismatch&1;
1114
1115     s->block_last_index[n] = i;
1116     return 0;
1117 }
1118
1119 static inline int mpeg2_fast_decode_block_intra(MpegEncContext *s,
1120                                DCTELEM *block,
1121                                int n)
1122 {
1123     int level, dc, diff, j, run;
1124     int component;
1125     RLTable *rl;
1126     uint8_t * scantable= s->intra_scantable.permutated;
1127     const uint16_t *quant_matrix;
1128     const int qscale= s->qscale;
1129
1130     /* DC coef */
1131     if (n < 4){
1132         quant_matrix = s->intra_matrix;
1133         component = 0;
1134     }else{
1135         quant_matrix = s->chroma_intra_matrix;
1136         component = (n&1) + 1;
1137     }
1138     diff = decode_dc(&s->gb, component);
1139     if (diff >= 0xffff)
1140         return -1;
1141     dc = s->last_dc[component];
1142     dc += diff;
1143     s->last_dc[component] = dc;
1144     block[0] = dc << (3 - s->intra_dc_precision);
1145     if (s->intra_vlc_format)
1146         rl = &ff_rl_mpeg2;
1147     else
1148         rl = &ff_rl_mpeg1;
1149
1150     {
1151         OPEN_READER(re, &s->gb);
1152         /* now quantify & encode AC coefs */
1153         for(;;) {
1154             UPDATE_CACHE(re, &s->gb);
1155             GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
1156
1157             if(level == 127){
1158                 break;
1159             } else if(level != 0) {
1160                 scantable += run;
1161                 j = *scantable;
1162                 level= (level*qscale*quant_matrix[j])>>4;
1163                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1164                 LAST_SKIP_BITS(re, &s->gb, 1);
1165             } else {
1166                 /* escape */
1167                 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1168                 UPDATE_CACHE(re, &s->gb);
1169                 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1170                 scantable += run;
1171                 j = *scantable;
1172                 if(level<0){
1173                     level= (-level*qscale*quant_matrix[j])>>4;
1174                     level= -level;
1175                 }else{
1176                     level= (level*qscale*quant_matrix[j])>>4;
1177                 }
1178             }
1179
1180             block[j] = level;
1181         }
1182         CLOSE_READER(re, &s->gb);
1183     }
1184
1185     s->block_last_index[n] = scantable - s->intra_scantable.permutated;
1186     return 0;
1187 }
1188
1189 typedef struct Mpeg1Context {
1190     MpegEncContext mpeg_enc_ctx;
1191     int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1192     int repeat_field; /* true if we must repeat the field */
1193     AVPanScan pan_scan; /** some temporary storage for the panscan */
1194     int slice_count;
1195     int swap_uv;//indicate VCR2
1196     int save_aspect_info;
1197     int save_width, save_height;
1198     AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
1199
1200 } Mpeg1Context;
1201
1202 static int mpeg_decode_init(AVCodecContext *avctx)
1203 {
1204     Mpeg1Context *s = avctx->priv_data;
1205     MpegEncContext *s2 = &s->mpeg_enc_ctx;
1206     int i;
1207
1208     //we need some parmutation to store
1209     //matrixes, until MPV_common_init()
1210     //set the real permutatuon
1211     for(i=0;i<64;i++)
1212        s2->dsp.idct_permutation[i]=i;
1213
1214     MPV_decode_defaults(s2);
1215
1216     s->mpeg_enc_ctx.avctx= avctx;
1217     s->mpeg_enc_ctx.flags= avctx->flags;
1218     s->mpeg_enc_ctx.flags2= avctx->flags2;
1219     ff_mpeg12_common_init(&s->mpeg_enc_ctx);
1220     init_vlcs();
1221
1222     s->mpeg_enc_ctx_allocated = 0;
1223     s->mpeg_enc_ctx.picture_number = 0;
1224     s->repeat_field = 0;
1225     s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1226     return 0;
1227 }
1228
1229 static void quant_matrix_rebuild(uint16_t *matrix, const uint8_t *old_perm,
1230                                      const uint8_t *new_perm){
1231     uint16_t temp_matrix[64];
1232     int i;
1233
1234     memcpy(temp_matrix,matrix,64*sizeof(uint16_t));
1235
1236     for(i=0;i<64;i++){
1237         matrix[new_perm[i]] = temp_matrix[old_perm[i]];
1238     }
1239 }
1240
1241 //Call this function when we know all parameters
1242 //it may be called in different places for mpeg1 and mpeg2
1243 static int mpeg_decode_postinit(AVCodecContext *avctx){
1244     Mpeg1Context *s1 = avctx->priv_data;
1245     MpegEncContext *s = &s1->mpeg_enc_ctx;
1246     uint8_t old_permutation[64];
1247
1248     if (
1249         (s1->mpeg_enc_ctx_allocated == 0)||
1250         avctx->coded_width  != s->width ||
1251         avctx->coded_height != s->height||
1252         s1->save_width != s->width ||
1253         s1->save_height != s->height ||
1254         s1->save_aspect_info != s->aspect_ratio_info||
1255         0)
1256     {
1257
1258         if (s1->mpeg_enc_ctx_allocated) {
1259             ParseContext pc= s->parse_context;
1260             s->parse_context.buffer=0;
1261             MPV_common_end(s);
1262             s->parse_context= pc;
1263         }
1264
1265         if( (s->width == 0 )||(s->height == 0))
1266             return -2;
1267
1268         avcodec_set_dimensions(avctx, s->width, s->height);
1269         avctx->bit_rate = s->bit_rate;
1270         s1->save_aspect_info = s->aspect_ratio_info;
1271         s1->save_width = s->width;
1272         s1->save_height = s->height;
1273
1274      //low_delay may be forced, in this case we will have B frames
1275      //that behave like P frames
1276         avctx->has_b_frames = !(s->low_delay);
1277
1278         if(avctx->sub_id==1){//s->codec_id==avctx->codec_id==CODEC_ID
1279             //mpeg1 fps
1280             avctx->time_base.den= ff_frame_rate_tab[s->frame_rate_index].num;
1281             avctx->time_base.num= ff_frame_rate_tab[s->frame_rate_index].den;
1282             //mpeg1 aspect
1283             avctx->sample_aspect_ratio= av_d2q(
1284                     1.0/ff_mpeg1_aspect[s->aspect_ratio_info], 255);
1285
1286         }else{//mpeg2
1287         //mpeg2 fps
1288             av_reduce(
1289                 &s->avctx->time_base.den,
1290                 &s->avctx->time_base.num,
1291                 ff_frame_rate_tab[s->frame_rate_index].num * s1->frame_rate_ext.num,
1292                 ff_frame_rate_tab[s->frame_rate_index].den * s1->frame_rate_ext.den,
1293                 1<<30);
1294         //mpeg2 aspect
1295             if(s->aspect_ratio_info > 1){
1296                 if( (s1->pan_scan.width == 0 )||(s1->pan_scan.height == 0) ){
1297                     s->avctx->sample_aspect_ratio=
1298                         av_div_q(
1299                          ff_mpeg2_aspect[s->aspect_ratio_info],
1300                          (AVRational){s->width, s->height}
1301                          );
1302                 }else{
1303                     s->avctx->sample_aspect_ratio=
1304                         av_div_q(
1305                          ff_mpeg2_aspect[s->aspect_ratio_info],
1306                          (AVRational){s1->pan_scan.width, s1->pan_scan.height}
1307                         );
1308                 }
1309             }else{
1310                 s->avctx->sample_aspect_ratio=
1311                     ff_mpeg2_aspect[s->aspect_ratio_info];
1312             }
1313         }//mpeg2
1314
1315         if(avctx->xvmc_acceleration){
1316             avctx->pix_fmt = avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
1317         }else{
1318             if(s->chroma_format <  2){
1319                 avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_420);
1320             }else
1321             if(s->chroma_format == 2){
1322                 avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_422);
1323             }else
1324             if(s->chroma_format >  2){
1325                 avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_444);
1326             }
1327         }
1328         //until then pix_fmt may be changed right after codec init
1329         if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
1330             if( avctx->idct_algo == FF_IDCT_AUTO )
1331                 avctx->idct_algo = FF_IDCT_SIMPLE;
1332
1333         //quantization matrixes may need reordering
1334         //if dct permutation is changed
1335         memcpy(old_permutation,s->dsp.idct_permutation,64*sizeof(uint8_t));
1336
1337         if (MPV_common_init(s) < 0)
1338             return -2;
1339
1340         quant_matrix_rebuild(s->intra_matrix,       old_permutation,s->dsp.idct_permutation);
1341         quant_matrix_rebuild(s->inter_matrix,       old_permutation,s->dsp.idct_permutation);
1342         quant_matrix_rebuild(s->chroma_intra_matrix,old_permutation,s->dsp.idct_permutation);
1343         quant_matrix_rebuild(s->chroma_inter_matrix,old_permutation,s->dsp.idct_permutation);
1344
1345         s1->mpeg_enc_ctx_allocated = 1;
1346     }
1347     return 0;
1348 }
1349
1350 static int mpeg1_decode_picture(AVCodecContext *avctx,
1351                                 const uint8_t *buf, int buf_size)
1352 {
1353     Mpeg1Context *s1 = avctx->priv_data;
1354     MpegEncContext *s = &s1->mpeg_enc_ctx;
1355     int ref, f_code, vbv_delay;
1356
1357     if(mpeg_decode_postinit(s->avctx) < 0)
1358        return -2;
1359
1360     init_get_bits(&s->gb, buf, buf_size*8);
1361
1362     ref = get_bits(&s->gb, 10); /* temporal ref */
1363     s->pict_type = get_bits(&s->gb, 3);
1364     if(s->pict_type == 0 || s->pict_type > 3)
1365         return -1;
1366
1367     vbv_delay= get_bits(&s->gb, 16);
1368     if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1369         s->full_pel[0] = get_bits1(&s->gb);
1370         f_code = get_bits(&s->gb, 3);
1371         if (f_code == 0 && avctx->error_resilience >= FF_ER_COMPLIANT)
1372             return -1;
1373         s->mpeg_f_code[0][0] = f_code;
1374         s->mpeg_f_code[0][1] = f_code;
1375     }
1376     if (s->pict_type == B_TYPE) {
1377         s->full_pel[1] = get_bits1(&s->gb);
1378         f_code = get_bits(&s->gb, 3);
1379         if (f_code == 0 && avctx->error_resilience >= FF_ER_COMPLIANT)
1380             return -1;
1381         s->mpeg_f_code[1][0] = f_code;
1382         s->mpeg_f_code[1][1] = f_code;
1383     }
1384     s->current_picture.pict_type= s->pict_type;
1385     s->current_picture.key_frame= s->pict_type == I_TYPE;
1386
1387     if(avctx->debug & FF_DEBUG_PICT_INFO)
1388         av_log(avctx, AV_LOG_DEBUG, "vbv_delay %d, ref %d type:%d\n", vbv_delay, ref, s->pict_type);
1389
1390     s->y_dc_scale = 8;
1391     s->c_dc_scale = 8;
1392     s->first_slice = 1;
1393     return 0;
1394 }
1395
1396 static void mpeg_decode_sequence_extension(Mpeg1Context *s1)
1397 {
1398     MpegEncContext *s= &s1->mpeg_enc_ctx;
1399     int horiz_size_ext, vert_size_ext;
1400     int bit_rate_ext;
1401
1402     skip_bits(&s->gb, 1); /* profil and level esc*/
1403     s->avctx->profile= get_bits(&s->gb, 3);
1404     s->avctx->level= get_bits(&s->gb, 4);
1405     s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1406     s->chroma_format = get_bits(&s->gb, 2); /* chroma_format 1=420, 2=422, 3=444 */
1407     horiz_size_ext = get_bits(&s->gb, 2);
1408     vert_size_ext = get_bits(&s->gb, 2);
1409     s->width |= (horiz_size_ext << 12);
1410     s->height |= (vert_size_ext << 12);
1411     bit_rate_ext = get_bits(&s->gb, 12);  /* XXX: handle it */
1412     s->bit_rate += (bit_rate_ext << 18) * 400;
1413     skip_bits1(&s->gb); /* marker */
1414     s->avctx->rc_buffer_size += get_bits(&s->gb, 8)*1024*16<<10;
1415
1416     s->low_delay = get_bits1(&s->gb);
1417     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
1418
1419     s1->frame_rate_ext.num = get_bits(&s->gb, 2)+1;
1420     s1->frame_rate_ext.den = get_bits(&s->gb, 5)+1;
1421
1422     dprintf(s->avctx, "sequence extension\n");
1423     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
1424     s->avctx->sub_id = 2; /* indicates mpeg2 found */
1425
1426     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1427         av_log(s->avctx, AV_LOG_DEBUG, "profile: %d, level: %d vbv buffer: %d, bitrate:%d\n",
1428                s->avctx->profile, s->avctx->level, s->avctx->rc_buffer_size, s->bit_rate);
1429
1430 }
1431
1432 static void mpeg_decode_sequence_display_extension(Mpeg1Context *s1)
1433 {
1434     MpegEncContext *s= &s1->mpeg_enc_ctx;
1435     int color_description, w, h;
1436
1437     skip_bits(&s->gb, 3); /* video format */
1438     color_description= get_bits1(&s->gb);
1439     if(color_description){
1440         skip_bits(&s->gb, 8); /* color primaries */
1441         skip_bits(&s->gb, 8); /* transfer_characteristics */
1442         skip_bits(&s->gb, 8); /* matrix_coefficients */
1443     }
1444     w= get_bits(&s->gb, 14);
1445     skip_bits(&s->gb, 1); //marker
1446     h= get_bits(&s->gb, 14);
1447     skip_bits(&s->gb, 1); //marker
1448
1449     s1->pan_scan.width= 16*w;
1450     s1->pan_scan.height=16*h;
1451
1452     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1453         av_log(s->avctx, AV_LOG_DEBUG, "sde w:%d, h:%d\n", w, h);
1454 }
1455
1456 static void mpeg_decode_picture_display_extension(Mpeg1Context *s1)
1457 {
1458     MpegEncContext *s= &s1->mpeg_enc_ctx;
1459     int i,nofco;
1460
1461     nofco = 1;
1462     if(s->progressive_sequence){
1463         if(s->repeat_first_field){
1464             nofco++;
1465             if(s->top_field_first)
1466                 nofco++;
1467         }
1468     }else{
1469         if(s->picture_structure == PICT_FRAME){
1470             nofco++;
1471             if(s->repeat_first_field)
1472                 nofco++;
1473         }
1474     }
1475     for(i=0; i<nofco; i++){
1476         s1->pan_scan.position[i][0]= get_sbits(&s->gb, 16);
1477         skip_bits(&s->gb, 1); //marker
1478         s1->pan_scan.position[i][1]= get_sbits(&s->gb, 16);
1479         skip_bits(&s->gb, 1); //marker
1480     }
1481
1482     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
1483         av_log(s->avctx, AV_LOG_DEBUG, "pde (%d,%d) (%d,%d) (%d,%d)\n",
1484             s1->pan_scan.position[0][0], s1->pan_scan.position[0][1],
1485             s1->pan_scan.position[1][0], s1->pan_scan.position[1][1],
1486             s1->pan_scan.position[2][0], s1->pan_scan.position[2][1]
1487         );
1488 }
1489
1490 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1491 {
1492     int i, v, j;
1493
1494     dprintf(s->avctx, "matrix extension\n");
1495
1496     if (get_bits1(&s->gb)) {
1497         for(i=0;i<64;i++) {
1498             v = get_bits(&s->gb, 8);
1499             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1500             s->intra_matrix[j] = v;
1501             s->chroma_intra_matrix[j] = v;
1502         }
1503     }
1504     if (get_bits1(&s->gb)) {
1505         for(i=0;i<64;i++) {
1506             v = get_bits(&s->gb, 8);
1507             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1508             s->inter_matrix[j] = v;
1509             s->chroma_inter_matrix[j] = v;
1510         }
1511     }
1512     if (get_bits1(&s->gb)) {
1513         for(i=0;i<64;i++) {
1514             v = get_bits(&s->gb, 8);
1515             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1516             s->chroma_intra_matrix[j] = v;
1517         }
1518     }
1519     if (get_bits1(&s->gb)) {
1520         for(i=0;i<64;i++) {
1521             v = get_bits(&s->gb, 8);
1522             j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1523             s->chroma_inter_matrix[j] = v;
1524         }
1525     }
1526 }
1527
1528 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1529 {
1530     s->full_pel[0] = s->full_pel[1] = 0;
1531     s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1532     s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1533     s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1534     s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1535     s->intra_dc_precision = get_bits(&s->gb, 2);
1536     s->picture_structure = get_bits(&s->gb, 2);
1537     s->top_field_first = get_bits1(&s->gb);
1538     s->frame_pred_frame_dct = get_bits1(&s->gb);
1539     s->concealment_motion_vectors = get_bits1(&s->gb);
1540     s->q_scale_type = get_bits1(&s->gb);
1541     s->intra_vlc_format = get_bits1(&s->gb);
1542     s->alternate_scan = get_bits1(&s->gb);
1543     s->repeat_first_field = get_bits1(&s->gb);
1544     s->chroma_420_type = get_bits1(&s->gb);
1545     s->progressive_frame = get_bits1(&s->gb);
1546
1547     if(s->picture_structure == PICT_FRAME){
1548         s->first_field=0;
1549         s->v_edge_pos= 16*s->mb_height;
1550     }else{
1551         s->first_field ^= 1;
1552         s->v_edge_pos=  8*s->mb_height;
1553         memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
1554     }
1555
1556     if(s->alternate_scan){
1557         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
1558         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
1559     }else{
1560         ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
1561         ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
1562     }
1563
1564     /* composite display not parsed */
1565     dprintf(s->avctx, "intra_dc_precision=%d\n", s->intra_dc_precision);
1566     dprintf(s->avctx, "picture_structure=%d\n", s->picture_structure);
1567     dprintf(s->avctx, "top field first=%d\n", s->top_field_first);
1568     dprintf(s->avctx, "repeat first field=%d\n", s->repeat_first_field);
1569     dprintf(s->avctx, "conceal=%d\n", s->concealment_motion_vectors);
1570     dprintf(s->avctx, "intra_vlc_format=%d\n", s->intra_vlc_format);
1571     dprintf(s->avctx, "alternate_scan=%d\n", s->alternate_scan);
1572     dprintf(s->avctx, "frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1573     dprintf(s->avctx, "progressive_frame=%d\n", s->progressive_frame);
1574 }
1575
1576 static void mpeg_decode_extension(AVCodecContext *avctx,
1577                                   const uint8_t *buf, int buf_size)
1578 {
1579     Mpeg1Context *s1 = avctx->priv_data;
1580     MpegEncContext *s = &s1->mpeg_enc_ctx;
1581     int ext_type;
1582
1583     init_get_bits(&s->gb, buf, buf_size*8);
1584
1585     ext_type = get_bits(&s->gb, 4);
1586     switch(ext_type) {
1587     case 0x1:
1588         mpeg_decode_sequence_extension(s1);
1589         break;
1590     case 0x2:
1591         mpeg_decode_sequence_display_extension(s1);
1592         break;
1593     case 0x3:
1594         mpeg_decode_quant_matrix_extension(s);
1595         break;
1596     case 0x7:
1597         mpeg_decode_picture_display_extension(s1);
1598         break;
1599     case 0x8:
1600         mpeg_decode_picture_coding_extension(s);
1601         break;
1602     }
1603 }
1604
1605 static void exchange_uv(MpegEncContext *s){
1606     short * tmp = s->pblocks[4];
1607     s->pblocks[4] = s->pblocks[5];
1608     s->pblocks[5] = tmp;
1609 }
1610
1611 static int mpeg_field_start(MpegEncContext *s){
1612     AVCodecContext *avctx= s->avctx;
1613     Mpeg1Context *s1 = (Mpeg1Context*)s;
1614
1615     /* start frame decoding */
1616     if(s->first_field || s->picture_structure==PICT_FRAME){
1617         if(MPV_frame_start(s, avctx) < 0)
1618             return -1;
1619
1620         ff_er_frame_start(s);
1621
1622         /* first check if we must repeat the frame */
1623         s->current_picture_ptr->repeat_pict = 0;
1624         if (s->repeat_first_field) {
1625             if (s->progressive_sequence) {
1626                 if (s->top_field_first)
1627                     s->current_picture_ptr->repeat_pict = 4;
1628                 else
1629                     s->current_picture_ptr->repeat_pict = 2;
1630             } else if (s->progressive_frame) {
1631                 s->current_picture_ptr->repeat_pict = 1;
1632             }
1633         }
1634
1635         *s->current_picture_ptr->pan_scan= s1->pan_scan;
1636     }else{ //second field
1637             int i;
1638
1639             if(!s->current_picture_ptr){
1640                 av_log(s->avctx, AV_LOG_ERROR, "first field missing\n");
1641                 return -1;
1642             }
1643
1644             for(i=0; i<4; i++){
1645                 s->current_picture.data[i] = s->current_picture_ptr->data[i];
1646                 if(s->picture_structure == PICT_BOTTOM_FIELD){
1647                     s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
1648                 }
1649             }
1650     }
1651 #ifdef HAVE_XVMC
1652 // MPV_frame_start will call this function too,
1653 // but we need to call it on every field
1654     if(s->avctx->xvmc_acceleration)
1655          XVMC_field_start(s,avctx);
1656 #endif
1657
1658     return 0;
1659 }
1660
1661 #define DECODE_SLICE_ERROR -1
1662 #define DECODE_SLICE_OK 0
1663
1664 /**
1665  * decodes a slice. MpegEncContext.mb_y must be set to the MB row from the startcode
1666  * @return DECODE_SLICE_ERROR if the slice is damaged<br>
1667  *         DECODE_SLICE_OK if this slice is ok<br>
1668  */
1669 static int mpeg_decode_slice(Mpeg1Context *s1, int mb_y,
1670                              const uint8_t **buf, int buf_size)
1671 {
1672     MpegEncContext *s = &s1->mpeg_enc_ctx;
1673     AVCodecContext *avctx= s->avctx;
1674     const int field_pic= s->picture_structure != PICT_FRAME;
1675     const int lowres= s->avctx->lowres;
1676
1677     s->resync_mb_x=
1678     s->resync_mb_y= -1;
1679
1680     if (mb_y<<field_pic >= s->mb_height){
1681         av_log(s->avctx, AV_LOG_ERROR, "slice below image (%d >= %d)\n", mb_y, s->mb_height);
1682         return -1;
1683     }
1684
1685     init_get_bits(&s->gb, *buf, buf_size*8);
1686
1687     ff_mpeg1_clean_buffers(s);
1688     s->interlaced_dct = 0;
1689
1690     s->qscale = get_qscale(s);
1691
1692     if(s->qscale == 0){
1693         av_log(s->avctx, AV_LOG_ERROR, "qscale == 0\n");
1694         return -1;
1695     }
1696
1697     /* extra slice info */
1698     while (get_bits1(&s->gb) != 0) {
1699         skip_bits(&s->gb, 8);
1700     }
1701
1702     s->mb_x=0;
1703
1704     for(;;) {
1705         int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1706         if (code < 0){
1707             av_log(s->avctx, AV_LOG_ERROR, "first mb_incr damaged\n");
1708             return -1;
1709         }
1710         if (code >= 33) {
1711             if (code == 33) {
1712                 s->mb_x += 33;
1713             }
1714             /* otherwise, stuffing, nothing to do */
1715         } else {
1716             s->mb_x += code;
1717             break;
1718         }
1719     }
1720     if(s->mb_x >= (unsigned)s->mb_width){
1721         av_log(s->avctx, AV_LOG_ERROR, "initial skip overflow\n");
1722         return -1;
1723     }
1724
1725     s->resync_mb_x= s->mb_x;
1726     s->resync_mb_y= s->mb_y= mb_y;
1727     s->mb_skip_run= 0;
1728     ff_init_block_index(s);
1729
1730     if (s->mb_y==0 && s->mb_x==0 && (s->first_field || s->picture_structure==PICT_FRAME)) {
1731         if(s->avctx->debug&FF_DEBUG_PICT_INFO){
1732              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",
1733                  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],
1734                  s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")),
1735                  s->progressive_sequence ? "ps" :"", s->progressive_frame ? "pf" : "", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
1736                  s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
1737                  s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
1738         }
1739     }
1740
1741     for(;;) {
1742 #ifdef HAVE_XVMC
1743         //one 1 we memcpy blocks in xvmcvideo
1744         if(s->avctx->xvmc_acceleration > 1)
1745             XVMC_init_block(s);//set s->block
1746 #endif
1747
1748         if(mpeg_decode_mb(s, s->block) < 0)
1749             return -1;
1750
1751         if(s->current_picture.motion_val[0] && !s->encoding){ //note motion_val is normally NULL unless we want to extract the MVs
1752             const int wrap = field_pic ? 2*s->b8_stride : s->b8_stride;
1753             int xy = s->mb_x*2 + s->mb_y*2*wrap;
1754             int motion_x, motion_y, dir, i;
1755             if(field_pic && !s->first_field)
1756                 xy += wrap/2;
1757
1758             for(i=0; i<2; i++){
1759                 for(dir=0; dir<2; dir++){
1760                     if (s->mb_intra || (dir==1 && s->pict_type != B_TYPE)) {
1761                         motion_x = motion_y = 0;
1762                     }else if (s->mv_type == MV_TYPE_16X16 || (s->mv_type == MV_TYPE_FIELD && field_pic)){
1763                         motion_x = s->mv[dir][0][0];
1764                         motion_y = s->mv[dir][0][1];
1765                     } else /*if ((s->mv_type == MV_TYPE_FIELD) || (s->mv_type == MV_TYPE_16X8))*/ {
1766                         motion_x = s->mv[dir][i][0];
1767                         motion_y = s->mv[dir][i][1];
1768                     }
1769
1770                     s->current_picture.motion_val[dir][xy    ][0] = motion_x;
1771                     s->current_picture.motion_val[dir][xy    ][1] = motion_y;
1772                     s->current_picture.motion_val[dir][xy + 1][0] = motion_x;
1773                     s->current_picture.motion_val[dir][xy + 1][1] = motion_y;
1774                     s->current_picture.ref_index [dir][xy    ]=
1775                     s->current_picture.ref_index [dir][xy + 1]= s->field_select[dir][i];
1776                     assert(s->field_select[dir][i]==0 || s->field_select[dir][i]==1);
1777                 }
1778                 xy += wrap;
1779             }
1780         }
1781
1782         s->dest[0] += 16 >> lowres;
1783         s->dest[1] +=(16 >> lowres) >> s->chroma_x_shift;
1784         s->dest[2] +=(16 >> lowres) >> s->chroma_x_shift;
1785
1786         MPV_decode_mb(s, s->block);
1787
1788         if (++s->mb_x >= s->mb_width) {
1789             const int mb_size= 16>>s->avctx->lowres;
1790
1791             ff_draw_horiz_band(s, mb_size*s->mb_y, mb_size);
1792
1793             s->mb_x = 0;
1794             s->mb_y++;
1795
1796             if(s->mb_y<<field_pic >= s->mb_height){
1797                 int left= s->gb.size_in_bits - get_bits_count(&s->gb);
1798                 int is_d10= s->chroma_format==2 && s->pict_type==I_TYPE && avctx->profile==0 && avctx->level==5
1799                             && s->intra_dc_precision == 2 && s->q_scale_type == 1 && s->alternate_scan == 0
1800                             && s->progressive_frame == 0 /* vbv_delay == 0xBBB || 0xE10*/;
1801
1802                 if(left < 0 || (left && show_bits(&s->gb, FFMIN(left, 23)) && !is_d10)
1803                    || (avctx->error_resilience >= FF_ER_AGGRESSIVE && left>8)){
1804                     av_log(avctx, AV_LOG_ERROR, "end mismatch left=%d %0X\n", left, show_bits(&s->gb, FFMIN(left, 23)));
1805                     return -1;
1806                 }else
1807                     goto eos;
1808             }
1809
1810             ff_init_block_index(s);
1811         }
1812
1813         /* skip mb handling */
1814         if (s->mb_skip_run == -1) {
1815             /* read again increment */
1816             s->mb_skip_run = 0;
1817             for(;;) {
1818                 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1819                 if (code < 0){
1820                     av_log(s->avctx, AV_LOG_ERROR, "mb incr damaged\n");
1821                     return -1;
1822                 }
1823                 if (code >= 33) {
1824                     if (code == 33) {
1825                         s->mb_skip_run += 33;
1826                     }else if(code == 35){
1827                         if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
1828                             av_log(s->avctx, AV_LOG_ERROR, "slice mismatch\n");
1829                             return -1;
1830                         }
1831                         goto eos; /* end of slice */
1832                     }
1833                     /* otherwise, stuffing, nothing to do */
1834                 } else {
1835                     s->mb_skip_run += code;
1836                     break;
1837                 }
1838             }
1839             if(s->mb_skip_run){
1840                 int i;
1841                 if(s->pict_type == I_TYPE){
1842                     av_log(s->avctx, AV_LOG_ERROR, "skipped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
1843                     return -1;
1844                 }
1845
1846                 /* skip mb */
1847                 s->mb_intra = 0;
1848                 for(i=0;i<12;i++)
1849                     s->block_last_index[i] = -1;
1850                 if(s->picture_structure == PICT_FRAME)
1851                     s->mv_type = MV_TYPE_16X16;
1852                 else
1853                     s->mv_type = MV_TYPE_FIELD;
1854                 if (s->pict_type == P_TYPE) {
1855                     /* if P type, zero motion vector is implied */
1856                     s->mv_dir = MV_DIR_FORWARD;
1857                     s->mv[0][0][0] = s->mv[0][0][1] = 0;
1858                     s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
1859                     s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
1860                     s->field_select[0][0]= s->picture_structure - 1;
1861                 } else {
1862                     /* if B type, reuse previous vectors and directions */
1863                     s->mv[0][0][0] = s->last_mv[0][0][0];
1864                     s->mv[0][0][1] = s->last_mv[0][0][1];
1865                     s->mv[1][0][0] = s->last_mv[1][0][0];
1866                     s->mv[1][0][1] = s->last_mv[1][0][1];
1867                 }
1868             }
1869         }
1870     }
1871 eos: // end of slice
1872     *buf += get_bits_count(&s->gb)/8 - 1;
1873 //printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
1874     return 0;
1875 }
1876
1877 static int slice_decode_thread(AVCodecContext *c, void *arg){
1878     MpegEncContext *s= arg;
1879     const uint8_t *buf= s->gb.buffer;
1880     int mb_y= s->start_mb_y;
1881
1882     s->error_count= 3*(s->end_mb_y - s->start_mb_y)*s->mb_width;
1883
1884     for(;;){
1885         uint32_t start_code;
1886         int ret;
1887
1888         ret= mpeg_decode_slice((Mpeg1Context*)s, mb_y, &buf, s->gb.buffer_end - buf);
1889         emms_c();
1890 //av_log(c, AV_LOG_DEBUG, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
1891 //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);
1892         if(ret < 0){
1893             if(s->resync_mb_x>=0 && s->resync_mb_y>=0)
1894                 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);
1895         }else{
1896             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);
1897         }
1898
1899         if(s->mb_y == s->end_mb_y)
1900             return 0;
1901
1902         start_code= -1;
1903         buf = ff_find_start_code(buf, s->gb.buffer_end, &start_code);
1904         mb_y= start_code - SLICE_MIN_START_CODE;
1905         if(mb_y < 0 || mb_y >= s->end_mb_y)
1906             return -1;
1907     }
1908
1909     return 0; //not reached
1910 }
1911
1912 /**
1913  * handles slice ends.
1914  * @return 1 if it seems to be the last slice of
1915  */
1916 static int slice_end(AVCodecContext *avctx, AVFrame *pict)
1917 {
1918     Mpeg1Context *s1 = avctx->priv_data;
1919     MpegEncContext *s = &s1->mpeg_enc_ctx;
1920
1921     if (!s1->mpeg_enc_ctx_allocated || !s->current_picture_ptr)
1922         return 0;
1923
1924 #ifdef HAVE_XVMC
1925     if(s->avctx->xvmc_acceleration)
1926         XVMC_field_end(s);
1927 #endif
1928     /* end of slice reached */
1929     if (/*s->mb_y<<field_pic == s->mb_height &&*/ !s->first_field) {
1930         /* end of image */
1931
1932         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
1933
1934         ff_er_frame_end(s);
1935
1936         MPV_frame_end(s);
1937
1938         if (s->pict_type == B_TYPE || s->low_delay) {
1939             *pict= *(AVFrame*)s->current_picture_ptr;
1940             ff_print_debug_info(s, pict);
1941         } else {
1942             s->picture_number++;
1943             /* latency of 1 frame for I and P frames */
1944             /* XXX: use another variable than picture_number */
1945             if (s->last_picture_ptr != NULL) {
1946                 *pict= *(AVFrame*)s->last_picture_ptr;
1947                  ff_print_debug_info(s, pict);
1948             }
1949         }
1950
1951         return 1;
1952     } else {
1953         return 0;
1954     }
1955 }
1956
1957 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1958                                  const uint8_t *buf, int buf_size)
1959 {
1960     Mpeg1Context *s1 = avctx->priv_data;
1961     MpegEncContext *s = &s1->mpeg_enc_ctx;
1962     int width,height;
1963     int i, v, j;
1964
1965     init_get_bits(&s->gb, buf, buf_size*8);
1966
1967     width = get_bits(&s->gb, 12);
1968     height = get_bits(&s->gb, 12);
1969     if (width <= 0 || height <= 0 ||
1970         (width % 2) != 0 || (height % 2) != 0)
1971         return -1;
1972     s->aspect_ratio_info= get_bits(&s->gb, 4);
1973     if (s->aspect_ratio_info == 0)
1974         return -1;
1975     s->frame_rate_index = get_bits(&s->gb, 4);
1976     if (s->frame_rate_index == 0 || s->frame_rate_index > 13)
1977         return -1;
1978     s->bit_rate = get_bits(&s->gb, 18) * 400;
1979     if (get_bits1(&s->gb) == 0) /* marker */
1980         return -1;
1981     s->width = width;
1982     s->height = height;
1983
1984     s->avctx->rc_buffer_size= get_bits(&s->gb, 10) * 1024*16;
1985     skip_bits(&s->gb, 1);
1986
1987     /* get matrix */
1988     if (get_bits1(&s->gb)) {
1989         for(i=0;i<64;i++) {
1990             v = get_bits(&s->gb, 8);
1991             if(v==0){
1992                 av_log(s->avctx, AV_LOG_ERROR, "intra matrix damaged\n");
1993                 return -1;
1994             }
1995             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
1996             s->intra_matrix[j] = v;
1997             s->chroma_intra_matrix[j] = v;
1998         }
1999 #ifdef DEBUG
2000         dprintf(s->avctx, "intra matrix present\n");
2001         for(i=0;i<64;i++)
2002             dprintf(s->avctx, " %d", s->intra_matrix[s->dsp.idct_permutation[i]]);
2003         dprintf(s->avctx, "\n");
2004 #endif
2005     } else {
2006         for(i=0;i<64;i++) {
2007             j = s->dsp.idct_permutation[i];
2008             v = ff_mpeg1_default_intra_matrix[i];
2009             s->intra_matrix[j] = v;
2010             s->chroma_intra_matrix[j] = v;
2011         }
2012     }
2013     if (get_bits1(&s->gb)) {
2014         for(i=0;i<64;i++) {
2015             v = get_bits(&s->gb, 8);
2016             if(v==0){
2017                 av_log(s->avctx, AV_LOG_ERROR, "inter matrix damaged\n");
2018                 return -1;
2019             }
2020             j = s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
2021             s->inter_matrix[j] = v;
2022             s->chroma_inter_matrix[j] = v;
2023         }
2024 #ifdef DEBUG
2025         dprintf(s->avctx, "non intra matrix present\n");
2026         for(i=0;i<64;i++)
2027             dprintf(s->avctx, " %d", s->inter_matrix[s->dsp.idct_permutation[i]]);
2028         dprintf(s->avctx, "\n");
2029 #endif
2030     } else {
2031         for(i=0;i<64;i++) {
2032             int j= s->dsp.idct_permutation[i];
2033             v = ff_mpeg1_default_non_intra_matrix[i];
2034             s->inter_matrix[j] = v;
2035             s->chroma_inter_matrix[j] = v;
2036         }
2037     }
2038
2039     if(show_bits(&s->gb, 23) != 0){
2040         av_log(s->avctx, AV_LOG_ERROR, "sequence header damaged\n");
2041         return -1;
2042     }
2043
2044     /* we set mpeg2 parameters so that it emulates mpeg1 */
2045     s->progressive_sequence = 1;
2046     s->progressive_frame = 1;
2047     s->picture_structure = PICT_FRAME;
2048     s->frame_pred_frame_dct = 1;
2049     s->chroma_format = 1;
2050     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG1VIDEO;
2051     avctx->sub_id = 1; /* indicates mpeg1 */
2052     s->out_format = FMT_MPEG1;
2053     s->swap_uv = 0;//AFAIK VCR2 don't have SEQ_HEADER
2054     if(s->flags & CODEC_FLAG_LOW_DELAY) s->low_delay=1;
2055
2056     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2057         av_log(s->avctx, AV_LOG_DEBUG, "vbv buffer: %d, bitrate:%d\n",
2058                s->avctx->rc_buffer_size, s->bit_rate);
2059
2060     return 0;
2061 }
2062
2063 static int vcr2_init_sequence(AVCodecContext *avctx)
2064 {
2065     Mpeg1Context *s1 = avctx->priv_data;
2066     MpegEncContext *s = &s1->mpeg_enc_ctx;
2067     int i, v;
2068
2069     /* start new mpeg1 context decoding */
2070     s->out_format = FMT_MPEG1;
2071     if (s1->mpeg_enc_ctx_allocated) {
2072         MPV_common_end(s);
2073     }
2074     s->width  = avctx->coded_width;
2075     s->height = avctx->coded_height;
2076     avctx->has_b_frames= 0; //true?
2077     s->low_delay= 1;
2078
2079     if(avctx->xvmc_acceleration){
2080         avctx->pix_fmt = avctx->get_format(avctx,pixfmt_xvmc_mpg2_420);
2081     }else{
2082         avctx->pix_fmt = avctx->get_format(avctx,pixfmt_yuv_420);
2083     }
2084
2085     if( avctx->pix_fmt == PIX_FMT_XVMC_MPEG2_IDCT )
2086         if( avctx->idct_algo == FF_IDCT_AUTO )
2087             avctx->idct_algo = FF_IDCT_SIMPLE;
2088
2089     if (MPV_common_init(s) < 0)
2090         return -1;
2091     exchange_uv(s);//common init reset pblocks, so we swap them here
2092     s->swap_uv = 1;// in case of xvmc we need to swap uv for each MB
2093     s1->mpeg_enc_ctx_allocated = 1;
2094
2095     for(i=0;i<64;i++) {
2096         int j= s->dsp.idct_permutation[i];
2097         v = ff_mpeg1_default_intra_matrix[i];
2098         s->intra_matrix[j] = v;
2099         s->chroma_intra_matrix[j] = v;
2100
2101         v = ff_mpeg1_default_non_intra_matrix[i];
2102         s->inter_matrix[j] = v;
2103         s->chroma_inter_matrix[j] = v;
2104     }
2105
2106     s->progressive_sequence = 1;
2107     s->progressive_frame = 1;
2108     s->picture_structure = PICT_FRAME;
2109     s->frame_pred_frame_dct = 1;
2110     s->chroma_format = 1;
2111     s->codec_id= s->avctx->codec_id= CODEC_ID_MPEG2VIDEO;
2112     avctx->sub_id = 2; /* indicates mpeg2 */
2113     return 0;
2114 }
2115
2116
2117 static void mpeg_decode_user_data(AVCodecContext *avctx,
2118                                   const uint8_t *buf, int buf_size)
2119 {
2120     const uint8_t *p;
2121     int len, flags;
2122     p = buf;
2123     len = buf_size;
2124
2125     /* we parse the DTG active format information */
2126     if (len >= 5 &&
2127         p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
2128         flags = p[4];
2129         p += 5;
2130         len -= 5;
2131         if (flags & 0x80) {
2132             /* skip event id */
2133             if (len < 2)
2134                 return;
2135             p += 2;
2136             len -= 2;
2137         }
2138         if (flags & 0x40) {
2139             if (len < 1)
2140                 return;
2141             avctx->dtg_active_format = p[0] & 0x0f;
2142         }
2143     }
2144 }
2145
2146 static void mpeg_decode_gop(AVCodecContext *avctx,
2147                             const uint8_t *buf, int buf_size){
2148     Mpeg1Context *s1 = avctx->priv_data;
2149     MpegEncContext *s = &s1->mpeg_enc_ctx;
2150
2151     int drop_frame_flag;
2152     int time_code_hours, time_code_minutes;
2153     int time_code_seconds, time_code_pictures;
2154     int broken_link;
2155
2156     init_get_bits(&s->gb, buf, buf_size*8);
2157
2158     drop_frame_flag = get_bits1(&s->gb);
2159
2160     time_code_hours=get_bits(&s->gb,5);
2161     time_code_minutes = get_bits(&s->gb,6);
2162     skip_bits1(&s->gb);//marker bit
2163     time_code_seconds = get_bits(&s->gb,6);
2164     time_code_pictures = get_bits(&s->gb,6);
2165
2166     /*broken_link indicate that after editing the
2167       reference frames of the first B-Frames after GOP I-Frame
2168       are missing (open gop)*/
2169     broken_link = get_bits1(&s->gb);
2170
2171     if(s->avctx->debug & FF_DEBUG_PICT_INFO)
2172         av_log(s->avctx, AV_LOG_DEBUG, "GOP (%2d:%02d:%02d.[%02d]) broken_link=%d\n",
2173             time_code_hours, time_code_minutes, time_code_seconds,
2174             time_code_pictures, broken_link);
2175 }
2176 /**
2177  * finds the end of the current frame in the bitstream.
2178  * @return the position of the first byte of the next frame, or -1
2179  */
2180 int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
2181 {
2182     int i;
2183     uint32_t state= pc->state;
2184
2185     i=0;
2186     if(!pc->frame_start_found){
2187         for(i=0; i<buf_size; i++){
2188             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2189             if(state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
2190                 i++;
2191                 pc->frame_start_found=1;
2192                 break;
2193             }
2194             if(state == SEQ_END_CODE){
2195                 pc->state=-1;
2196                 return i+1;
2197             }
2198         }
2199     }
2200
2201     if(pc->frame_start_found){
2202         /* EOF considered as end of frame */
2203         if (buf_size == 0)
2204             return 0;
2205         for(; i<buf_size; i++){
2206             i= ff_find_start_code(buf+i, buf+buf_size, &state) - buf - 1;
2207             if((state&0xFFFFFF00) == 0x100){
2208                 if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
2209                     pc->frame_start_found=0;
2210                     pc->state=-1;
2211                     return i-3;
2212                 }
2213             }
2214         }
2215     }
2216     pc->state= state;
2217     return END_NOT_FOUND;
2218 }
2219
2220 /* handle buffering and image synchronisation */
2221 static int mpeg_decode_frame(AVCodecContext *avctx,
2222                              void *data, int *data_size,
2223                              uint8_t *buf, int buf_size)
2224 {
2225     Mpeg1Context *s = avctx->priv_data;
2226     const uint8_t *buf_end;
2227     const uint8_t *buf_ptr;
2228     uint32_t start_code;
2229     int ret, input_size;
2230     AVFrame *picture = data;
2231     MpegEncContext *s2 = &s->mpeg_enc_ctx;
2232     dprintf(avctx, "fill_buffer\n");
2233
2234     if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == SEQ_END_CODE)) {
2235         /* special case for last picture */
2236         if (s2->low_delay==0 && s2->next_picture_ptr) {
2237             *picture= *(AVFrame*)s2->next_picture_ptr;
2238             s2->next_picture_ptr= NULL;
2239
2240             *data_size = sizeof(AVFrame);
2241         }
2242         return buf_size;
2243     }
2244
2245     if(s2->flags&CODEC_FLAG_TRUNCATED){
2246         int next= ff_mpeg1_find_frame_end(&s2->parse_context, buf, buf_size);
2247
2248         if( ff_combine_frame(&s2->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
2249             return buf_size;
2250     }
2251
2252     buf_ptr = buf;
2253     buf_end = buf + buf_size;
2254
2255 #if 0
2256     if (s->repeat_field % 2 == 1) {
2257         s->repeat_field++;
2258         //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
2259         //        s2->picture_number, s->repeat_field);
2260         if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
2261             *data_size = sizeof(AVPicture);
2262             goto the_end;
2263         }
2264     }
2265 #endif
2266
2267     if(s->mpeg_enc_ctx_allocated==0 && avctx->codec_tag == ff_get_fourcc("VCR2"))
2268         vcr2_init_sequence(avctx);
2269
2270     s->slice_count= 0;
2271
2272     for(;;) {
2273         /* find start next code */
2274         start_code = -1;
2275         buf_ptr = ff_find_start_code(buf_ptr,buf_end, &start_code);
2276         if (start_code > 0x1ff){
2277             if(s2->pict_type != B_TYPE || avctx->skip_frame <= AVDISCARD_DEFAULT){
2278                 if(avctx->thread_count > 1){
2279                     int i;
2280
2281                     avctx->execute(avctx, slice_decode_thread,  (void**)&(s2->thread_context[0]), NULL, s->slice_count);
2282                     for(i=0; i<s->slice_count; i++)
2283                         s2->error_count += s2->thread_context[i]->error_count;
2284                 }
2285                 if (slice_end(avctx, picture)) {
2286                     if(s2->last_picture_ptr || s2->low_delay) //FIXME merge with the stuff in mpeg_decode_slice
2287                         *data_size = sizeof(AVPicture);
2288                 }
2289             }
2290             return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
2291         }
2292
2293         input_size = buf_end - buf_ptr;
2294
2295         if(avctx->debug & FF_DEBUG_STARTCODE){
2296             av_log(avctx, AV_LOG_DEBUG, "%3X at %zd left %d\n", start_code, buf_ptr-buf, input_size);
2297         }
2298
2299         /* prepare data for next start code */
2300         switch(start_code) {
2301         case SEQ_START_CODE:
2302             mpeg1_decode_sequence(avctx, buf_ptr,
2303                                     input_size);
2304             break;
2305
2306         case PICTURE_START_CODE:
2307             /* we have a complete image : we try to decompress it */
2308             mpeg1_decode_picture(avctx,
2309                                     buf_ptr, input_size);
2310             break;
2311         case EXT_START_CODE:
2312             mpeg_decode_extension(avctx,
2313                                     buf_ptr, input_size);
2314             break;
2315         case USER_START_CODE:
2316             mpeg_decode_user_data(avctx,
2317                                     buf_ptr, input_size);
2318             break;
2319         case GOP_START_CODE:
2320             s2->first_field=0;
2321             mpeg_decode_gop(avctx,
2322                                     buf_ptr, input_size);
2323             break;
2324         default:
2325             if (start_code >= SLICE_MIN_START_CODE &&
2326                 start_code <= SLICE_MAX_START_CODE) {
2327                 int mb_y= start_code - SLICE_MIN_START_CODE;
2328
2329                 if(s2->last_picture_ptr==NULL){
2330                 /* Skip B-frames if we do not have reference frames. */
2331                     if(s2->pict_type==B_TYPE) break;
2332                 }
2333                 if(s2->next_picture_ptr==NULL){
2334                 /* Skip P-frames if we do not have reference frame no valid header. */
2335                     if(s2->pict_type==P_TYPE && (s2->first_field || s2->picture_structure==PICT_FRAME)) break;
2336                 }
2337                 /* Skip B-frames if we are in a hurry. */
2338                 if(avctx->hurry_up && s2->pict_type==B_TYPE) break;
2339                 if(  (avctx->skip_frame >= AVDISCARD_NONREF && s2->pict_type==B_TYPE)
2340                     ||(avctx->skip_frame >= AVDISCARD_NONKEY && s2->pict_type!=I_TYPE)
2341                     || avctx->skip_frame >= AVDISCARD_ALL)
2342                     break;
2343                 /* Skip everything if we are in a hurry>=5. */
2344                 if(avctx->hurry_up>=5) break;
2345
2346                 if (!s->mpeg_enc_ctx_allocated) break;
2347
2348                 if(s2->codec_id == CODEC_ID_MPEG2VIDEO){
2349                     if(mb_y < avctx->skip_top || mb_y >= s2->mb_height - avctx->skip_bottom)
2350                         break;
2351                 }
2352
2353                 if(s2->first_slice){
2354                     s2->first_slice=0;
2355                             if(mpeg_field_start(s2) < 0)
2356                         return -1;
2357                     }
2358                 if(!s2->current_picture_ptr){
2359                     av_log(avctx, AV_LOG_ERROR, "current_picture not initialized\n");
2360                     return -1;
2361                 }
2362
2363                 if(avctx->thread_count > 1){
2364                     int threshold= (s2->mb_height*s->slice_count + avctx->thread_count/2) / avctx->thread_count;
2365                     if(threshold <= mb_y){
2366                         MpegEncContext *thread_context= s2->thread_context[s->slice_count];
2367
2368                         thread_context->start_mb_y= mb_y;
2369                         thread_context->end_mb_y  = s2->mb_height;
2370                         if(s->slice_count){
2371                             s2->thread_context[s->slice_count-1]->end_mb_y= mb_y;
2372                             ff_update_duplicate_context(thread_context, s2);
2373                         }
2374                         init_get_bits(&thread_context->gb, buf_ptr, input_size*8);
2375                         s->slice_count++;
2376                     }
2377                     buf_ptr += 2; //FIXME add minimum num of bytes per slice
2378                 }else{
2379                     ret = mpeg_decode_slice(s, mb_y, &buf_ptr, input_size);
2380                     emms_c();
2381
2382                     if(ret < 0){
2383                         if(s2->resync_mb_x>=0 && s2->resync_mb_y>=0)
2384                             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);
2385                     }else{
2386                         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);
2387                     }
2388                 }
2389             }
2390             break;
2391         }
2392     }
2393 }
2394
2395 static int mpeg_decode_end(AVCodecContext *avctx)
2396 {
2397     Mpeg1Context *s = avctx->priv_data;
2398
2399     if (s->mpeg_enc_ctx_allocated)
2400         MPV_common_end(&s->mpeg_enc_ctx);
2401     return 0;
2402 }
2403
2404 AVCodec mpeg1video_decoder = {
2405     "mpeg1video",
2406     CODEC_TYPE_VIDEO,
2407     CODEC_ID_MPEG1VIDEO,
2408     sizeof(Mpeg1Context),
2409     mpeg_decode_init,
2410     NULL,
2411     mpeg_decode_end,
2412     mpeg_decode_frame,
2413     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2414     .flush= ff_mpeg_flush,
2415 };
2416
2417 AVCodec mpeg2video_decoder = {
2418     "mpeg2video",
2419     CODEC_TYPE_VIDEO,
2420     CODEC_ID_MPEG2VIDEO,
2421     sizeof(Mpeg1Context),
2422     mpeg_decode_init,
2423     NULL,
2424     mpeg_decode_end,
2425     mpeg_decode_frame,
2426     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2427     .flush= ff_mpeg_flush,
2428 };
2429
2430 //legacy decoder
2431 AVCodec mpegvideo_decoder = {
2432     "mpegvideo",
2433     CODEC_TYPE_VIDEO,
2434     CODEC_ID_MPEG2VIDEO,
2435     sizeof(Mpeg1Context),
2436     mpeg_decode_init,
2437     NULL,
2438     mpeg_decode_end,
2439     mpeg_decode_frame,
2440     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
2441     .flush= ff_mpeg_flush,
2442 };
2443
2444 #ifdef HAVE_XVMC
2445 static int mpeg_mc_decode_init(AVCodecContext *avctx){
2446     Mpeg1Context *s;
2447
2448     if( avctx->thread_count > 1)
2449         return -1;
2450     if( !(avctx->slice_flags & SLICE_FLAG_CODED_ORDER) )
2451         return -1;
2452     if( !(avctx->slice_flags & SLICE_FLAG_ALLOW_FIELD) ){
2453         dprintf(avctx, "mpeg12.c: XvMC decoder will work better if SLICE_FLAG_ALLOW_FIELD is set\n");
2454     }
2455     mpeg_decode_init(avctx);
2456     s = avctx->priv_data;
2457
2458     avctx->pix_fmt = PIX_FMT_XVMC_MPEG2_IDCT;
2459     avctx->xvmc_acceleration = 2;//2 - the blocks are packed!
2460
2461     return 0;
2462 }
2463
2464 AVCodec mpeg_xvmc_decoder = {
2465     "mpegvideo_xvmc",
2466     CODEC_TYPE_VIDEO,
2467     CODEC_ID_MPEG2VIDEO_XVMC,
2468     sizeof(Mpeg1Context),
2469     mpeg_mc_decode_init,
2470     NULL,
2471     mpeg_decode_end,
2472     mpeg_decode_frame,
2473     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED| CODEC_CAP_HWACCEL | CODEC_CAP_DELAY,
2474     .flush= ff_mpeg_flush,
2475 };
2476
2477 #endif
2478
2479 /* this is ugly i know, but the alternative is too make
2480    hundreds of vars global and prefix them with ff_mpeg1_
2481    which is far uglier. */
2482 #include "mdec.c"