git.sesse.net Git - ffmpeg/blob - libavcodec/h263dec.c

   1 /*
   2  * H263 decoder
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avcodec.h"
  20 #include "dsputil.h"
  21 #include "mpegvideo.h"
  22
  23 #if 1
  24 #define PRINT_QP(a, b) {}
  25 #else
  26 #define PRINT_QP(a, b) printf(a, b)
  27 #endif
  28
  29 //#define DEBUG
  30 //#define PRINT_FRAME_TIME
  31 #ifdef PRINT_FRAME_TIME
  32 static inline long long rdtsc()
  33 {
  34         long long l;
  35         asm volatile(   "rdtsc\n\t"
  36                 : "=A" (l)
  37         );
  38 //      printf("%d\n", int(l/1000));
  39         return l;
  40 }
  41 #endif
  42
  43 static int h263_decode_init(AVCodecContext *avctx)
  44 {
  45     MpegEncContext *s = avctx->priv_data;
  46
  47     s->avctx = avctx;
  48     s->out_format = FMT_H263;
  49
  50     s->width = avctx->width;
  51     s->height = avctx->height;
  52     s->workaround_bugs= avctx->workaround_bugs;
  53
  54     // set defaults
  55     s->quant_precision=5;
  56     s->progressive_sequence=1;
  57     s->decode_mb= ff_h263_decode_mb;
  58
  59     /* select sub codec */
  60     switch(avctx->codec->id) {
  61     case CODEC_ID_H263:
  62         s->gob_number = 0;
  63         break;
  64     case CODEC_ID_MPEG4:
  65         s->time_increment_bits = 4; /* default value for broken headers */
  66         s->h263_pred = 1;
  67         s->has_b_frames = 1; //default, might be overriden in the vol header during header parsing
  68         break;
  69     case CODEC_ID_MSMPEG4V1:
  70         s->h263_msmpeg4 = 1;
  71         s->h263_pred = 1;
  72         s->msmpeg4_version=1;
  73         break;
  74     case CODEC_ID_MSMPEG4V2:
  75         s->h263_msmpeg4 = 1;
  76         s->h263_pred = 1;
  77         s->msmpeg4_version=2;
  78         break;
  79     case CODEC_ID_MSMPEG4V3:
  80         s->h263_msmpeg4 = 1;
  81         s->h263_pred = 1;
  82         s->msmpeg4_version=3;
  83         break;
  84     case CODEC_ID_WMV1:
  85         s->h263_msmpeg4 = 1;
  86         s->h263_pred = 1;
  87         s->msmpeg4_version=4;
  88         break;
  89     case CODEC_ID_WMV2:
  90         s->h263_msmpeg4 = 1;
  91         s->h263_pred = 1;
  92         s->msmpeg4_version=5;
  93         break;
  94     case CODEC_ID_H263I:
  95         s->h263_intel = 1;
  96         break;
  97     default:
  98         return -1;
  99     }
 100     s->codec_id= avctx->codec->id;
 101
 102     /* for h263, we allocate the images after having read the header */
 103     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 104         if (MPV_common_init(s) < 0)
 105             return -1;
 106
 107     if (s->h263_msmpeg4)
 108         ff_msmpeg4_decode_init(s);
 109     else
 110         h263_decode_init_vlc(s);
 111
 112     return 0;
 113 }
 114
 115 static int h263_decode_end(AVCodecContext *avctx)
 116 {
 117     MpegEncContext *s = avctx->priv_data;
 118
 119     MPV_common_end(s);
 120     return 0;
 121 }
 122
 123 /**
 124  * retunrs the number of bytes consumed for building the current frame
 125  */
 126 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 127     int pos= (get_bits_count(&s->gb)+7)>>3;
 128
 129     if(s->divx_version>=500){
 130         //we would have to scan through the whole buf to handle the weird reordering ...
 131         return buf_size;
 132     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 133         pos -= s->parse_context.last_index;
 134         if(pos<0) pos=0; // padding is not really read so this might be -1
 135         return pos;
 136     }else{
 137         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
 138         if(pos+10>buf_size) pos=buf_size; // oops ;)
 139
 140         return pos;
 141     }
 142 }
 143
 144 static int decode_slice(MpegEncContext *s){
 145     s->last_resync_gb= s->gb;
 146     s->first_slice_line= 1;
 147
 148     s->resync_mb_x= s->mb_x;
 149     s->resync_mb_y= s->mb_y;
 150
 151     s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 152     s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 153
 154     if(s->partitioned_frame){
 155         const int qscale= s->qscale;
 156
 157         if(s->codec_id==CODEC_ID_MPEG4){
 158             if(ff_mpeg4_decode_partitions(s) < 0)
 159                 return -1;
 160         }
 161
 162         /* restore variables which where modified */
 163         s->first_slice_line=1;
 164         s->mb_x= s->resync_mb_x;
 165         s->mb_y= s->resync_mb_y;
 166         s->qscale= qscale;
 167         s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 168         s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 169     }
 170
 171     for(; s->mb_y < s->mb_height; s->mb_y++) {
 172         /* per-row end of slice checks */
 173         if(s->msmpeg4_version){
 174             if(s->resync_mb_y + s->slice_height == s->mb_y){
 175                 const int xy= s->mb_x + s->mb_y*s->mb_width;
 176                 s->error_status_table[xy-1]|= AC_END|DC_END|MV_END;
 177                 return 0;
 178             }
 179         }
 180
 181         if(s->msmpeg4_version==1){
 182             s->last_dc[0]=
 183             s->last_dc[1]=
 184             s->last_dc[2]= 128;
 185         }
 186
 187         ff_init_block_index(s);
 188         for(; s->mb_x < s->mb_width; s->mb_x++) {
 189             int ret;
 190
 191             ff_update_block_index(s);
 192
 193             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 194                 s->first_slice_line=0;
 195             }
 196
 197             /* DCT & quantize */
 198             s->dsp.clear_blocks(s->block[0]);
 199
 200             s->mv_dir = MV_DIR_FORWARD;
 201             s->mv_type = MV_TYPE_16X16;
 202 //            s->mb_skiped = 0;
 203 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 204             ret= s->decode_mb(s, s->block);
 205
 206             PRINT_QP("%2d", s->qscale);
 207             MPV_decode_mb(s, s->block);
 208
 209             if(ret<0){
 210                 const int xy= s->mb_x + s->mb_y*s->mb_width;
 211                 if(ret==SLICE_END){
 212 //printf("%d %d %d %06X\n", s->mb_x, s->mb_y, s->gb.size*8 - get_bits_count(&s->gb), show_bits(&s->gb, 24));
 213                     s->error_status_table[xy]|= AC_END;
 214                     if(!s->partitioned_frame)
 215                         s->error_status_table[xy]|= MV_END|DC_END;
 216
 217                     s->padding_bug_score--;
 218
 219                     if(++s->mb_x >= s->mb_width){
 220                         s->mb_x=0;
 221                         ff_draw_horiz_band(s);
 222                         s->mb_y++;
 223                     }
 224                     return 0;
 225                 }else if(ret==SLICE_NOEND){
 226                     fprintf(stderr,"Slice mismatch at MB: %d\n", xy);
 227                     return -1;
 228                 }
 229                 fprintf(stderr,"Error at MB: %d\n", xy);
 230                 s->error_status_table[xy]|= AC_ERROR;
 231                 if(!s->partitioned_frame)
 232                     s->error_status_table[xy]|= DC_ERROR|MV_ERROR;
 233
 234                 return -1;
 235             }
 236         }
 237
 238         ff_draw_horiz_band(s);
 239
 240         PRINT_QP("%s", "\n");
 241
 242         s->mb_x= 0;
 243     }
 244
 245     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 246
 247     /* try to detect the padding bug */
 248     if(      s->codec_id==CODEC_ID_MPEG4
 249        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 250        &&    s->gb.size*8 - get_bits_count(&s->gb) >=0
 251        &&    s->gb.size*8 - get_bits_count(&s->gb) < 48
 252        &&   !s->resync_marker
 253        &&   !s->data_partitioning){
 254
 255         const int bits_count= get_bits_count(&s->gb);
 256         const int bits_left = s->gb.size*8 - bits_count;
 257
 258         if(bits_left==0 || bits_left>8){
 259             s->padding_bug_score++;
 260         } else if(bits_left != 1){
 261             int v= show_bits(&s->gb, 8);
 262             v|= 0x7F >> (7-(bits_count&7));
 263
 264             if(v==0x7F)
 265                 s->padding_bug_score--;
 266             else
 267                 s->padding_bug_score++;
 268         }
 269
 270         if(s->padding_bug_score > -2)
 271             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 272         else
 273             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 274     }
 275
 276     // handle formats which dont have unique end markers
 277     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 278         int left= s->gb.size*8 - get_bits_count(&s->gb);
 279         int max_extra=7;
 280
 281         /* no markers in M$ crap */
 282         if(s->msmpeg4_version && s->pict_type==I_TYPE)
 283             max_extra+= 17;
 284
 285         /* buggy padding but the frame should still end approximately at the bitstream end */
 286         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
 287             max_extra+= 48;
 288         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 289             max_extra+= 256*256*256*64;
 290
 291         if(left>max_extra){
 292             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 293         }
 294         else if(left<0){
 295             fprintf(stderr, "overreading %d bits\n", -left);
 296         }else
 297             s->error_status_table[s->mb_num-1]|= AC_END|MV_END|DC_END;
 298
 299         return 0;
 300     }
 301
 302     fprintf(stderr, "slice end not reached but screenspace end (%d left %06X)\n",
 303             s->gb.size*8 - get_bits_count(&s->gb),
 304             show_bits(&s->gb, 24));
 305     return -1;
 306 }
 307
 308 /**
 309  * finds the end of the current frame in the bitstream.
 310  * @return the position of the first byte of the next frame, or -1
 311  */
 312 static int mpeg4_find_frame_end(MpegEncContext *s, UINT8 *buf, int buf_size){
 313     ParseContext *pc= &s->parse_context;
 314     int vop_found, i;
 315     uint32_t state;
 316
 317     vop_found= pc->frame_start_found;
 318     state= pc->state;
 319
 320     i=0;
 321     if(!vop_found){
 322         for(i=0; i<buf_size; i++){
 323             state= (state<<8) | buf[i];
 324             if(state == 0x1B6){
 325                 i++;
 326                 vop_found=1;
 327                 break;
 328             }
 329         }
 330     }
 331
 332     for(; i<buf_size; i++){
 333         state= (state<<8) | buf[i];
 334         if((state&0xFFFFFF00) == 0x100){
 335             pc->frame_start_found=0;
 336             pc->state=-1;
 337             return i-3;
 338         }
 339     }
 340     pc->frame_start_found= vop_found;
 341     pc->state= state;
 342     return -1;
 343 }
 344
 345 static int h263_decode_frame(AVCodecContext *avctx,
 346                              void *data, int *data_size,
 347                              UINT8 *buf, int buf_size)
 348 {
 349     MpegEncContext *s = avctx->priv_data;
 350     int ret,i;
 351     AVVideoFrame *pict = data;
 352     float new_aspect;
 353
 354 #ifdef PRINT_FRAME_TIME
 355 uint64_t time= rdtsc();
 356 #endif
 357 #ifdef DEBUG
 358     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 359     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 360 #endif
 361     s->flags= avctx->flags;
 362
 363     *data_size = 0;
 364
 365    /* no supplementary picture */
 366     if (buf_size == 0) {
 367         return 0;
 368     }
 369
 370     if(s->flags&CODEC_FLAG_TRUNCATED){
 371         int next;
 372         ParseContext *pc= &s->parse_context;
 373
 374         pc->last_index= pc->index;
 375
 376         if(s->codec_id==CODEC_ID_MPEG4){
 377             next= mpeg4_find_frame_end(s, buf, buf_size);
 378         }else{
 379             fprintf(stderr, "this codec doesnt support truncated bitstreams\n");
 380             return -1;
 381         }
 382         if(next==-1){
 383             if(buf_size + FF_INPUT_BUFFER_PADDING_SIZE + pc->index > pc->buffer_size){
 384                 pc->buffer_size= buf_size + pc->index + 10*1024;
 385                 pc->buffer= realloc(pc->buffer, pc->buffer_size);
 386             }
 387
 388             memcpy(&pc->buffer[pc->index], buf, buf_size);
 389             pc->index += buf_size;
 390             return buf_size;
 391         }
 392
 393         if(pc->index){
 394             if(next + FF_INPUT_BUFFER_PADDING_SIZE + pc->index > pc->buffer_size){
 395                 pc->buffer_size= next + pc->index + 10*1024;
 396                 pc->buffer= realloc(pc->buffer, pc->buffer_size);
 397             }
 398
 399             memcpy(&pc->buffer[pc->index], buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
 400             pc->index = 0;
 401             buf= pc->buffer;
 402             buf_size= pc->last_index + next;
 403         }
 404     }
 405
 406 retry:
 407
 408     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
 409         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size);
 410     }else
 411         init_get_bits(&s->gb, buf, buf_size);
 412     s->bitstream_buffer_size=0;
 413
 414     if (!s->context_initialized) {
 415         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 416             return -1;
 417     }
 418
 419     /* let's go :-) */
 420     if (s->h263_msmpeg4) {
 421         ret = msmpeg4_decode_picture_header(s);
 422     } else if (s->h263_pred) {
 423         if(s->avctx->extradata_size && s->picture_number==0){
 424             GetBitContext gb;
 425
 426             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size);
 427             ret = ff_mpeg4_decode_picture_header(s, &gb);
 428         }
 429         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 430
 431         if(s->flags& CODEC_FLAG_LOW_DELAY)
 432             s->low_delay=1;
 433
 434         s->has_b_frames= !s->low_delay;
 435     } else if (s->h263_intel) {
 436         ret = intel_h263_decode_picture_header(s);
 437     } else {
 438         ret = h263_decode_picture_header(s);
 439     }
 440     avctx->has_b_frames= s->has_b_frames;
 441
 442     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 443         if(s->avctx->fourcc == ff_get_fourcc("XVIX"))
 444             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 445
 446         if(s->avctx->fourcc == ff_get_fourcc("MP4S"))
 447             s->workaround_bugs|= FF_BUG_AC_VLC;
 448
 449         if(s->avctx->fourcc == ff_get_fourcc("M4S2"))
 450             s->workaround_bugs|= FF_BUG_AC_VLC;
 451
 452         if(s->avctx->fourcc == ff_get_fourcc("UMP4")){
 453             s->workaround_bugs|= FF_BUG_UMP4;
 454             s->workaround_bugs|= FF_BUG_AC_VLC;
 455         }
 456
 457         if(s->divx_version){
 458             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 459         }
 460
 461         if(s->avctx->fourcc == ff_get_fourcc("XVID") && s->xvid_build==0)
 462             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 463
 464         if(s->avctx->fourcc == ff_get_fourcc("XVID") && s->xvid_build==0)
 465             s->padding_bug_score= 256*256*256*64;
 466
 467         if(s->xvid_build && s->xvid_build<=1)
 468             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 469
 470 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 471 #if 0
 472         if(s->divx_version==500)
 473             s->workaround_bugs|= FF_BUG_NO_PADDING;
 474
 475         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 476          * lets hope this at least works
 477          */
 478         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 479            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 480             s->workaround_bugs|= FF_BUG_NO_PADDING;
 481
 482         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 483             s->workaround_bugs|= FF_BUG_NO_PADDING;
 484 #endif
 485     }
 486
 487
 488 #if 0 // dump bits per frame / qp / complexity
 489 {
 490     static FILE *f=NULL;
 491     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 492     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 493 }
 494 #endif
 495
 496         /* After H263 & mpeg4 header decode we have the height, width,*/
 497         /* and other parameters. So then we could init the picture   */
 498         /* FIXME: By the way H263 decoder is evolving it should have */
 499         /* an H263EncContext                                         */
 500     if(s->aspected_height)
 501         new_aspect= s->aspected_width*s->width / (float)(s->height*s->aspected_height);
 502     else
 503         new_aspect=0;
 504
 505     if (   s->width != avctx->width || s->height != avctx->height
 506         || ABS(new_aspect - avctx->aspect_ratio) > 0.001) {
 507         /* H.263 could change picture size any time */
 508         MPV_common_end(s);
 509         s->context_initialized=0;
 510     }
 511     if (!s->context_initialized) {
 512         avctx->width = s->width;
 513         avctx->height = s->height;
 514         avctx->aspect_ratio= new_aspect;
 515
 516         goto retry;
 517     }
 518
 519     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 520         s->gob_index = ff_h263_get_gob_height(s);
 521
 522     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 523     /* skip if the header was thrashed */
 524     if (ret < 0){
 525         fprintf(stderr, "header damaged\n");
 526         return -1;
 527     }
 528
 529     // for hurry_up==5
 530     s->current_picture.pict_type= s->pict_type;
 531     s->current_picture.key_frame= s->pict_type == I_TYPE;
 532
 533     /* skip b frames if we dont have reference frames */
 534     if(s->num_available_buffers<2 && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 535     /* skip b frames if we are in a hurry */
 536     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 537     /* skip everything if we are in a hurry>=5 */
 538     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 539
 540     if(s->next_p_frame_damaged){
 541         if(s->pict_type==B_TYPE)
 542             return get_consumed_bytes(s, buf_size);
 543         else
 544             s->next_p_frame_damaged=0;
 545     }
 546
 547     if(MPV_frame_start(s, avctx) < 0)
 548         return -1;
 549
 550 #ifdef DEBUG
 551     printf("qscale=%d\n", s->qscale);
 552 #endif
 553
 554     if(s->error_resilience)
 555         memset(s->error_status_table, MV_ERROR|AC_ERROR|DC_ERROR|VP_START|AC_END|DC_END|MV_END, s->mb_num*sizeof(UINT8));
 556
 557     /* decode each macroblock */
 558     s->block_wrap[0]=
 559     s->block_wrap[1]=
 560     s->block_wrap[2]=
 561     s->block_wrap[3]= s->mb_width*2 + 2;
 562     s->block_wrap[4]=
 563     s->block_wrap[5]= s->mb_width + 2;
 564     s->mb_x=0;
 565     s->mb_y=0;
 566
 567     decode_slice(s);
 568     s->error_status_table[0]|= VP_START;
 569     while(s->mb_y<s->mb_height && s->gb.size*8 - get_bits_count(&s->gb)>16){
 570         if(s->msmpeg4_version){
 571             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0)
 572                 break;
 573         }else{
 574             if(ff_h263_resync(s)<0)
 575                 break;
 576         }
 577
 578         if(s->msmpeg4_version!=4 && s->h263_pred)
 579             ff_mpeg4_clean_buffers(s);
 580
 581         decode_slice(s);
 582
 583         s->error_status_table[s->resync_mb_x + s->resync_mb_y*s->mb_width]|= VP_START;
 584     }
 585
 586     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
 587         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
 588             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 589         }
 590
 591     /* divx 5.01+ bistream reorder stuff */
 592     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_version>=500){
 593         int current_pos= get_bits_count(&s->gb)>>3;
 594
 595         if(   buf_size - current_pos > 5
 596            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 597             int i;
 598             int startcode_found=0;
 599             for(i=current_pos; i<buf_size-3; i++){
 600                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 601                     startcode_found=1;
 602                     break;
 603                 }
 604             }
 605             if(startcode_found){
 606                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 607                 s->bitstream_buffer_size= buf_size - current_pos;
 608             }
 609         }
 610     }
 611
 612     if(s->error_resilience){
 613         int error=0, num_end_markers=0;
 614         for(i=0; i<s->mb_num; i++){
 615             int status= s->error_status_table[i];
 616 #if 0
 617             if(i%s->mb_width == 0) printf("\n");
 618             printf("%2X ", status);
 619 #endif
 620             if(status==0) continue;
 621
 622             if(status&(DC_ERROR|AC_ERROR|MV_ERROR))
 623                 error=1;
 624             if(status&VP_START){
 625                 if(num_end_markers)
 626                     error=1;
 627                 num_end_markers=3;
 628             }
 629             if(status&AC_END)
 630                 num_end_markers--;
 631             if(status&DC_END)
 632                 num_end_markers--;
 633             if(status&MV_END)
 634                 num_end_markers--;
 635         }
 636         if(num_end_markers || error){
 637             fprintf(stderr, "concealing errors\n");
 638 //printf("type:%d\n", s->pict_type);
 639             ff_error_resilience(s);
 640         }
 641     }
 642
 643     MPV_frame_end(s);
 644 #if 0 //dirty show MVs, we should export the MV tables and write a filter to show them
 645 {
 646   int mb_y;
 647   s->has_b_frames=1;
 648   for(mb_y=0; mb_y<s->mb_height; mb_y++){
 649     int mb_x;
 650     int y= mb_y*16 + 8;
 651     for(mb_x=0; mb_x<s->mb_width; mb_x++){
 652       int x= mb_x*16 + 8;
 653       uint8_t *ptr= s->last_picture.data[0];
 654       int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
 655       int mx= (s->motion_val[xy][0]>>1) + x;
 656       int my= (s->motion_val[xy][1]>>1) + y;
 657       int i;
 658       int max;
 659
 660       if(mx<0) mx=0;
 661       if(my<0) my=0;
 662       if(mx>=s->width)  mx= s->width -1;
 663       if(my>=s->height) my= s->height-1;
 664       max= ABS(mx-x);
 665       if(ABS(my-y) > max) max= ABS(my-y);
 666       /* the ugliest linedrawing routine ... */
 667       for(i=0; i<max; i++){
 668         int x1= x + (mx-x)*i/max;
 669         int y1= y + (my-y)*i/max;
 670         ptr[y1*s->linesize + x1]+=100;
 671       }
 672       ptr[y*s->linesize + x]+=100;
 673       s->mbskip_table[mb_x + mb_y*s->mb_width]=0;
 674     }
 675   }
 676
 677 }
 678 #endif
 679     if(s->pict_type==B_TYPE || (!s->has_b_frames)){
 680         *pict= *(AVVideoFrame*)&s->current_picture;
 681     } else {
 682         *pict= *(AVVideoFrame*)&s->last_picture;
 683     }
 684
 685     /* Return the Picture timestamp as the frame number */
 686     /* we substract 1 because it is added on utils.c    */
 687     avctx->frame_number = s->picture_number - 1;
 688
 689     /* dont output the last pic after seeking
 690        note we allready added +1 for the current pix in MPV_frame_end(s) */
 691     if(s->num_available_buffers>=2 || (!s->has_b_frames))
 692         *data_size = sizeof(AVVideoFrame);
 693 #ifdef PRINT_FRAME_TIME
 694 printf("%Ld\n", rdtsc()-time);
 695 #endif
 696     return get_consumed_bytes(s, buf_size);
 697 }
 698
 699 AVCodec mpeg4_decoder = {
 700     "mpeg4",
 701     CODEC_TYPE_VIDEO,
 702     CODEC_ID_MPEG4,
 703     sizeof(MpegEncContext),
 704     h263_decode_init,
 705     NULL,
 706     h263_decode_end,
 707     h263_decode_frame,
 708     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 709 };
 710
 711 AVCodec h263_decoder = {
 712     "h263",
 713     CODEC_TYPE_VIDEO,
 714     CODEC_ID_H263,
 715     sizeof(MpegEncContext),
 716     h263_decode_init,
 717     NULL,
 718     h263_decode_end,
 719     h263_decode_frame,
 720     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 721 };
 722
 723 AVCodec msmpeg4v1_decoder = {
 724     "msmpeg4v1",
 725     CODEC_TYPE_VIDEO,
 726     CODEC_ID_MSMPEG4V1,
 727     sizeof(MpegEncContext),
 728     h263_decode_init,
 729     NULL,
 730     h263_decode_end,
 731     h263_decode_frame,
 732     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 733 };
 734
 735 AVCodec msmpeg4v2_decoder = {
 736     "msmpeg4v2",
 737     CODEC_TYPE_VIDEO,
 738     CODEC_ID_MSMPEG4V2,
 739     sizeof(MpegEncContext),
 740     h263_decode_init,
 741     NULL,
 742     h263_decode_end,
 743     h263_decode_frame,
 744     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 745 };
 746
 747 AVCodec msmpeg4v3_decoder = {
 748     "msmpeg4",
 749     CODEC_TYPE_VIDEO,
 750     CODEC_ID_MSMPEG4V3,
 751     sizeof(MpegEncContext),
 752     h263_decode_init,
 753     NULL,
 754     h263_decode_end,
 755     h263_decode_frame,
 756     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 757 };
 758
 759 AVCodec wmv1_decoder = {
 760     "wmv1",
 761     CODEC_TYPE_VIDEO,
 762     CODEC_ID_WMV1,
 763     sizeof(MpegEncContext),
 764     h263_decode_init,
 765     NULL,
 766     h263_decode_end,
 767     h263_decode_frame,
 768     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 769 };
 770
 771 AVCodec wmv2_decoder = {
 772     "wmv2",
 773     CODEC_TYPE_VIDEO,
 774     CODEC_ID_WMV2,
 775     sizeof(MpegEncContext),
 776     h263_decode_init,
 777     NULL,
 778     h263_decode_end,
 779     h263_decode_frame,
 780     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 781 };
 782
 783 AVCodec h263i_decoder = {
 784     "h263i",
 785     CODEC_TYPE_VIDEO,
 786     CODEC_ID_H263I,
 787     sizeof(MpegEncContext),
 788     h263_decode_init,
 789     NULL,
 790     h263_decode_end,
 791     h263_decode_frame,
 792     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 793 };
 794