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 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 203             ret= s->decode_mb(s, s->block);
 204
 205             PRINT_QP("%2d", s->qscale);
 206             MPV_decode_mb(s, s->block);
 207
 208             if(ret<0){
 209                 const int xy= s->mb_x + s->mb_y*s->mb_width;
 210                 if(ret==SLICE_END){
 211 //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));
 212                     s->error_status_table[xy]|= AC_END;
 213                     if(!s->partitioned_frame)
 214                         s->error_status_table[xy]|= MV_END|DC_END;
 215
 216                     s->padding_bug_score--;
 217
 218                     if(++s->mb_x >= s->mb_width){
 219                         s->mb_x=0;
 220                         ff_draw_horiz_band(s);
 221                         s->mb_y++;
 222                     }
 223                     return 0;
 224                 }else if(ret==SLICE_NOEND){
 225                     fprintf(stderr,"Slice mismatch at MB: %d\n", xy);
 226                     return -1;
 227                 }
 228                 fprintf(stderr,"Error at MB: %d\n", xy);
 229                 s->error_status_table[xy]|= AC_ERROR;
 230                 if(!s->partitioned_frame)
 231                     s->error_status_table[xy]|= DC_ERROR|MV_ERROR;
 232
 233                 return -1;
 234             }
 235         }
 236
 237         ff_draw_horiz_band(s);
 238
 239         PRINT_QP("%s", "\n");
 240
 241         s->mb_x= 0;
 242     }
 243
 244     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 245
 246     /* try to detect the padding bug */
 247     if(      s->codec_id==CODEC_ID_MPEG4
 248        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 249        &&    s->gb.size*8 - get_bits_count(&s->gb) >=0
 250        &&    s->gb.size*8 - get_bits_count(&s->gb) < 48
 251        &&   !s->resync_marker
 252        &&   !s->data_partitioning){
 253
 254         const int bits_count= get_bits_count(&s->gb);
 255         const int bits_left = s->gb.size*8 - bits_count;
 256
 257         if(bits_left==0 || bits_left>8){
 258             s->padding_bug_score++;
 259         } else if(bits_left != 1){
 260             int v= show_bits(&s->gb, 8);
 261             v|= 0x7F >> (7-(bits_count&7));
 262
 263             if(v==0x7F)
 264                 s->padding_bug_score--;
 265             else
 266                 s->padding_bug_score++;
 267         }
 268
 269         if(s->padding_bug_score > -2)
 270             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 271         else
 272             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 273     }
 274
 275     // handle formats which dont have unique end markers
 276     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 277         int left= s->gb.size*8 - get_bits_count(&s->gb);
 278         int max_extra=7;
 279
 280         /* no markers in M$ crap */
 281         if(s->msmpeg4_version && s->pict_type==I_TYPE)
 282             max_extra+= 17;
 283
 284         /* buggy padding but the frame should still end approximately at the bitstream end */
 285         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
 286             max_extra+= 48;
 287         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 288             max_extra+= 256*256*256*64;
 289
 290         if(left>max_extra){
 291             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 292         }
 293         else if(left<0){
 294             fprintf(stderr, "overreading %d bits\n", -left);
 295         }else
 296             s->error_status_table[s->mb_num-1]|= AC_END|MV_END|DC_END;
 297
 298         return 0;
 299     }
 300
 301     fprintf(stderr, "slice end not reached but screenspace end (%d left %06X)\n",
 302             s->gb.size*8 - get_bits_count(&s->gb),
 303             show_bits(&s->gb, 24));
 304     return -1;
 305 }
 306
 307 /**
 308  * finds the end of the current frame in the bitstream.
 309  * @return the position of the first byte of the next frame, or -1
 310  */
 311 static int mpeg4_find_frame_end(MpegEncContext *s, UINT8 *buf, int buf_size){
 312     ParseContext *pc= &s->parse_context;
 313     int vop_found, i;
 314     uint32_t state;
 315
 316     vop_found= pc->frame_start_found;
 317     state= pc->state;
 318
 319     i=0;
 320     if(!vop_found){
 321         for(i=0; i<buf_size; i++){
 322             state= (state<<8) | buf[i];
 323             if(state == 0x1B6){
 324                 i++;
 325                 vop_found=1;
 326                 break;
 327             }
 328         }
 329     }
 330
 331     for(; i<buf_size; i++){
 332         state= (state<<8) | buf[i];
 333         if((state&0xFFFFFF00) == 0x100){
 334             pc->frame_start_found=0;
 335             pc->state=-1;
 336             return i-3;
 337         }
 338     }
 339     pc->frame_start_found= vop_found;
 340     pc->state= state;
 341     return -1;
 342 }
 343
 344 static int h263_decode_frame(AVCodecContext *avctx,
 345                              void *data, int *data_size,
 346                              UINT8 *buf, int buf_size)
 347 {
 348     MpegEncContext *s = avctx->priv_data;
 349     int ret,i;
 350     AVPicture *pict = data;
 351     float new_aspect;
 352
 353 #ifdef PRINT_FRAME_TIME
 354 uint64_t time= rdtsc();
 355 #endif
 356 #ifdef DEBUG
 357     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 358     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 359 #endif
 360
 361     s->hurry_up= avctx->hurry_up;
 362     s->error_resilience= avctx->error_resilience;
 363
 364     s->flags= avctx->flags;
 365
 366     *data_size = 0;
 367
 368    /* no supplementary picture */
 369     if (buf_size == 0) {
 370         return 0;
 371     }
 372
 373     if(s->flags&CODEC_FLAG_TRUNCATED){
 374         int next;
 375         ParseContext *pc= &s->parse_context;
 376
 377         pc->last_index= pc->index;
 378
 379         if(s->codec_id==CODEC_ID_MPEG4){
 380             next= mpeg4_find_frame_end(s, buf, buf_size);
 381         }else{
 382             fprintf(stderr, "this codec doesnt support truncated bitstreams\n");
 383             return -1;
 384         }
 385         if(next==-1){
 386             if(buf_size + FF_INPUT_BUFFER_PADDING_SIZE + pc->index > pc->buffer_size){
 387                 pc->buffer_size= buf_size + pc->index + 10*1024;
 388                 pc->buffer= realloc(pc->buffer, pc->buffer_size);
 389             }
 390
 391             memcpy(&pc->buffer[pc->index], buf, buf_size);
 392             pc->index += buf_size;
 393             return buf_size;
 394         }
 395
 396         if(pc->index){
 397             if(next + FF_INPUT_BUFFER_PADDING_SIZE + pc->index > pc->buffer_size){
 398                 pc->buffer_size= next + pc->index + 10*1024;
 399                 pc->buffer= realloc(pc->buffer, pc->buffer_size);
 400             }
 401
 402             memcpy(&pc->buffer[pc->index], buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
 403             pc->index = 0;
 404             buf= pc->buffer;
 405             buf_size= pc->last_index + next;
 406         }
 407     }
 408
 409 retry:
 410
 411     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
 412         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size);
 413     }else
 414         init_get_bits(&s->gb, buf, buf_size);
 415     s->bitstream_buffer_size=0;
 416
 417     if (!s->context_initialized) {
 418         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 419             return -1;
 420     }
 421
 422     /* let's go :-) */
 423     if (s->h263_msmpeg4) {
 424         ret = msmpeg4_decode_picture_header(s);
 425     } else if (s->h263_pred) {
 426         if(s->avctx->extradata_size && s->picture_number==0){
 427             GetBitContext gb;
 428
 429             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size);
 430             ret = ff_mpeg4_decode_picture_header(s, &gb);
 431         }
 432         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 433
 434         if(s->flags& CODEC_FLAG_LOW_DELAY)
 435             s->low_delay=1;
 436
 437         s->has_b_frames= !s->low_delay;
 438     } else if (s->h263_intel) {
 439         ret = intel_h263_decode_picture_header(s);
 440     } else {
 441         ret = h263_decode_picture_header(s);
 442     }
 443     avctx->has_b_frames= s->has_b_frames;
 444
 445     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 446         if(s->avctx->fourcc == ff_get_fourcc("XVIX"))
 447             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 448
 449         if(s->avctx->fourcc == ff_get_fourcc("MP4S"))
 450             s->workaround_bugs|= FF_BUG_AC_VLC;
 451
 452         if(s->avctx->fourcc == ff_get_fourcc("M4S2"))
 453             s->workaround_bugs|= FF_BUG_AC_VLC;
 454
 455         if(s->avctx->fourcc == ff_get_fourcc("UMP4")){
 456             s->workaround_bugs|= FF_BUG_UMP4;
 457             s->workaround_bugs|= FF_BUG_AC_VLC;
 458         }
 459
 460         if(s->divx_version){
 461             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 462         }
 463
 464         if(s->avctx->fourcc == ff_get_fourcc("XVID") && s->xvid_build==0)
 465             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 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= (float)s->aspected_width / (float)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->aspect_ratio= new_aspect;
 513
 514         goto retry;
 515     }
 516
 517     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 518         s->gob_index = ff_h263_get_gob_height(s);
 519
 520     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 521     /* skip if the header was thrashed */
 522     if (ret < 0){
 523         fprintf(stderr, "header damaged\n");
 524         return -1;
 525     }
 526
 527     s->avctx->key_frame   = (s->pict_type == I_TYPE);
 528     s->avctx->pict_type   = s->pict_type;
 529
 530     /* skip b frames if we dont have reference frames */
 531     if(s->num_available_buffers<2 && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 532     /* skip b frames if we are in a hurry */
 533     if(s->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 534     /* skip everything if we are in a hurry>=5 */
 535     if(s->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 536
 537     if(s->next_p_frame_damaged){
 538         if(s->pict_type==B_TYPE)
 539             return get_consumed_bytes(s, buf_size);
 540         else
 541             s->next_p_frame_damaged=0;
 542     }
 543
 544     if(MPV_frame_start(s, avctx) < 0)
 545         return -1;
 546
 547 #ifdef DEBUG
 548     printf("qscale=%d\n", s->qscale);
 549 #endif
 550
 551     if(s->error_resilience)
 552         memset(s->error_status_table, MV_ERROR|AC_ERROR|DC_ERROR|VP_START|AC_END|DC_END|MV_END, s->mb_num*sizeof(UINT8));
 553
 554     /* decode each macroblock */
 555     s->block_wrap[0]=
 556     s->block_wrap[1]=
 557     s->block_wrap[2]=
 558     s->block_wrap[3]= s->mb_width*2 + 2;
 559     s->block_wrap[4]=
 560     s->block_wrap[5]= s->mb_width + 2;
 561     s->mb_x=0;
 562     s->mb_y=0;
 563
 564     decode_slice(s);
 565     s->error_status_table[0]|= VP_START;
 566     while(s->mb_y<s->mb_height && s->gb.size*8 - get_bits_count(&s->gb)>16){
 567         if(s->msmpeg4_version){
 568             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0)
 569                 break;
 570         }else{
 571             if(ff_h263_resync(s)<0)
 572                 break;
 573         }
 574
 575         if(s->msmpeg4_version!=4 && s->h263_pred)
 576             ff_mpeg4_clean_buffers(s);
 577
 578         decode_slice(s);
 579
 580         s->error_status_table[s->resync_mb_x + s->resync_mb_y*s->mb_width]|= VP_START;
 581     }
 582
 583     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
 584         if(msmpeg4_decode_ext_header(s, buf_size) < 0) return -1;
 585
 586     /* divx 5.01+ bistream reorder stuff */
 587     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_version>=500){
 588         int current_pos= get_bits_count(&s->gb)>>3;
 589
 590         if(   buf_size - current_pos > 5
 591            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 592             int i;
 593             int startcode_found=0;
 594             for(i=current_pos; i<buf_size-3; i++){
 595                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 596                     startcode_found=1;
 597                     break;
 598                 }
 599             }
 600             if(startcode_found){
 601                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 602                 s->bitstream_buffer_size= buf_size - current_pos;
 603             }
 604         }
 605     }
 606
 607     if(s->error_resilience){
 608         int error=0, num_end_markers=0;
 609         for(i=0; i<s->mb_num; i++){
 610             int status= s->error_status_table[i];
 611 #if 0
 612             if(i%s->mb_width == 0) printf("\n");
 613             printf("%2X ", status);
 614 #endif
 615             if(status==0) continue;
 616
 617             if(status&(DC_ERROR|AC_ERROR|MV_ERROR))
 618                 error=1;
 619             if(status&VP_START){
 620                 if(num_end_markers)
 621                     error=1;
 622                 num_end_markers=3;
 623             }
 624             if(status&AC_END)
 625                 num_end_markers--;
 626             if(status&DC_END)
 627                 num_end_markers--;
 628             if(status&MV_END)
 629                 num_end_markers--;
 630         }
 631         if(num_end_markers || error){
 632             fprintf(stderr, "concealing errors\n");
 633 //printf("type:%d\n", s->pict_type);
 634             ff_error_resilience(s);
 635         }
 636     }
 637
 638     MPV_frame_end(s);
 639 #if 0 //dirty show MVs, we should export the MV tables and write a filter to show them
 640 {
 641   int mb_y;
 642   s->has_b_frames=1;
 643   for(mb_y=0; mb_y<s->mb_height; mb_y++){
 644     int mb_x;
 645     int y= mb_y*16 + 8;
 646     for(mb_x=0; mb_x<s->mb_width; mb_x++){
 647       int x= mb_x*16 + 8;
 648       uint8_t *ptr= s->last_picture[0];
 649       int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
 650       int mx= (s->motion_val[xy][0]>>1) + x;
 651       int my= (s->motion_val[xy][1]>>1) + y;
 652       int i;
 653       int max;
 654
 655       if(mx<0) mx=0;
 656       if(my<0) my=0;
 657       if(mx>=s->width)  mx= s->width -1;
 658       if(my>=s->height) my= s->height-1;
 659       max= ABS(mx-x);
 660       if(ABS(my-y) > max) max= ABS(my-y);
 661       /* the ugliest linedrawing routine ... */
 662       for(i=0; i<max; i++){
 663         int x1= x + (mx-x)*i/max;
 664         int y1= y + (my-y)*i/max;
 665         ptr[y1*s->linesize + x1]+=100;
 666       }
 667       ptr[y*s->linesize + x]+=100;
 668       s->mbskip_table[mb_x + mb_y*s->mb_width]=0;
 669     }
 670   }
 671
 672 }
 673 #endif
 674     if(s->pict_type==B_TYPE || (!s->has_b_frames)){
 675         pict->data[0] = s->current_picture[0];
 676         pict->data[1] = s->current_picture[1];
 677         pict->data[2] = s->current_picture[2];
 678     } else {
 679         pict->data[0] = s->last_picture[0];
 680         pict->data[1] = s->last_picture[1];
 681         pict->data[2] = s->last_picture[2];
 682     }
 683     pict->linesize[0] = s->linesize;
 684     pict->linesize[1] = s->uvlinesize;
 685     pict->linesize[2] = s->uvlinesize;
 686
 687     avctx->quality = s->qscale;
 688
 689     /* Return the Picture timestamp as the frame number */
 690     /* we substract 1 because it is added on utils.c    */
 691     avctx->frame_number = s->picture_number - 1;
 692
 693     /* dont output the last pic after seeking
 694        note we allready added +1 for the current pix in MPV_frame_end(s) */
 695     if(s->num_available_buffers>=2 || (!s->has_b_frames))
 696         *data_size = sizeof(AVPicture);
 697 #ifdef PRINT_FRAME_TIME
 698 printf("%Ld\n", rdtsc()-time);
 699 #endif
 700     return get_consumed_bytes(s, buf_size);
 701 }
 702
 703 AVCodec mpeg4_decoder = {
 704     "mpeg4",
 705     CODEC_TYPE_VIDEO,
 706     CODEC_ID_MPEG4,
 707     sizeof(MpegEncContext),
 708     h263_decode_init,
 709     NULL,
 710     h263_decode_end,
 711     h263_decode_frame,
 712     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 713 };
 714
 715 AVCodec h263_decoder = {
 716     "h263",
 717     CODEC_TYPE_VIDEO,
 718     CODEC_ID_H263,
 719     sizeof(MpegEncContext),
 720     h263_decode_init,
 721     NULL,
 722     h263_decode_end,
 723     h263_decode_frame,
 724     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 725 };
 726
 727 AVCodec msmpeg4v1_decoder = {
 728     "msmpeg4v1",
 729     CODEC_TYPE_VIDEO,
 730     CODEC_ID_MSMPEG4V1,
 731     sizeof(MpegEncContext),
 732     h263_decode_init,
 733     NULL,
 734     h263_decode_end,
 735     h263_decode_frame,
 736     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 737 };
 738
 739 AVCodec msmpeg4v2_decoder = {
 740     "msmpeg4v2",
 741     CODEC_TYPE_VIDEO,
 742     CODEC_ID_MSMPEG4V2,
 743     sizeof(MpegEncContext),
 744     h263_decode_init,
 745     NULL,
 746     h263_decode_end,
 747     h263_decode_frame,
 748     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 749 };
 750
 751 AVCodec msmpeg4v3_decoder = {
 752     "msmpeg4",
 753     CODEC_TYPE_VIDEO,
 754     CODEC_ID_MSMPEG4V3,
 755     sizeof(MpegEncContext),
 756     h263_decode_init,
 757     NULL,
 758     h263_decode_end,
 759     h263_decode_frame,
 760     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 761 };
 762
 763 AVCodec wmv1_decoder = {
 764     "wmv1",
 765     CODEC_TYPE_VIDEO,
 766     CODEC_ID_WMV1,
 767     sizeof(MpegEncContext),
 768     h263_decode_init,
 769     NULL,
 770     h263_decode_end,
 771     h263_decode_frame,
 772     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 773 };
 774
 775 AVCodec wmv2_decoder = {
 776     "wmv2",
 777     CODEC_TYPE_VIDEO,
 778     CODEC_ID_WMV2,
 779     sizeof(MpegEncContext),
 780     h263_decode_init,
 781     NULL,
 782     h263_decode_end,
 783     h263_decode_frame,
 784     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 785 };
 786
 787 AVCodec h263i_decoder = {
 788     "h263i",
 789     CODEC_TYPE_VIDEO,
 790     CODEC_ID_H263I,
 791     sizeof(MpegEncContext),
 792     h263_decode_init,
 793     NULL,
 794     h263_decode_end,
 795     h263_decode_frame,
 796     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 797 };
 798