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

   1 /*
   2  * H.263 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
  20 /**
  21  * @file h263dec.c
  22  * H.263 decoder.
  23  */
  24
  25 #include "avcodec.h"
  26 #include "dsputil.h"
  27 #include "mpegvideo.h"
  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 int ff_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     s->low_delay= 1;
  59     avctx->pix_fmt= PIX_FMT_YUV420P;
  60
  61     /* select sub codec */
  62     switch(avctx->codec->id) {
  63     case CODEC_ID_H263:
  64         s->gob_number = 0;
  65         break;
  66     case CODEC_ID_MPEG4:
  67         s->time_increment_bits = 4; /* default value for broken headers */
  68         s->h263_pred = 1;
  69         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  70         break;
  71     case CODEC_ID_MSMPEG4V1:
  72         s->h263_msmpeg4 = 1;
  73         s->h263_pred = 1;
  74         s->msmpeg4_version=1;
  75         break;
  76     case CODEC_ID_MSMPEG4V2:
  77         s->h263_msmpeg4 = 1;
  78         s->h263_pred = 1;
  79         s->msmpeg4_version=2;
  80         break;
  81     case CODEC_ID_MSMPEG4V3:
  82         s->h263_msmpeg4 = 1;
  83         s->h263_pred = 1;
  84         s->msmpeg4_version=3;
  85         break;
  86     case CODEC_ID_WMV1:
  87         s->h263_msmpeg4 = 1;
  88         s->h263_pred = 1;
  89         s->msmpeg4_version=4;
  90         break;
  91     case CODEC_ID_WMV2:
  92         s->h263_msmpeg4 = 1;
  93         s->h263_pred = 1;
  94         s->msmpeg4_version=5;
  95         break;
  96     case CODEC_ID_H263I:
  97         s->h263_intel = 1;
  98         break;
  99     default:
 100         return -1;
 101     }
 102     s->codec_id= avctx->codec->id;
 103
 104     /* for h263, we allocate the images after having read the header */
 105     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 106         if (MPV_common_init(s) < 0)
 107             return -1;
 108
 109     if (s->h263_msmpeg4)
 110         ff_msmpeg4_decode_init(s);
 111     else
 112         h263_decode_init_vlc(s);
 113
 114     return 0;
 115 }
 116
 117 int ff_h263_decode_end(AVCodecContext *avctx)
 118 {
 119     MpegEncContext *s = avctx->priv_data;
 120
 121     MPV_common_end(s);
 122     return 0;
 123 }
 124
 125 /**
 126  * retunrs the number of bytes consumed for building the current frame
 127  */
 128 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 129     int pos= (get_bits_count(&s->gb)+7)>>3;
 130
 131     if(s->divx_packed){
 132         //we would have to scan through the whole buf to handle the weird reordering ...
 133         return buf_size;
 134     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 135         pos -= s->parse_context.last_index;
 136         if(pos<0) pos=0; // padding is not really read so this might be -1
 137         return pos;
 138     }else{
 139         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
 140         if(pos+10>buf_size) pos=buf_size; // oops ;)
 141
 142         return pos;
 143     }
 144 }
 145
 146 static int decode_slice(MpegEncContext *s){
 147     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
 148     s->last_resync_gb= s->gb;
 149     s->first_slice_line= 1;
 150
 151     s->resync_mb_x= s->mb_x;
 152     s->resync_mb_y= s->mb_y;
 153
 154     s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 155     s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 156
 157     if(s->partitioned_frame){
 158         const int qscale= s->qscale;
 159
 160         if(s->codec_id==CODEC_ID_MPEG4){
 161             if(ff_mpeg4_decode_partitions(s) < 0)
 162                 return -1;
 163         }
 164
 165         /* restore variables which where modified */
 166         s->first_slice_line=1;
 167         s->mb_x= s->resync_mb_x;
 168         s->mb_y= s->resync_mb_y;
 169         s->qscale= qscale;
 170         s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 171         s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 172     }
 173
 174     for(; s->mb_y < s->mb_height; s->mb_y++) {
 175         /* per-row end of slice checks */
 176         if(s->msmpeg4_version){
 177             if(s->resync_mb_y + s->slice_height == s->mb_y){
 178                 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);
 179
 180                 return 0;
 181             }
 182         }
 183
 184         if(s->msmpeg4_version==1){
 185             s->last_dc[0]=
 186             s->last_dc[1]=
 187             s->last_dc[2]= 128;
 188         }
 189
 190         ff_init_block_index(s);
 191         for(; s->mb_x < s->mb_width; s->mb_x++) {
 192             int ret;
 193
 194             ff_update_block_index(s);
 195
 196             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 197                 s->first_slice_line=0;
 198             }
 199
 200             /* DCT & quantize */
 201             s->dsp.clear_blocks(s->block[0]);
 202
 203             s->mv_dir = MV_DIR_FORWARD;
 204             s->mv_type = MV_TYPE_16X16;
 205 //            s->mb_skiped = 0;
 206 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 207             ret= s->decode_mb(s, s->block);
 208
 209             MPV_decode_mb(s, s->block);
 210
 211             if(ret<0){
 212                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 213                 if(ret==SLICE_END){
 214 //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));
 215                     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
 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, s->mb_y*16, 16);
 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                     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)&part_mask);
 228                     return -1;
 229                 }
 230                 fprintf(stderr,"Error at MB: %d\n", xy);
 231                 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)&part_mask);
 232
 233                 return -1;
 234             }
 235         }
 236
 237         ff_draw_horiz_band(s, s->mb_y*16, 16);
 238
 239         s->mb_x= 0;
 240     }
 241
 242     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 243
 244     /* try to detect the padding bug */
 245     if(      s->codec_id==CODEC_ID_MPEG4
 246        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 247        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 248        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 249 //       &&   !s->resync_marker
 250        &&   !s->data_partitioning){
 251
 252         const int bits_count= get_bits_count(&s->gb);
 253         const int bits_left = s->gb.size_in_bits - bits_count;
 254
 255         if(bits_left==0){
 256             s->padding_bug_score+=16;
 257         }else if(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
 270     // handle formats which dont have unique end markers
 271     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 272         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 273         int max_extra=7;
 274
 275         /* no markers in M$ crap */
 276         if(s->msmpeg4_version && s->pict_type==I_TYPE)
 277             max_extra+= 17;
 278
 279         /* buggy padding but the frame should still end approximately at the bitstream end */
 280         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
 281             max_extra+= 48;
 282         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 283             max_extra+= 256*256*256*64;
 284
 285         if(left>max_extra){
 286             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 287         }
 288         else if(left<0){
 289             fprintf(stderr, "overreading %d bits\n", -left);
 290         }else
 291             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);
 292
 293         return 0;
 294     }
 295
 296     fprintf(stderr, "slice end not reached but screenspace end (%d left %06X)\n",
 297             s->gb.size_in_bits - get_bits_count(&s->gb),
 298             show_bits(&s->gb, 24));
 299
 300     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
 301
 302     return -1;
 303 }
 304
 305 /**
 306  * finds the end of the current frame in the bitstream.
 307  * @return the position of the first byte of the next frame, or -1
 308  */
 309 static int mpeg4_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
 310     ParseContext *pc= &s->parse_context;
 311     int vop_found, i;
 312     uint32_t state;
 313
 314     vop_found= pc->frame_start_found;
 315     state= pc->state;
 316
 317     i=0;
 318     if(!vop_found){
 319         for(i=0; i<buf_size; i++){
 320             state= (state<<8) | buf[i];
 321             if(state == 0x1B6){
 322                 i++;
 323                 vop_found=1;
 324                 break;
 325             }
 326         }
 327     }
 328
 329     if(vop_found){
 330       for(; i<buf_size; i++){
 331         state= (state<<8) | buf[i];
 332         if((state&0xFFFFFF00) == 0x100){
 333             pc->frame_start_found=0;
 334             pc->state=-1;
 335             return i-3;
 336         }
 337       }
 338     }
 339     pc->frame_start_found= vop_found;
 340     pc->state= state;
 341     return END_NOT_FOUND;
 342 }
 343
 344 /**
 345  * draws an line from (ex, ey) -> (sx, sy).
 346  * @param w width of the image
 347  * @param h height of the image
 348  * @param stride stride/linesize of the image
 349  * @param color color of the arrow
 350  */
 351 static void draw_line(uint8_t *buf, int sx, int sy, int ex, int ey, int w, int h, int stride, int color){
 352     int t, x, y, f;
 353
 354     ex= clip(ex, 0, w-1);
 355     ey= clip(ey, 0, h-1);
 356
 357     buf[sy*stride + sx]+= color;
 358
 359     if(ABS(ex - sx) > ABS(ey - sy)){
 360         if(sx > ex){
 361             t=sx; sx=ex; ex=t;
 362             t=sy; sy=ey; ey=t;
 363         }
 364         buf+= sx + sy*stride;
 365         ex-= sx;
 366         f= ((ey-sy)<<16)/ex;
 367         for(x= 0; x <= ex; x++){
 368             y= ((x*f) + (1<<15))>>16;
 369             buf[y*stride + x]+= color;
 370         }
 371     }else{
 372         if(sy > ey){
 373             t=sx; sx=ex; ex=t;
 374             t=sy; sy=ey; ey=t;
 375         }
 376         buf+= sx + sy*stride;
 377         ey-= sy;
 378         if(ey) f= ((ex-sx)<<16)/ey;
 379         else   f= 0;
 380         for(y= 0; y <= ey; y++){
 381             x= ((y*f) + (1<<15))>>16;
 382             buf[y*stride + x]+= color;
 383         }
 384     }
 385 }
 386
 387 /**
 388  * draws an arrow from (ex, ey) -> (sx, sy).
 389  * @param w width of the image
 390  * @param h height of the image
 391  * @param stride stride/linesize of the image
 392  * @param color color of the arrow
 393  */
 394 static void draw_arrow(uint8_t *buf, int sx, int sy, int ex, int ey, int w, int h, int stride, int color){
 395     int dx= ex - sx;
 396     int dy= ey - sy;
 397
 398     if(dx*dx + dy*dy > 3*3){
 399         int rx=  dx + dy;
 400         int ry= -dx + dy;
 401         int length= ff_sqrt((rx*rx + ry*ry)<<8);
 402
 403         //FIXME subpixel accuracy
 404         rx= ROUNDED_DIV(rx*3<<4, length);
 405         ry= ROUNDED_DIV(ry*3<<4, length);
 406
 407         draw_line(buf, sx, sy, sx + rx, sy + ry, w, h, stride, color);
 408         draw_line(buf, sx, sy, sx - ry, sy + rx, w, h, stride, color);
 409     }
 410     draw_line(buf, sx, sy, ex, ey, w, h, stride, color);
 411 }
 412
 413 int ff_h263_decode_frame(AVCodecContext *avctx,
 414                              void *data, int *data_size,
 415                              uint8_t *buf, int buf_size)
 416 {
 417     MpegEncContext *s = avctx->priv_data;
 418     int ret,i;
 419     AVFrame *pict = data;
 420     float new_aspect;
 421
 422 #ifdef PRINT_FRAME_TIME
 423 uint64_t time= rdtsc();
 424 #endif
 425 #ifdef DEBUG
 426     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 427     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 428 #endif
 429     s->flags= avctx->flags;
 430
 431     *data_size = 0;
 432
 433    /* no supplementary picture */
 434     if (buf_size == 0) {
 435         return 0;
 436     }
 437
 438     if(s->flags&CODEC_FLAG_TRUNCATED){
 439         int next;
 440
 441         if(s->codec_id==CODEC_ID_MPEG4){
 442             next= mpeg4_find_frame_end(s, buf, buf_size);
 443         }else{
 444             fprintf(stderr, "this codec doesnt support truncated bitstreams\n");
 445             return -1;
 446         }
 447
 448         if( ff_combine_frame(s, next, &buf, &buf_size) < 0 )
 449             return buf_size;
 450     }
 451
 452 retry:
 453
 454     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
 455         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 456     }else
 457         init_get_bits(&s->gb, buf, buf_size*8);
 458     s->bitstream_buffer_size=0;
 459
 460     if (!s->context_initialized) {
 461         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 462             return -1;
 463     }
 464
 465     /* let's go :-) */
 466     if (s->msmpeg4_version==5) {
 467         ret= ff_wmv2_decode_picture_header(s);
 468     } else if (s->msmpeg4_version) {
 469         ret = msmpeg4_decode_picture_header(s);
 470     } else if (s->h263_pred) {
 471         if(s->avctx->extradata_size && s->picture_number==0){
 472             GetBitContext gb;
 473
 474             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 475             ret = ff_mpeg4_decode_picture_header(s, &gb);
 476         }
 477         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 478
 479         if(s->flags& CODEC_FLAG_LOW_DELAY)
 480             s->low_delay=1;
 481     } else if (s->h263_intel) {
 482         ret = intel_h263_decode_picture_header(s);
 483     } else {
 484         ret = h263_decode_picture_header(s);
 485     }
 486     avctx->has_b_frames= !s->low_delay;
 487
 488     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 489         if(s->padding_bug_score > -2 && !s->data_partitioning && !s->resync_marker)
 490             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 491         else
 492             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 493
 494         if(s->avctx->codec_tag == ff_get_fourcc("XVIX"))
 495             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 496 #if 0
 497         if(s->avctx->codec_tag == ff_get_fourcc("MP4S"))
 498             s->workaround_bugs|= FF_BUG_AC_VLC;
 499
 500         if(s->avctx->codec_tag == ff_get_fourcc("M4S2"))
 501             s->workaround_bugs|= FF_BUG_AC_VLC;
 502 #endif
 503         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
 504             s->workaround_bugs|= FF_BUG_UMP4;
 505             s->workaround_bugs|= FF_BUG_AC_VLC;
 506         }
 507
 508         if(s->divx_version){
 509             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 510         }
 511
 512         if(s->divx_version>502){
 513             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 514         }
 515
 516         if(s->avctx->codec_tag == ff_get_fourcc("XVID") && s->xvid_build==0)
 517             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 518
 519         if(s->avctx->codec_tag == ff_get_fourcc("XVID") && s->xvid_build==0)
 520             s->padding_bug_score= 256*256*256*64;
 521
 522         if(s->xvid_build && s->xvid_build<=3)
 523             s->padding_bug_score= 256*256*256*64;
 524
 525         if(s->xvid_build && s->xvid_build<=1)
 526             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 527
 528 #define SET_QPEL_FUNC(postfix1, postfix2) \
 529     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 530     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 531     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 532
 533         if(s->lavc_build && s->lavc_build<4653)
 534             s->workaround_bugs|= FF_BUG_STD_QPEL;
 535
 536         if(s->lavc_build && s->lavc_build<4655)
 537             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 538
 539         if(s->divx_version)
 540             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 541 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 542         if(s->divx_version==501 && s->divx_build==20020416)
 543             s->padding_bug_score= 256*256*256*64;
 544
 545         if(s->divx_version>=500){
 546             s->workaround_bugs|= FF_BUG_EDGE;
 547         }
 548
 549 #if 0
 550         if(s->divx_version==500)
 551             s->padding_bug_score= 256*256*256*64;
 552
 553         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 554          * lets hope this at least works
 555          */
 556         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 557            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 558             s->workaround_bugs|= FF_BUG_NO_PADDING;
 559
 560         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 561             s->workaround_bugs|= FF_BUG_NO_PADDING;
 562 #endif
 563     }
 564
 565     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 566         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 567         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 568         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 569         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 570         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 571         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 572
 573         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 574         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 575         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 576         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 577         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 578         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 579     }
 580
 581 #if 0 // dump bits per frame / qp / complexity
 582 {
 583     static FILE *f=NULL;
 584     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 585     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 586 }
 587 #endif
 588
 589         /* After H263 & mpeg4 header decode we have the height, width,*/
 590         /* and other parameters. So then we could init the picture   */
 591         /* FIXME: By the way H263 decoder is evolving it should have */
 592         /* an H263EncContext                                         */
 593     if(s->aspected_height)
 594         new_aspect= s->aspected_width*s->width / (float)(s->height*s->aspected_height);
 595     else
 596         new_aspect=0;
 597
 598     if (   s->width != avctx->width || s->height != avctx->height
 599         || ABS(new_aspect - avctx->aspect_ratio) > 0.001) {
 600         /* H.263 could change picture size any time */
 601         MPV_common_end(s);
 602     }
 603     if (!s->context_initialized) {
 604         avctx->width = s->width;
 605         avctx->height = s->height;
 606         avctx->aspect_ratio= new_aspect;
 607
 608         goto retry;
 609     }
 610
 611     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 612         s->gob_index = ff_h263_get_gob_height(s);
 613
 614     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 615     /* skip if the header was thrashed */
 616     if (ret < 0){
 617         fprintf(stderr, "header damaged\n");
 618         return -1;
 619     }
 620
 621     // for hurry_up==5
 622     s->current_picture.pict_type= s->pict_type;
 623     s->current_picture.key_frame= s->pict_type == I_TYPE;
 624
 625     /* skip b frames if we dont have reference frames */
 626     if(s->last_picture_ptr==NULL && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 627     /* skip b frames if we are in a hurry */
 628     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 629     /* skip everything if we are in a hurry>=5 */
 630     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 631
 632     if(s->next_p_frame_damaged){
 633         if(s->pict_type==B_TYPE)
 634             return get_consumed_bytes(s, buf_size);
 635         else
 636             s->next_p_frame_damaged=0;
 637     }
 638
 639     if(MPV_frame_start(s, avctx) < 0)
 640         return -1;
 641
 642 #ifdef DEBUG
 643     printf("qscale=%d\n", s->qscale);
 644 #endif
 645
 646     ff_er_frame_start(s);
 647
 648     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 649     //which isnt available before MPV_frame_start()
 650     if (s->msmpeg4_version==5){
 651         if(ff_wmv2_decode_secondary_picture_header(s) < 0)
 652             return -1;
 653     }
 654
 655     /* decode each macroblock */
 656     s->mb_x=0;
 657     s->mb_y=0;
 658
 659     decode_slice(s);
 660     while(s->mb_y<s->mb_height){
 661         if(s->msmpeg4_version){
 662             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
 663                 break;
 664         }else{
 665             if(ff_h263_resync(s)<0)
 666                 break;
 667         }
 668
 669         if(s->msmpeg4_version<4 && s->h263_pred)
 670             ff_mpeg4_clean_buffers(s);
 671
 672         decode_slice(s);
 673     }
 674
 675     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
 676         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
 677             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 678         }
 679
 680     /* divx 5.01+ bistream reorder stuff */
 681     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
 682         int current_pos= get_bits_count(&s->gb)>>3;
 683
 684         if(   buf_size - current_pos > 5
 685            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 686             int i;
 687             int startcode_found=0;
 688             for(i=current_pos; i<buf_size-3; i++){
 689                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 690                     startcode_found=1;
 691                     break;
 692                 }
 693             }
 694             if(startcode_found){
 695                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 696                 s->bitstream_buffer_size= buf_size - current_pos;
 697             }
 698         }
 699     }
 700
 701     ff_er_frame_end(s);
 702
 703     MPV_frame_end(s);
 704
 705     if((avctx->debug&FF_DEBUG_VIS_MV) && s->last_picture_ptr){
 706         const int shift= 1 + s->quarter_sample;
 707         int mb_y;
 708         uint8_t *ptr= s->last_picture.data[0];
 709         s->low_delay=0; //needed to see the vectors without trashing the buffers
 710
 711         for(mb_y=0; mb_y<s->mb_height; mb_y++){
 712             int mb_x;
 713             for(mb_x=0; mb_x<s->mb_width; mb_x++){
 714                 const int mb_index= mb_x + mb_y*s->mb_stride;
 715                 if(IS_8X8(s->current_picture.mb_type[mb_index])){
 716                     int i;
 717                     for(i=0; i<4; i++){
 718                         int sx= mb_x*16 + 4 + 8*(i&1);
 719                         int sy= mb_y*16 + 4 + 8*(i>>1);
 720                         int xy= 1 + mb_x*2 + (i&1) + (mb_y*2 + 1 + (i>>1))*(s->mb_width*2 + 2);
 721                         int mx= (s->motion_val[xy][0]>>shift) + sx;
 722                         int my= (s->motion_val[xy][1]>>shift) + sy;
 723                         draw_arrow(ptr, sx, sy, mx, my, s->width, s->height, s->linesize, 100);
 724                     }
 725                 }else{
 726                     int sx= mb_x*16 + 8;
 727                     int sy= mb_y*16 + 8;
 728                     int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
 729                     int mx= (s->motion_val[xy][0]>>shift) + sx;
 730                     int my= (s->motion_val[xy][1]>>shift) + sy;
 731                     draw_arrow(ptr, sx, sy, mx, my, s->width, s->height, s->linesize, 100);
 732                 }
 733                 s->mbskip_table[mb_index]=0;
 734             }
 735         }
 736     }
 737
 738     if(s->pict_type==B_TYPE || s->low_delay){
 739         *pict= *(AVFrame*)&s->current_picture;
 740         ff_print_debug_info(s, s->current_picture_ptr);
 741     } else {
 742         *pict= *(AVFrame*)&s->last_picture;
 743         ff_print_debug_info(s, s->last_picture_ptr);
 744     }
 745
 746     /* Return the Picture timestamp as the frame number */
 747     /* we substract 1 because it is added on utils.c    */
 748     avctx->frame_number = s->picture_number - 1;
 749
 750     /* dont output the last pic after seeking */
 751     if(s->last_picture_ptr || s->low_delay)
 752         *data_size = sizeof(AVFrame);
 753 #ifdef PRINT_FRAME_TIME
 754 printf("%Ld\n", rdtsc()-time);
 755 #endif
 756     return get_consumed_bytes(s, buf_size);
 757 }
 758
 759 static const AVOption mpeg4_decoptions[] =
 760 {
 761     AVOPTION_SUB(avoptions_workaround_bug),
 762     AVOPTION_END()
 763 };
 764
 765 AVCodec mpeg4_decoder = {
 766     "mpeg4",
 767     CODEC_TYPE_VIDEO,
 768     CODEC_ID_MPEG4,
 769     sizeof(MpegEncContext),
 770     ff_h263_decode_init,
 771     NULL,
 772     ff_h263_decode_end,
 773     ff_h263_decode_frame,
 774     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 775     .options = mpeg4_decoptions,
 776 };
 777
 778 AVCodec h263_decoder = {
 779     "h263",
 780     CODEC_TYPE_VIDEO,
 781     CODEC_ID_H263,
 782     sizeof(MpegEncContext),
 783     ff_h263_decode_init,
 784     NULL,
 785     ff_h263_decode_end,
 786     ff_h263_decode_frame,
 787     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 788 };
 789
 790 AVCodec msmpeg4v1_decoder = {
 791     "msmpeg4v1",
 792     CODEC_TYPE_VIDEO,
 793     CODEC_ID_MSMPEG4V1,
 794     sizeof(MpegEncContext),
 795     ff_h263_decode_init,
 796     NULL,
 797     ff_h263_decode_end,
 798     ff_h263_decode_frame,
 799     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 800     mpeg4_decoptions,
 801 };
 802
 803 AVCodec msmpeg4v2_decoder = {
 804     "msmpeg4v2",
 805     CODEC_TYPE_VIDEO,
 806     CODEC_ID_MSMPEG4V2,
 807     sizeof(MpegEncContext),
 808     ff_h263_decode_init,
 809     NULL,
 810     ff_h263_decode_end,
 811     ff_h263_decode_frame,
 812     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 813     mpeg4_decoptions,
 814 };
 815
 816 AVCodec msmpeg4v3_decoder = {
 817     "msmpeg4",
 818     CODEC_TYPE_VIDEO,
 819     CODEC_ID_MSMPEG4V3,
 820     sizeof(MpegEncContext),
 821     ff_h263_decode_init,
 822     NULL,
 823     ff_h263_decode_end,
 824     ff_h263_decode_frame,
 825     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 826     .options = mpeg4_decoptions,
 827 };
 828
 829 AVCodec wmv1_decoder = {
 830     "wmv1",
 831     CODEC_TYPE_VIDEO,
 832     CODEC_ID_WMV1,
 833     sizeof(MpegEncContext),
 834     ff_h263_decode_init,
 835     NULL,
 836     ff_h263_decode_end,
 837     ff_h263_decode_frame,
 838     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 839     mpeg4_decoptions,
 840 };
 841
 842 AVCodec h263i_decoder = {
 843     "h263i",
 844     CODEC_TYPE_VIDEO,
 845     CODEC_ID_H263I,
 846     sizeof(MpegEncContext),
 847     ff_h263_decode_init,
 848     NULL,
 849     ff_h263_decode_end,
 850     ff_h263_decode_frame,
 851     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 852     mpeg4_decoptions,
 853 };
 854