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     case CODEC_ID_FLV1:
 100         s->h263_flv = 1;
 101         break;
 102     default:
 103         return -1;
 104     }
 105     s->codec_id= avctx->codec->id;
 106
 107     /* for h263, we allocate the images after having read the header */
 108     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 109         if (MPV_common_init(s) < 0)
 110             return -1;
 111
 112     if (s->h263_msmpeg4)
 113         ff_msmpeg4_decode_init(s);
 114     else
 115         h263_decode_init_vlc(s);
 116
 117     return 0;
 118 }
 119
 120 int ff_h263_decode_end(AVCodecContext *avctx)
 121 {
 122     MpegEncContext *s = avctx->priv_data;
 123
 124     MPV_common_end(s);
 125     return 0;
 126 }
 127
 128 /**
 129  * retunrs the number of bytes consumed for building the current frame
 130  */
 131 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 132     int pos= (get_bits_count(&s->gb)+7)>>3;
 133
 134     if(s->divx_packed){
 135         //we would have to scan through the whole buf to handle the weird reordering ...
 136         return buf_size;
 137     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 138         pos -= s->parse_context.last_index;
 139         if(pos<0) pos=0; // padding is not really read so this might be -1
 140         return pos;
 141     }else{
 142         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
 143         if(pos+10>buf_size) pos=buf_size; // oops ;)
 144
 145         return pos;
 146     }
 147 }
 148
 149 static int decode_slice(MpegEncContext *s){
 150     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
 151     s->last_resync_gb= s->gb;
 152     s->first_slice_line= 1;
 153
 154     s->resync_mb_x= s->mb_x;
 155     s->resync_mb_y= s->mb_y;
 156
 157     s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 158     s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 159
 160     if(s->partitioned_frame){
 161         const int qscale= s->qscale;
 162
 163         if(s->codec_id==CODEC_ID_MPEG4){
 164             if(ff_mpeg4_decode_partitions(s) < 0)
 165                 return -1;
 166         }
 167
 168         /* restore variables which were modified */
 169         s->first_slice_line=1;
 170         s->mb_x= s->resync_mb_x;
 171         s->mb_y= s->resync_mb_y;
 172         s->qscale= qscale;
 173         s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 174         s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 175     }
 176
 177     for(; s->mb_y < s->mb_height; s->mb_y++) {
 178         /* per-row end of slice checks */
 179         if(s->msmpeg4_version){
 180             if(s->resync_mb_y + s->slice_height == s->mb_y){
 181                 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);
 182
 183                 return 0;
 184             }
 185         }
 186
 187         if(s->msmpeg4_version==1){
 188             s->last_dc[0]=
 189             s->last_dc[1]=
 190             s->last_dc[2]= 128;
 191         }
 192
 193         ff_init_block_index(s);
 194         for(; s->mb_x < s->mb_width; s->mb_x++) {
 195             int ret;
 196
 197             ff_update_block_index(s);
 198
 199             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 200                 s->first_slice_line=0;
 201             }
 202
 203             /* DCT & quantize */
 204             s->dsp.clear_blocks(s->block[0]);
 205
 206             s->mv_dir = MV_DIR_FORWARD;
 207             s->mv_type = MV_TYPE_16X16;
 208 //            s->mb_skiped = 0;
 209 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 210             ret= s->decode_mb(s, s->block);
 211
 212             if (s->pict_type!=B_TYPE)
 213                 ff_h263_update_motion_val(s);
 214
 215             if(ret<0){
 216                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 217                 if(ret==SLICE_END){
 218                     MPV_decode_mb(s, s->block);
 219
 220 //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));
 221                     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);
 222
 223                     s->padding_bug_score--;
 224
 225                     if(++s->mb_x >= s->mb_width){
 226                         s->mb_x=0;
 227                         ff_draw_horiz_band(s, s->mb_y*16, 16);
 228                         s->mb_y++;
 229                     }
 230                     return 0;
 231                 }else if(ret==SLICE_NOEND){
 232                     fprintf(stderr,"Slice mismatch at MB: %d\n", xy);
 233                     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);
 234                     return -1;
 235                 }
 236                 fprintf(stderr,"Error at MB: %d\n", xy);
 237                 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);
 238
 239                 return -1;
 240             }
 241
 242             MPV_decode_mb(s, s->block);
 243         }
 244
 245         ff_draw_horiz_band(s, s->mb_y*16, 16);
 246
 247         s->mb_x= 0;
 248     }
 249
 250     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 251
 252     /* try to detect the padding bug */
 253     if(      s->codec_id==CODEC_ID_MPEG4
 254        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 255        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 256        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 257 //       &&   !s->resync_marker
 258        &&   !s->data_partitioning){
 259
 260         const int bits_count= get_bits_count(&s->gb);
 261         const int bits_left = s->gb.size_in_bits - bits_count;
 262
 263         if(bits_left==0){
 264             s->padding_bug_score+=16;
 265         }else if(bits_left>8){
 266             s->padding_bug_score++;
 267         } else if(bits_left != 1){
 268             int v= show_bits(&s->gb, 8);
 269             v|= 0x7F >> (7-(bits_count&7));
 270
 271             if(v==0x7F)
 272                 s->padding_bug_score--;
 273             else
 274                 s->padding_bug_score++;
 275         }
 276     }
 277
 278     // handle formats which dont have unique end markers
 279     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 280         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 281         int max_extra=7;
 282
 283         /* no markers in M$ crap */
 284         if(s->msmpeg4_version && s->pict_type==I_TYPE)
 285             max_extra+= 17;
 286
 287         /* buggy padding but the frame should still end approximately at the bitstream end */
 288         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
 289             max_extra+= 48;
 290         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 291             max_extra+= 256*256*256*64;
 292
 293         if(left>max_extra){
 294             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 295         }
 296         else if(left<0){
 297             fprintf(stderr, "overreading %d bits\n", -left);
 298         }else
 299             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);
 300
 301         return 0;
 302     }
 303
 304     fprintf(stderr, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 305             s->gb.size_in_bits - get_bits_count(&s->gb),
 306             show_bits(&s->gb, 24), s->padding_bug_score);
 307
 308     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);
 309
 310     return -1;
 311 }
 312
 313 /**
 314  * finds the end of the current frame in the bitstream.
 315  * @return the position of the first byte of the next frame, or -1
 316  */
 317 static int mpeg4_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
 318     ParseContext *pc= &s->parse_context;
 319     int vop_found, i;
 320     uint32_t state;
 321
 322     vop_found= pc->frame_start_found;
 323     state= pc->state;
 324
 325     i=0;
 326     if(!vop_found){
 327         for(i=0; i<buf_size; i++){
 328             state= (state<<8) | buf[i];
 329             if(state == 0x1B6){
 330                 i++;
 331                 vop_found=1;
 332                 break;
 333             }
 334         }
 335     }
 336
 337     if(vop_found){
 338       for(; i<buf_size; i++){
 339         state= (state<<8) | buf[i];
 340         if((state&0xFFFFFF00) == 0x100){
 341             pc->frame_start_found=0;
 342             pc->state=-1;
 343             return i-3;
 344         }
 345       }
 346     }
 347     pc->frame_start_found= vop_found;
 348     pc->state= state;
 349     return END_NOT_FOUND;
 350 }
 351
 352 static int h263_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
 353     ParseContext *pc= &s->parse_context;
 354     int vop_found, i;
 355     uint32_t state;
 356
 357     vop_found= pc->frame_start_found;
 358     state= pc->state;
 359
 360     i=0;
 361     if(!vop_found){
 362         for(i=0; i<buf_size; i++){
 363             state= (state<<8) | buf[i];
 364             if(state>>(32-22) == 0x20){
 365                 i++;
 366                 vop_found=1;
 367                 break;
 368             }
 369         }
 370     }
 371
 372     if(vop_found){
 373       for(; i<buf_size; i++){
 374         state= (state<<8) | buf[i];
 375         if(state>>(32-22) == 0x20){
 376             pc->frame_start_found=0;
 377             pc->state=-1;
 378             return i-3;
 379         }
 380       }
 381     }
 382     pc->frame_start_found= vop_found;
 383     pc->state= state;
 384
 385     return END_NOT_FOUND;
 386 }
 387
 388 int ff_h263_decode_frame(AVCodecContext *avctx,
 389                              void *data, int *data_size,
 390                              uint8_t *buf, int buf_size)
 391 {
 392     MpegEncContext *s = avctx->priv_data;
 393     int ret;
 394     AVFrame *pict = data;
 395     float new_aspect;
 396
 397 #ifdef PRINT_FRAME_TIME
 398 uint64_t time= rdtsc();
 399 #endif
 400 #ifdef DEBUG
 401     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 402     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 403 #endif
 404     s->flags= avctx->flags;
 405
 406     *data_size = 0;
 407
 408     /* no supplementary picture */
 409     if (buf_size == 0) {
 410         /* special case for last picture */
 411         if (s->low_delay==0 && s->next_picture_ptr) {
 412             *pict= *(AVFrame*)s->next_picture_ptr;
 413             s->next_picture_ptr= NULL;
 414
 415             *data_size = sizeof(AVFrame);
 416         }
 417
 418         return 0;
 419     }
 420
 421     if(s->flags&CODEC_FLAG_TRUNCATED){
 422         int next;
 423
 424         if(s->codec_id==CODEC_ID_MPEG4){
 425             next= mpeg4_find_frame_end(s, buf, buf_size);
 426         }else if(s->codec_id==CODEC_ID_H263){
 427             next= h263_find_frame_end(s, buf, buf_size);
 428         }else{
 429             fprintf(stderr, "this codec doesnt support truncated bitstreams\n");
 430             return -1;
 431         }
 432
 433         if( ff_combine_frame(s, next, &buf, &buf_size) < 0 )
 434             return buf_size;
 435     }
 436
 437 retry:
 438
 439     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
 440         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 441     }else
 442         init_get_bits(&s->gb, buf, buf_size*8);
 443     s->bitstream_buffer_size=0;
 444
 445     if (!s->context_initialized) {
 446         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 447             return -1;
 448     }
 449
 450     /* let's go :-) */
 451     if (s->msmpeg4_version==5) {
 452         ret= ff_wmv2_decode_picture_header(s);
 453     } else if (s->msmpeg4_version) {
 454         ret = msmpeg4_decode_picture_header(s);
 455     } else if (s->h263_pred) {
 456         if(s->avctx->extradata_size && s->picture_number==0){
 457             GetBitContext gb;
 458
 459             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 460             ret = ff_mpeg4_decode_picture_header(s, &gb);
 461         }
 462         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 463
 464         if(s->flags& CODEC_FLAG_LOW_DELAY)
 465             s->low_delay=1;
 466     } else if (s->h263_intel) {
 467         ret = intel_h263_decode_picture_header(s);
 468     } else if (s->h263_flv) {
 469         ret = flv_h263_decode_picture_header(s);
 470     } else {
 471         ret = h263_decode_picture_header(s);
 472     }
 473
 474     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 475
 476     /* skip if the header was thrashed */
 477     if (ret < 0){
 478         fprintf(stderr, "header damaged\n");
 479         return -1;
 480     }
 481
 482     avctx->has_b_frames= !s->low_delay;
 483
 484     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 485         if(s->avctx->codec_tag == ff_get_fourcc("XVID") || s->avctx->codec_tag == ff_get_fourcc("XVIX"))
 486             s->xvid_build= -1;
 487
 488         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 489            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 490             s->xvid_build= -1;
 491
 492         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 493             s->divx_version= 400; //divx 4
 494     }
 495
 496     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 497         s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 498
 499         if(s->padding_bug_score > -2 && !s->data_partitioning && (s->divx_version || !s->resync_marker))
 500             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 501
 502         if(s->avctx->codec_tag == ff_get_fourcc("XVIX"))
 503             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 504
 505         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
 506             s->workaround_bugs|= FF_BUG_UMP4;
 507             s->workaround_bugs|= FF_BUG_AC_VLC;
 508         }
 509
 510         if(s->divx_version>=500){
 511             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 512         }
 513
 514         if(s->divx_version>502){
 515             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 516         }
 517
 518         if(s->xvid_build && s->xvid_build<=3)
 519             s->padding_bug_score= 256*256*256*64;
 520
 521         if(s->xvid_build && s->xvid_build<=1)
 522             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 523
 524         if(s->xvid_build && s->xvid_build<=12)
 525             s->workaround_bugs|= FF_BUG_EDGE;
 526
 527 #define SET_QPEL_FUNC(postfix1, postfix2) \
 528     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 529     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 530     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 531
 532         if(s->lavc_build && s->lavc_build<4653)
 533             s->workaround_bugs|= FF_BUG_STD_QPEL;
 534
 535         if(s->lavc_build && s->lavc_build<4655)
 536             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 537
 538         if(s->lavc_build && s->lavc_build<4618){
 539             s->workaround_bugs|= FF_BUG_EDGE;
 540         }
 541
 542         if(s->divx_version)
 543             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 544 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 545         if(s->divx_version==501 && s->divx_build==20020416)
 546             s->padding_bug_score= 256*256*256*64;
 547
 548         if(s->divx_version && s->divx_version<500){
 549             s->workaround_bugs|= FF_BUG_EDGE;
 550         }
 551
 552 #if 0
 553         if(s->divx_version==500)
 554             s->padding_bug_score= 256*256*256*64;
 555
 556         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 557          * lets hope this at least works
 558          */
 559         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 560            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 561             s->workaround_bugs|= FF_BUG_NO_PADDING;
 562
 563         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 564             s->workaround_bugs|= FF_BUG_NO_PADDING;
 565 #endif
 566     }
 567
 568     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 569         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 570         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 571         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 572         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 573         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 574         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 575
 576         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 577         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 578         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 579         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 580         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 581         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 582     }
 583
 584     if(avctx->debug & FF_DEBUG_BUGS)
 585         printf("bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 586                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 587                s->divx_packed ? "p" : "");
 588
 589 #if 0 // dump bits per frame / qp / complexity
 590 {
 591     static FILE *f=NULL;
 592     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 593     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 594 }
 595 #endif
 596
 597         /* After H263 & mpeg4 header decode we have the height, width,*/
 598         /* and other parameters. So then we could init the picture   */
 599         /* FIXME: By the way H263 decoder is evolving it should have */
 600         /* an H263EncContext                                         */
 601     if(s->aspected_height)
 602         new_aspect= s->aspected_width*s->width / (float)(s->height*s->aspected_height);
 603     else
 604         new_aspect=0;
 605
 606     if (   s->width != avctx->width || s->height != avctx->height
 607         || ABS(new_aspect - avctx->aspect_ratio) > 0.001) {
 608         /* H.263 could change picture size any time */
 609         MPV_common_end(s);
 610     }
 611     if (!s->context_initialized) {
 612         avctx->width = s->width;
 613         avctx->height = s->height;
 614         avctx->aspect_ratio= new_aspect;
 615
 616         goto retry;
 617     }
 618
 619     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 620         s->gob_index = ff_h263_get_gob_height(s);
 621
 622     // for hurry_up==5
 623     s->current_picture.pict_type= s->pict_type;
 624     s->current_picture.key_frame= s->pict_type == I_TYPE;
 625
 626     /* skip b frames if we dont have reference frames */
 627     if(s->last_picture_ptr==NULL && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 628     /* skip b frames if we are in a hurry */
 629     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 630     /* skip everything if we are in a hurry>=5 */
 631     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 632
 633     if(s->next_p_frame_damaged){
 634         if(s->pict_type==B_TYPE)
 635             return get_consumed_bytes(s, buf_size);
 636         else
 637             s->next_p_frame_damaged=0;
 638     }
 639
 640     if(MPV_frame_start(s, avctx) < 0)
 641         return -1;
 642
 643 #ifdef DEBUG
 644     printf("qscale=%d\n", s->qscale);
 645 #endif
 646
 647     ff_er_frame_start(s);
 648
 649     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 650     //which isnt available before MPV_frame_start()
 651     if (s->msmpeg4_version==5){
 652         if(ff_wmv2_decode_secondary_picture_header(s) < 0)
 653             return -1;
 654     }
 655
 656     /* decode each macroblock */
 657     s->mb_x=0;
 658     s->mb_y=0;
 659
 660     decode_slice(s);
 661     while(s->mb_y<s->mb_height){
 662         if(s->msmpeg4_version){
 663             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
 664                 break;
 665         }else{
 666             if(ff_h263_resync(s)<0)
 667                 break;
 668         }
 669
 670         if(s->msmpeg4_version<4 && s->h263_pred)
 671             ff_mpeg4_clean_buffers(s);
 672
 673         decode_slice(s);
 674     }
 675
 676     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
 677         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
 678             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 679         }
 680
 681     /* divx 5.01+ bistream reorder stuff */
 682     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
 683         int current_pos= get_bits_count(&s->gb)>>3;
 684
 685         if(   buf_size - current_pos > 5
 686            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 687             int i;
 688             int startcode_found=0;
 689             for(i=current_pos; i<buf_size-3; i++){
 690                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 691                     startcode_found=1;
 692                     break;
 693                 }
 694             }
 695             if(startcode_found){
 696                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 697                 s->bitstream_buffer_size= buf_size - current_pos;
 698             }
 699         }
 700     }
 701
 702     ff_er_frame_end(s);
 703
 704     MPV_frame_end(s);
 705
 706 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 707 assert(s->current_picture.pict_type == s->pict_type);
 708     if(s->pict_type==B_TYPE || s->low_delay){
 709         *pict= *(AVFrame*)&s->current_picture;
 710         ff_print_debug_info(s, s->current_picture_ptr);
 711     } else {
 712         *pict= *(AVFrame*)&s->last_picture;
 713         ff_print_debug_info(s, s->last_picture_ptr);
 714     }
 715
 716     /* Return the Picture timestamp as the frame number */
 717     /* we substract 1 because it is added on utils.c    */
 718     avctx->frame_number = s->picture_number - 1;
 719
 720     /* dont output the last pic after seeking */
 721     if(s->last_picture_ptr || s->low_delay)
 722         *data_size = sizeof(AVFrame);
 723 #ifdef PRINT_FRAME_TIME
 724 printf("%Ld\n", rdtsc()-time);
 725 #endif
 726
 727     return get_consumed_bytes(s, buf_size);
 728 }
 729
 730 static const AVOption mpeg4_decoptions[] =
 731 {
 732     AVOPTION_SUB(avoptions_workaround_bug),
 733     AVOPTION_END()
 734 };
 735
 736 AVCodec mpeg4_decoder = {
 737     "mpeg4",
 738     CODEC_TYPE_VIDEO,
 739     CODEC_ID_MPEG4,
 740     sizeof(MpegEncContext),
 741     ff_h263_decode_init,
 742     NULL,
 743     ff_h263_decode_end,
 744     ff_h263_decode_frame,
 745     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 746     .options = mpeg4_decoptions,
 747     .flush= ff_mpeg_flush,
 748 };
 749
 750 AVCodec h263_decoder = {
 751     "h263",
 752     CODEC_TYPE_VIDEO,
 753     CODEC_ID_H263,
 754     sizeof(MpegEncContext),
 755     ff_h263_decode_init,
 756     NULL,
 757     ff_h263_decode_end,
 758     ff_h263_decode_frame,
 759     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 760     .flush= ff_mpeg_flush,
 761 };
 762
 763 AVCodec msmpeg4v1_decoder = {
 764     "msmpeg4v1",
 765     CODEC_TYPE_VIDEO,
 766     CODEC_ID_MSMPEG4V1,
 767     sizeof(MpegEncContext),
 768     ff_h263_decode_init,
 769     NULL,
 770     ff_h263_decode_end,
 771     ff_h263_decode_frame,
 772     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 773     mpeg4_decoptions,
 774 };
 775
 776 AVCodec msmpeg4v2_decoder = {
 777     "msmpeg4v2",
 778     CODEC_TYPE_VIDEO,
 779     CODEC_ID_MSMPEG4V2,
 780     sizeof(MpegEncContext),
 781     ff_h263_decode_init,
 782     NULL,
 783     ff_h263_decode_end,
 784     ff_h263_decode_frame,
 785     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 786     mpeg4_decoptions,
 787 };
 788
 789 AVCodec msmpeg4v3_decoder = {
 790     "msmpeg4",
 791     CODEC_TYPE_VIDEO,
 792     CODEC_ID_MSMPEG4V3,
 793     sizeof(MpegEncContext),
 794     ff_h263_decode_init,
 795     NULL,
 796     ff_h263_decode_end,
 797     ff_h263_decode_frame,
 798     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 799     .options = mpeg4_decoptions,
 800 };
 801
 802 AVCodec wmv1_decoder = {
 803     "wmv1",
 804     CODEC_TYPE_VIDEO,
 805     CODEC_ID_WMV1,
 806     sizeof(MpegEncContext),
 807     ff_h263_decode_init,
 808     NULL,
 809     ff_h263_decode_end,
 810     ff_h263_decode_frame,
 811     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 812     mpeg4_decoptions,
 813 };
 814
 815 AVCodec h263i_decoder = {
 816     "h263i",
 817     CODEC_TYPE_VIDEO,
 818     CODEC_ID_H263I,
 819     sizeof(MpegEncContext),
 820     ff_h263_decode_init,
 821     NULL,
 822     ff_h263_decode_end,
 823     ff_h263_decode_frame,
 824     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 825     mpeg4_decoptions,
 826 };
 827
 828 AVCodec flv_decoder = {
 829     "flv",
 830     CODEC_TYPE_VIDEO,
 831     CODEC_ID_FLV1,
 832     sizeof(MpegEncContext),
 833     ff_h263_decode_init,
 834     NULL,
 835     ff_h263_decode_end,
 836     ff_h263_decode_frame,
 837     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1
 838 };