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

   1 /*
   2  * H.263 decoder
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /**
  22  * @file h263dec.c
  23  * H.263 decoder.
  24  */
  25
  26 #include "avcodec.h"
  27 #include "dsputil.h"
  28 #include "mpegvideo.h"
  29
  30 //#define DEBUG
  31 //#define PRINT_FRAME_TIME
  32
  33 int ff_h263_decode_init(AVCodecContext *avctx)
  34 {
  35     MpegEncContext *s = avctx->priv_data;
  36
  37     s->avctx = avctx;
  38     s->out_format = FMT_H263;
  39
  40     s->width = avctx->width;
  41     s->height = avctx->height;
  42     s->workaround_bugs= avctx->workaround_bugs;
  43
  44     // set defaults
  45     MPV_decode_defaults(s);
  46     s->quant_precision=5;
  47     s->decode_mb= ff_h263_decode_mb;
  48     s->low_delay= 1;
  49     avctx->pix_fmt= PIX_FMT_YUV420P;
  50     s->unrestricted_mv= 1;
  51
  52     /* select sub codec */
  53     switch(avctx->codec->id) {
  54     case CODEC_ID_H263:
  55         s->unrestricted_mv= 0;
  56         break;
  57     case CODEC_ID_MPEG4:
  58         s->decode_mb= ff_mpeg4_decode_mb;
  59         s->time_increment_bits = 4; /* default value for broken headers */
  60         s->h263_pred = 1;
  61         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  62         break;
  63     case CODEC_ID_MSMPEG4V1:
  64         s->h263_msmpeg4 = 1;
  65         s->h263_pred = 1;
  66         s->msmpeg4_version=1;
  67         break;
  68     case CODEC_ID_MSMPEG4V2:
  69         s->h263_msmpeg4 = 1;
  70         s->h263_pred = 1;
  71         s->msmpeg4_version=2;
  72         break;
  73     case CODEC_ID_MSMPEG4V3:
  74         s->h263_msmpeg4 = 1;
  75         s->h263_pred = 1;
  76         s->msmpeg4_version=3;
  77         break;
  78     case CODEC_ID_WMV1:
  79         s->h263_msmpeg4 = 1;
  80         s->h263_pred = 1;
  81         s->msmpeg4_version=4;
  82         break;
  83     case CODEC_ID_WMV2:
  84         s->h263_msmpeg4 = 1;
  85         s->h263_pred = 1;
  86         s->msmpeg4_version=5;
  87         break;
  88     case CODEC_ID_H263I:
  89         break;
  90     case CODEC_ID_FLV1:
  91         s->h263_flv = 1;
  92         break;
  93     default:
  94         return -1;
  95     }
  96     s->codec_id= avctx->codec->id;
  97
  98     /* for h263, we allocate the images after having read the header */
  99     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 100         if (MPV_common_init(s) < 0)
 101             return -1;
 102
 103     if (s->h263_msmpeg4)
 104         ff_msmpeg4_decode_init(s);
 105     else
 106         h263_decode_init_vlc(s);
 107
 108     return 0;
 109 }
 110
 111 int ff_h263_decode_end(AVCodecContext *avctx)
 112 {
 113     MpegEncContext *s = avctx->priv_data;
 114
 115     MPV_common_end(s);
 116     return 0;
 117 }
 118
 119 /**
 120  * retunrs the number of bytes consumed for building the current frame
 121  */
 122 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 123     int pos= (get_bits_count(&s->gb)+7)>>3;
 124
 125     if(s->divx_packed){
 126         //we would have to scan through the whole buf to handle the weird reordering ...
 127         return buf_size;
 128     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 129         pos -= s->parse_context.last_index;
 130         if(pos<0) pos=0; // padding is not really read so this might be -1
 131         return pos;
 132     }else{
 133         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
 134         if(pos+10>buf_size) pos=buf_size; // oops ;)
 135
 136         return pos;
 137     }
 138 }
 139
 140 static int decode_slice(MpegEncContext *s){
 141     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
 142     s->last_resync_gb= s->gb;
 143     s->first_slice_line= 1;
 144
 145     s->resync_mb_x= s->mb_x;
 146     s->resync_mb_y= s->mb_y;
 147
 148     ff_set_qscale(s, s->qscale);
 149
 150     if(s->partitioned_frame){
 151         const int qscale= s->qscale;
 152
 153         if(s->codec_id==CODEC_ID_MPEG4){
 154             if(ff_mpeg4_decode_partitions(s) < 0)
 155                 return -1;
 156         }
 157
 158         /* restore variables which were modified */
 159         s->first_slice_line=1;
 160         s->mb_x= s->resync_mb_x;
 161         s->mb_y= s->resync_mb_y;
 162         ff_set_qscale(s, qscale);
 163     }
 164
 165     for(; s->mb_y < s->mb_height; s->mb_y++) {
 166         /* per-row end of slice checks */
 167         if(s->msmpeg4_version){
 168             if(s->resync_mb_y + s->slice_height == s->mb_y){
 169                 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);
 170
 171                 return 0;
 172             }
 173         }
 174
 175         if(s->msmpeg4_version==1){
 176             s->last_dc[0]=
 177             s->last_dc[1]=
 178             s->last_dc[2]= 128;
 179         }
 180
 181         ff_init_block_index(s);
 182         for(; s->mb_x < s->mb_width; s->mb_x++) {
 183             int ret;
 184
 185             ff_update_block_index(s);
 186
 187             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 188                 s->first_slice_line=0;
 189             }
 190
 191             /* DCT & quantize */
 192             s->dsp.clear_blocks(s->block[0]);
 193
 194             s->mv_dir = MV_DIR_FORWARD;
 195             s->mv_type = MV_TYPE_16X16;
 196 //            s->mb_skiped = 0;
 197 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 198             ret= s->decode_mb(s, s->block);
 199
 200             if (s->pict_type!=B_TYPE)
 201                 ff_h263_update_motion_val(s);
 202
 203             if(ret<0){
 204                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 205                 if(ret==SLICE_END){
 206                     MPV_decode_mb(s, s->block);
 207                     if(s->loop_filter)
 208                         ff_h263_loop_filter(s);
 209
 210 //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));
 211                     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);
 212
 213                     s->padding_bug_score--;
 214
 215                     if(++s->mb_x >= s->mb_width){
 216                         s->mb_x=0;
 217                         ff_draw_horiz_band(s, s->mb_y*16, 16);
 218                         s->mb_y++;
 219                     }
 220                     return 0;
 221                 }else if(ret==SLICE_NOEND){
 222                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 223                     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);
 224                     return -1;
 225                 }
 226                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 227                 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);
 228
 229                 return -1;
 230             }
 231
 232             MPV_decode_mb(s, s->block);
 233             if(s->loop_filter)
 234                 ff_h263_loop_filter(s);
 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             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 287         }
 288         else if(left<0){
 289             av_log(s->avctx, AV_LOG_ERROR, "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     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 297             s->gb.size_in_bits - get_bits_count(&s->gb),
 298             show_bits(&s->gb, 24), s->padding_bug_score);
 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 static int h263_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
 345     ParseContext *pc= &s->parse_context;
 346     int vop_found, i;
 347     uint32_t state;
 348
 349     vop_found= pc->frame_start_found;
 350     state= pc->state;
 351
 352     i=0;
 353     if(!vop_found){
 354         for(i=0; i<buf_size; i++){
 355             state= (state<<8) | buf[i];
 356             if(state>>(32-22) == 0x20){
 357                 i++;
 358                 vop_found=1;
 359                 break;
 360             }
 361         }
 362     }
 363
 364     if(vop_found){
 365       for(; i<buf_size; i++){
 366         state= (state<<8) | buf[i];
 367         if(state>>(32-22) == 0x20){
 368             pc->frame_start_found=0;
 369             pc->state=-1;
 370             return i-3;
 371         }
 372       }
 373     }
 374     pc->frame_start_found= vop_found;
 375     pc->state= state;
 376
 377     return END_NOT_FOUND;
 378 }
 379
 380 int ff_h263_decode_frame(AVCodecContext *avctx,
 381                              void *data, int *data_size,
 382                              uint8_t *buf, int buf_size)
 383 {
 384     MpegEncContext *s = avctx->priv_data;
 385     int ret;
 386     AVFrame *pict = data;
 387
 388 #ifdef PRINT_FRAME_TIME
 389 uint64_t time= rdtsc();
 390 #endif
 391 #ifdef DEBUG
 392     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 393     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 394 #endif
 395     s->flags= avctx->flags;
 396     s->flags2= avctx->flags2;
 397
 398     *data_size = 0;
 399
 400     /* no supplementary picture */
 401     if (buf_size == 0) {
 402         /* special case for last picture */
 403         if (s->low_delay==0 && s->next_picture_ptr) {
 404             *pict= *(AVFrame*)s->next_picture_ptr;
 405             s->next_picture_ptr= NULL;
 406
 407             *data_size = sizeof(AVFrame);
 408         }
 409
 410         return 0;
 411     }
 412
 413     if(s->flags&CODEC_FLAG_TRUNCATED){
 414         int next;
 415
 416         if(s->codec_id==CODEC_ID_MPEG4){
 417             next= mpeg4_find_frame_end(s, buf, buf_size);
 418         }else if(s->codec_id==CODEC_ID_H263){
 419             next= h263_find_frame_end(s, buf, buf_size);
 420         }else{
 421             av_log(s->avctx, AV_LOG_ERROR, "this codec doesnt support truncated bitstreams\n");
 422             return -1;
 423         }
 424
 425         if( ff_combine_frame(s, next, &buf, &buf_size) < 0 )
 426             return buf_size;
 427     }
 428
 429
 430 retry:
 431
 432     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 433         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 434     }else
 435         init_get_bits(&s->gb, buf, buf_size*8);
 436     s->bitstream_buffer_size=0;
 437
 438     if (!s->context_initialized) {
 439         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 440             return -1;
 441     }
 442
 443     //we need to set current_picture_ptr before reading the header, otherwise we cant store anyting im there
 444     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
 445         int i= ff_find_unused_picture(s, 0);
 446         s->current_picture_ptr= &s->picture[i];
 447     }
 448
 449     /* let's go :-) */
 450     if (s->msmpeg4_version==5) {
 451         ret= ff_wmv2_decode_picture_header(s);
 452     } else if (s->msmpeg4_version) {
 453         ret = msmpeg4_decode_picture_header(s);
 454     } else if (s->h263_pred) {
 455         if(s->avctx->extradata_size && s->picture_number==0){
 456             GetBitContext gb;
 457
 458             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 459             ret = ff_mpeg4_decode_picture_header(s, &gb);
 460         }
 461         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 462
 463         if(s->flags& CODEC_FLAG_LOW_DELAY)
 464             s->low_delay=1;
 465     } else if (s->codec_id == CODEC_ID_H263I) {
 466         ret = intel_h263_decode_picture_header(s);
 467     } else if (s->h263_flv) {
 468         ret = flv_h263_decode_picture_header(s);
 469     } else {
 470         ret = h263_decode_picture_header(s);
 471     }
 472
 473     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 474
 475     /* skip if the header was thrashed */
 476     if (ret < 0){
 477         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 478         return -1;
 479     }
 480
 481     avctx->has_b_frames= !s->low_delay;
 482
 483     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 484         if(s->avctx->stream_codec_tag == ff_get_fourcc("XVID") ||
 485            s->avctx->codec_tag == ff_get_fourcc("XVID") || s->avctx->codec_tag == ff_get_fourcc("XVIX"))
 486             s->xvid_build= -1;
 487 #if 0
 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 #endif
 492     }
 493
 494     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 495         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 496             s->divx_version= 400; //divx 4
 497     }
 498
 499     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 500         s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 501
 502         if(s->padding_bug_score > -2 && !s->data_partitioning && (s->divx_version || !s->resync_marker))
 503             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 504
 505         if(s->avctx->codec_tag == ff_get_fourcc("XVIX"))
 506             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 507
 508         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
 509             s->workaround_bugs|= FF_BUG_UMP4;
 510         }
 511
 512         if(s->divx_version>=500){
 513             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 514         }
 515
 516         if(s->divx_version>502){
 517             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 518         }
 519
 520         if(s->xvid_build && s->xvid_build<=3)
 521             s->padding_bug_score= 256*256*256*64;
 522
 523         if(s->xvid_build && s->xvid_build<=1)
 524             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 525
 526         if(s->xvid_build && s->xvid_build<=12)
 527             s->workaround_bugs|= FF_BUG_EDGE;
 528
 529 #define SET_QPEL_FUNC(postfix1, postfix2) \
 530     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 531     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 532     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 533
 534         if(s->lavc_build && s->lavc_build<4653)
 535             s->workaround_bugs|= FF_BUG_STD_QPEL;
 536
 537         if(s->lavc_build && s->lavc_build<4655)
 538             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 539
 540         if(s->lavc_build && s->lavc_build<4670){
 541             s->workaround_bugs|= FF_BUG_EDGE;
 542         }
 543
 544         if(s->divx_version)
 545             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 546 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 547         if(s->divx_version==501 && s->divx_build==20020416)
 548             s->padding_bug_score= 256*256*256*64;
 549
 550         if(s->divx_version && s->divx_version<500){
 551             s->workaround_bugs|= FF_BUG_EDGE;
 552         }
 553
 554 #if 0
 555         if(s->divx_version==500)
 556             s->padding_bug_score= 256*256*256*64;
 557
 558         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 559          * lets hope this at least works
 560          */
 561         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 562            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 563             s->workaround_bugs|= FF_BUG_NO_PADDING;
 564
 565         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 566             s->workaround_bugs|= FF_BUG_NO_PADDING;
 567 #endif
 568     }
 569
 570     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 571         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 572         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 573         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 574         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 575         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 576         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 577
 578         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 579         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 580         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 581         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 582         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 583         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 584     }
 585
 586     if(avctx->debug & FF_DEBUG_BUGS)
 587         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 588                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 589                s->divx_packed ? "p" : "");
 590
 591 #if 0 // dump bits per frame / qp / complexity
 592 {
 593     static FILE *f=NULL;
 594     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 595     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 596 }
 597 #endif
 598
 599         /* After H263 & mpeg4 header decode we have the height, width,*/
 600         /* and other parameters. So then we could init the picture   */
 601         /* FIXME: By the way H263 decoder is evolving it should have */
 602         /* an H263EncContext                                         */
 603
 604     if (   s->width != avctx->width || s->height != avctx->height) {
 605         /* H.263 could change picture size any time */
 606         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 607         s->parse_context.buffer=0;
 608         MPV_common_end(s);
 609         s->parse_context= pc;
 610     }
 611     if (!s->context_initialized) {
 612         avctx->width = s->width;
 613         avctx->height = s->height;
 614
 615         goto retry;
 616     }
 617
 618     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 619         s->gob_index = ff_h263_get_gob_height(s);
 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         int startcode_found=0;
 684
 685         if(   buf_size - current_pos > 5
 686            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 687             int i;
 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         }
 695         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
 696             startcode_found=1;
 697             current_pos=0;
 698         }
 699
 700         if(startcode_found){
 701             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 702             s->bitstream_buffer_size= buf_size - current_pos;
 703         }
 704     }
 705
 706     ff_er_frame_end(s);
 707
 708     MPV_frame_end(s);
 709
 710 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 711 assert(s->current_picture.pict_type == s->pict_type);
 712     if(s->pict_type==B_TYPE || s->low_delay){
 713         *pict= *(AVFrame*)&s->current_picture;
 714         ff_print_debug_info(s, pict);
 715     } else {
 716         *pict= *(AVFrame*)&s->last_picture;
 717         ff_print_debug_info(s, pict);
 718     }
 719
 720     /* Return the Picture timestamp as the frame number */
 721     /* we substract 1 because it is added on utils.c    */
 722     avctx->frame_number = s->picture_number - 1;
 723
 724     /* dont output the last pic after seeking */
 725     if(s->last_picture_ptr || s->low_delay)
 726         *data_size = sizeof(AVFrame);
 727 #ifdef PRINT_FRAME_TIME
 728 printf("%Ld\n", rdtsc()-time);
 729 #endif
 730
 731     return get_consumed_bytes(s, buf_size);
 732 }
 733
 734 static const AVOption mpeg4_decoptions[] =
 735 {
 736     AVOPTION_SUB(avoptions_workaround_bug),
 737     AVOPTION_END()
 738 };
 739
 740 AVCodec mpeg4_decoder = {
 741     "mpeg4",
 742     CODEC_TYPE_VIDEO,
 743     CODEC_ID_MPEG4,
 744     sizeof(MpegEncContext),
 745     ff_h263_decode_init,
 746     NULL,
 747     ff_h263_decode_end,
 748     ff_h263_decode_frame,
 749     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 750     .options = mpeg4_decoptions,
 751     .flush= ff_mpeg_flush,
 752 };
 753
 754 AVCodec h263_decoder = {
 755     "h263",
 756     CODEC_TYPE_VIDEO,
 757     CODEC_ID_H263,
 758     sizeof(MpegEncContext),
 759     ff_h263_decode_init,
 760     NULL,
 761     ff_h263_decode_end,
 762     ff_h263_decode_frame,
 763     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
 764     .flush= ff_mpeg_flush,
 765 };
 766
 767 AVCodec msmpeg4v1_decoder = {
 768     "msmpeg4v1",
 769     CODEC_TYPE_VIDEO,
 770     CODEC_ID_MSMPEG4V1,
 771     sizeof(MpegEncContext),
 772     ff_h263_decode_init,
 773     NULL,
 774     ff_h263_decode_end,
 775     ff_h263_decode_frame,
 776     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 777     mpeg4_decoptions,
 778 };
 779
 780 AVCodec msmpeg4v2_decoder = {
 781     "msmpeg4v2",
 782     CODEC_TYPE_VIDEO,
 783     CODEC_ID_MSMPEG4V2,
 784     sizeof(MpegEncContext),
 785     ff_h263_decode_init,
 786     NULL,
 787     ff_h263_decode_end,
 788     ff_h263_decode_frame,
 789     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 790     mpeg4_decoptions,
 791 };
 792
 793 AVCodec msmpeg4v3_decoder = {
 794     "msmpeg4",
 795     CODEC_TYPE_VIDEO,
 796     CODEC_ID_MSMPEG4V3,
 797     sizeof(MpegEncContext),
 798     ff_h263_decode_init,
 799     NULL,
 800     ff_h263_decode_end,
 801     ff_h263_decode_frame,
 802     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 803     .options = mpeg4_decoptions,
 804 };
 805
 806 AVCodec wmv1_decoder = {
 807     "wmv1",
 808     CODEC_TYPE_VIDEO,
 809     CODEC_ID_WMV1,
 810     sizeof(MpegEncContext),
 811     ff_h263_decode_init,
 812     NULL,
 813     ff_h263_decode_end,
 814     ff_h263_decode_frame,
 815     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 816     mpeg4_decoptions,
 817 };
 818
 819 AVCodec h263i_decoder = {
 820     "h263i",
 821     CODEC_TYPE_VIDEO,
 822     CODEC_ID_H263I,
 823     sizeof(MpegEncContext),
 824     ff_h263_decode_init,
 825     NULL,
 826     ff_h263_decode_end,
 827     ff_h263_decode_frame,
 828     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 829     mpeg4_decoptions,
 830 };
 831
 832 AVCodec flv_decoder = {
 833     "flv",
 834     CODEC_TYPE_VIDEO,
 835     CODEC_ID_FLV1,
 836     sizeof(MpegEncContext),
 837     ff_h263_decode_init,
 838     NULL,
 839     ff_h263_decode_end,
 840     ff_h263_decode_frame,
 841     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1
 842 };