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 file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file libavcodec/h263dec.c
  25  * H.263 decoder.
  26  */
  27
  28 #include "internal.h"
  29 #include "avcodec.h"
  30 #include "dsputil.h"
  31 #include "mpegvideo.h"
  32 #include "h263_parser.h"
  33 #include "mpeg4video_parser.h"
  34 #include "msmpeg4.h"
  35
  36 //#define DEBUG
  37 //#define PRINT_FRAME_TIME
  38
  39 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  40 {
  41     MpegEncContext *s = avctx->priv_data;
  42
  43     s->avctx = avctx;
  44     s->out_format = FMT_H263;
  45
  46     s->width  = avctx->coded_width;
  47     s->height = avctx->coded_height;
  48     s->workaround_bugs= avctx->workaround_bugs;
  49
  50     // set defaults
  51     MPV_decode_defaults(s);
  52     s->quant_precision=5;
  53     s->decode_mb= ff_h263_decode_mb;
  54     s->low_delay= 1;
  55     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
  56     s->unrestricted_mv= 1;
  57
  58     /* select sub codec */
  59     switch(avctx->codec->id) {
  60     case CODEC_ID_H263:
  61         s->unrestricted_mv= 0;
  62         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
  63         break;
  64     case CODEC_ID_MPEG4:
  65         s->decode_mb= ff_mpeg4_decode_mb;
  66         s->time_increment_bits = 4; /* default value for broken headers */
  67         s->h263_pred = 1;
  68         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  69         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
  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_VC1:
  97     case CODEC_ID_WMV3:
  98         s->h263_msmpeg4 = 1;
  99         s->h263_pred = 1;
 100         s->msmpeg4_version=6;
 101         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 102         break;
 103     case CODEC_ID_H263I:
 104         break;
 105     case CODEC_ID_FLV1:
 106         s->h263_flv = 1;
 107         break;
 108     default:
 109         return -1;
 110     }
 111     s->codec_id= avctx->codec->id;
 112     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
 113
 114     /* for h263, we allocate the images after having read the header */
 115     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 116         if (MPV_common_init(s) < 0)
 117             return -1;
 118
 119     if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
 120         ff_msmpeg4_decode_init(s);
 121     else
 122         h263_decode_init_vlc(s);
 123
 124     return 0;
 125 }
 126
 127 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
 128 {
 129     MpegEncContext *s = avctx->priv_data;
 130
 131     MPV_common_end(s);
 132     return 0;
 133 }
 134
 135 /**
 136  * returns the number of bytes consumed for building the current frame
 137  */
 138 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 139     int pos= (get_bits_count(&s->gb)+7)>>3;
 140
 141     if(s->divx_packed || s->avctx->hwaccel){
 142         //we would have to scan through the whole buf to handle the weird reordering ...
 143         return buf_size;
 144     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 145         pos -= s->parse_context.last_index;
 146         if(pos<0) pos=0; // padding is not really read so this might be -1
 147         return pos;
 148     }else{
 149         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
 150         if(pos+10>buf_size) pos=buf_size; // oops ;)
 151
 152         return pos;
 153     }
 154 }
 155
 156 static int decode_slice(MpegEncContext *s){
 157     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
 158     const int mb_size= 16>>s->avctx->lowres;
 159     s->last_resync_gb= s->gb;
 160     s->first_slice_line= 1;
 161
 162     s->resync_mb_x= s->mb_x;
 163     s->resync_mb_y= s->mb_y;
 164
 165     ff_set_qscale(s, s->qscale);
 166
 167     if (s->avctx->hwaccel) {
 168         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
 169         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
 170         skip_bits_long(&s->gb, 8*(end - start));
 171         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
 172     }
 173
 174     if(s->partitioned_frame){
 175         const int qscale= s->qscale;
 176
 177         if(s->codec_id==CODEC_ID_MPEG4){
 178             if(ff_mpeg4_decode_partitions(s) < 0)
 179                 return -1;
 180         }
 181
 182         /* restore variables which were modified */
 183         s->first_slice_line=1;
 184         s->mb_x= s->resync_mb_x;
 185         s->mb_y= s->resync_mb_y;
 186         ff_set_qscale(s, qscale);
 187     }
 188
 189     for(; s->mb_y < s->mb_height; s->mb_y++) {
 190         /* per-row end of slice checks */
 191         if(s->msmpeg4_version){
 192             if(s->resync_mb_y + s->slice_height == s->mb_y){
 193                 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);
 194
 195                 return 0;
 196             }
 197         }
 198
 199         if(s->msmpeg4_version==1){
 200             s->last_dc[0]=
 201             s->last_dc[1]=
 202             s->last_dc[2]= 128;
 203         }
 204
 205         ff_init_block_index(s);
 206         for(; s->mb_x < s->mb_width; s->mb_x++) {
 207             int ret;
 208
 209             ff_update_block_index(s);
 210
 211             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 212                 s->first_slice_line=0;
 213             }
 214
 215             /* DCT & quantize */
 216
 217             s->mv_dir = MV_DIR_FORWARD;
 218             s->mv_type = MV_TYPE_16X16;
 219 //            s->mb_skipped = 0;
 220 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 221             ret= s->decode_mb(s, s->block);
 222
 223             if (s->pict_type!=FF_B_TYPE)
 224                 ff_h263_update_motion_val(s);
 225
 226             if(ret<0){
 227                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 228                 if(ret==SLICE_END){
 229                     MPV_decode_mb(s, s->block);
 230                     if(s->loop_filter)
 231                         ff_h263_loop_filter(s);
 232
 233 //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));
 234                     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);
 235
 236                     s->padding_bug_score--;
 237
 238                     if(++s->mb_x >= s->mb_width){
 239                         s->mb_x=0;
 240                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 241                         s->mb_y++;
 242                     }
 243                     return 0;
 244                 }else if(ret==SLICE_NOEND){
 245                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 246                     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);
 247                     return -1;
 248                 }
 249                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 250                 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);
 251
 252                 return -1;
 253             }
 254
 255             MPV_decode_mb(s, s->block);
 256             if(s->loop_filter)
 257                 ff_h263_loop_filter(s);
 258         }
 259
 260         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 261
 262         s->mb_x= 0;
 263     }
 264
 265     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 266
 267     /* try to detect the padding bug */
 268     if(      s->codec_id==CODEC_ID_MPEG4
 269        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 270        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 271        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 272 //       &&   !s->resync_marker
 273        &&   !s->data_partitioning){
 274
 275         const int bits_count= get_bits_count(&s->gb);
 276         const int bits_left = s->gb.size_in_bits - bits_count;
 277
 278         if(bits_left==0){
 279             s->padding_bug_score+=16;
 280         } else if(bits_left != 1){
 281             int v= show_bits(&s->gb, 8);
 282             v|= 0x7F >> (7-(bits_count&7));
 283
 284             if(v==0x7F && bits_left<=8)
 285                 s->padding_bug_score--;
 286             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 287                 s->padding_bug_score+= 4;
 288             else
 289                 s->padding_bug_score++;
 290         }
 291     }
 292
 293     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 294         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
 295             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 296         else
 297             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 298     }
 299
 300     // handle formats which don't have unique end markers
 301     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 302         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 303         int max_extra=7;
 304
 305         /* no markers in M$ crap */
 306         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
 307             max_extra+= 17;
 308
 309         /* buggy padding but the frame should still end approximately at the bitstream end */
 310         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
 311             max_extra+= 48;
 312         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 313             max_extra+= 256*256*256*64;
 314
 315         if(left>max_extra){
 316             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 317         }
 318         else if(left<0){
 319             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 320         }else
 321             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);
 322
 323         return 0;
 324     }
 325
 326     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 327             s->gb.size_in_bits - get_bits_count(&s->gb),
 328             show_bits(&s->gb, 24), s->padding_bug_score);
 329
 330     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);
 331
 332     return -1;
 333 }
 334
 335 int ff_h263_decode_frame(AVCodecContext *avctx,
 336                              void *data, int *data_size,
 337                              AVPacket *avpkt)
 338 {
 339     const uint8_t *buf = avpkt->data;
 340     int buf_size = avpkt->size;
 341     MpegEncContext *s = avctx->priv_data;
 342     int ret;
 343     AVFrame *pict = data;
 344
 345 #ifdef PRINT_FRAME_TIME
 346 uint64_t time= rdtsc();
 347 #endif
 348 #ifdef DEBUG
 349     av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
 350     if(buf_size>0)
 351         av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 352 #endif
 353     s->flags= avctx->flags;
 354     s->flags2= avctx->flags2;
 355
 356     /* no supplementary picture */
 357     if (buf_size == 0) {
 358         /* special case for last picture */
 359         if (s->low_delay==0 && s->next_picture_ptr) {
 360             *pict= *(AVFrame*)s->next_picture_ptr;
 361             s->next_picture_ptr= NULL;
 362
 363             *data_size = sizeof(AVFrame);
 364         }
 365
 366         return 0;
 367     }
 368
 369     if(s->flags&CODEC_FLAG_TRUNCATED){
 370         int next;
 371
 372         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
 373             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 374         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
 375             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 376         }else{
 377             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 378             return -1;
 379         }
 380
 381         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 382             return buf_size;
 383     }
 384
 385
 386 retry:
 387
 388     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 389         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 390     }else
 391         init_get_bits(&s->gb, buf, buf_size*8);
 392     s->bitstream_buffer_size=0;
 393
 394     if (!s->context_initialized) {
 395         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 396             return -1;
 397     }
 398
 399     /* We need to set current_picture_ptr before reading the header,
 400      * otherwise we cannot store anyting in there */
 401     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
 402         int i= ff_find_unused_picture(s, 0);
 403         s->current_picture_ptr= &s->picture[i];
 404     }
 405
 406     /* let's go :-) */
 407     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 408         ret= ff_wmv2_decode_picture_header(s);
 409     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 410         ret = msmpeg4_decode_picture_header(s);
 411     } else if (s->h263_pred) {
 412         if(s->avctx->extradata_size && s->picture_number==0){
 413             GetBitContext gb;
 414
 415             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 416             ret = ff_mpeg4_decode_picture_header(s, &gb);
 417         }
 418         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 419     } else if (s->codec_id == CODEC_ID_H263I) {
 420         ret = intel_h263_decode_picture_header(s);
 421     } else if (s->h263_flv) {
 422         ret = flv_h263_decode_picture_header(s);
 423     } else {
 424         ret = h263_decode_picture_header(s);
 425     }
 426
 427     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 428
 429     /* skip if the header was thrashed */
 430     if (ret < 0){
 431         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 432         return -1;
 433     }
 434
 435     avctx->has_b_frames= !s->low_delay;
 436
 437     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 438         if(s->stream_codec_tag == AV_RL32("XVID") ||
 439            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 440            s->codec_tag == AV_RL32("RMP4"))
 441             s->xvid_build= -1;
 442 #if 0
 443         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 444            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 445             s->xvid_build= -1;
 446 #endif
 447     }
 448
 449     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 450         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 451             s->divx_version= 400; //divx 4
 452     }
 453
 454     if(s->xvid_build && s->divx_version){
 455         s->divx_version=
 456         s->divx_build= 0;
 457     }
 458
 459     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 460         if(s->codec_tag == AV_RL32("XVIX"))
 461             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 462
 463         if(s->codec_tag == AV_RL32("UMP4")){
 464             s->workaround_bugs|= FF_BUG_UMP4;
 465         }
 466
 467         if(s->divx_version>=500 && s->divx_build<1814){
 468             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 469         }
 470
 471         if(s->divx_version>502 && s->divx_build<1814){
 472             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 473         }
 474
 475         if(s->xvid_build && s->xvid_build<=3)
 476             s->padding_bug_score= 256*256*256*64;
 477
 478         if(s->xvid_build && s->xvid_build<=1)
 479             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 480
 481         if(s->xvid_build && s->xvid_build<=12)
 482             s->workaround_bugs|= FF_BUG_EDGE;
 483
 484         if(s->xvid_build && s->xvid_build<=32)
 485             s->workaround_bugs|= FF_BUG_DC_CLIP;
 486
 487 #define SET_QPEL_FUNC(postfix1, postfix2) \
 488     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 489     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 490     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 491
 492         if(s->lavc_build && s->lavc_build<4653)
 493             s->workaround_bugs|= FF_BUG_STD_QPEL;
 494
 495         if(s->lavc_build && s->lavc_build<4655)
 496             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 497
 498         if(s->lavc_build && s->lavc_build<4670){
 499             s->workaround_bugs|= FF_BUG_EDGE;
 500         }
 501
 502         if(s->lavc_build && s->lavc_build<=4712)
 503             s->workaround_bugs|= FF_BUG_DC_CLIP;
 504
 505         if(s->divx_version)
 506             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 507 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 508         if(s->divx_version==501 && s->divx_build==20020416)
 509             s->padding_bug_score= 256*256*256*64;
 510
 511         if(s->divx_version && s->divx_version<500){
 512             s->workaround_bugs|= FF_BUG_EDGE;
 513         }
 514
 515         if(s->divx_version)
 516             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 517 #if 0
 518         if(s->divx_version==500)
 519             s->padding_bug_score= 256*256*256*64;
 520
 521         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 522          * Let us hope this at least works.
 523          */
 524         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 525            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 526             s->workaround_bugs|= FF_BUG_NO_PADDING;
 527
 528         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 529             s->workaround_bugs|= FF_BUG_NO_PADDING;
 530 #endif
 531     }
 532
 533     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 534         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 535         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 536         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 537         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 538         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 539         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 540
 541         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 542         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 543         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 544         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 545         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 546         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 547     }
 548
 549     if(avctx->debug & FF_DEBUG_BUGS)
 550         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 551                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 552                s->divx_packed ? "p" : "");
 553
 554 #if 0 // dump bits per frame / qp / complexity
 555 {
 556     static FILE *f=NULL;
 557     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 558     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 559 }
 560 #endif
 561
 562 #if HAVE_MMX
 563     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
 564         avctx->idct_algo= FF_IDCT_XVIDMMX;
 565         avctx->coded_width= 0; // force reinit
 566 //        dsputil_init(&s->dsp, avctx);
 567         s->picture_number=0;
 568     }
 569 #endif
 570
 571         /* After H263 & mpeg4 header decode we have the height, width,*/
 572         /* and other parameters. So then we could init the picture   */
 573         /* FIXME: By the way H263 decoder is evolving it should have */
 574         /* an H263EncContext                                         */
 575
 576     if (   s->width  != avctx->coded_width
 577         || s->height != avctx->coded_height) {
 578         /* H.263 could change picture size any time */
 579         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 580         s->parse_context.buffer=0;
 581         MPV_common_end(s);
 582         s->parse_context= pc;
 583     }
 584     if (!s->context_initialized) {
 585         avcodec_set_dimensions(avctx, s->width, s->height);
 586
 587         goto retry;
 588     }
 589
 590     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
 591         s->gob_index = ff_h263_get_gob_height(s);
 592
 593     // for hurry_up==5
 594     s->current_picture.pict_type= s->pict_type;
 595     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
 596
 597     /* skip B-frames if we don't have reference frames */
 598     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
 599     /* skip b frames if we are in a hurry */
 600     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
 601     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
 602        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
 603        ||  avctx->skip_frame >= AVDISCARD_ALL)
 604         return get_consumed_bytes(s, buf_size);
 605     /* skip everything if we are in a hurry>=5 */
 606     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 607
 608     if(s->next_p_frame_damaged){
 609         if(s->pict_type==FF_B_TYPE)
 610             return get_consumed_bytes(s, buf_size);
 611         else
 612             s->next_p_frame_damaged=0;
 613     }
 614
 615     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
 616         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
 617         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
 618     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
 619         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 620         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 621     }else{
 622         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 623         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 624     }
 625
 626     if(MPV_frame_start(s, avctx) < 0)
 627         return -1;
 628
 629     if (avctx->hwaccel) {
 630         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
 631             return -1;
 632     }
 633
 634 #ifdef DEBUG
 635     av_log(avctx, AV_LOG_DEBUG, "qscale=%d\n", s->qscale);
 636 #endif
 637
 638     ff_er_frame_start(s);
 639
 640     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 641     //which is not available before MPV_frame_start()
 642     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 643         ret = ff_wmv2_decode_secondary_picture_header(s);
 644         if(ret<0) return ret;
 645         if(ret==1) goto intrax8_decoded;
 646     }
 647
 648     /* decode each macroblock */
 649     s->mb_x=0;
 650     s->mb_y=0;
 651
 652     decode_slice(s);
 653     while(s->mb_y<s->mb_height){
 654         if(s->msmpeg4_version){
 655             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
 656                 break;
 657         }else{
 658             if(ff_h263_resync(s)<0)
 659                 break;
 660         }
 661
 662         if(s->msmpeg4_version<4 && s->h263_pred)
 663             ff_mpeg4_clean_buffers(s);
 664
 665         decode_slice(s);
 666     }
 667
 668     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
 669         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
 670             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 671         }
 672
 673     /* divx 5.01+ bistream reorder stuff */
 674     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
 675         int current_pos= get_bits_count(&s->gb)>>3;
 676         int startcode_found=0;
 677
 678         if(buf_size - current_pos > 5){
 679             int i;
 680             for(i=current_pos; i<buf_size-3; i++){
 681                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 682                     startcode_found=1;
 683                     break;
 684                 }
 685             }
 686         }
 687         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
 688             startcode_found=1;
 689             current_pos=0;
 690         }
 691
 692         if(startcode_found){
 693             av_fast_malloc(
 694                 &s->bitstream_buffer,
 695                 &s->allocated_bitstream_buffer_size,
 696                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 697             if (!s->bitstream_buffer)
 698                 return AVERROR(ENOMEM);
 699             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 700             s->bitstream_buffer_size= buf_size - current_pos;
 701         }
 702     }
 703
 704 intrax8_decoded:
 705     ff_er_frame_end(s);
 706
 707     if (avctx->hwaccel) {
 708         if (avctx->hwaccel->end_frame(avctx) < 0)
 709             return -1;
 710     }
 711
 712     MPV_frame_end(s);
 713
 714 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 715 assert(s->current_picture.pict_type == s->pict_type);
 716     if (s->pict_type == FF_B_TYPE || s->low_delay) {
 717         *pict= *(AVFrame*)s->current_picture_ptr;
 718     } else if (s->last_picture_ptr != NULL) {
 719         *pict= *(AVFrame*)s->last_picture_ptr;
 720     }
 721
 722     if(s->last_picture_ptr || s->low_delay){
 723         *data_size = sizeof(AVFrame);
 724         ff_print_debug_info(s, pict);
 725     }
 726
 727 #ifdef PRINT_FRAME_TIME
 728 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 729 #endif
 730
 731     return get_consumed_bytes(s, buf_size);
 732 }
 733
 734 AVCodec mpeg4_decoder = {
 735     "mpeg4",
 736     CODEC_TYPE_VIDEO,
 737     CODEC_ID_MPEG4,
 738     sizeof(MpegEncContext),
 739     ff_h263_decode_init,
 740     NULL,
 741     ff_h263_decode_end,
 742     ff_h263_decode_frame,
 743     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 744     .flush= ff_mpeg_flush,
 745     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
 746     .pix_fmts= ff_hwaccel_pixfmt_list_420,
 747 };
 748
 749 AVCodec h263_decoder = {
 750     "h263",
 751     CODEC_TYPE_VIDEO,
 752     CODEC_ID_H263,
 753     sizeof(MpegEncContext),
 754     ff_h263_decode_init,
 755     NULL,
 756     ff_h263_decode_end,
 757     ff_h263_decode_frame,
 758     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 759     .flush= ff_mpeg_flush,
 760     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 761     .pix_fmts= ff_hwaccel_pixfmt_list_420,
 762 };
 763
 764 AVCodec msmpeg4v1_decoder = {
 765     "msmpeg4v1",
 766     CODEC_TYPE_VIDEO,
 767     CODEC_ID_MSMPEG4V1,
 768     sizeof(MpegEncContext),
 769     ff_h263_decode_init,
 770     NULL,
 771     ff_h263_decode_end,
 772     ff_h263_decode_frame,
 773     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 774     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
 775     .pix_fmts= ff_pixfmt_list_420,
 776 };
 777
 778 AVCodec msmpeg4v2_decoder = {
 779     "msmpeg4v2",
 780     CODEC_TYPE_VIDEO,
 781     CODEC_ID_MSMPEG4V2,
 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     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
 789     .pix_fmts= ff_pixfmt_list_420,
 790 };
 791
 792 AVCodec msmpeg4v3_decoder = {
 793     "msmpeg4",
 794     CODEC_TYPE_VIDEO,
 795     CODEC_ID_MSMPEG4V3,
 796     sizeof(MpegEncContext),
 797     ff_h263_decode_init,
 798     NULL,
 799     ff_h263_decode_end,
 800     ff_h263_decode_frame,
 801     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 802     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
 803     .pix_fmts= ff_pixfmt_list_420,
 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     .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
 817     .pix_fmts= ff_pixfmt_list_420,
 818 };
 819
 820 AVCodec h263i_decoder = {
 821     "h263i",
 822     CODEC_TYPE_VIDEO,
 823     CODEC_ID_H263I,
 824     sizeof(MpegEncContext),
 825     ff_h263_decode_init,
 826     NULL,
 827     ff_h263_decode_end,
 828     ff_h263_decode_frame,
 829     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 830     .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
 831     .pix_fmts= ff_pixfmt_list_420,
 832 };
 833
 834 AVCodec flv_decoder = {
 835     "flv",
 836     CODEC_TYPE_VIDEO,
 837     CODEC_ID_FLV1,
 838     sizeof(MpegEncContext),
 839     ff_h263_decode_init,
 840     NULL,
 841     ff_h263_decode_end,
 842     ff_h263_decode_frame,
 843     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 844     .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV)"),
 845     .pix_fmts= ff_pixfmt_list_420,
 846 };