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 h263dec.c
  25  * H.263 decoder.
  26  */
  27
  28 #include "avcodec.h"
  29 #include "dsputil.h"
  30 #include "mpegvideo.h"
  31 #include "h263_parser.h"
  32 #include "mpeg4video_parser.h"
  33 #include "msmpeg4.h"
  34
  35 //#define DEBUG
  36 //#define PRINT_FRAME_TIME
  37
  38 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  39 {
  40     MpegEncContext *s = avctx->priv_data;
  41
  42     s->avctx = avctx;
  43     s->out_format = FMT_H263;
  44
  45     s->width  = avctx->coded_width;
  46     s->height = avctx->coded_height;
  47     s->workaround_bugs= avctx->workaround_bugs;
  48
  49     // set defaults
  50     MPV_decode_defaults(s);
  51     s->quant_precision=5;
  52     s->decode_mb= ff_h263_decode_mb;
  53     s->low_delay= 1;
  54     avctx->pix_fmt= PIX_FMT_YUV420P;
  55     s->unrestricted_mv= 1;
  56
  57     /* select sub codec */
  58     switch(avctx->codec->id) {
  59     case CODEC_ID_H263:
  60         s->unrestricted_mv= 0;
  61         break;
  62     case CODEC_ID_MPEG4:
  63         s->decode_mb= ff_mpeg4_decode_mb;
  64         s->time_increment_bits = 4; /* default value for broken headers */
  65         s->h263_pred = 1;
  66         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  67         break;
  68     case CODEC_ID_MSMPEG4V1:
  69         s->h263_msmpeg4 = 1;
  70         s->h263_pred = 1;
  71         s->msmpeg4_version=1;
  72         break;
  73     case CODEC_ID_MSMPEG4V2:
  74         s->h263_msmpeg4 = 1;
  75         s->h263_pred = 1;
  76         s->msmpeg4_version=2;
  77         break;
  78     case CODEC_ID_MSMPEG4V3:
  79         s->h263_msmpeg4 = 1;
  80         s->h263_pred = 1;
  81         s->msmpeg4_version=3;
  82         break;
  83     case CODEC_ID_WMV1:
  84         s->h263_msmpeg4 = 1;
  85         s->h263_pred = 1;
  86         s->msmpeg4_version=4;
  87         break;
  88     case CODEC_ID_WMV2:
  89         s->h263_msmpeg4 = 1;
  90         s->h263_pred = 1;
  91         s->msmpeg4_version=5;
  92         break;
  93     case CODEC_ID_VC1:
  94     case CODEC_ID_WMV3:
  95         s->h263_msmpeg4 = 1;
  96         s->h263_pred = 1;
  97         s->msmpeg4_version=6;
  98         break;
  99     case CODEC_ID_H263I:
 100         break;
 101     case CODEC_ID_FLV1:
 102         s->h263_flv = 1;
 103         break;
 104     default:
 105         return -1;
 106     }
 107     s->codec_id= avctx->codec->id;
 108
 109     /* for h263, we allocate the images after having read the header */
 110     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 111         if (MPV_common_init(s) < 0)
 112             return -1;
 113
 114     if (ENABLE_MSMPEG4_DECODER && s->h263_msmpeg4)
 115         ff_msmpeg4_decode_init(s);
 116     else
 117         h263_decode_init_vlc(s);
 118
 119     return 0;
 120 }
 121
 122 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
 123 {
 124     MpegEncContext *s = avctx->priv_data;
 125
 126     MPV_common_end(s);
 127     return 0;
 128 }
 129
 130 /**
 131  * returns the number of bytes consumed for building the current frame
 132  */
 133 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 134     int pos= (get_bits_count(&s->gb)+7)>>3;
 135
 136     if(s->divx_packed){
 137         //we would have to scan through the whole buf to handle the weird reordering ...
 138         return buf_size;
 139     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 140         pos -= s->parse_context.last_index;
 141         if(pos<0) pos=0; // padding is not really read so this might be -1
 142         return pos;
 143     }else{
 144         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
 145         if(pos+10>buf_size) pos=buf_size; // oops ;)
 146
 147         return pos;
 148     }
 149 }
 150
 151 static int decode_slice(MpegEncContext *s){
 152     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
 153     const int mb_size= 16>>s->avctx->lowres;
 154     s->last_resync_gb= s->gb;
 155     s->first_slice_line= 1;
 156
 157     s->resync_mb_x= s->mb_x;
 158     s->resync_mb_y= s->mb_y;
 159
 160     ff_set_qscale(s, s->qscale);
 161
 162     if(s->partitioned_frame){
 163         const int qscale= s->qscale;
 164
 165         if(s->codec_id==CODEC_ID_MPEG4){
 166             if(ff_mpeg4_decode_partitions(s) < 0)
 167                 return -1;
 168         }
 169
 170         /* restore variables which were modified */
 171         s->first_slice_line=1;
 172         s->mb_x= s->resync_mb_x;
 173         s->mb_y= s->resync_mb_y;
 174         ff_set_qscale(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
 205             s->mv_dir = MV_DIR_FORWARD;
 206             s->mv_type = MV_TYPE_16X16;
 207 //            s->mb_skipped = 0;
 208 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 209             ret= s->decode_mb(s, s->block);
 210
 211             if (s->pict_type!=FF_B_TYPE)
 212                 ff_h263_update_motion_val(s);
 213
 214             if(ret<0){
 215                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 216                 if(ret==SLICE_END){
 217                     MPV_decode_mb(s, s->block);
 218                     if(s->loop_filter)
 219                         ff_h263_loop_filter(s);
 220
 221 //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));
 222                     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);
 223
 224                     s->padding_bug_score--;
 225
 226                     if(++s->mb_x >= s->mb_width){
 227                         s->mb_x=0;
 228                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 229                         s->mb_y++;
 230                     }
 231                     return 0;
 232                 }else if(ret==SLICE_NOEND){
 233                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 234                     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);
 235                     return -1;
 236                 }
 237                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 238                 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);
 239
 240                 return -1;
 241             }
 242
 243             MPV_decode_mb(s, s->block);
 244             if(s->loop_filter)
 245                 ff_h263_loop_filter(s);
 246         }
 247
 248         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 249
 250         s->mb_x= 0;
 251     }
 252
 253     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 254
 255     /* try to detect the padding bug */
 256     if(      s->codec_id==CODEC_ID_MPEG4
 257        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 258        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 259        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 260 //       &&   !s->resync_marker
 261        &&   !s->data_partitioning){
 262
 263         const int bits_count= get_bits_count(&s->gb);
 264         const int bits_left = s->gb.size_in_bits - bits_count;
 265
 266         if(bits_left==0){
 267             s->padding_bug_score+=16;
 268         } else if(bits_left != 1){
 269             int v= show_bits(&s->gb, 8);
 270             v|= 0x7F >> (7-(bits_count&7));
 271
 272             if(v==0x7F && bits_left<=8)
 273                 s->padding_bug_score--;
 274             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 275                 s->padding_bug_score+= 4;
 276             else
 277                 s->padding_bug_score++;
 278         }
 279     }
 280
 281     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 282         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
 283             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 284         else
 285             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 286     }
 287
 288     // handle formats which don't have unique end markers
 289     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 290         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 291         int max_extra=7;
 292
 293         /* no markers in M$ crap */
 294         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
 295             max_extra+= 17;
 296
 297         /* buggy padding but the frame should still end approximately at the bitstream end */
 298         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
 299             max_extra+= 48;
 300         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 301             max_extra+= 256*256*256*64;
 302
 303         if(left>max_extra){
 304             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 305         }
 306         else if(left<0){
 307             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 308         }else
 309             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);
 310
 311         return 0;
 312     }
 313
 314     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 315             s->gb.size_in_bits - get_bits_count(&s->gb),
 316             show_bits(&s->gb, 24), s->padding_bug_score);
 317
 318     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);
 319
 320     return -1;
 321 }
 322
 323 int ff_h263_decode_frame(AVCodecContext *avctx,
 324                              void *data, int *data_size,
 325                              const uint8_t *buf, int buf_size)
 326 {
 327     MpegEncContext *s = avctx->priv_data;
 328     int ret;
 329     AVFrame *pict = data;
 330
 331 #ifdef PRINT_FRAME_TIME
 332 uint64_t time= rdtsc();
 333 #endif
 334 #ifdef DEBUG
 335     av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
 336     if(buf_size>0)
 337         av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 338 #endif
 339     s->flags= avctx->flags;
 340     s->flags2= avctx->flags2;
 341
 342     /* no supplementary picture */
 343     if (buf_size == 0) {
 344         /* special case for last picture */
 345         if (s->low_delay==0 && s->next_picture_ptr) {
 346             *pict= *(AVFrame*)s->next_picture_ptr;
 347             s->next_picture_ptr= NULL;
 348
 349             *data_size = sizeof(AVFrame);
 350         }
 351
 352         return 0;
 353     }
 354
 355     if(s->flags&CODEC_FLAG_TRUNCATED){
 356         int next;
 357
 358         if(ENABLE_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
 359             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 360         }else if(ENABLE_H263_DECODER && s->codec_id==CODEC_ID_H263){
 361             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 362         }else{
 363             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 364             return -1;
 365         }
 366
 367         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 368             return buf_size;
 369     }
 370
 371
 372 retry:
 373
 374     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 375         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 376     }else
 377         init_get_bits(&s->gb, buf, buf_size*8);
 378     s->bitstream_buffer_size=0;
 379
 380     if (!s->context_initialized) {
 381         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 382             return -1;
 383     }
 384
 385     /* We need to set current_picture_ptr before reading the header,
 386      * otherwise we cannot store anyting in there */
 387     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
 388         int i= ff_find_unused_picture(s, 0);
 389         s->current_picture_ptr= &s->picture[i];
 390     }
 391
 392     /* let's go :-) */
 393     if (ENABLE_WMV2_DECODER && s->msmpeg4_version==5) {
 394         ret= ff_wmv2_decode_picture_header(s);
 395     } else if (ENABLE_MSMPEG4_DECODER && s->msmpeg4_version) {
 396         ret = msmpeg4_decode_picture_header(s);
 397     } else if (s->h263_pred) {
 398         if(s->avctx->extradata_size && s->picture_number==0){
 399             GetBitContext gb;
 400
 401             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 402             ret = ff_mpeg4_decode_picture_header(s, &gb);
 403         }
 404         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 405
 406         if(s->flags& CODEC_FLAG_LOW_DELAY)
 407             s->low_delay=1;
 408     } else if (s->codec_id == CODEC_ID_H263I) {
 409         ret = intel_h263_decode_picture_header(s);
 410     } else if (s->h263_flv) {
 411         ret = flv_h263_decode_picture_header(s);
 412     } else {
 413         ret = h263_decode_picture_header(s);
 414     }
 415
 416     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 417
 418     /* skip if the header was thrashed */
 419     if (ret < 0){
 420         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 421         return -1;
 422     }
 423
 424     avctx->has_b_frames= !s->low_delay;
 425
 426     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 427         if(s->stream_codec_tag == ff_get_fourcc("XVID") ||
 428            s->codec_tag == ff_get_fourcc("XVID") || s->codec_tag == ff_get_fourcc("XVIX") ||
 429            s->codec_tag == ff_get_fourcc("RMP4"))
 430             s->xvid_build= -1;
 431 #if 0
 432         if(s->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 433            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 434             s->xvid_build= -1;
 435 #endif
 436     }
 437
 438     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 439         if(s->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 440             s->divx_version= 400; //divx 4
 441     }
 442
 443     if(s->xvid_build && s->divx_version){
 444         s->divx_version=
 445         s->divx_build= 0;
 446     }
 447
 448     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 449         if(s->codec_tag == ff_get_fourcc("XVIX"))
 450             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 451
 452         if(s->codec_tag == ff_get_fourcc("UMP4")){
 453             s->workaround_bugs|= FF_BUG_UMP4;
 454         }
 455
 456         if(s->divx_version>=500 && s->divx_build<1814){
 457             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 458         }
 459
 460         if(s->divx_version>502 && s->divx_build<1814){
 461             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 462         }
 463
 464         if(s->xvid_build && s->xvid_build<=3)
 465             s->padding_bug_score= 256*256*256*64;
 466
 467         if(s->xvid_build && s->xvid_build<=1)
 468             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 469
 470         if(s->xvid_build && s->xvid_build<=12)
 471             s->workaround_bugs|= FF_BUG_EDGE;
 472
 473         if(s->xvid_build && s->xvid_build<=32)
 474             s->workaround_bugs|= FF_BUG_DC_CLIP;
 475
 476 #define SET_QPEL_FUNC(postfix1, postfix2) \
 477     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 478     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 479     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 480
 481         if(s->lavc_build && s->lavc_build<4653)
 482             s->workaround_bugs|= FF_BUG_STD_QPEL;
 483
 484         if(s->lavc_build && s->lavc_build<4655)
 485             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 486
 487         if(s->lavc_build && s->lavc_build<4670){
 488             s->workaround_bugs|= FF_BUG_EDGE;
 489         }
 490
 491         if(s->lavc_build && s->lavc_build<=4712)
 492             s->workaround_bugs|= FF_BUG_DC_CLIP;
 493
 494         if(s->divx_version)
 495             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 496 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 497         if(s->divx_version==501 && s->divx_build==20020416)
 498             s->padding_bug_score= 256*256*256*64;
 499
 500         if(s->divx_version && s->divx_version<500){
 501             s->workaround_bugs|= FF_BUG_EDGE;
 502         }
 503
 504         if(s->divx_version)
 505             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 506 #if 0
 507         if(s->divx_version==500)
 508             s->padding_bug_score= 256*256*256*64;
 509
 510         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 511          * lets hope this at least works
 512          */
 513         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 514            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 515             s->workaround_bugs|= FF_BUG_NO_PADDING;
 516
 517         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 518             s->workaround_bugs|= FF_BUG_NO_PADDING;
 519 #endif
 520     }
 521
 522     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 523         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 524         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 525         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 526         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 527         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 528         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 529
 530         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 531         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 532         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 533         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 534         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 535         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 536     }
 537
 538     if(avctx->debug & FF_DEBUG_BUGS)
 539         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 540                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 541                s->divx_packed ? "p" : "");
 542
 543 #if 0 // dump bits per frame / qp / complexity
 544 {
 545     static FILE *f=NULL;
 546     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 547     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 548 }
 549 #endif
 550
 551 #if defined(HAVE_MMX)
 552     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & MM_MMX)){
 553         avctx->idct_algo= FF_IDCT_XVIDMMX;
 554         avctx->coded_width= 0; // force reinit
 555 //        dsputil_init(&s->dsp, avctx);
 556         s->picture_number=0;
 557     }
 558 #endif
 559
 560         /* After H263 & mpeg4 header decode we have the height, width,*/
 561         /* and other parameters. So then we could init the picture   */
 562         /* FIXME: By the way H263 decoder is evolving it should have */
 563         /* an H263EncContext                                         */
 564
 565     if (   s->width  != avctx->coded_width
 566         || s->height != avctx->coded_height) {
 567         /* H.263 could change picture size any time */
 568         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 569         s->parse_context.buffer=0;
 570         MPV_common_end(s);
 571         s->parse_context= pc;
 572     }
 573     if (!s->context_initialized) {
 574         avcodec_set_dimensions(avctx, s->width, s->height);
 575
 576         goto retry;
 577     }
 578
 579     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 580         s->gob_index = ff_h263_get_gob_height(s);
 581
 582     // for hurry_up==5
 583     s->current_picture.pict_type= s->pict_type;
 584     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
 585
 586     /* skip B-frames if we don't have reference frames */
 587     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
 588     /* skip b frames if we are in a hurry */
 589     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
 590     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
 591        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
 592        ||  avctx->skip_frame >= AVDISCARD_ALL)
 593         return get_consumed_bytes(s, buf_size);
 594     /* skip everything if we are in a hurry>=5 */
 595     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 596
 597     if(s->next_p_frame_damaged){
 598         if(s->pict_type==FF_B_TYPE)
 599             return get_consumed_bytes(s, buf_size);
 600         else
 601             s->next_p_frame_damaged=0;
 602     }
 603
 604     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
 605         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
 606         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
 607     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
 608         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 609         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 610     }else{
 611         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 612         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 613     }
 614
 615     if(MPV_frame_start(s, avctx) < 0)
 616         return -1;
 617
 618 #ifdef DEBUG
 619     av_log(avctx, AV_LOG_DEBUG, "qscale=%d\n", s->qscale);
 620 #endif
 621
 622     ff_er_frame_start(s);
 623
 624     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 625     //which is not available before MPV_frame_start()
 626     if (ENABLE_WMV2_DECODER && s->msmpeg4_version==5){
 627         ret = ff_wmv2_decode_secondary_picture_header(s);
 628         if(ret<0) return ret;
 629         if(ret==1) goto intrax8_decoded;
 630     }
 631
 632     /* decode each macroblock */
 633     s->mb_x=0;
 634     s->mb_y=0;
 635
 636     decode_slice(s);
 637     while(s->mb_y<s->mb_height){
 638         if(s->msmpeg4_version){
 639             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)
 640                 break;
 641         }else{
 642             if(ff_h263_resync(s)<0)
 643                 break;
 644         }
 645
 646         if(s->msmpeg4_version<4 && s->h263_pred)
 647             ff_mpeg4_clean_buffers(s);
 648
 649         decode_slice(s);
 650     }
 651
 652     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
 653         if(!ENABLE_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
 654             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 655         }
 656
 657     /* divx 5.01+ bistream reorder stuff */
 658     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
 659         int current_pos= get_bits_count(&s->gb)>>3;
 660         int startcode_found=0;
 661
 662         if(buf_size - current_pos > 5){
 663             int i;
 664             for(i=current_pos; i<buf_size-3; i++){
 665                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 666                     startcode_found=1;
 667                     break;
 668                 }
 669             }
 670         }
 671         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
 672             startcode_found=1;
 673             current_pos=0;
 674         }
 675
 676         if(startcode_found){
 677             s->bitstream_buffer= av_fast_realloc(
 678                 s->bitstream_buffer,
 679                 &s->allocated_bitstream_buffer_size,
 680                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 681             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 682             s->bitstream_buffer_size= buf_size - current_pos;
 683         }
 684     }
 685
 686 intrax8_decoded:
 687     ff_er_frame_end(s);
 688
 689     MPV_frame_end(s);
 690
 691 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 692 assert(s->current_picture.pict_type == s->pict_type);
 693     if (s->pict_type == FF_B_TYPE || s->low_delay) {
 694         *pict= *(AVFrame*)s->current_picture_ptr;
 695     } else if (s->last_picture_ptr != NULL) {
 696         *pict= *(AVFrame*)s->last_picture_ptr;
 697     }
 698
 699     if(s->last_picture_ptr || s->low_delay){
 700         *data_size = sizeof(AVFrame);
 701         ff_print_debug_info(s, pict);
 702     }
 703
 704     /* Return the Picture timestamp as the frame number */
 705     /* we subtract 1 because it is added on utils.c     */
 706     avctx->frame_number = s->picture_number - 1;
 707
 708 #ifdef PRINT_FRAME_TIME
 709 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 710 #endif
 711
 712     return get_consumed_bytes(s, buf_size);
 713 }
 714
 715 AVCodec mpeg4_decoder = {
 716     "mpeg4",
 717     CODEC_TYPE_VIDEO,
 718     CODEC_ID_MPEG4,
 719     sizeof(MpegEncContext),
 720     ff_h263_decode_init,
 721     NULL,
 722     ff_h263_decode_end,
 723     ff_h263_decode_frame,
 724     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 725     .flush= ff_mpeg_flush,
 726     .long_name= "MPEG-4 part 2",
 727 };
 728
 729 AVCodec h263_decoder = {
 730     "h263",
 731     CODEC_TYPE_VIDEO,
 732     CODEC_ID_H263,
 733     sizeof(MpegEncContext),
 734     ff_h263_decode_init,
 735     NULL,
 736     ff_h263_decode_end,
 737     ff_h263_decode_frame,
 738     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 739     .flush= ff_mpeg_flush,
 740     .long_name="H.263",
 741 };
 742
 743 AVCodec msmpeg4v1_decoder = {
 744     "msmpeg4v1",
 745     CODEC_TYPE_VIDEO,
 746     CODEC_ID_MSMPEG4V1,
 747     sizeof(MpegEncContext),
 748     ff_h263_decode_init,
 749     NULL,
 750     ff_h263_decode_end,
 751     ff_h263_decode_frame,
 752     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 753     .long_name="MPEG-4 part 2 Microsoft variant version 1",
 754 };
 755
 756 AVCodec msmpeg4v2_decoder = {
 757     "msmpeg4v2",
 758     CODEC_TYPE_VIDEO,
 759     CODEC_ID_MSMPEG4V2,
 760     sizeof(MpegEncContext),
 761     ff_h263_decode_init,
 762     NULL,
 763     ff_h263_decode_end,
 764     ff_h263_decode_frame,
 765     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 766     .long_name="MPEG-4 part 2 Microsoft variant version 2",
 767 };
 768
 769 AVCodec msmpeg4v3_decoder = {
 770     "msmpeg4",
 771     CODEC_TYPE_VIDEO,
 772     CODEC_ID_MSMPEG4V3,
 773     sizeof(MpegEncContext),
 774     ff_h263_decode_init,
 775     NULL,
 776     ff_h263_decode_end,
 777     ff_h263_decode_frame,
 778     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 779     .long_name="MPEG-4 part 2 Microsoft variant version 3",
 780 };
 781
 782 AVCodec wmv1_decoder = {
 783     "wmv1",
 784     CODEC_TYPE_VIDEO,
 785     CODEC_ID_WMV1,
 786     sizeof(MpegEncContext),
 787     ff_h263_decode_init,
 788     NULL,
 789     ff_h263_decode_end,
 790     ff_h263_decode_frame,
 791     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 792     .long_name= "Windows Media Video 7",
 793 };
 794
 795 AVCodec h263i_decoder = {
 796     "h263i",
 797     CODEC_TYPE_VIDEO,
 798     CODEC_ID_H263I,
 799     sizeof(MpegEncContext),
 800     ff_h263_decode_init,
 801     NULL,
 802     ff_h263_decode_end,
 803     ff_h263_decode_frame,
 804     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 805     .long_name = "H.263i",
 806 };
 807
 808 AVCodec flv_decoder = {
 809     "flv",
 810     CODEC_TYPE_VIDEO,
 811     CODEC_ID_FLV1,
 812     sizeof(MpegEncContext),
 813     ff_h263_decode_init,
 814     NULL,
 815     ff_h263_decode_end,
 816     ff_h263_decode_frame,
 817     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 818     .long_name= "Flash Video",
 819 };