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= PIX_FMT_YUV420P;
  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         break;
  63     case CODEC_ID_MPEG4:
  64         s->decode_mb= ff_mpeg4_decode_mb;
  65         s->time_increment_bits = 4; /* default value for broken headers */
  66         s->h263_pred = 1;
  67         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  68         break;
  69     case CODEC_ID_MSMPEG4V1:
  70         s->h263_msmpeg4 = 1;
  71         s->h263_pred = 1;
  72         s->msmpeg4_version=1;
  73         break;
  74     case CODEC_ID_MSMPEG4V2:
  75         s->h263_msmpeg4 = 1;
  76         s->h263_pred = 1;
  77         s->msmpeg4_version=2;
  78         break;
  79     case CODEC_ID_MSMPEG4V3:
  80         s->h263_msmpeg4 = 1;
  81         s->h263_pred = 1;
  82         s->msmpeg4_version=3;
  83         break;
  84     case CODEC_ID_WMV1:
  85         s->h263_msmpeg4 = 1;
  86         s->h263_pred = 1;
  87         s->msmpeg4_version=4;
  88         break;
  89     case CODEC_ID_WMV2:
  90         s->h263_msmpeg4 = 1;
  91         s->h263_pred = 1;
  92         s->msmpeg4_version=5;
  93         break;
  94     case CODEC_ID_VC1:
  95     case CODEC_ID_WMV3:
  96         s->h263_msmpeg4 = 1;
  97         s->h263_pred = 1;
  98         s->msmpeg4_version=6;
  99         break;
 100     case CODEC_ID_H263I:
 101         break;
 102     case CODEC_ID_FLV1:
 103         s->h263_flv = 1;
 104         break;
 105     default:
 106         return -1;
 107     }
 108     s->codec_id= avctx->codec->id;
 109
 110     /* for h263, we allocate the images after having read the header */
 111     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 112         if (MPV_common_init(s) < 0)
 113             return -1;
 114
 115     if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
 116         ff_msmpeg4_decode_init(s);
 117     else
 118         h263_decode_init_vlc(s);
 119
 120     return 0;
 121 }
 122
 123 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
 124 {
 125     MpegEncContext *s = avctx->priv_data;
 126
 127     MPV_common_end(s);
 128     return 0;
 129 }
 130
 131 /**
 132  * returns the number of bytes consumed for building the current frame
 133  */
 134 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 135     int pos= (get_bits_count(&s->gb)+7)>>3;
 136
 137     if(s->divx_packed){
 138         //we would have to scan through the whole buf to handle the weird reordering ...
 139         return buf_size;
 140     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 141         pos -= s->parse_context.last_index;
 142         if(pos<0) pos=0; // padding is not really read so this might be -1
 143         return pos;
 144     }else{
 145         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
 146         if(pos+10>buf_size) pos=buf_size; // oops ;)
 147
 148         return pos;
 149     }
 150 }
 151
 152 static int decode_slice(MpegEncContext *s){
 153     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
 154     const int mb_size= 16>>s->avctx->lowres;
 155     s->last_resync_gb= s->gb;
 156     s->first_slice_line= 1;
 157
 158     s->resync_mb_x= s->mb_x;
 159     s->resync_mb_y= s->mb_y;
 160
 161     ff_set_qscale(s, s->qscale);
 162
 163     if (s->avctx->hwaccel)
 164         return 0;
 165
 166     if(s->partitioned_frame){
 167         const int qscale= s->qscale;
 168
 169         if(s->codec_id==CODEC_ID_MPEG4){
 170             if(ff_mpeg4_decode_partitions(s) < 0)
 171                 return -1;
 172         }
 173
 174         /* restore variables which were modified */
 175         s->first_slice_line=1;
 176         s->mb_x= s->resync_mb_x;
 177         s->mb_y= s->resync_mb_y;
 178         ff_set_qscale(s, qscale);
 179     }
 180
 181     for(; s->mb_y < s->mb_height; s->mb_y++) {
 182         /* per-row end of slice checks */
 183         if(s->msmpeg4_version){
 184             if(s->resync_mb_y + s->slice_height == s->mb_y){
 185                 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);
 186
 187                 return 0;
 188             }
 189         }
 190
 191         if(s->msmpeg4_version==1){
 192             s->last_dc[0]=
 193             s->last_dc[1]=
 194             s->last_dc[2]= 128;
 195         }
 196
 197         ff_init_block_index(s);
 198         for(; s->mb_x < s->mb_width; s->mb_x++) {
 199             int ret;
 200
 201             ff_update_block_index(s);
 202
 203             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 204                 s->first_slice_line=0;
 205             }
 206
 207             /* DCT & quantize */
 208
 209             s->mv_dir = MV_DIR_FORWARD;
 210             s->mv_type = MV_TYPE_16X16;
 211 //            s->mb_skipped = 0;
 212 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 213             ret= s->decode_mb(s, s->block);
 214
 215             if (s->pict_type!=FF_B_TYPE)
 216                 ff_h263_update_motion_val(s);
 217
 218             if(ret<0){
 219                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 220                 if(ret==SLICE_END){
 221                     MPV_decode_mb(s, s->block);
 222                     if(s->loop_filter)
 223                         ff_h263_loop_filter(s);
 224
 225 //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));
 226                     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);
 227
 228                     s->padding_bug_score--;
 229
 230                     if(++s->mb_x >= s->mb_width){
 231                         s->mb_x=0;
 232                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 233                         s->mb_y++;
 234                     }
 235                     return 0;
 236                 }else if(ret==SLICE_NOEND){
 237                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 238                     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);
 239                     return -1;
 240                 }
 241                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 242                 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);
 243
 244                 return -1;
 245             }
 246
 247             MPV_decode_mb(s, s->block);
 248             if(s->loop_filter)
 249                 ff_h263_loop_filter(s);
 250         }
 251
 252         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 253
 254         s->mb_x= 0;
 255     }
 256
 257     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 258
 259     /* try to detect the padding bug */
 260     if(      s->codec_id==CODEC_ID_MPEG4
 261        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 262        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 263        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 264 //       &&   !s->resync_marker
 265        &&   !s->data_partitioning){
 266
 267         const int bits_count= get_bits_count(&s->gb);
 268         const int bits_left = s->gb.size_in_bits - bits_count;
 269
 270         if(bits_left==0){
 271             s->padding_bug_score+=16;
 272         } else if(bits_left != 1){
 273             int v= show_bits(&s->gb, 8);
 274             v|= 0x7F >> (7-(bits_count&7));
 275
 276             if(v==0x7F && bits_left<=8)
 277                 s->padding_bug_score--;
 278             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 279                 s->padding_bug_score+= 4;
 280             else
 281                 s->padding_bug_score++;
 282         }
 283     }
 284
 285     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 286         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
 287             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 288         else
 289             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 290     }
 291
 292     // handle formats which don't have unique end markers
 293     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 294         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 295         int max_extra=7;
 296
 297         /* no markers in M$ crap */
 298         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
 299             max_extra+= 17;
 300
 301         /* buggy padding but the frame should still end approximately at the bitstream end */
 302         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
 303             max_extra+= 48;
 304         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 305             max_extra+= 256*256*256*64;
 306
 307         if(left>max_extra){
 308             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 309         }
 310         else if(left<0){
 311             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 312         }else
 313             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);
 314
 315         return 0;
 316     }
 317
 318     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 319             s->gb.size_in_bits - get_bits_count(&s->gb),
 320             show_bits(&s->gb, 24), s->padding_bug_score);
 321
 322     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);
 323
 324     return -1;
 325 }
 326
 327 int ff_h263_decode_frame(AVCodecContext *avctx,
 328                              void *data, int *data_size,
 329                              const uint8_t *buf, int buf_size)
 330 {
 331     MpegEncContext *s = avctx->priv_data;
 332     int ret;
 333     AVFrame *pict = data;
 334
 335 #ifdef PRINT_FRAME_TIME
 336 uint64_t time= rdtsc();
 337 #endif
 338 #ifdef DEBUG
 339     av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
 340     if(buf_size>0)
 341         av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 342 #endif
 343     s->flags= avctx->flags;
 344     s->flags2= avctx->flags2;
 345
 346     /* no supplementary picture */
 347     if (buf_size == 0) {
 348         /* special case for last picture */
 349         if (s->low_delay==0 && s->next_picture_ptr) {
 350             *pict= *(AVFrame*)s->next_picture_ptr;
 351             s->next_picture_ptr= NULL;
 352
 353             *data_size = sizeof(AVFrame);
 354         }
 355
 356         return 0;
 357     }
 358
 359     if(s->flags&CODEC_FLAG_TRUNCATED){
 360         int next;
 361
 362         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
 363             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 364         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
 365             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 366         }else{
 367             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 368             return -1;
 369         }
 370
 371         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 372             return buf_size;
 373     }
 374
 375
 376 retry:
 377
 378     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 379         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 380     }else
 381         init_get_bits(&s->gb, buf, buf_size*8);
 382     s->bitstream_buffer_size=0;
 383
 384     if (!s->context_initialized) {
 385         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 386             return -1;
 387     }
 388
 389     /* We need to set current_picture_ptr before reading the header,
 390      * otherwise we cannot store anyting in there */
 391     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
 392         int i= ff_find_unused_picture(s, 0);
 393         s->current_picture_ptr= &s->picture[i];
 394     }
 395
 396     /* let's go :-) */
 397     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 398         ret= ff_wmv2_decode_picture_header(s);
 399     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 400         ret = msmpeg4_decode_picture_header(s);
 401     } else if (s->h263_pred) {
 402         if(s->avctx->extradata_size && s->picture_number==0){
 403             GetBitContext gb;
 404
 405             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 406             ret = ff_mpeg4_decode_picture_header(s, &gb);
 407         }
 408         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 409     } else if (s->codec_id == CODEC_ID_H263I) {
 410         ret = intel_h263_decode_picture_header(s);
 411     } else if (s->h263_flv) {
 412         ret = flv_h263_decode_picture_header(s);
 413     } else {
 414         ret = h263_decode_picture_header(s);
 415     }
 416
 417     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 418
 419     /* skip if the header was thrashed */
 420     if (ret < 0){
 421         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 422         return -1;
 423     }
 424
 425     avctx->has_b_frames= !s->low_delay;
 426
 427     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 428         if(s->stream_codec_tag == AV_RL32("XVID") ||
 429            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 430            s->codec_tag == AV_RL32("RMP4"))
 431             s->xvid_build= -1;
 432 #if 0
 433         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 434            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 435             s->xvid_build= -1;
 436 #endif
 437     }
 438
 439     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 440         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 441             s->divx_version= 400; //divx 4
 442     }
 443
 444     if(s->xvid_build && s->divx_version){
 445         s->divx_version=
 446         s->divx_build= 0;
 447     }
 448
 449     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 450         if(s->codec_tag == AV_RL32("XVIX"))
 451             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 452
 453         if(s->codec_tag == AV_RL32("UMP4")){
 454             s->workaround_bugs|= FF_BUG_UMP4;
 455         }
 456
 457         if(s->divx_version>=500 && s->divx_build<1814){
 458             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 459         }
 460
 461         if(s->divx_version>502 && s->divx_build<1814){
 462             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 463         }
 464
 465         if(s->xvid_build && s->xvid_build<=3)
 466             s->padding_bug_score= 256*256*256*64;
 467
 468         if(s->xvid_build && s->xvid_build<=1)
 469             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 470
 471         if(s->xvid_build && s->xvid_build<=12)
 472             s->workaround_bugs|= FF_BUG_EDGE;
 473
 474         if(s->xvid_build && s->xvid_build<=32)
 475             s->workaround_bugs|= FF_BUG_DC_CLIP;
 476
 477 #define SET_QPEL_FUNC(postfix1, postfix2) \
 478     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 479     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 480     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 481
 482         if(s->lavc_build && s->lavc_build<4653)
 483             s->workaround_bugs|= FF_BUG_STD_QPEL;
 484
 485         if(s->lavc_build && s->lavc_build<4655)
 486             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 487
 488         if(s->lavc_build && s->lavc_build<4670){
 489             s->workaround_bugs|= FF_BUG_EDGE;
 490         }
 491
 492         if(s->lavc_build && s->lavc_build<=4712)
 493             s->workaround_bugs|= FF_BUG_DC_CLIP;
 494
 495         if(s->divx_version)
 496             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 497 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 498         if(s->divx_version==501 && s->divx_build==20020416)
 499             s->padding_bug_score= 256*256*256*64;
 500
 501         if(s->divx_version && s->divx_version<500){
 502             s->workaround_bugs|= FF_BUG_EDGE;
 503         }
 504
 505         if(s->divx_version)
 506             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 507 #if 0
 508         if(s->divx_version==500)
 509             s->padding_bug_score= 256*256*256*64;
 510
 511         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 512          * Let us hope this at least works.
 513          */
 514         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 515            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 516             s->workaround_bugs|= FF_BUG_NO_PADDING;
 517
 518         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 519             s->workaround_bugs|= FF_BUG_NO_PADDING;
 520 #endif
 521     }
 522
 523     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 524         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 525         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 526         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 527         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 528         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 529         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 530
 531         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 532         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 533         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 534         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 535         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 536         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 537     }
 538
 539     if(avctx->debug & FF_DEBUG_BUGS)
 540         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 541                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 542                s->divx_packed ? "p" : "");
 543
 544 #if 0 // dump bits per frame / qp / complexity
 545 {
 546     static FILE *f=NULL;
 547     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 548     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 549 }
 550 #endif
 551
 552 #if HAVE_MMX
 553     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
 554         avctx->idct_algo= FF_IDCT_XVIDMMX;
 555         avctx->coded_width= 0; // force reinit
 556 //        dsputil_init(&s->dsp, avctx);
 557         s->picture_number=0;
 558     }
 559 #endif
 560
 561         /* After H263 & mpeg4 header decode we have the height, width,*/
 562         /* and other parameters. So then we could init the picture   */
 563         /* FIXME: By the way H263 decoder is evolving it should have */
 564         /* an H263EncContext                                         */
 565
 566     if (   s->width  != avctx->coded_width
 567         || s->height != avctx->coded_height) {
 568         /* H.263 could change picture size any time */
 569         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 570         s->parse_context.buffer=0;
 571         MPV_common_end(s);
 572         s->parse_context= pc;
 573     }
 574     if (!s->context_initialized) {
 575         avcodec_set_dimensions(avctx, s->width, s->height);
 576
 577         goto retry;
 578     }
 579
 580     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
 581         s->gob_index = ff_h263_get_gob_height(s);
 582
 583     // for hurry_up==5
 584     s->current_picture.pict_type= s->pict_type;
 585     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
 586
 587     /* skip B-frames if we don't have reference frames */
 588     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
 589     /* skip b frames if we are in a hurry */
 590     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
 591     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
 592        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
 593        ||  avctx->skip_frame >= AVDISCARD_ALL)
 594         return get_consumed_bytes(s, buf_size);
 595     /* skip everything if we are in a hurry>=5 */
 596     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 597
 598     if(s->next_p_frame_damaged){
 599         if(s->pict_type==FF_B_TYPE)
 600             return get_consumed_bytes(s, buf_size);
 601         else
 602             s->next_p_frame_damaged=0;
 603     }
 604
 605     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
 606         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
 607         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
 608     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
 609         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 610         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 611     }else{
 612         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 613         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 614     }
 615
 616     if(MPV_frame_start(s, avctx) < 0)
 617         return -1;
 618
 619 #ifdef DEBUG
 620     av_log(avctx, AV_LOG_DEBUG, "qscale=%d\n", s->qscale);
 621 #endif
 622
 623     ff_er_frame_start(s);
 624
 625     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 626     //which is not available before MPV_frame_start()
 627     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 628         ret = ff_wmv2_decode_secondary_picture_header(s);
 629         if(ret<0) return ret;
 630         if(ret==1) goto intrax8_decoded;
 631     }
 632
 633     /* decode each macroblock */
 634     s->mb_x=0;
 635     s->mb_y=0;
 636
 637     decode_slice(s);
 638     while(s->mb_y<s->mb_height){
 639         if(s->msmpeg4_version){
 640             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)
 641                 break;
 642         }else{
 643             if(ff_h263_resync(s)<0)
 644                 break;
 645         }
 646
 647         if(s->msmpeg4_version<4 && s->h263_pred)
 648             ff_mpeg4_clean_buffers(s);
 649
 650         decode_slice(s);
 651     }
 652
 653     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
 654         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
 655             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 656         }
 657
 658     /* divx 5.01+ bistream reorder stuff */
 659     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
 660         int current_pos= get_bits_count(&s->gb)>>3;
 661         int startcode_found=0;
 662
 663         if(buf_size - current_pos > 5){
 664             int i;
 665             for(i=current_pos; i<buf_size-3; i++){
 666                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 667                     startcode_found=1;
 668                     break;
 669                 }
 670             }
 671         }
 672         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
 673             startcode_found=1;
 674             current_pos=0;
 675         }
 676
 677         if(startcode_found){
 678             s->bitstream_buffer= av_fast_realloc(
 679                 s->bitstream_buffer,
 680                 &s->allocated_bitstream_buffer_size,
 681                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 682             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 683             s->bitstream_buffer_size= buf_size - current_pos;
 684         }
 685     }
 686
 687 intrax8_decoded:
 688     ff_er_frame_end(s);
 689
 690     MPV_frame_end(s);
 691
 692 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 693 assert(s->current_picture.pict_type == s->pict_type);
 694     if (s->pict_type == FF_B_TYPE || s->low_delay) {
 695         *pict= *(AVFrame*)s->current_picture_ptr;
 696     } else if (s->last_picture_ptr != NULL) {
 697         *pict= *(AVFrame*)s->last_picture_ptr;
 698     }
 699
 700     if(s->last_picture_ptr || s->low_delay){
 701         *data_size = sizeof(AVFrame);
 702         ff_print_debug_info(s, pict);
 703     }
 704
 705     /* Return the Picture timestamp as the frame number */
 706     /* we subtract 1 because it is added on utils.c     */
 707     avctx->frame_number = s->picture_number - 1;
 708
 709 #ifdef PRINT_FRAME_TIME
 710 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 711 #endif
 712
 713     return get_consumed_bytes(s, buf_size);
 714 }
 715
 716 AVCodec mpeg4_decoder = {
 717     "mpeg4",
 718     CODEC_TYPE_VIDEO,
 719     CODEC_ID_MPEG4,
 720     sizeof(MpegEncContext),
 721     ff_h263_decode_init,
 722     NULL,
 723     ff_h263_decode_end,
 724     ff_h263_decode_frame,
 725     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 726     .flush= ff_mpeg_flush,
 727     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
 728 };
 729
 730 AVCodec h263_decoder = {
 731     "h263",
 732     CODEC_TYPE_VIDEO,
 733     CODEC_ID_H263,
 734     sizeof(MpegEncContext),
 735     ff_h263_decode_init,
 736     NULL,
 737     ff_h263_decode_end,
 738     ff_h263_decode_frame,
 739     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 740     .flush= ff_mpeg_flush,
 741     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998"),
 742 };
 743
 744 AVCodec msmpeg4v1_decoder = {
 745     "msmpeg4v1",
 746     CODEC_TYPE_VIDEO,
 747     CODEC_ID_MSMPEG4V1,
 748     sizeof(MpegEncContext),
 749     ff_h263_decode_init,
 750     NULL,
 751     ff_h263_decode_end,
 752     ff_h263_decode_frame,
 753     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 754     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
 755 };
 756
 757 AVCodec msmpeg4v2_decoder = {
 758     "msmpeg4v2",
 759     CODEC_TYPE_VIDEO,
 760     CODEC_ID_MSMPEG4V2,
 761     sizeof(MpegEncContext),
 762     ff_h263_decode_init,
 763     NULL,
 764     ff_h263_decode_end,
 765     ff_h263_decode_frame,
 766     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 767     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
 768 };
 769
 770 AVCodec msmpeg4v3_decoder = {
 771     "msmpeg4",
 772     CODEC_TYPE_VIDEO,
 773     CODEC_ID_MSMPEG4V3,
 774     sizeof(MpegEncContext),
 775     ff_h263_decode_init,
 776     NULL,
 777     ff_h263_decode_end,
 778     ff_h263_decode_frame,
 779     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 780     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
 781 };
 782
 783 AVCodec wmv1_decoder = {
 784     "wmv1",
 785     CODEC_TYPE_VIDEO,
 786     CODEC_ID_WMV1,
 787     sizeof(MpegEncContext),
 788     ff_h263_decode_init,
 789     NULL,
 790     ff_h263_decode_end,
 791     ff_h263_decode_frame,
 792     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 793     .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
 794 };
 795
 796 AVCodec h263i_decoder = {
 797     "h263i",
 798     CODEC_TYPE_VIDEO,
 799     CODEC_ID_H263I,
 800     sizeof(MpegEncContext),
 801     ff_h263_decode_init,
 802     NULL,
 803     ff_h263_decode_end,
 804     ff_h263_decode_frame,
 805     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 806     .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
 807 };
 808
 809 AVCodec flv_decoder = {
 810     "flv",
 811     CODEC_TYPE_VIDEO,
 812     CODEC_ID_FLV1,
 813     sizeof(MpegEncContext),
 814     ff_h263_decode_init,
 815     NULL,
 816     ff_h263_decode_end,
 817     ff_h263_decode_frame,
 818     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 819     .long_name= NULL_IF_CONFIG_SMALL("Flash Video"),
 820 };