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   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 Libav.
   7  *
   8  * Libav 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  * Libav 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 Libav; 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
  25  * H.263 decoder.
  26  */
  27
  28 #include "libavutil/cpu.h"
  29 #include "internal.h"
  30 #include "avcodec.h"
  31 #include "mpegvideo.h"
  32 #include "h263.h"
  33 #include "h263_parser.h"
  34 #include "mpeg4video_parser.h"
  35 #include "msmpeg4.h"
  36 #include "vdpau_internal.h"
  37 #include "thread.h"
  38 #include "flv.h"
  39 #include "mpeg4video.h"
  40
  41 //#define DEBUG
  42 //#define PRINT_FRAME_TIME
  43
  44 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  45 {
  46     MpegEncContext *s = avctx->priv_data;
  47
  48     s->avctx = avctx;
  49     s->out_format = FMT_H263;
  50
  51     s->width  = avctx->coded_width;
  52     s->height = avctx->coded_height;
  53     s->workaround_bugs= avctx->workaround_bugs;
  54
  55     // set defaults
  56     ff_MPV_decode_defaults(s);
  57     s->quant_precision=5;
  58     s->decode_mb= ff_h263_decode_mb;
  59     s->low_delay= 1;
  60     if (avctx->codec->id == AV_CODEC_ID_MSS2)
  61         avctx->pix_fmt = AV_PIX_FMT_YUV420P;
  62     else
  63         avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
  64     s->unrestricted_mv= 1;
  65
  66     /* select sub codec */
  67     switch(avctx->codec->id) {
  68     case AV_CODEC_ID_H263:
  69         s->unrestricted_mv= 0;
  70         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
  71         break;
  72     case AV_CODEC_ID_MPEG4:
  73         break;
  74     case AV_CODEC_ID_MSMPEG4V1:
  75         s->h263_pred = 1;
  76         s->msmpeg4_version=1;
  77         break;
  78     case AV_CODEC_ID_MSMPEG4V2:
  79         s->h263_pred = 1;
  80         s->msmpeg4_version=2;
  81         break;
  82     case AV_CODEC_ID_MSMPEG4V3:
  83         s->h263_pred = 1;
  84         s->msmpeg4_version=3;
  85         break;
  86     case AV_CODEC_ID_WMV1:
  87         s->h263_pred = 1;
  88         s->msmpeg4_version=4;
  89         break;
  90     case AV_CODEC_ID_WMV2:
  91         s->h263_pred = 1;
  92         s->msmpeg4_version=5;
  93         break;
  94     case AV_CODEC_ID_VC1:
  95     case AV_CODEC_ID_WMV3:
  96     case AV_CODEC_ID_VC1IMAGE:
  97     case AV_CODEC_ID_WMV3IMAGE:
  98     case AV_CODEC_ID_MSS2:
  99         s->h263_pred = 1;
 100         s->msmpeg4_version=6;
 101         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 102         break;
 103     case AV_CODEC_ID_H263I:
 104         break;
 105     case AV_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 != AV_CODEC_ID_H263 && avctx->codec->id != AV_CODEC_ID_MPEG4)
 116         if (ff_MPV_common_init(s) < 0)
 117             return -1;
 118
 119         ff_h263_decode_init_vlc();
 120
 121     return 0;
 122 }
 123
 124 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
 125 {
 126     MpegEncContext *s = avctx->priv_data;
 127
 128     ff_MPV_common_end(s);
 129     return 0;
 130 }
 131
 132 /**
 133  * Return the number of bytes consumed for building the current frame.
 134  */
 135 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 136     int pos= (get_bits_count(&s->gb)+7)>>3;
 137
 138     if(s->divx_packed || s->avctx->hwaccel){
 139         //we would have to scan through the whole buf to handle the weird reordering ...
 140         return buf_size;
 141     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 142         pos -= s->parse_context.last_index;
 143         if(pos<0) pos=0; // padding is not really read so this might be -1
 144         return pos;
 145     }else{
 146         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
 147         if(pos+10>buf_size) pos=buf_size; // oops ;)
 148
 149         return pos;
 150     }
 151 }
 152
 153 static int decode_slice(MpegEncContext *s){
 154     const int part_mask= s->partitioned_frame ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
 155     const int mb_size = 16;
 156     s->last_resync_gb= s->gb;
 157     s->first_slice_line= 1;
 158
 159     s->resync_mb_x= s->mb_x;
 160     s->resync_mb_y= s->mb_y;
 161
 162     ff_set_qscale(s, s->qscale);
 163
 164     if (s->avctx->hwaccel) {
 165         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
 166         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
 167         skip_bits_long(&s->gb, 8*(end - start));
 168         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
 169     }
 170
 171     if(s->partitioned_frame){
 172         const int qscale= s->qscale;
 173
 174         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 175             if(ff_mpeg4_decode_partitions(s) < 0)
 176                 return -1;
 177         }
 178
 179         /* restore variables which were modified */
 180         s->first_slice_line=1;
 181         s->mb_x= s->resync_mb_x;
 182         s->mb_y= s->resync_mb_y;
 183         ff_set_qscale(s, qscale);
 184     }
 185
 186     for(; s->mb_y < s->mb_height; s->mb_y++) {
 187         /* per-row end of slice checks */
 188         if(s->msmpeg4_version){
 189             if(s->resync_mb_y + s->slice_height == s->mb_y){
 190                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
 191
 192                 return 0;
 193             }
 194         }
 195
 196         if(s->msmpeg4_version==1){
 197             s->last_dc[0]=
 198             s->last_dc[1]=
 199             s->last_dc[2]= 128;
 200         }
 201
 202         ff_init_block_index(s);
 203         for(; s->mb_x < s->mb_width; s->mb_x++) {
 204             int ret;
 205
 206             ff_update_block_index(s);
 207
 208             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 209                 s->first_slice_line=0;
 210             }
 211
 212             /* DCT & quantize */
 213
 214             s->mv_dir = MV_DIR_FORWARD;
 215             s->mv_type = MV_TYPE_16X16;
 216 //            s->mb_skipped = 0;
 217             av_dlog(s, "%d %d %06X\n",
 218                     ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 219             ret= s->decode_mb(s, s->block);
 220
 221             if (s->pict_type!=AV_PICTURE_TYPE_B)
 222                 ff_h263_update_motion_val(s);
 223
 224             if(ret<0){
 225                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 226                 if(ret==SLICE_END){
 227                     ff_MPV_decode_mb(s, s->block);
 228                     if(s->loop_filter)
 229                         ff_h263_loop_filter(s);
 230
 231                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
 232
 233                     s->padding_bug_score--;
 234
 235                     if(++s->mb_x >= s->mb_width){
 236                         s->mb_x=0;
 237                         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 238                         ff_MPV_report_decode_progress(s);
 239                         s->mb_y++;
 240                     }
 241                     return 0;
 242                 }else if(ret==SLICE_NOEND){
 243                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 244                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, ER_MB_END&part_mask);
 245                     return -1;
 246                 }
 247                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 248                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR&part_mask);
 249
 250                 return -1;
 251             }
 252
 253             ff_MPV_decode_mb(s, s->block);
 254             if(s->loop_filter)
 255                 ff_h263_loop_filter(s);
 256         }
 257
 258         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 259         ff_MPV_report_decode_progress(s);
 260
 261         s->mb_x= 0;
 262     }
 263
 264     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 265
 266     if(s->codec_id==AV_CODEC_ID_MPEG4
 267        && (s->workaround_bugs&FF_BUG_AUTODETECT)
 268        && get_bits_left(&s->gb) >= 48
 269        && show_bits(&s->gb, 24)==0x4010
 270        && !s->data_partitioning)
 271         s->padding_bug_score+=32;
 272
 273     /* try to detect the padding bug */
 274     if(      s->codec_id==AV_CODEC_ID_MPEG4
 275        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 276        &&    get_bits_left(&s->gb) >=0
 277        &&    get_bits_left(&s->gb) < 48
 278 //       &&   !s->resync_marker
 279        &&   !s->data_partitioning){
 280
 281         const int bits_count= get_bits_count(&s->gb);
 282         const int bits_left = s->gb.size_in_bits - bits_count;
 283
 284         if(bits_left==0){
 285             s->padding_bug_score+=16;
 286         } else if(bits_left != 1){
 287             int v= show_bits(&s->gb, 8);
 288             v|= 0x7F >> (7-(bits_count&7));
 289
 290             if(v==0x7F && bits_left<=8)
 291                 s->padding_bug_score--;
 292             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 293                 s->padding_bug_score+= 4;
 294             else
 295                 s->padding_bug_score++;
 296         }
 297     }
 298
 299     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 300         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
 301             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 302         else
 303             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 304     }
 305
 306     // handle formats which don't have unique end markers
 307     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 308         int left= get_bits_left(&s->gb);
 309         int max_extra=7;
 310
 311         /* no markers in M$ crap */
 312         if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
 313             max_extra+= 17;
 314
 315         /* buggy padding but the frame should still end approximately at the bitstream end */
 316         if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&AV_EF_BUFFER))
 317             max_extra+= 48;
 318         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 319             max_extra+= 256*256*256*64;
 320
 321         if(left>max_extra){
 322             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 323         }
 324         else if(left<0){
 325             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 326         }else
 327             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
 328
 329         return 0;
 330     }
 331
 332     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 333             get_bits_left(&s->gb),
 334             show_bits(&s->gb, 24), s->padding_bug_score);
 335
 336     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
 337
 338     return -1;
 339 }
 340
 341 int ff_h263_decode_frame(AVCodecContext *avctx,
 342                              void *data, int *got_frame,
 343                              AVPacket *avpkt)
 344 {
 345     const uint8_t *buf = avpkt->data;
 346     int buf_size = avpkt->size;
 347     MpegEncContext *s = avctx->priv_data;
 348     int ret;
 349     AVFrame *pict = data;
 350
 351 #ifdef PRINT_FRAME_TIME
 352 uint64_t time= rdtsc();
 353 #endif
 354     s->flags= avctx->flags;
 355     s->flags2= avctx->flags2;
 356
 357     /* no supplementary picture */
 358     if (buf_size == 0) {
 359         /* special case for last picture */
 360         if (s->low_delay==0 && s->next_picture_ptr) {
 361             *pict = s->next_picture_ptr->f;
 362             s->next_picture_ptr= NULL;
 363
 364             *got_frame = 1;
 365         }
 366
 367         return 0;
 368     }
 369
 370     if(s->flags&CODEC_FLAG_TRUNCATED){
 371         int next;
 372
 373         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 374             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 375         }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
 376             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 377         }else{
 378             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 379             return -1;
 380         }
 381
 382         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 383             return buf_size;
 384     }
 385
 386
 387 retry:
 388
 389     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 390         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 391     }else
 392         init_get_bits(&s->gb, buf, buf_size*8);
 393     s->bitstream_buffer_size=0;
 394
 395     if (!s->context_initialized) {
 396         if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 397             return -1;
 398     }
 399
 400     /* We need to set current_picture_ptr before reading the header,
 401      * otherwise we cannot store anyting in there */
 402     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
 403         int i= ff_find_unused_picture(s, 0);
 404         if (i < 0)
 405             return i;
 406         s->current_picture_ptr= &s->picture[i];
 407     }
 408
 409     /* let's go :-) */
 410     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 411         ret= ff_wmv2_decode_picture_header(s);
 412     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 413         ret = ff_msmpeg4_decode_picture_header(s);
 414     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
 415         if(s->avctx->extradata_size && s->picture_number==0){
 416             GetBitContext gb;
 417
 418             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 419             ret = ff_mpeg4_decode_picture_header(s, &gb);
 420         }
 421         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 422     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
 423         ret = ff_intel_h263_decode_picture_header(s);
 424     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
 425         ret = ff_flv_decode_picture_header(s);
 426     } else {
 427         ret = ff_h263_decode_picture_header(s);
 428     }
 429
 430     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 431
 432     /* skip if the header was thrashed */
 433     if (ret < 0){
 434         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 435         return -1;
 436     }
 437
 438     avctx->has_b_frames= !s->low_delay;
 439
 440     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 441         if(s->stream_codec_tag == AV_RL32("XVID") ||
 442            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 443            s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||
 444            s->codec_tag == AV_RL32("SIPP")
 445            )
 446             s->xvid_build= 0;
 447 #if 0
 448         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 449            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 450             s->xvid_build= 0;
 451 #endif
 452     }
 453
 454     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 455         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 456             s->divx_version= 400; //divx 4
 457     }
 458
 459     if(s->xvid_build>=0 && s->divx_version>=0){
 460         s->divx_version=
 461         s->divx_build= -1;
 462     }
 463
 464     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 465         if(s->codec_tag == AV_RL32("XVIX"))
 466             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 467
 468         if(s->codec_tag == AV_RL32("UMP4")){
 469             s->workaround_bugs|= FF_BUG_UMP4;
 470         }
 471
 472         if(s->divx_version>=500 && s->divx_build<1814){
 473             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 474         }
 475
 476         if(s->divx_version>502 && s->divx_build<1814){
 477             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 478         }
 479
 480         if(s->xvid_build<=3U)
 481             s->padding_bug_score= 256*256*256*64;
 482
 483         if(s->xvid_build<=1U)
 484             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 485
 486         if(s->xvid_build<=12U)
 487             s->workaround_bugs|= FF_BUG_EDGE;
 488
 489         if(s->xvid_build<=32U)
 490             s->workaround_bugs|= FF_BUG_DC_CLIP;
 491
 492 #define SET_QPEL_FUNC(postfix1, postfix2) \
 493     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 494     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 495     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 496
 497         if(s->lavc_build<4653U)
 498             s->workaround_bugs|= FF_BUG_STD_QPEL;
 499
 500         if(s->lavc_build<4655U)
 501             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 502
 503         if(s->lavc_build<4670U){
 504             s->workaround_bugs|= FF_BUG_EDGE;
 505         }
 506
 507         if(s->lavc_build<=4712U)
 508             s->workaround_bugs|= FF_BUG_DC_CLIP;
 509
 510         if(s->divx_version>=0)
 511             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 512         if(s->divx_version==501 && s->divx_build==20020416)
 513             s->padding_bug_score= 256*256*256*64;
 514
 515         if(s->divx_version<500U){
 516             s->workaround_bugs|= FF_BUG_EDGE;
 517         }
 518
 519         if(s->divx_version>=0)
 520             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 521 #if 0
 522         if(s->divx_version==500)
 523             s->padding_bug_score= 256*256*256*64;
 524
 525         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 526          * Let us hope this at least works.
 527          */
 528         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
 529            && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
 530             s->workaround_bugs|= FF_BUG_NO_PADDING;
 531
 532         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
 533             s->workaround_bugs|= FF_BUG_NO_PADDING;
 534 #endif
 535     }
 536
 537     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 538         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 539         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 540         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 541         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 542         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 543         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 544
 545         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 546         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 547         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 548         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 549         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 550         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 551     }
 552
 553     if(avctx->debug & FF_DEBUG_BUGS)
 554         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 555                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 556                s->divx_packed ? "p" : "");
 557
 558 #if HAVE_MMX
 559     if (s->codec_id == AV_CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
 560         avctx->idct_algo= FF_IDCT_XVIDMMX;
 561         ff_dct_common_init(s);
 562         s->picture_number=0;
 563     }
 564 #endif
 565
 566         /* After H263 & mpeg4 header decode we have the height, width,*/
 567         /* and other parameters. So then we could init the picture   */
 568         /* FIXME: By the way H263 decoder is evolving it should have */
 569         /* an H263EncContext                                         */
 570
 571     if (!avctx->coded_width || !avctx->coded_height) {
 572         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 573
 574         s->parse_context.buffer=0;
 575         ff_MPV_common_end(s);
 576         s->parse_context= pc;
 577         avcodec_set_dimensions(avctx, s->width, s->height);
 578
 579         goto retry;
 580     }
 581
 582     if (s->width  != avctx->coded_width  ||
 583         s->height != avctx->coded_height ||
 584         s->context_reinit) {
 585         /* H.263 could change picture size any time */
 586         s->context_reinit = 0;
 587
 588         avcodec_set_dimensions(avctx, s->width, s->height);
 589
 590         if ((ret = ff_MPV_common_frame_size_change(s)))
 591             return ret;
 592     }
 593
 594     if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
 595         s->gob_index = ff_h263_get_gob_height(s);
 596
 597     // for skipping the frame
 598     s->current_picture.f.pict_type = s->pict_type;
 599     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
 600
 601     /* skip B-frames if we don't have reference frames */
 602     if (s->last_picture_ptr == NULL &&
 603         (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
 604         return get_consumed_bytes(s, buf_size);
 605     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
 606        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
 607        ||  avctx->skip_frame >= AVDISCARD_ALL)
 608         return get_consumed_bytes(s, buf_size);
 609
 610     if(s->next_p_frame_damaged){
 611         if(s->pict_type==AV_PICTURE_TYPE_B)
 612             return get_consumed_bytes(s, buf_size);
 613         else
 614             s->next_p_frame_damaged=0;
 615     }
 616
 617     if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
 618         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 619         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 620     }else{
 621         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 622         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 623     }
 624
 625     if(ff_MPV_frame_start(s, avctx) < 0)
 626         return -1;
 627
 628     if (!s->divx_packed) ff_thread_finish_setup(avctx);
 629
 630     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
 631         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
 632         goto frame_end;
 633     }
 634
 635     if (avctx->hwaccel) {
 636         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
 637             return -1;
 638     }
 639
 640     ff_mpeg_er_frame_start(s);
 641
 642     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 643     //which is not available before ff_MPV_frame_start()
 644     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 645         ret = ff_wmv2_decode_secondary_picture_header(s);
 646         if(ret<0) return ret;
 647         if(ret==1) goto intrax8_decoded;
 648     }
 649
 650     /* decode each macroblock */
 651     s->mb_x=0;
 652     s->mb_y=0;
 653
 654     ret = decode_slice(s);
 655     while(s->mb_y<s->mb_height){
 656         if(s->msmpeg4_version){
 657             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
 658                 break;
 659         }else{
 660             int prev_x=s->mb_x, prev_y=s->mb_y;
 661             if(ff_h263_resync(s)<0)
 662                 break;
 663             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
 664                 s->er.error_occurred = 1;
 665         }
 666
 667         if(s->msmpeg4_version<4 && s->h263_pred)
 668             ff_mpeg4_clean_buffers(s);
 669
 670         if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
 671     }
 672
 673     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
 674         if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
 675             s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
 676         }
 677
 678     assert(s->bitstream_buffer_size==0);
 679 frame_end:
 680     /* divx 5.01+ bistream reorder stuff */
 681     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
 682         int current_pos= get_bits_count(&s->gb)>>3;
 683         int startcode_found=0;
 684
 685         if(buf_size - current_pos > 5){
 686             int i;
 687             for(i=current_pos; i<buf_size-3; i++){
 688                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 689                     startcode_found=1;
 690                     break;
 691                 }
 692             }
 693         }
 694         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
 695             startcode_found=1;
 696             current_pos=0;
 697         }
 698
 699         if(startcode_found){
 700             av_fast_malloc(
 701                 &s->bitstream_buffer,
 702                 &s->allocated_bitstream_buffer_size,
 703                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 704             if (!s->bitstream_buffer)
 705                 return AVERROR(ENOMEM);
 706             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 707             s->bitstream_buffer_size= buf_size - current_pos;
 708         }
 709     }
 710
 711 intrax8_decoded:
 712     ff_er_frame_end(&s->er);
 713
 714     if (avctx->hwaccel) {
 715         if (avctx->hwaccel->end_frame(avctx) < 0)
 716             return -1;
 717     }
 718
 719     ff_MPV_frame_end(s);
 720
 721     assert(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
 722     assert(s->current_picture.f.pict_type == s->pict_type);
 723     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
 724         *pict = s->current_picture_ptr->f;
 725     } else if (s->last_picture_ptr != NULL) {
 726         *pict = s->last_picture_ptr->f;
 727     }
 728
 729     if(s->last_picture_ptr || s->low_delay){
 730         *got_frame = 1;
 731         ff_print_debug_info(s, pict);
 732     }
 733
 734 #ifdef PRINT_FRAME_TIME
 735 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 736 #endif
 737
 738     return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
 739 }
 740
 741 AVCodec ff_h263_decoder = {
 742     .name           = "h263",
 743     .type           = AVMEDIA_TYPE_VIDEO,
 744     .id             = AV_CODEC_ID_H263,
 745     .priv_data_size = sizeof(MpegEncContext),
 746     .init           = ff_h263_decode_init,
 747     .close          = ff_h263_decode_end,
 748     .decode         = ff_h263_decode_frame,
 749     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
 750                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 751     .flush          = ff_mpeg_flush,
 752     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 753     .pix_fmts       = ff_hwaccel_pixfmt_list_420,
 754 };