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

   1 /*
   2  * H.263 decoder
   3  * Copyright (c) 2001 Fabrice Bellard
   4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This 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 "error_resilience.h"
  32 #include "mpegvideo.h"
  33 #include "h263.h"
  34 #include "h263_parser.h"
  35 #include "mpeg4video_parser.h"
  36 #include "msmpeg4.h"
  37 #include "vdpau_internal.h"
  38 #include "thread.h"
  39 #include "flv.h"
  40 #include "mpeg4video.h"
  41
  42 //#define DEBUG
  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     s->flags= avctx->flags;
 352     s->flags2= avctx->flags2;
 353
 354     /* no supplementary picture */
 355     if (buf_size == 0) {
 356         /* special case for last picture */
 357         if (s->low_delay==0 && s->next_picture_ptr) {
 358             if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)
 359                 return ret;
 360             s->next_picture_ptr= NULL;
 361
 362             *got_frame = 1;
 363         }
 364
 365         return 0;
 366     }
 367
 368     if(s->flags&CODEC_FLAG_TRUNCATED){
 369         int next;
 370
 371         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 372             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 373         }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
 374             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 375         }else{
 376             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 377             return -1;
 378         }
 379
 380         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 381             return buf_size;
 382     }
 383
 384
 385 retry:
 386
 387     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 388         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 389     }else
 390         init_get_bits(&s->gb, buf, buf_size*8);
 391     s->bitstream_buffer_size=0;
 392
 393     if (!s->context_initialized) {
 394         if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 395             return -1;
 396     }
 397
 398     /* We need to set current_picture_ptr before reading the header,
 399      * otherwise we cannot store anyting in there */
 400     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
 401         int i= ff_find_unused_picture(s, 0);
 402         if (i < 0)
 403             return i;
 404         s->current_picture_ptr= &s->picture[i];
 405     }
 406
 407     /* let's go :-) */
 408     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 409         ret= ff_wmv2_decode_picture_header(s);
 410     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 411         ret = ff_msmpeg4_decode_picture_header(s);
 412     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
 413         if(s->avctx->extradata_size && s->picture_number==0){
 414             GetBitContext gb;
 415
 416             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 417             ret = ff_mpeg4_decode_picture_header(s, &gb);
 418         }
 419         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 420     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
 421         ret = ff_intel_h263_decode_picture_header(s);
 422     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
 423         ret = ff_flv_decode_picture_header(s);
 424     } else {
 425         ret = ff_h263_decode_picture_header(s);
 426     }
 427
 428     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 429
 430     /* skip if the header was thrashed */
 431     if (ret < 0){
 432         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 433         return -1;
 434     }
 435
 436     avctx->has_b_frames= !s->low_delay;
 437
 438     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 439         if(s->stream_codec_tag == AV_RL32("XVID") ||
 440            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 441            s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||
 442            s->codec_tag == AV_RL32("SIPP")
 443            )
 444             s->xvid_build= 0;
 445 #if 0
 446         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 447            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 448             s->xvid_build= 0;
 449 #endif
 450     }
 451
 452     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 453         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 454             s->divx_version= 400; //divx 4
 455     }
 456
 457     if(s->xvid_build>=0 && s->divx_version>=0){
 458         s->divx_version=
 459         s->divx_build= -1;
 460     }
 461
 462     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 463         if(s->codec_tag == AV_RL32("XVIX"))
 464             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 465
 466         if(s->codec_tag == AV_RL32("UMP4")){
 467             s->workaround_bugs|= FF_BUG_UMP4;
 468         }
 469
 470         if(s->divx_version>=500 && s->divx_build<1814){
 471             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 472         }
 473
 474         if(s->divx_version>502 && s->divx_build<1814){
 475             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 476         }
 477
 478         if(s->xvid_build<=3U)
 479             s->padding_bug_score= 256*256*256*64;
 480
 481         if(s->xvid_build<=1U)
 482             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 483
 484         if(s->xvid_build<=12U)
 485             s->workaround_bugs|= FF_BUG_EDGE;
 486
 487         if(s->xvid_build<=32U)
 488             s->workaround_bugs|= FF_BUG_DC_CLIP;
 489
 490 #define SET_QPEL_FUNC(postfix1, postfix2) \
 491     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 492     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 493     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 494
 495         if(s->lavc_build<4653U)
 496             s->workaround_bugs|= FF_BUG_STD_QPEL;
 497
 498         if(s->lavc_build<4655U)
 499             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 500
 501         if(s->lavc_build<4670U){
 502             s->workaround_bugs|= FF_BUG_EDGE;
 503         }
 504
 505         if(s->lavc_build<=4712U)
 506             s->workaround_bugs|= FF_BUG_DC_CLIP;
 507
 508         if(s->divx_version>=0)
 509             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 510         if(s->divx_version==501 && s->divx_build==20020416)
 511             s->padding_bug_score= 256*256*256*64;
 512
 513         if(s->divx_version<500U){
 514             s->workaround_bugs|= FF_BUG_EDGE;
 515         }
 516
 517         if(s->divx_version>=0)
 518             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 519 #if 0
 520         if(s->divx_version==500)
 521             s->padding_bug_score= 256*256*256*64;
 522
 523         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 524          * Let us hope this at least works.
 525          */
 526         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
 527            && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
 528             s->workaround_bugs|= FF_BUG_NO_PADDING;
 529
 530         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
 531             s->workaround_bugs|= FF_BUG_NO_PADDING;
 532 #endif
 533     }
 534
 535     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 536         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 537         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 538         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 539         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 540         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 541         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 542
 543         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 544         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 545         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 546         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 547         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 548         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 549     }
 550
 551     if(avctx->debug & FF_DEBUG_BUGS)
 552         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 553                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 554                s->divx_packed ? "p" : "");
 555
 556 #if HAVE_MMX
 557     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)) {
 558         avctx->idct_algo= FF_IDCT_XVIDMMX;
 559         ff_dct_common_init(s);
 560         s->picture_number=0;
 561     }
 562 #endif
 563
 564         /* After H263 & mpeg4 header decode we have the height, width,*/
 565         /* and other parameters. So then we could init the picture   */
 566         /* FIXME: By the way H263 decoder is evolving it should have */
 567         /* an H263EncContext                                         */
 568
 569     if (!avctx->coded_width || !avctx->coded_height) {
 570         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 571
 572         s->parse_context.buffer=0;
 573         ff_MPV_common_end(s);
 574         s->parse_context= pc;
 575         avcodec_set_dimensions(avctx, s->width, s->height);
 576
 577         goto retry;
 578     }
 579
 580     if (s->width  != avctx->coded_width  ||
 581         s->height != avctx->coded_height ||
 582         s->context_reinit) {
 583         /* H.263 could change picture size any time */
 584         s->context_reinit = 0;
 585
 586         avcodec_set_dimensions(avctx, s->width, s->height);
 587
 588         if ((ret = ff_MPV_common_frame_size_change(s)))
 589             return ret;
 590     }
 591
 592     if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
 593         s->gob_index = ff_h263_get_gob_height(s);
 594
 595     // for skipping the frame
 596     s->current_picture.f.pict_type = s->pict_type;
 597     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
 598
 599     /* skip B-frames if we don't have reference frames */
 600     if (s->last_picture_ptr == NULL &&
 601         (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
 602         return get_consumed_bytes(s, buf_size);
 603     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
 604        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
 605        ||  avctx->skip_frame >= AVDISCARD_ALL)
 606         return get_consumed_bytes(s, buf_size);
 607
 608     if(s->next_p_frame_damaged){
 609         if(s->pict_type==AV_PICTURE_TYPE_B)
 610             return get_consumed_bytes(s, buf_size);
 611         else
 612             s->next_p_frame_damaged=0;
 613     }
 614
 615     if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
 616         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 617         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 618     }else{
 619         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 620         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 621     }
 622
 623     if(ff_MPV_frame_start(s, avctx) < 0)
 624         return -1;
 625
 626     if (!s->divx_packed && !avctx->hwaccel)
 627         ff_thread_finish_setup(avctx);
 628
 629     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
 630         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
 631         goto frame_end;
 632     }
 633
 634     if (avctx->hwaccel) {
 635         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
 636             return -1;
 637     }
 638
 639     ff_mpeg_er_frame_start(s);
 640
 641     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 642     //which is not available before ff_MPV_frame_start()
 643     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 644         ret = ff_wmv2_decode_secondary_picture_header(s);
 645         if(ret<0) return ret;
 646         if(ret==1) goto intrax8_decoded;
 647     }
 648
 649     /* decode each macroblock */
 650     s->mb_x=0;
 651     s->mb_y=0;
 652
 653     ret = decode_slice(s);
 654     while(s->mb_y<s->mb_height){
 655         if(s->msmpeg4_version){
 656             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
 657                 break;
 658         }else{
 659             int prev_x=s->mb_x, prev_y=s->mb_y;
 660             if(ff_h263_resync(s)<0)
 661                 break;
 662             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
 663                 s->er.error_occurred = 1;
 664         }
 665
 666         if(s->msmpeg4_version<4 && s->h263_pred)
 667             ff_mpeg4_clean_buffers(s);
 668
 669         if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
 670     }
 671
 672     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
 673         if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
 674             s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
 675         }
 676
 677     assert(s->bitstream_buffer_size==0);
 678 frame_end:
 679     /* divx 5.01+ bistream reorder stuff */
 680     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
 681         int current_pos= get_bits_count(&s->gb)>>3;
 682         int startcode_found=0;
 683
 684         if(buf_size - current_pos > 5){
 685             int i;
 686             for(i=current_pos; i<buf_size-3; i++){
 687                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 688                     startcode_found=1;
 689                     break;
 690                 }
 691             }
 692         }
 693         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
 694             startcode_found=1;
 695             current_pos=0;
 696         }
 697
 698         if(startcode_found){
 699             av_fast_malloc(
 700                 &s->bitstream_buffer,
 701                 &s->allocated_bitstream_buffer_size,
 702                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 703             if (!s->bitstream_buffer)
 704                 return AVERROR(ENOMEM);
 705             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 706             s->bitstream_buffer_size= buf_size - current_pos;
 707         }
 708     }
 709
 710 intrax8_decoded:
 711     ff_er_frame_end(&s->er);
 712
 713     if (avctx->hwaccel) {
 714         if (avctx->hwaccel->end_frame(avctx) < 0)
 715             return -1;
 716     }
 717
 718     ff_MPV_frame_end(s);
 719
 720     if (!s->divx_packed && avctx->hwaccel)
 721         ff_thread_finish_setup(avctx);
 722
 723     assert(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
 724     assert(s->current_picture.f.pict_type == s->pict_type);
 725     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
 726         if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)
 727             return ret;
 728         ff_print_debug_info(s, s->current_picture_ptr);
 729     } else if (s->last_picture_ptr != NULL) {
 730         if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)
 731             return ret;
 732         ff_print_debug_info(s, s->last_picture_ptr);
 733     }
 734
 735     if(s->last_picture_ptr || s->low_delay){
 736         *got_frame = 1;
 737     }
 738
 739     return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
 740 }
 741
 742 const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[] = {
 743 #if CONFIG_VAAPI
 744     AV_PIX_FMT_VAAPI_VLD,
 745 #endif
 746 #if CONFIG_VDPAU
 747     AV_PIX_FMT_VDPAU,
 748 #endif
 749     AV_PIX_FMT_YUV420P,
 750     AV_PIX_FMT_NONE
 751 };
 752
 753 AVCodec ff_h263_decoder = {
 754     .name           = "h263",
 755     .type           = AVMEDIA_TYPE_VIDEO,
 756     .id             = AV_CODEC_ID_H263,
 757     .priv_data_size = sizeof(MpegEncContext),
 758     .init           = ff_h263_decode_init,
 759     .close          = ff_h263_decode_end,
 760     .decode         = ff_h263_decode_frame,
 761     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
 762                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 763     .flush          = ff_mpeg_flush,
 764     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 765     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
 766 };