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 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  43 {
  44     MpegEncContext *s = avctx->priv_data;
  45
  46     s->avctx = avctx;
  47     s->out_format = FMT_H263;
  48
  49     s->width  = avctx->coded_width;
  50     s->height = avctx->coded_height;
  51     s->workaround_bugs= avctx->workaround_bugs;
  52
  53     // set defaults
  54     ff_MPV_decode_defaults(s);
  55     s->quant_precision=5;
  56     s->decode_mb= ff_h263_decode_mb;
  57     s->low_delay= 1;
  58     if (avctx->codec->id == AV_CODEC_ID_MSS2)
  59         avctx->pix_fmt = AV_PIX_FMT_YUV420P;
  60     else
  61         avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
  62     s->unrestricted_mv= 1;
  63
  64     /* select sub codec */
  65     switch(avctx->codec->id) {
  66     case AV_CODEC_ID_H263:
  67         s->unrestricted_mv= 0;
  68         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
  69         break;
  70     case AV_CODEC_ID_MPEG4:
  71         break;
  72     case AV_CODEC_ID_MSMPEG4V1:
  73         s->h263_pred = 1;
  74         s->msmpeg4_version=1;
  75         break;
  76     case AV_CODEC_ID_MSMPEG4V2:
  77         s->h263_pred = 1;
  78         s->msmpeg4_version=2;
  79         break;
  80     case AV_CODEC_ID_MSMPEG4V3:
  81         s->h263_pred = 1;
  82         s->msmpeg4_version=3;
  83         break;
  84     case AV_CODEC_ID_WMV1:
  85         s->h263_pred = 1;
  86         s->msmpeg4_version=4;
  87         break;
  88     case AV_CODEC_ID_WMV2:
  89         s->h263_pred = 1;
  90         s->msmpeg4_version=5;
  91         break;
  92     case AV_CODEC_ID_VC1:
  93     case AV_CODEC_ID_WMV3:
  94     case AV_CODEC_ID_VC1IMAGE:
  95     case AV_CODEC_ID_WMV3IMAGE:
  96     case AV_CODEC_ID_MSS2:
  97         s->h263_pred = 1;
  98         s->msmpeg4_version=6;
  99         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 100         break;
 101     case AV_CODEC_ID_H263I:
 102         break;
 103     case AV_CODEC_ID_FLV1:
 104         s->h263_flv = 1;
 105         break;
 106     default:
 107         return -1;
 108     }
 109     s->codec_id= avctx->codec->id;
 110     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
 111
 112     /* for h263, we allocate the images after having read the header */
 113     if (avctx->codec->id != AV_CODEC_ID_H263 && avctx->codec->id != AV_CODEC_ID_MPEG4)
 114         if (ff_MPV_common_init(s) < 0)
 115             return -1;
 116
 117         ff_h263_decode_init_vlc();
 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     ff_MPV_common_end(s);
 127     return 0;
 128 }
 129
 130 /**
 131  * Return 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 || s->avctx->hwaccel){
 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 ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
 153     const int mb_size = 16;
 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->avctx->hwaccel) {
 163         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
 164         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
 165         skip_bits_long(&s->gb, 8*(end - start));
 166         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
 167     }
 168
 169     if(s->partitioned_frame){
 170         const int qscale= s->qscale;
 171
 172         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 173             if(ff_mpeg4_decode_partitions(s) < 0)
 174                 return -1;
 175         }
 176
 177         /* restore variables which were modified */
 178         s->first_slice_line=1;
 179         s->mb_x= s->resync_mb_x;
 180         s->mb_y= s->resync_mb_y;
 181         ff_set_qscale(s, qscale);
 182     }
 183
 184     for(; s->mb_y < s->mb_height; s->mb_y++) {
 185         /* per-row end of slice checks */
 186         if(s->msmpeg4_version){
 187             if(s->resync_mb_y + s->slice_height == s->mb_y){
 188                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
 189
 190                 return 0;
 191             }
 192         }
 193
 194         if(s->msmpeg4_version==1){
 195             s->last_dc[0]=
 196             s->last_dc[1]=
 197             s->last_dc[2]= 128;
 198         }
 199
 200         ff_init_block_index(s);
 201         for(; s->mb_x < s->mb_width; s->mb_x++) {
 202             int ret;
 203
 204             ff_update_block_index(s);
 205
 206             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 207                 s->first_slice_line=0;
 208             }
 209
 210             /* DCT & quantize */
 211
 212             s->mv_dir = MV_DIR_FORWARD;
 213             s->mv_type = MV_TYPE_16X16;
 214 //            s->mb_skipped = 0;
 215             av_dlog(s, "%d %d %06X\n",
 216                     ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 217             ret= s->decode_mb(s, s->block);
 218
 219             if (s->pict_type!=AV_PICTURE_TYPE_B)
 220                 ff_h263_update_motion_val(s);
 221
 222             if(ret<0){
 223                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 224                 if(ret==SLICE_END){
 225                     ff_MPV_decode_mb(s, s->block);
 226                     if(s->loop_filter)
 227                         ff_h263_loop_filter(s);
 228
 229                     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);
 230
 231                     s->padding_bug_score--;
 232
 233                     if(++s->mb_x >= s->mb_width){
 234                         s->mb_x=0;
 235                         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 236                         ff_MPV_report_decode_progress(s);
 237                         s->mb_y++;
 238                     }
 239                     return 0;
 240                 }else if(ret==SLICE_NOEND){
 241                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 242                     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);
 243                     return -1;
 244                 }
 245                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 246                 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);
 247
 248                 return -1;
 249             }
 250
 251             ff_MPV_decode_mb(s, s->block);
 252             if(s->loop_filter)
 253                 ff_h263_loop_filter(s);
 254         }
 255
 256         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 257         ff_MPV_report_decode_progress(s);
 258
 259         s->mb_x= 0;
 260     }
 261
 262     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 263
 264     if(s->codec_id==AV_CODEC_ID_MPEG4
 265        && (s->workaround_bugs&FF_BUG_AUTODETECT)
 266        && get_bits_left(&s->gb) >= 48
 267        && show_bits(&s->gb, 24)==0x4010
 268        && !s->data_partitioning)
 269         s->padding_bug_score+=32;
 270
 271     /* try to detect the padding bug */
 272     if(      s->codec_id==AV_CODEC_ID_MPEG4
 273        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 274        &&    get_bits_left(&s->gb) >=0
 275        &&    get_bits_left(&s->gb) < 48
 276 //       &&   !s->resync_marker
 277        &&   !s->data_partitioning){
 278
 279         const int bits_count= get_bits_count(&s->gb);
 280         const int bits_left = s->gb.size_in_bits - bits_count;
 281
 282         if(bits_left==0){
 283             s->padding_bug_score+=16;
 284         } else if(bits_left != 1){
 285             int v= show_bits(&s->gb, 8);
 286             v|= 0x7F >> (7-(bits_count&7));
 287
 288             if(v==0x7F && bits_left<=8)
 289                 s->padding_bug_score--;
 290             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 291                 s->padding_bug_score+= 4;
 292             else
 293                 s->padding_bug_score++;
 294         }
 295     }
 296
 297     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 298         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
 299             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 300         else
 301             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 302     }
 303
 304     // handle formats which don't have unique end markers
 305     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 306         int left= get_bits_left(&s->gb);
 307         int max_extra=7;
 308
 309         /* no markers in M$ crap */
 310         if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
 311             max_extra+= 17;
 312
 313         /* buggy padding but the frame should still end approximately at the bitstream end */
 314         if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&AV_EF_BUFFER))
 315             max_extra+= 48;
 316         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 317             max_extra+= 256*256*256*64;
 318
 319         if(left>max_extra){
 320             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 321         }
 322         else if(left<0){
 323             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 324         }else
 325             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
 326
 327         return 0;
 328     }
 329
 330     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 331             get_bits_left(&s->gb),
 332             show_bits(&s->gb, 24), s->padding_bug_score);
 333
 334     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);
 335
 336     return -1;
 337 }
 338
 339 int ff_h263_decode_frame(AVCodecContext *avctx,
 340                              void *data, int *got_frame,
 341                              AVPacket *avpkt)
 342 {
 343     const uint8_t *buf = avpkt->data;
 344     int buf_size = avpkt->size;
 345     MpegEncContext *s = avctx->priv_data;
 346     int ret;
 347     AVFrame *pict = data;
 348
 349     s->flags= avctx->flags;
 350     s->flags2= avctx->flags2;
 351
 352     /* no supplementary picture */
 353     if (buf_size == 0) {
 354         /* special case for last picture */
 355         if (s->low_delay==0 && s->next_picture_ptr) {
 356             if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)
 357                 return ret;
 358             s->next_picture_ptr= NULL;
 359
 360             *got_frame = 1;
 361         }
 362
 363         return 0;
 364     }
 365
 366     if(s->flags&CODEC_FLAG_TRUNCATED){
 367         int next;
 368
 369         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 370             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 371         }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
 372             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 373         }else{
 374             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 375             return -1;
 376         }
 377
 378         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 379             return buf_size;
 380     }
 381
 382
 383 retry:
 384
 385     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 386         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 387     }else
 388         init_get_bits(&s->gb, buf, buf_size*8);
 389     s->bitstream_buffer_size=0;
 390
 391     if (!s->context_initialized) {
 392         if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 393             return -1;
 394     }
 395
 396     /* We need to set current_picture_ptr before reading the header,
 397      * otherwise we cannot store anyting in there */
 398     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
 399         int i= ff_find_unused_picture(s, 0);
 400         if (i < 0)
 401             return i;
 402         s->current_picture_ptr= &s->picture[i];
 403     }
 404
 405     /* let's go :-) */
 406     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 407         ret= ff_wmv2_decode_picture_header(s);
 408     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 409         ret = ff_msmpeg4_decode_picture_header(s);
 410     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
 411         if(s->avctx->extradata_size && s->picture_number==0){
 412             GetBitContext gb;
 413
 414             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 415             ret = ff_mpeg4_decode_picture_header(s, &gb);
 416         }
 417         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 418     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
 419         ret = ff_intel_h263_decode_picture_header(s);
 420     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
 421         ret = ff_flv_decode_picture_header(s);
 422     } else {
 423         ret = ff_h263_decode_picture_header(s);
 424     }
 425
 426     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 427
 428     /* skip if the header was thrashed */
 429     if (ret < 0){
 430         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 431         return -1;
 432     }
 433
 434     avctx->has_b_frames= !s->low_delay;
 435
 436     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 437         if(s->stream_codec_tag == AV_RL32("XVID") ||
 438            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 439            s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||
 440            s->codec_tag == AV_RL32("SIPP")
 441            )
 442             s->xvid_build= 0;
 443 #if 0
 444         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 445            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 446             s->xvid_build= 0;
 447 #endif
 448     }
 449
 450     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 451         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 452             s->divx_version= 400; //divx 4
 453     }
 454
 455     if(s->xvid_build>=0 && s->divx_version>=0){
 456         s->divx_version=
 457         s->divx_build= -1;
 458     }
 459
 460     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 461         if(s->codec_tag == AV_RL32("XVIX"))
 462             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 463
 464         if(s->codec_tag == AV_RL32("UMP4")){
 465             s->workaround_bugs|= FF_BUG_UMP4;
 466         }
 467
 468         if(s->divx_version>=500 && s->divx_build<1814){
 469             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 470         }
 471
 472         if(s->divx_version>502 && s->divx_build<1814){
 473             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 474         }
 475
 476         if(s->xvid_build<=3U)
 477             s->padding_bug_score= 256*256*256*64;
 478
 479         if(s->xvid_build<=1U)
 480             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 481
 482         if(s->xvid_build<=12U)
 483             s->workaround_bugs|= FF_BUG_EDGE;
 484
 485         if(s->xvid_build<=32U)
 486             s->workaround_bugs|= FF_BUG_DC_CLIP;
 487
 488 #define SET_QPEL_FUNC(postfix1, postfix2) \
 489     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 490     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 491     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 492
 493         if(s->lavc_build<4653U)
 494             s->workaround_bugs|= FF_BUG_STD_QPEL;
 495
 496         if(s->lavc_build<4655U)
 497             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 498
 499         if(s->lavc_build<4670U){
 500             s->workaround_bugs|= FF_BUG_EDGE;
 501         }
 502
 503         if(s->lavc_build<=4712U)
 504             s->workaround_bugs|= FF_BUG_DC_CLIP;
 505
 506         if(s->divx_version>=0)
 507             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 508         if(s->divx_version==501 && s->divx_build==20020416)
 509             s->padding_bug_score= 256*256*256*64;
 510
 511         if(s->divx_version<500U){
 512             s->workaround_bugs|= FF_BUG_EDGE;
 513         }
 514
 515         if(s->divx_version>=0)
 516             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 517 #if 0
 518         if(s->divx_version==500)
 519             s->padding_bug_score= 256*256*256*64;
 520
 521         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 522          * Let us hope this at least works.
 523          */
 524         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
 525            && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
 526             s->workaround_bugs|= FF_BUG_NO_PADDING;
 527
 528         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
 529             s->workaround_bugs|= FF_BUG_NO_PADDING;
 530 #endif
 531     }
 532
 533     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 534         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 535         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 536         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 537         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 538         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 539         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 540
 541         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 542         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 543         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 544         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 545         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 546         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 547     }
 548
 549     if(avctx->debug & FF_DEBUG_BUGS)
 550         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 551                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 552                s->divx_packed ? "p" : "");
 553
 554 #if HAVE_MMX
 555     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)) {
 556         avctx->idct_algo= FF_IDCT_XVIDMMX;
 557         ff_dct_common_init(s);
 558         s->picture_number=0;
 559     }
 560 #endif
 561
 562         /* After H263 & mpeg4 header decode we have the height, width,*/
 563         /* and other parameters. So then we could init the picture   */
 564         /* FIXME: By the way H263 decoder is evolving it should have */
 565         /* an H263EncContext                                         */
 566
 567     if (!avctx->coded_width || !avctx->coded_height) {
 568         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 569
 570         s->parse_context.buffer=0;
 571         ff_MPV_common_end(s);
 572         s->parse_context= pc;
 573         avcodec_set_dimensions(avctx, s->width, s->height);
 574
 575         goto retry;
 576     }
 577
 578     if (s->width  != avctx->coded_width  ||
 579         s->height != avctx->coded_height ||
 580         s->context_reinit) {
 581         /* H.263 could change picture size any time */
 582         s->context_reinit = 0;
 583
 584         avcodec_set_dimensions(avctx, s->width, s->height);
 585
 586         if ((ret = ff_MPV_common_frame_size_change(s)))
 587             return ret;
 588     }
 589
 590     if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
 591         s->gob_index = ff_h263_get_gob_height(s);
 592
 593     // for skipping the frame
 594     s->current_picture.f.pict_type = s->pict_type;
 595     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
 596
 597     /* skip B-frames if we don't have reference frames */
 598     if (s->last_picture_ptr == NULL &&
 599         (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
 600         return get_consumed_bytes(s, buf_size);
 601     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
 602        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
 603        ||  avctx->skip_frame >= AVDISCARD_ALL)
 604         return get_consumed_bytes(s, buf_size);
 605
 606     if(s->next_p_frame_damaged){
 607         if(s->pict_type==AV_PICTURE_TYPE_B)
 608             return get_consumed_bytes(s, buf_size);
 609         else
 610             s->next_p_frame_damaged=0;
 611     }
 612
 613     if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
 614         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 615         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 616     }else{
 617         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 618         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 619     }
 620
 621     if(ff_MPV_frame_start(s, avctx) < 0)
 622         return -1;
 623
 624     if (!s->divx_packed && !avctx->hwaccel)
 625         ff_thread_finish_setup(avctx);
 626
 627     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
 628         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
 629         goto frame_end;
 630     }
 631
 632     if (avctx->hwaccel) {
 633         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
 634             return -1;
 635     }
 636
 637     ff_mpeg_er_frame_start(s);
 638
 639     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 640     //which is not available before ff_MPV_frame_start()
 641     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 642         ret = ff_wmv2_decode_secondary_picture_header(s);
 643         if(ret<0) return ret;
 644         if(ret==1) goto intrax8_decoded;
 645     }
 646
 647     /* decode each macroblock */
 648     s->mb_x=0;
 649     s->mb_y=0;
 650
 651     ret = decode_slice(s);
 652     while(s->mb_y<s->mb_height){
 653         if(s->msmpeg4_version){
 654             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
 655                 break;
 656         }else{
 657             int prev_x=s->mb_x, prev_y=s->mb_y;
 658             if(ff_h263_resync(s)<0)
 659                 break;
 660             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
 661                 s->er.error_occurred = 1;
 662         }
 663
 664         if(s->msmpeg4_version<4 && s->h263_pred)
 665             ff_mpeg4_clean_buffers(s);
 666
 667         if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
 668     }
 669
 670     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
 671         if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
 672             s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
 673         }
 674
 675     assert(s->bitstream_buffer_size==0);
 676 frame_end:
 677     /* divx 5.01+ bistream reorder stuff */
 678     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
 679         int current_pos= get_bits_count(&s->gb)>>3;
 680         int startcode_found=0;
 681
 682         if(buf_size - current_pos > 5){
 683             int i;
 684             for(i=current_pos; i<buf_size-3; i++){
 685                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 686                     startcode_found=1;
 687                     break;
 688                 }
 689             }
 690         }
 691         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
 692             startcode_found=1;
 693             current_pos=0;
 694         }
 695
 696         if(startcode_found){
 697             av_fast_malloc(
 698                 &s->bitstream_buffer,
 699                 &s->allocated_bitstream_buffer_size,
 700                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 701             if (!s->bitstream_buffer)
 702                 return AVERROR(ENOMEM);
 703             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 704             s->bitstream_buffer_size= buf_size - current_pos;
 705         }
 706     }
 707
 708 intrax8_decoded:
 709     ff_er_frame_end(&s->er);
 710
 711     if (avctx->hwaccel) {
 712         if (avctx->hwaccel->end_frame(avctx) < 0)
 713             return -1;
 714     }
 715
 716     ff_MPV_frame_end(s);
 717
 718     if (!s->divx_packed && avctx->hwaccel)
 719         ff_thread_finish_setup(avctx);
 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         if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)
 725             return ret;
 726         ff_print_debug_info(s, s->current_picture_ptr);
 727     } else if (s->last_picture_ptr != NULL) {
 728         if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)
 729             return ret;
 730         ff_print_debug_info(s, s->last_picture_ptr);
 731     }
 732
 733     if(s->last_picture_ptr || s->low_delay){
 734         *got_frame = 1;
 735     }
 736
 737     return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
 738 }
 739
 740 const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[] = {
 741 #if CONFIG_VAAPI
 742     AV_PIX_FMT_VAAPI_VLD,
 743 #endif
 744 #if CONFIG_VDPAU
 745     AV_PIX_FMT_VDPAU,
 746 #endif
 747     AV_PIX_FMT_YUV420P,
 748     AV_PIX_FMT_NONE
 749 };
 750
 751 AVCodec ff_h263_decoder = {
 752     .name           = "h263",
 753     .type           = AVMEDIA_TYPE_VIDEO,
 754     .id             = AV_CODEC_ID_H263,
 755     .priv_data_size = sizeof(MpegEncContext),
 756     .init           = ff_h263_decode_init,
 757     .close          = ff_h263_decode_end,
 758     .decode         = ff_h263_decode_frame,
 759     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
 760                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 761     .flush          = ff_mpeg_flush,
 762     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 763     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
 764 };