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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 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
  25  * H.263 decoder.
  26  */
  27
  28 #define UNCHECKED_BITSTREAM_READER 1
  29
  30 #include "libavutil/cpu.h"
  31 #include "internal.h"
  32 #include "avcodec.h"
  33 #include "dsputil.h"
  34 #include "mpegvideo.h"
  35 #include "h263.h"
  36 #include "h263_parser.h"
  37 #include "mpeg4video_parser.h"
  38 #include "msmpeg4.h"
  39 #include "vdpau_internal.h"
  40 #include "thread.h"
  41 #include "flv.h"
  42 #include "mpeg4video.h"
  43
  44 //#define DEBUG
  45 //#define PRINT_FRAME_TIME
  46
  47 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  48 {
  49     MpegEncContext *s = avctx->priv_data;
  50
  51     s->avctx = avctx;
  52     s->out_format = FMT_H263;
  53
  54     s->width  = avctx->coded_width;
  55     s->height = avctx->coded_height;
  56     s->workaround_bugs= avctx->workaround_bugs;
  57
  58     // set defaults
  59     ff_MPV_decode_defaults(s);
  60     s->quant_precision=5;
  61     s->decode_mb= ff_h263_decode_mb;
  62     s->low_delay= 1;
  63     if (avctx->codec->id == AV_CODEC_ID_MSS2)
  64         avctx->pix_fmt = PIX_FMT_YUV420P;
  65     else
  66         avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
  67     s->unrestricted_mv= 1;
  68
  69     /* select sub codec */
  70     switch(avctx->codec->id) {
  71     case AV_CODEC_ID_H263:
  72     case AV_CODEC_ID_H263P:
  73         s->unrestricted_mv= 0;
  74         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
  75         break;
  76     case AV_CODEC_ID_MPEG4:
  77         break;
  78     case AV_CODEC_ID_MSMPEG4V1:
  79         s->h263_pred = 1;
  80         s->msmpeg4_version=1;
  81         break;
  82     case AV_CODEC_ID_MSMPEG4V2:
  83         s->h263_pred = 1;
  84         s->msmpeg4_version=2;
  85         break;
  86     case AV_CODEC_ID_MSMPEG4V3:
  87         s->h263_pred = 1;
  88         s->msmpeg4_version=3;
  89         break;
  90     case AV_CODEC_ID_WMV1:
  91         s->h263_pred = 1;
  92         s->msmpeg4_version=4;
  93         break;
  94     case AV_CODEC_ID_WMV2:
  95         s->h263_pred = 1;
  96         s->msmpeg4_version=5;
  97         break;
  98     case AV_CODEC_ID_VC1:
  99     case AV_CODEC_ID_WMV3:
 100     case AV_CODEC_ID_VC1IMAGE:
 101     case AV_CODEC_ID_WMV3IMAGE:
 102     case AV_CODEC_ID_MSS2:
 103         s->h263_pred = 1;
 104         s->msmpeg4_version=6;
 105         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 106         break;
 107     case AV_CODEC_ID_H263I:
 108         break;
 109     case AV_CODEC_ID_FLV1:
 110         s->h263_flv = 1;
 111         break;
 112     default:
 113         return -1;
 114     }
 115     s->codec_id= avctx->codec->id;
 116     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
 117
 118     /* for h263, we allocate the images after having read the header */
 119     if (avctx->codec->id != AV_CODEC_ID_H263 && avctx->codec->id != AV_CODEC_ID_H263P && avctx->codec->id != AV_CODEC_ID_MPEG4)
 120         if (ff_MPV_common_init(s) < 0)
 121             return -1;
 122
 123         ff_h263_decode_init_vlc(s);
 124
 125     return 0;
 126 }
 127
 128 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
 129 {
 130     MpegEncContext *s = avctx->priv_data;
 131
 132     ff_MPV_common_end(s);
 133     return 0;
 134 }
 135
 136 /**
 137  * Return the number of bytes consumed for building the current frame.
 138  */
 139 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 140     int pos= (get_bits_count(&s->gb)+7)>>3;
 141
 142     if(s->divx_packed || s->avctx->hwaccel){
 143         //we would have to scan through the whole buf to handle the weird reordering ...
 144         return buf_size;
 145     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 146         pos -= s->parse_context.last_index;
 147         if(pos<0) pos=0; // padding is not really read so this might be -1
 148         return pos;
 149     }else{
 150         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
 151         if(pos+10>buf_size) pos=buf_size; // oops ;)
 152
 153         return pos;
 154     }
 155 }
 156
 157 static int decode_slice(MpegEncContext *s){
 158     const int part_mask= s->partitioned_frame ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
 159     const int mb_size= 16>>s->avctx->lowres;
 160     s->last_resync_gb= s->gb;
 161     s->first_slice_line= 1;
 162
 163     s->resync_mb_x= s->mb_x;
 164     s->resync_mb_y= s->mb_y;
 165
 166     ff_set_qscale(s, s->qscale);
 167
 168     if (s->avctx->hwaccel) {
 169         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
 170         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
 171         skip_bits_long(&s->gb, 8*(end - start));
 172         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
 173     }
 174
 175     if(s->partitioned_frame){
 176         const int qscale= s->qscale;
 177
 178         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 179             if(ff_mpeg4_decode_partitions(s) < 0)
 180                 return -1;
 181         }
 182
 183         /* restore variables which were modified */
 184         s->first_slice_line=1;
 185         s->mb_x= s->resync_mb_x;
 186         s->mb_y= s->resync_mb_y;
 187         ff_set_qscale(s, qscale);
 188     }
 189
 190     for(; s->mb_y < s->mb_height; s->mb_y++) {
 191         /* per-row end of slice checks */
 192         if(s->msmpeg4_version){
 193             if(s->resync_mb_y + s->slice_height == s->mb_y){
 194                 ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
 195
 196                 return 0;
 197             }
 198         }
 199
 200         if(s->msmpeg4_version==1){
 201             s->last_dc[0]=
 202             s->last_dc[1]=
 203             s->last_dc[2]= 128;
 204         }
 205
 206         ff_init_block_index(s);
 207         for(; s->mb_x < s->mb_width; s->mb_x++) {
 208             int ret;
 209
 210             ff_update_block_index(s);
 211
 212             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 213                 s->first_slice_line=0;
 214             }
 215
 216             /* DCT & quantize */
 217
 218             s->mv_dir = MV_DIR_FORWARD;
 219             s->mv_type = MV_TYPE_16X16;
 220 //            s->mb_skipped = 0;
 221 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 222             ret= s->decode_mb(s, s->block);
 223
 224             if (s->pict_type!=AV_PICTURE_TYPE_B)
 225                 ff_h263_update_motion_val(s);
 226
 227             if(ret<0){
 228                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 229                 if(ret==SLICE_END){
 230                     ff_MPV_decode_mb(s, s->block);
 231                     if(s->loop_filter)
 232                         ff_h263_loop_filter(s);
 233
 234 //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));
 235                     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
 236
 237                     s->padding_bug_score--;
 238
 239                     if(++s->mb_x >= s->mb_width){
 240                         s->mb_x=0;
 241                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 242                         ff_MPV_report_decode_progress(s);
 243                         s->mb_y++;
 244                     }
 245                     return 0;
 246                 }else if(ret==SLICE_NOEND){
 247                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 248                     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, ER_MB_END&part_mask);
 249                     return -1;
 250                 }
 251                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 252                 ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR&part_mask);
 253
 254                 return -1;
 255             }
 256
 257             ff_MPV_decode_mb(s, s->block);
 258             if(s->loop_filter)
 259                 ff_h263_loop_filter(s);
 260         }
 261
 262         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 263         ff_MPV_report_decode_progress(s);
 264
 265         s->mb_x= 0;
 266     }
 267
 268     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 269
 270     if(s->codec_id==AV_CODEC_ID_MPEG4
 271        && (s->workaround_bugs&FF_BUG_AUTODETECT)
 272        && get_bits_left(&s->gb) >= 48
 273        && show_bits(&s->gb, 24)==0x4010
 274        && !s->data_partitioning)
 275         s->padding_bug_score+=32;
 276
 277     /* try to detect the padding bug */
 278     if(      s->codec_id==AV_CODEC_ID_MPEG4
 279        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 280        &&    get_bits_left(&s->gb) >=0
 281        &&    get_bits_left(&s->gb) < 137
 282 //       &&   !s->resync_marker
 283        &&   !s->data_partitioning){
 284
 285         const int bits_count= get_bits_count(&s->gb);
 286         const int bits_left = s->gb.size_in_bits - bits_count;
 287
 288         if(bits_left==0){
 289             s->padding_bug_score+=16;
 290         } else if(bits_left != 1){
 291             int v= show_bits(&s->gb, 8);
 292             v|= 0x7F >> (7-(bits_count&7));
 293
 294             if(v==0x7F && bits_left<=8)
 295                 s->padding_bug_score--;
 296             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 297                 s->padding_bug_score+= 4;
 298             else
 299                 s->padding_bug_score++;
 300         }
 301     }
 302
 303     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 304         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
 305             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 306         else
 307             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 308     }
 309
 310     // handle formats which don't have unique end markers
 311     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 312         int left= get_bits_left(&s->gb);
 313         int max_extra=7;
 314
 315         /* no markers in M$ crap */
 316         if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
 317             max_extra+= 17;
 318
 319         /* buggy padding but the frame should still end approximately at the bitstream end */
 320         if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&(AV_EF_BUFFER|AV_EF_AGGRESSIVE)))
 321             max_extra+= 48;
 322         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 323             max_extra+= 256*256*256*64;
 324
 325         if(left>max_extra){
 326             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 327         }
 328         else if(left<0){
 329             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 330         }else
 331             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
 332
 333         return 0;
 334     }
 335
 336     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 337             get_bits_left(&s->gb),
 338             show_bits(&s->gb, 24), s->padding_bug_score);
 339
 340     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
 341
 342     return -1;
 343 }
 344
 345 int ff_h263_decode_frame(AVCodecContext *avctx,
 346                              void *data, int *data_size,
 347                              AVPacket *avpkt)
 348 {
 349     const uint8_t *buf = avpkt->data;
 350     int buf_size = avpkt->size;
 351     MpegEncContext *s = avctx->priv_data;
 352     int ret;
 353     AVFrame *pict = data;
 354
 355 #ifdef PRINT_FRAME_TIME
 356 uint64_t time= rdtsc();
 357 #endif
 358     s->flags= avctx->flags;
 359     s->flags2= avctx->flags2;
 360
 361     /* no supplementary picture */
 362     if (buf_size == 0) {
 363         /* special case for last picture */
 364         if (s->low_delay==0 && s->next_picture_ptr) {
 365             *pict = s->next_picture_ptr->f;
 366             s->next_picture_ptr= NULL;
 367
 368             *data_size = sizeof(AVFrame);
 369         }
 370
 371         return 0;
 372     }
 373
 374     if(s->flags&CODEC_FLAG_TRUNCATED){
 375         int next;
 376
 377         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
 378             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 379         }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
 380             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 381         }else if(CONFIG_H263P_DECODER && s->codec_id==AV_CODEC_ID_H263P){
 382             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 383         }else{
 384             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 385             return -1;
 386         }
 387
 388         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 389             return buf_size;
 390     }
 391
 392
 393 retry:
 394     if(s->divx_packed && s->bitstream_buffer_size){
 395         int i;
 396         for(i=0; i<buf_size-3; i++){
 397             if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1){
 398                 if(buf[i+3]==0xB0){
 399                     av_log(s->avctx, AV_LOG_WARNING, "Discarding excessive bitstream in packed xvid\n");
 400                     s->bitstream_buffer_size=0;
 401                 }
 402                 break;
 403             }
 404         }
 405     }
 406
 407     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 408         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 409     }else
 410         init_get_bits(&s->gb, buf, buf_size*8);
 411     s->bitstream_buffer_size=0;
 412
 413     if (!s->context_initialized) {
 414         if (ff_MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 415             return -1;
 416     }
 417
 418     /* We need to set current_picture_ptr before reading the header,
 419      * otherwise we cannot store anyting in there */
 420     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
 421         int i= ff_find_unused_picture(s, 0);
 422         if (i < 0)
 423             return i;
 424         s->current_picture_ptr= &s->picture[i];
 425     }
 426
 427     /* let's go :-) */
 428     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 429         ret= ff_wmv2_decode_picture_header(s);
 430     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 431         ret = ff_msmpeg4_decode_picture_header(s);
 432     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
 433         if(s->avctx->extradata_size && s->picture_number==0){
 434             GetBitContext gb;
 435
 436             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 437             ret = ff_mpeg4_decode_picture_header(s, &gb);
 438         }
 439         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 440     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
 441         ret = ff_intel_h263_decode_picture_header(s);
 442     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
 443         ret = ff_flv_decode_picture_header(s);
 444     } else {
 445         ret = ff_h263_decode_picture_header(s);
 446     }
 447
 448     if (ret < 0 || ret==FRAME_SKIPPED) {
 449         if (   s->width  != avctx->coded_width
 450             || s->height != avctx->coded_height) {
 451                 av_log(s->avctx, AV_LOG_WARNING, "Reverting picture dimensions change due to header decoding failure\n");
 452                 s->width = avctx->coded_width;
 453                 s->height= avctx->coded_height;
 454         }
 455     }
 456     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 457
 458     /* skip if the header was thrashed */
 459     if (ret < 0){
 460         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 461         return -1;
 462     } else if ((s->width  != avctx->coded_width  ||
 463                 s->height != avctx->coded_height ||
 464                 (s->width  + 15) >> 4 != s->mb_width ||
 465                 (s->height + 15) >> 4 != s->mb_height) &&
 466                (HAVE_THREADS && (s->avctx->active_thread_type & FF_THREAD_FRAME))) {
 467         av_log_missing_feature(s->avctx, "Width/height/bit depth/chroma idc changing with threads is", 0);
 468         s->width = avctx->coded_width;
 469         s->height= avctx->coded_height;
 470         return AVERROR_PATCHWELCOME;   // width / height changed during parallelized decoding
 471     }
 472
 473     avctx->has_b_frames= !s->low_delay;
 474
 475     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 476         if(s->stream_codec_tag == AV_RL32("XVID") ||
 477            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 478            s->codec_tag == AV_RL32("RMP4") ||
 479            s->codec_tag == AV_RL32("SIPP")
 480            )
 481             s->xvid_build= 0;
 482 #if 0
 483         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 484            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 485             s->xvid_build= 0;
 486 #endif
 487     }
 488
 489     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 490         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 491             s->divx_version= 400; //divx 4
 492     }
 493
 494     if(s->xvid_build>=0 && s->divx_version>=0){
 495         s->divx_version=
 496         s->divx_build= -1;
 497     }
 498
 499     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 500         if(s->codec_tag == AV_RL32("XVIX"))
 501             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 502
 503         if(s->codec_tag == AV_RL32("UMP4")){
 504             s->workaround_bugs|= FF_BUG_UMP4;
 505         }
 506
 507         if(s->divx_version>=500 && s->divx_build<1814){
 508             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 509         }
 510
 511         if(s->divx_version>502 && s->divx_build<1814){
 512             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 513         }
 514
 515         if(s->xvid_build<=3U)
 516             s->padding_bug_score= 256*256*256*64;
 517
 518         if(s->xvid_build<=1U)
 519             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 520
 521         if(s->xvid_build<=12U)
 522             s->workaround_bugs|= FF_BUG_EDGE;
 523
 524         if(s->xvid_build<=32U)
 525             s->workaround_bugs|= FF_BUG_DC_CLIP;
 526
 527 #define SET_QPEL_FUNC(postfix1, postfix2) \
 528     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 529     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 530     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 531
 532         if(s->lavc_build<4653U)
 533             s->workaround_bugs|= FF_BUG_STD_QPEL;
 534
 535         if(s->lavc_build<4655U)
 536             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 537
 538         if(s->lavc_build<4670U){
 539             s->workaround_bugs|= FF_BUG_EDGE;
 540         }
 541
 542         if(s->lavc_build<=4712U)
 543             s->workaround_bugs|= FF_BUG_DC_CLIP;
 544
 545         if(s->divx_version>=0)
 546             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 547 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 548         if(s->divx_version==501 && s->divx_build==20020416)
 549             s->padding_bug_score= 256*256*256*64;
 550
 551         if(s->divx_version<500U){
 552             s->workaround_bugs|= FF_BUG_EDGE;
 553         }
 554
 555         if(s->divx_version>=0)
 556             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 557 #if 0
 558         if(s->divx_version==500)
 559             s->padding_bug_score= 256*256*256*64;
 560
 561         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 562          * Let us hope this at least works.
 563          */
 564         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
 565            && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
 566             s->workaround_bugs|= FF_BUG_NO_PADDING;
 567
 568         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
 569             s->workaround_bugs|= FF_BUG_NO_PADDING;
 570 #endif
 571     }
 572
 573     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 574         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 575         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 576         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 577         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 578         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 579         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 580
 581         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 582         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 583         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 584         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 585         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 586         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 587     }
 588
 589     if(avctx->debug & FF_DEBUG_BUGS)
 590         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 591                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 592                s->divx_packed ? "p" : "");
 593
 594 #if HAVE_MMX
 595     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)) {
 596         avctx->idct_algo= FF_IDCT_XVIDMMX;
 597         ff_dct_common_init(s);
 598         goto retry;
 599     }
 600 #endif
 601
 602         /* After H263 & mpeg4 header decode we have the height, width,*/
 603         /* and other parameters. So then we could init the picture   */
 604         /* FIXME: By the way H263 decoder is evolving it should have */
 605         /* an H263EncContext                                         */
 606
 607     if (   s->width  != avctx->coded_width
 608         || s->height != avctx->coded_height) {
 609         /* H.263 could change picture size any time */
 610         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 611
 612         s->parse_context.buffer=0;
 613         ff_MPV_common_end(s);
 614         s->parse_context= pc;
 615     }
 616     if (!s->context_initialized) {
 617         avcodec_set_dimensions(avctx, s->width, s->height);
 618
 619         goto retry;
 620     }
 621
 622     if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
 623         s->gob_index = ff_h263_get_gob_height(s);
 624
 625     // for skipping the frame
 626     s->current_picture.f.pict_type = s->pict_type;
 627     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
 628
 629     /* skip B-frames if we don't have reference frames */
 630     if(s->last_picture_ptr==NULL && (s->pict_type==AV_PICTURE_TYPE_B || s->dropable)) return get_consumed_bytes(s, buf_size);
 631     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
 632        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
 633        ||  avctx->skip_frame >= AVDISCARD_ALL)
 634         return get_consumed_bytes(s, buf_size);
 635
 636     if(s->next_p_frame_damaged){
 637         if(s->pict_type==AV_PICTURE_TYPE_B)
 638             return get_consumed_bytes(s, buf_size);
 639         else
 640             s->next_p_frame_damaged=0;
 641     }
 642
 643     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==AV_PICTURE_TYPE_B){
 644         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
 645         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
 646     }else if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
 647         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 648         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 649     }else{
 650         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 651         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 652     }
 653
 654     if(ff_MPV_frame_start(s, avctx) < 0)
 655         return -1;
 656
 657     if (!s->divx_packed) ff_thread_finish_setup(avctx);
 658
 659     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
 660         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
 661         goto frame_end;
 662     }
 663
 664     if (avctx->hwaccel) {
 665         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
 666             return -1;
 667     }
 668
 669     ff_er_frame_start(s);
 670
 671     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 672     //which is not available before ff_MPV_frame_start()
 673     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 674         ret = ff_wmv2_decode_secondary_picture_header(s);
 675         if(ret<0) return ret;
 676         if(ret==1) goto intrax8_decoded;
 677     }
 678
 679     /* decode each macroblock */
 680     s->mb_x=0;
 681     s->mb_y=0;
 682
 683     ret = decode_slice(s);
 684     while(s->mb_y<s->mb_height){
 685         if(s->msmpeg4_version){
 686             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
 687                 break;
 688         }else{
 689             int prev_x=s->mb_x, prev_y=s->mb_y;
 690             if(ff_h263_resync(s)<0)
 691                 break;
 692             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
 693                 s->error_occurred = 1;
 694         }
 695
 696         if(s->msmpeg4_version<4 && s->h263_pred)
 697             ff_mpeg4_clean_buffers(s);
 698
 699         if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
 700     }
 701
 702     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
 703         if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
 704             s->error_status_table[s->mb_num-1]= ER_MB_ERROR;
 705         }
 706
 707     assert(s->bitstream_buffer_size==0);
 708 frame_end:
 709     /* divx 5.01+ bistream reorder stuff */
 710     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
 711         int current_pos= s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb)>>3);
 712         int startcode_found=0;
 713
 714         if(buf_size - current_pos > 7){
 715             int i;
 716             for(i=current_pos; i<buf_size-4; i++){
 717                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 718                     startcode_found=!(buf[i+4]&0x40);
 719                     break;
 720                 }
 721             }
 722         }
 723
 724         if(startcode_found){
 725             av_fast_malloc(
 726                 &s->bitstream_buffer,
 727                 &s->allocated_bitstream_buffer_size,
 728                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 729             if (!s->bitstream_buffer)
 730                 return AVERROR(ENOMEM);
 731             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 732             s->bitstream_buffer_size= buf_size - current_pos;
 733         }
 734     }
 735
 736 intrax8_decoded:
 737     ff_er_frame_end(s);
 738
 739     if (avctx->hwaccel) {
 740         if (avctx->hwaccel->end_frame(avctx) < 0)
 741             return -1;
 742     }
 743
 744     ff_MPV_frame_end(s);
 745
 746     assert(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
 747     assert(s->current_picture.f.pict_type == s->pict_type);
 748     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
 749         *pict = s->current_picture_ptr->f;
 750     } else if (s->last_picture_ptr != NULL) {
 751         *pict = s->last_picture_ptr->f;
 752     }
 753
 754     if(s->last_picture_ptr || s->low_delay){
 755         *data_size = sizeof(AVFrame);
 756         ff_print_debug_info(s, pict);
 757     }
 758
 759 #ifdef PRINT_FRAME_TIME
 760 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 761 #endif
 762
 763     return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
 764 }
 765
 766 AVCodec ff_h263_decoder = {
 767     .name           = "h263",
 768     .type           = AVMEDIA_TYPE_VIDEO,
 769     .id             = AV_CODEC_ID_H263,
 770     .priv_data_size = sizeof(MpegEncContext),
 771     .init           = ff_h263_decode_init,
 772     .close          = ff_h263_decode_end,
 773     .decode         = ff_h263_decode_frame,
 774     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
 775                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 776     .flush          = ff_mpeg_flush,
 777     .max_lowres     = 3,
 778     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 779     .pix_fmts       = ff_hwaccel_pixfmt_list_420,
 780 };
 781
 782 AVCodec ff_h263p_decoder = {
 783     .name           = "h263p",
 784     .type           = AVMEDIA_TYPE_VIDEO,
 785     .id             = AV_CODEC_ID_H263P,
 786     .priv_data_size = sizeof(MpegEncContext),
 787     .init           = ff_h263_decode_init,
 788     .close          = ff_h263_decode_end,
 789     .decode         = ff_h263_decode_frame,
 790     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
 791                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 792     .flush          = ff_mpeg_flush,
 793     .max_lowres     = 3,
 794     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 795     .pix_fmts       = ff_hwaccel_pixfmt_list_420,
 796 };