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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 libavcodec/h263dec.c
  25  * H.263 decoder.
  26  */
  27
  28 #include "internal.h"
  29 #include "avcodec.h"
  30 #include "dsputil.h"
  31 #include "mpegvideo.h"
  32 #include "h263_parser.h"
  33 #include "mpeg4video_parser.h"
  34 #include "msmpeg4.h"
  35
  36 //#define DEBUG
  37 //#define PRINT_FRAME_TIME
  38
  39 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  40 {
  41     MpegEncContext *s = avctx->priv_data;
  42
  43     s->avctx = avctx;
  44     s->out_format = FMT_H263;
  45
  46     s->width  = avctx->coded_width;
  47     s->height = avctx->coded_height;
  48     s->workaround_bugs= avctx->workaround_bugs;
  49
  50     // set defaults
  51     MPV_decode_defaults(s);
  52     s->quant_precision=5;
  53     s->decode_mb= ff_h263_decode_mb;
  54     s->low_delay= 1;
  55     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
  56     s->unrestricted_mv= 1;
  57
  58     /* select sub codec */
  59     switch(avctx->codec->id) {
  60     case CODEC_ID_H263:
  61         s->unrestricted_mv= 0;
  62         break;
  63     case CODEC_ID_MPEG4:
  64         s->decode_mb= ff_mpeg4_decode_mb;
  65         s->time_increment_bits = 4; /* default value for broken headers */
  66         s->h263_pred = 1;
  67         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  68         break;
  69     case CODEC_ID_MSMPEG4V1:
  70         s->h263_msmpeg4 = 1;
  71         s->h263_pred = 1;
  72         s->msmpeg4_version=1;
  73         break;
  74     case CODEC_ID_MSMPEG4V2:
  75         s->h263_msmpeg4 = 1;
  76         s->h263_pred = 1;
  77         s->msmpeg4_version=2;
  78         break;
  79     case CODEC_ID_MSMPEG4V3:
  80         s->h263_msmpeg4 = 1;
  81         s->h263_pred = 1;
  82         s->msmpeg4_version=3;
  83         break;
  84     case CODEC_ID_WMV1:
  85         s->h263_msmpeg4 = 1;
  86         s->h263_pred = 1;
  87         s->msmpeg4_version=4;
  88         break;
  89     case CODEC_ID_WMV2:
  90         s->h263_msmpeg4 = 1;
  91         s->h263_pred = 1;
  92         s->msmpeg4_version=5;
  93         break;
  94     case CODEC_ID_VC1:
  95     case CODEC_ID_WMV3:
  96         s->h263_msmpeg4 = 1;
  97         s->h263_pred = 1;
  98         s->msmpeg4_version=6;
  99         break;
 100     case CODEC_ID_H263I:
 101         break;
 102     case CODEC_ID_FLV1:
 103         s->h263_flv = 1;
 104         break;
 105     default:
 106         return -1;
 107     }
 108     s->codec_id= avctx->codec->id;
 109     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
 110
 111     /* for h263, we allocate the images after having read the header */
 112     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 113         if (MPV_common_init(s) < 0)
 114             return -1;
 115
 116     if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
 117         ff_msmpeg4_decode_init(s);
 118     else
 119         h263_decode_init_vlc(s);
 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     MPV_common_end(s);
 129     return 0;
 130 }
 131
 132 /**
 133  * returns 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 ? (AC_END|AC_ERROR) : 0x7F;
 155     const int mb_size= 16>>s->avctx->lowres;
 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(s->codec_id==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, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_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 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 218             ret= s->decode_mb(s, s->block);
 219
 220             if (s->pict_type!=FF_B_TYPE)
 221                 ff_h263_update_motion_val(s);
 222
 223             if(ret<0){
 224                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
 225                 if(ret==SLICE_END){
 226                     MPV_decode_mb(s, s->block);
 227                     if(s->loop_filter)
 228                         ff_h263_loop_filter(s);
 229
 230 //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));
 231                     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
 232
 233                     s->padding_bug_score--;
 234
 235                     if(++s->mb_x >= s->mb_width){
 236                         s->mb_x=0;
 237                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 238                         s->mb_y++;
 239                     }
 240                     return 0;
 241                 }else if(ret==SLICE_NOEND){
 242                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
 243                     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
 244                     return -1;
 245                 }
 246                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
 247                 ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_ERROR|DC_ERROR|MV_ERROR)&part_mask);
 248
 249                 return -1;
 250             }
 251
 252             MPV_decode_mb(s, s->block);
 253             if(s->loop_filter)
 254                 ff_h263_loop_filter(s);
 255         }
 256
 257         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
 258
 259         s->mb_x= 0;
 260     }
 261
 262     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 263
 264     /* try to detect the padding bug */
 265     if(      s->codec_id==CODEC_ID_MPEG4
 266        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 267        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 268        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 269 //       &&   !s->resync_marker
 270        &&   !s->data_partitioning){
 271
 272         const int bits_count= get_bits_count(&s->gb);
 273         const int bits_left = s->gb.size_in_bits - bits_count;
 274
 275         if(bits_left==0){
 276             s->padding_bug_score+=16;
 277         } else if(bits_left != 1){
 278             int v= show_bits(&s->gb, 8);
 279             v|= 0x7F >> (7-(bits_count&7));
 280
 281             if(v==0x7F && bits_left<=8)
 282                 s->padding_bug_score--;
 283             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 284                 s->padding_bug_score+= 4;
 285             else
 286                 s->padding_bug_score++;
 287         }
 288     }
 289
 290     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 291         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
 292             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 293         else
 294             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 295     }
 296
 297     // handle formats which don't have unique end markers
 298     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 299         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 300         int max_extra=7;
 301
 302         /* no markers in M$ crap */
 303         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
 304             max_extra+= 17;
 305
 306         /* buggy padding but the frame should still end approximately at the bitstream end */
 307         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
 308             max_extra+= 48;
 309         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 310             max_extra+= 256*256*256*64;
 311
 312         if(left>max_extra){
 313             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 314         }
 315         else if(left<0){
 316             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 317         }else
 318             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
 319
 320         return 0;
 321     }
 322
 323     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 324             s->gb.size_in_bits - get_bits_count(&s->gb),
 325             show_bits(&s->gb, 24), s->padding_bug_score);
 326
 327     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
 328
 329     return -1;
 330 }
 331
 332 int ff_h263_decode_frame(AVCodecContext *avctx,
 333                              void *data, int *data_size,
 334                              const uint8_t *buf, int buf_size)
 335 {
 336     MpegEncContext *s = avctx->priv_data;
 337     int ret;
 338     AVFrame *pict = data;
 339
 340 #ifdef PRINT_FRAME_TIME
 341 uint64_t time= rdtsc();
 342 #endif
 343 #ifdef DEBUG
 344     av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
 345     if(buf_size>0)
 346         av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 347 #endif
 348     s->flags= avctx->flags;
 349     s->flags2= avctx->flags2;
 350
 351     /* no supplementary picture */
 352     if (buf_size == 0) {
 353         /* special case for last picture */
 354         if (s->low_delay==0 && s->next_picture_ptr) {
 355             *pict= *(AVFrame*)s->next_picture_ptr;
 356             s->next_picture_ptr= NULL;
 357
 358             *data_size = sizeof(AVFrame);
 359         }
 360
 361         return 0;
 362     }
 363
 364     if(s->flags&CODEC_FLAG_TRUNCATED){
 365         int next;
 366
 367         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
 368             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 369         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
 370             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 371         }else{
 372             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 373             return -1;
 374         }
 375
 376         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 377             return buf_size;
 378     }
 379
 380
 381 retry:
 382
 383     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 384         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 385     }else
 386         init_get_bits(&s->gb, buf, buf_size*8);
 387     s->bitstream_buffer_size=0;
 388
 389     if (!s->context_initialized) {
 390         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 391             return -1;
 392     }
 393
 394     /* We need to set current_picture_ptr before reading the header,
 395      * otherwise we cannot store anyting in there */
 396     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
 397         int i= ff_find_unused_picture(s, 0);
 398         s->current_picture_ptr= &s->picture[i];
 399     }
 400
 401     /* let's go :-) */
 402     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 403         ret= ff_wmv2_decode_picture_header(s);
 404     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 405         ret = msmpeg4_decode_picture_header(s);
 406     } else if (s->h263_pred) {
 407         if(s->avctx->extradata_size && s->picture_number==0){
 408             GetBitContext gb;
 409
 410             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 411             ret = ff_mpeg4_decode_picture_header(s, &gb);
 412         }
 413         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 414     } else if (s->codec_id == CODEC_ID_H263I) {
 415         ret = intel_h263_decode_picture_header(s);
 416     } else if (s->h263_flv) {
 417         ret = flv_h263_decode_picture_header(s);
 418     } else {
 419         ret = h263_decode_picture_header(s);
 420     }
 421
 422     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 423
 424     /* skip if the header was thrashed */
 425     if (ret < 0){
 426         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 427         return -1;
 428     }
 429
 430     avctx->has_b_frames= !s->low_delay;
 431
 432     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 433         if(s->stream_codec_tag == AV_RL32("XVID") ||
 434            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 435            s->codec_tag == AV_RL32("RMP4"))
 436             s->xvid_build= -1;
 437 #if 0
 438         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 439            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 440             s->xvid_build= -1;
 441 #endif
 442     }
 443
 444     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
 445         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 446             s->divx_version= 400; //divx 4
 447     }
 448
 449     if(s->xvid_build && s->divx_version){
 450         s->divx_version=
 451         s->divx_build= 0;
 452     }
 453
 454     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 455         if(s->codec_tag == AV_RL32("XVIX"))
 456             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 457
 458         if(s->codec_tag == AV_RL32("UMP4")){
 459             s->workaround_bugs|= FF_BUG_UMP4;
 460         }
 461
 462         if(s->divx_version>=500 && s->divx_build<1814){
 463             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 464         }
 465
 466         if(s->divx_version>502 && s->divx_build<1814){
 467             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 468         }
 469
 470         if(s->xvid_build && s->xvid_build<=3)
 471             s->padding_bug_score= 256*256*256*64;
 472
 473         if(s->xvid_build && s->xvid_build<=1)
 474             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 475
 476         if(s->xvid_build && s->xvid_build<=12)
 477             s->workaround_bugs|= FF_BUG_EDGE;
 478
 479         if(s->xvid_build && s->xvid_build<=32)
 480             s->workaround_bugs|= FF_BUG_DC_CLIP;
 481
 482 #define SET_QPEL_FUNC(postfix1, postfix2) \
 483     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 484     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 485     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 486
 487         if(s->lavc_build && s->lavc_build<4653)
 488             s->workaround_bugs|= FF_BUG_STD_QPEL;
 489
 490         if(s->lavc_build && s->lavc_build<4655)
 491             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 492
 493         if(s->lavc_build && s->lavc_build<4670){
 494             s->workaround_bugs|= FF_BUG_EDGE;
 495         }
 496
 497         if(s->lavc_build && s->lavc_build<=4712)
 498             s->workaround_bugs|= FF_BUG_DC_CLIP;
 499
 500         if(s->divx_version)
 501             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 502 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 503         if(s->divx_version==501 && s->divx_build==20020416)
 504             s->padding_bug_score= 256*256*256*64;
 505
 506         if(s->divx_version && s->divx_version<500){
 507             s->workaround_bugs|= FF_BUG_EDGE;
 508         }
 509
 510         if(s->divx_version)
 511             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 512 #if 0
 513         if(s->divx_version==500)
 514             s->padding_bug_score= 256*256*256*64;
 515
 516         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 517          * Let us hope this at least works.
 518          */
 519         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 520            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 521             s->workaround_bugs|= FF_BUG_NO_PADDING;
 522
 523         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 524             s->workaround_bugs|= FF_BUG_NO_PADDING;
 525 #endif
 526     }
 527
 528     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 529         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 530         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 531         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 532         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 533         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 534         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 535
 536         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 537         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 538         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 539         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 540         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 541         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 542     }
 543
 544     if(avctx->debug & FF_DEBUG_BUGS)
 545         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 546                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 547                s->divx_packed ? "p" : "");
 548
 549 #if 0 // dump bits per frame / qp / complexity
 550 {
 551     static FILE *f=NULL;
 552     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 553     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 554 }
 555 #endif
 556
 557 #if HAVE_MMX
 558     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
 559         avctx->idct_algo= FF_IDCT_XVIDMMX;
 560         avctx->coded_width= 0; // force reinit
 561 //        dsputil_init(&s->dsp, avctx);
 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 (   s->width  != avctx->coded_width
 572         || s->height != avctx->coded_height) {
 573         /* H.263 could change picture size any time */
 574         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 575         s->parse_context.buffer=0;
 576         MPV_common_end(s);
 577         s->parse_context= pc;
 578     }
 579     if (!s->context_initialized) {
 580         avcodec_set_dimensions(avctx, s->width, s->height);
 581
 582         goto retry;
 583     }
 584
 585     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
 586         s->gob_index = ff_h263_get_gob_height(s);
 587
 588     // for hurry_up==5
 589     s->current_picture.pict_type= s->pict_type;
 590     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
 591
 592     /* skip B-frames if we don't have reference frames */
 593     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
 594     /* skip b frames if we are in a hurry */
 595     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
 596     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
 597        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
 598        ||  avctx->skip_frame >= AVDISCARD_ALL)
 599         return get_consumed_bytes(s, buf_size);
 600     /* skip everything if we are in a hurry>=5 */
 601     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 602
 603     if(s->next_p_frame_damaged){
 604         if(s->pict_type==FF_B_TYPE)
 605             return get_consumed_bytes(s, buf_size);
 606         else
 607             s->next_p_frame_damaged=0;
 608     }
 609
 610     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
 611         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
 612         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
 613     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
 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(MPV_frame_start(s, avctx) < 0)
 622         return -1;
 623
 624     if (avctx->hwaccel) {
 625         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
 626             return -1;
 627     }
 628
 629 #ifdef DEBUG
 630     av_log(avctx, AV_LOG_DEBUG, "qscale=%d\n", s->qscale);
 631 #endif
 632
 633     ff_er_frame_start(s);
 634
 635     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 636     //which is not available before MPV_frame_start()
 637     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 638         ret = ff_wmv2_decode_secondary_picture_header(s);
 639         if(ret<0) return ret;
 640         if(ret==1) goto intrax8_decoded;
 641     }
 642
 643     /* decode each macroblock */
 644     s->mb_x=0;
 645     s->mb_y=0;
 646
 647     decode_slice(s);
 648     while(s->mb_y<s->mb_height){
 649         if(s->msmpeg4_version){
 650             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
 651                 break;
 652         }else{
 653             if(ff_h263_resync(s)<0)
 654                 break;
 655         }
 656
 657         if(s->msmpeg4_version<4 && s->h263_pred)
 658             ff_mpeg4_clean_buffers(s);
 659
 660         decode_slice(s);
 661     }
 662
 663     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
 664         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
 665             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 666         }
 667
 668     /* divx 5.01+ bistream reorder stuff */
 669     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
 670         int current_pos= get_bits_count(&s->gb)>>3;
 671         int startcode_found=0;
 672
 673         if(buf_size - current_pos > 5){
 674             int i;
 675             for(i=current_pos; i<buf_size-3; i++){
 676                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 677                     startcode_found=1;
 678                     break;
 679                 }
 680             }
 681         }
 682         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
 683             startcode_found=1;
 684             current_pos=0;
 685         }
 686
 687         if(startcode_found){
 688             s->bitstream_buffer= av_fast_realloc(
 689                 s->bitstream_buffer,
 690                 &s->allocated_bitstream_buffer_size,
 691                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 692             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 693             s->bitstream_buffer_size= buf_size - current_pos;
 694         }
 695     }
 696
 697 intrax8_decoded:
 698     ff_er_frame_end(s);
 699
 700     if (avctx->hwaccel) {
 701         if (avctx->hwaccel->end_frame(avctx) < 0)
 702             return -1;
 703     }
 704
 705     MPV_frame_end(s);
 706
 707 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 708 assert(s->current_picture.pict_type == s->pict_type);
 709     if (s->pict_type == FF_B_TYPE || s->low_delay) {
 710         *pict= *(AVFrame*)s->current_picture_ptr;
 711     } else if (s->last_picture_ptr != NULL) {
 712         *pict= *(AVFrame*)s->last_picture_ptr;
 713     }
 714
 715     if(s->last_picture_ptr || s->low_delay){
 716         *data_size = sizeof(AVFrame);
 717         ff_print_debug_info(s, pict);
 718     }
 719
 720     /* Return the Picture timestamp as the frame number */
 721     /* we subtract 1 because it is added on utils.c     */
 722     avctx->frame_number = s->picture_number - 1;
 723
 724 #ifdef PRINT_FRAME_TIME
 725 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 726 #endif
 727
 728     return get_consumed_bytes(s, buf_size);
 729 }
 730
 731 AVCodec mpeg4_decoder = {
 732     "mpeg4",
 733     CODEC_TYPE_VIDEO,
 734     CODEC_ID_MPEG4,
 735     sizeof(MpegEncContext),
 736     ff_h263_decode_init,
 737     NULL,
 738     ff_h263_decode_end,
 739     ff_h263_decode_frame,
 740     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 741     .flush= ff_mpeg_flush,
 742     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
 743     .pix_fmts= ff_hwaccel_pixfmt_list_420,
 744 };
 745
 746 AVCodec h263_decoder = {
 747     "h263",
 748     CODEC_TYPE_VIDEO,
 749     CODEC_ID_H263,
 750     sizeof(MpegEncContext),
 751     ff_h263_decode_init,
 752     NULL,
 753     ff_h263_decode_end,
 754     ff_h263_decode_frame,
 755     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 756     .flush= ff_mpeg_flush,
 757     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 758     .pix_fmts= ff_hwaccel_pixfmt_list_420,
 759 };
 760
 761 AVCodec msmpeg4v1_decoder = {
 762     "msmpeg4v1",
 763     CODEC_TYPE_VIDEO,
 764     CODEC_ID_MSMPEG4V1,
 765     sizeof(MpegEncContext),
 766     ff_h263_decode_init,
 767     NULL,
 768     ff_h263_decode_end,
 769     ff_h263_decode_frame,
 770     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 771     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
 772     .pix_fmts= ff_pixfmt_list_420,
 773 };
 774
 775 AVCodec msmpeg4v2_decoder = {
 776     "msmpeg4v2",
 777     CODEC_TYPE_VIDEO,
 778     CODEC_ID_MSMPEG4V2,
 779     sizeof(MpegEncContext),
 780     ff_h263_decode_init,
 781     NULL,
 782     ff_h263_decode_end,
 783     ff_h263_decode_frame,
 784     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 785     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
 786     .pix_fmts= ff_pixfmt_list_420,
 787 };
 788
 789 AVCodec msmpeg4v3_decoder = {
 790     "msmpeg4",
 791     CODEC_TYPE_VIDEO,
 792     CODEC_ID_MSMPEG4V3,
 793     sizeof(MpegEncContext),
 794     ff_h263_decode_init,
 795     NULL,
 796     ff_h263_decode_end,
 797     ff_h263_decode_frame,
 798     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 799     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
 800     .pix_fmts= ff_pixfmt_list_420,
 801 };
 802
 803 AVCodec wmv1_decoder = {
 804     "wmv1",
 805     CODEC_TYPE_VIDEO,
 806     CODEC_ID_WMV1,
 807     sizeof(MpegEncContext),
 808     ff_h263_decode_init,
 809     NULL,
 810     ff_h263_decode_end,
 811     ff_h263_decode_frame,
 812     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 813     .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
 814     .pix_fmts= ff_pixfmt_list_420,
 815 };
 816
 817 AVCodec h263i_decoder = {
 818     "h263i",
 819     CODEC_TYPE_VIDEO,
 820     CODEC_ID_H263I,
 821     sizeof(MpegEncContext),
 822     ff_h263_decode_init,
 823     NULL,
 824     ff_h263_decode_end,
 825     ff_h263_decode_frame,
 826     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 827     .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
 828     .pix_fmts= ff_pixfmt_list_420,
 829 };
 830
 831 AVCodec flv_decoder = {
 832     "flv",
 833     CODEC_TYPE_VIDEO,
 834     CODEC_ID_FLV1,
 835     sizeof(MpegEncContext),
 836     ff_h263_decode_init,
 837     NULL,
 838     ff_h263_decode_end,
 839     ff_h263_decode_frame,
 840     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 841     .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV)"),
 842     .pix_fmts= ff_pixfmt_list_420,
 843 };