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

   1 /*
   2  * H263 decoder
   3  * Copyright (c) 2001 Fabrice Bellard.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avcodec.h"
  20 #include "dsputil.h"
  21 #include "mpegvideo.h"
  22
  23 //#define DEBUG
  24 //#define PRINT_FRAME_TIME
  25 #ifdef PRINT_FRAME_TIME
  26 static inline long long rdtsc()
  27 {
  28         long long l;
  29         asm volatile(   "rdtsc\n\t"
  30                 : "=A" (l)
  31         );
  32 //      printf("%d\n", int(l/1000));
  33         return l;
  34 }
  35 #endif
  36
  37 int ff_h263_decode_init(AVCodecContext *avctx)
  38 {
  39     MpegEncContext *s = avctx->priv_data;
  40
  41     s->avctx = avctx;
  42     s->out_format = FMT_H263;
  43
  44     s->width = avctx->width;
  45     s->height = avctx->height;
  46     s->workaround_bugs= avctx->workaround_bugs;
  47
  48     // set defaults
  49     s->quant_precision=5;
  50     s->progressive_sequence=1;
  51     s->decode_mb= ff_h263_decode_mb;
  52     s->low_delay= 1;
  53     avctx->pix_fmt= PIX_FMT_YUV420P;
  54
  55     /* select sub codec */
  56     switch(avctx->codec->id) {
  57     case CODEC_ID_H263:
  58         s->gob_number = 0;
  59         break;
  60     case CODEC_ID_MPEG4:
  61         s->time_increment_bits = 4; /* default value for broken headers */
  62         s->h263_pred = 1;
  63         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
  64         break;
  65     case CODEC_ID_MSMPEG4V1:
  66         s->h263_msmpeg4 = 1;
  67         s->h263_pred = 1;
  68         s->msmpeg4_version=1;
  69         break;
  70     case CODEC_ID_MSMPEG4V2:
  71         s->h263_msmpeg4 = 1;
  72         s->h263_pred = 1;
  73         s->msmpeg4_version=2;
  74         break;
  75     case CODEC_ID_MSMPEG4V3:
  76         s->h263_msmpeg4 = 1;
  77         s->h263_pred = 1;
  78         s->msmpeg4_version=3;
  79         break;
  80     case CODEC_ID_WMV1:
  81         s->h263_msmpeg4 = 1;
  82         s->h263_pred = 1;
  83         s->msmpeg4_version=4;
  84         break;
  85     case CODEC_ID_WMV2:
  86         s->h263_msmpeg4 = 1;
  87         s->h263_pred = 1;
  88         s->msmpeg4_version=5;
  89         break;
  90     case CODEC_ID_H263I:
  91         s->h263_intel = 1;
  92         break;
  93     default:
  94         return -1;
  95     }
  96     s->codec_id= avctx->codec->id;
  97
  98     /* for h263, we allocate the images after having read the header */
  99     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 100         if (MPV_common_init(s) < 0)
 101             return -1;
 102
 103     if (s->h263_msmpeg4)
 104         ff_msmpeg4_decode_init(s);
 105     else
 106         h263_decode_init_vlc(s);
 107
 108     return 0;
 109 }
 110
 111 int ff_h263_decode_end(AVCodecContext *avctx)
 112 {
 113     MpegEncContext *s = avctx->priv_data;
 114
 115     MPV_common_end(s);
 116     return 0;
 117 }
 118
 119 /**
 120  * retunrs the number of bytes consumed for building the current frame
 121  */
 122 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
 123     int pos= (get_bits_count(&s->gb)+7)>>3;
 124
 125     if(s->divx_version>=500){
 126         //we would have to scan through the whole buf to handle the weird reordering ...
 127         return buf_size;
 128     }else if(s->flags&CODEC_FLAG_TRUNCATED){
 129         pos -= s->parse_context.last_index;
 130         if(pos<0) pos=0; // padding is not really read so this might be -1
 131         return pos;
 132     }else{
 133         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
 134         if(pos+10>buf_size) pos=buf_size; // oops ;)
 135
 136         return pos;
 137     }
 138 }
 139
 140 static int decode_slice(MpegEncContext *s){
 141     s->last_resync_gb= s->gb;
 142     s->first_slice_line= 1;
 143
 144     s->resync_mb_x= s->mb_x;
 145     s->resync_mb_y= s->mb_y;
 146
 147     s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 148     s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 149
 150     if(s->partitioned_frame){
 151         const int qscale= s->qscale;
 152
 153         if(s->codec_id==CODEC_ID_MPEG4){
 154             if(ff_mpeg4_decode_partitions(s) < 0)
 155                 return -1;
 156         }
 157
 158         /* restore variables which where modified */
 159         s->first_slice_line=1;
 160         s->mb_x= s->resync_mb_x;
 161         s->mb_y= s->resync_mb_y;
 162         s->qscale= qscale;
 163         s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
 164         s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
 165     }
 166
 167     for(; s->mb_y < s->mb_height; s->mb_y++) {
 168         /* per-row end of slice checks */
 169         if(s->msmpeg4_version){
 170             if(s->resync_mb_y + s->slice_height == s->mb_y){
 171                 const int xy= s->mb_x + s->mb_y*s->mb_width;
 172                 s->error_status_table[xy-1]|= AC_END|DC_END|MV_END;
 173                 return 0;
 174             }
 175         }
 176
 177         if(s->msmpeg4_version==1){
 178             s->last_dc[0]=
 179             s->last_dc[1]=
 180             s->last_dc[2]= 128;
 181         }
 182
 183         ff_init_block_index(s);
 184         for(; s->mb_x < s->mb_width; s->mb_x++) {
 185             int ret;
 186
 187             ff_update_block_index(s);
 188
 189             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
 190                 s->first_slice_line=0;
 191             }
 192
 193             /* DCT & quantize */
 194             s->dsp.clear_blocks(s->block[0]);
 195
 196             s->mv_dir = MV_DIR_FORWARD;
 197             s->mv_type = MV_TYPE_16X16;
 198 //            s->mb_skiped = 0;
 199 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
 200             ret= s->decode_mb(s, s->block);
 201
 202             MPV_decode_mb(s, s->block);
 203
 204             if(ret<0){
 205                 const int xy= s->mb_x + s->mb_y*s->mb_width;
 206                 if(ret==SLICE_END){
 207 //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));
 208                     s->error_status_table[xy]|= AC_END;
 209                     if(!s->partitioned_frame)
 210                         s->error_status_table[xy]|= MV_END|DC_END;
 211
 212                     s->padding_bug_score--;
 213
 214                     if(++s->mb_x >= s->mb_width){
 215                         s->mb_x=0;
 216                         ff_draw_horiz_band(s, s->mb_y*16, 16);
 217                         s->mb_y++;
 218                     }
 219                     return 0;
 220                 }else if(ret==SLICE_NOEND){
 221                     fprintf(stderr,"Slice mismatch at MB: %d\n", xy);
 222                     return -1;
 223                 }
 224                 fprintf(stderr,"Error at MB: %d\n", xy);
 225                 s->error_status_table[xy]|= AC_ERROR;
 226                 if(!s->partitioned_frame)
 227                     s->error_status_table[xy]|= DC_ERROR|MV_ERROR;
 228
 229                 return -1;
 230             }
 231         }
 232
 233         ff_draw_horiz_band(s, s->mb_y*16, 16);
 234
 235         s->mb_x= 0;
 236     }
 237
 238     assert(s->mb_x==0 && s->mb_y==s->mb_height);
 239
 240     /* try to detect the padding bug */
 241     if(      s->codec_id==CODEC_ID_MPEG4
 242        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 243        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
 244        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
 245 //       &&   !s->resync_marker
 246        &&   !s->data_partitioning){
 247
 248         const int bits_count= get_bits_count(&s->gb);
 249         const int bits_left = s->gb.size_in_bits - bits_count;
 250
 251         if(bits_left==0){
 252             s->padding_bug_score+=16;
 253         }else if(bits_left>8){
 254             s->padding_bug_score++;
 255         } else if(bits_left != 1){
 256             int v= show_bits(&s->gb, 8);
 257             v|= 0x7F >> (7-(bits_count&7));
 258
 259             if(v==0x7F)
 260                 s->padding_bug_score--;
 261             else
 262                 s->padding_bug_score++;
 263         }
 264     }
 265
 266     // handle formats which dont have unique end markers
 267     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 268         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
 269         int max_extra=7;
 270
 271         /* no markers in M$ crap */
 272         if(s->msmpeg4_version && s->pict_type==I_TYPE)
 273             max_extra+= 17;
 274
 275         /* buggy padding but the frame should still end approximately at the bitstream end */
 276         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
 277             max_extra+= 48;
 278         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 279             max_extra+= 256*256*256*64;
 280
 281         if(left>max_extra){
 282             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 283         }
 284         else if(left<0){
 285             fprintf(stderr, "overreading %d bits\n", -left);
 286         }else
 287             s->error_status_table[s->mb_num-1]|= AC_END|MV_END|DC_END;
 288
 289         return 0;
 290     }
 291
 292     fprintf(stderr, "slice end not reached but screenspace end (%d left %06X)\n",
 293             s->gb.size_in_bits - get_bits_count(&s->gb),
 294             show_bits(&s->gb, 24));
 295     return -1;
 296 }
 297
 298 /**
 299  * finds the end of the current frame in the bitstream.
 300  * @return the position of the first byte of the next frame, or -1
 301  */
 302 static int mpeg4_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
 303     ParseContext *pc= &s->parse_context;
 304     int vop_found, i;
 305     uint32_t state;
 306
 307     vop_found= pc->frame_start_found;
 308     state= pc->state;
 309
 310     i=0;
 311     if(!vop_found){
 312         for(i=0; i<buf_size; i++){
 313             state= (state<<8) | buf[i];
 314             if(state == 0x1B6){
 315                 i++;
 316                 vop_found=1;
 317                 break;
 318             }
 319         }
 320     }
 321
 322     for(; i<buf_size; i++){
 323         state= (state<<8) | buf[i];
 324         if((state&0xFFFFFF00) == 0x100){
 325             pc->frame_start_found=0;
 326             pc->state=-1;
 327             return i-3;
 328         }
 329     }
 330     pc->frame_start_found= vop_found;
 331     pc->state= state;
 332     return -1;
 333 }
 334
 335 /**
 336  * draws an line from (ex, ey) -> (sx, sy).
 337  * @param w width of the image
 338  * @param h height of the image
 339  * @param stride stride/linesize of the image
 340  * @param color color of the arrow
 341  */
 342 static void draw_line(uint8_t *buf, int sx, int sy, int ex, int ey, int w, int h, int stride, int color){
 343     int t, x, y, f;
 344
 345     ex= clip(ex, 0, w-1);
 346     ey= clip(ey, 0, h-1);
 347
 348     buf[sy*stride + sx]+= color;
 349
 350     if(ABS(ex - sx) > ABS(ey - sy)){
 351         if(sx > ex){
 352             t=sx; sx=ex; ex=t;
 353             t=sy; sy=ey; ey=t;
 354         }
 355         buf+= sx + sy*stride;
 356         ex-= sx;
 357         f= ((ey-sy)<<16)/ex;
 358         for(x= 0; x <= ex; x++){
 359             y= ((x*f) + (1<<15))>>16;
 360             buf[y*stride + x]+= color;
 361         }
 362     }else{
 363         if(sy > ey){
 364             t=sx; sx=ex; ex=t;
 365             t=sy; sy=ey; ey=t;
 366         }
 367         buf+= sx + sy*stride;
 368         ey-= sy;
 369         if(ey) f= ((ex-sx)<<16)/ey;
 370         else   f= 0;
 371         for(y= 0; y <= ey; y++){
 372             x= ((y*f) + (1<<15))>>16;
 373             buf[y*stride + x]+= color;
 374         }
 375     }
 376 }
 377
 378 /**
 379  * draws an arrow from (ex, ey) -> (sx, sy).
 380  * @param w width of the image
 381  * @param h height of the image
 382  * @param stride stride/linesize of the image
 383  * @param color color of the arrow
 384  */
 385 static void draw_arrow(uint8_t *buf, int sx, int sy, int ex, int ey, int w, int h, int stride, int color){
 386     int dx= ex - sx;
 387     int dy= ey - sy;
 388
 389     if(dx*dx + dy*dy > 3*3){
 390         int rx=  dx + dy;
 391         int ry= -dx + dy;
 392         int length= ff_sqrt((rx*rx + ry*ry)<<8);
 393
 394         //FIXME subpixel accuracy
 395         rx= ROUNDED_DIV(rx*3<<4, length);
 396         ry= ROUNDED_DIV(ry*3<<4, length);
 397
 398         draw_line(buf, sx, sy, sx + rx, sy + ry, w, h, stride, color);
 399         draw_line(buf, sx, sy, sx - ry, sy + rx, w, h, stride, color);
 400     }
 401     draw_line(buf, sx, sy, ex, ey, w, h, stride, color);
 402 }
 403
 404 int ff_h263_decode_frame(AVCodecContext *avctx,
 405                              void *data, int *data_size,
 406                              uint8_t *buf, int buf_size)
 407 {
 408     MpegEncContext *s = avctx->priv_data;
 409     int ret,i;
 410     AVFrame *pict = data;
 411     float new_aspect;
 412
 413 #ifdef PRINT_FRAME_TIME
 414 uint64_t time= rdtsc();
 415 #endif
 416 #ifdef DEBUG
 417     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
 418     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
 419 #endif
 420     s->flags= avctx->flags;
 421
 422     *data_size = 0;
 423
 424    /* no supplementary picture */
 425     if (buf_size == 0) {
 426         return 0;
 427     }
 428
 429     if(s->flags&CODEC_FLAG_TRUNCATED){
 430         int next;
 431
 432         if(s->codec_id==CODEC_ID_MPEG4){
 433             next= mpeg4_find_frame_end(s, buf, buf_size);
 434         }else{
 435             fprintf(stderr, "this codec doesnt support truncated bitstreams\n");
 436             return -1;
 437         }
 438
 439         if( ff_combine_frame(s, next, &buf, &buf_size) < 0 )
 440             return buf_size;
 441     }
 442
 443 retry:
 444
 445     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
 446         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 447     }else
 448         init_get_bits(&s->gb, buf, buf_size*8);
 449     s->bitstream_buffer_size=0;
 450
 451     if (!s->context_initialized) {
 452         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 453             return -1;
 454     }
 455
 456     /* let's go :-) */
 457     if (s->msmpeg4_version==5) {
 458         ret= ff_wmv2_decode_picture_header(s);
 459     } else if (s->msmpeg4_version) {
 460         ret = msmpeg4_decode_picture_header(s);
 461     } else if (s->h263_pred) {
 462         if(s->avctx->extradata_size && s->picture_number==0){
 463             GetBitContext gb;
 464
 465             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 466             ret = ff_mpeg4_decode_picture_header(s, &gb);
 467         }
 468         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 469
 470         if(s->flags& CODEC_FLAG_LOW_DELAY)
 471             s->low_delay=1;
 472     } else if (s->h263_intel) {
 473         ret = intel_h263_decode_picture_header(s);
 474     } else {
 475         ret = h263_decode_picture_header(s);
 476     }
 477     avctx->has_b_frames= !s->low_delay;
 478
 479     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 480         if(s->padding_bug_score > -2 && !s->data_partitioning)
 481             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 482         else
 483             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 484
 485         if(s->avctx->fourcc == ff_get_fourcc("XVIX"))
 486             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 487 #if 0
 488         if(s->avctx->fourcc == ff_get_fourcc("MP4S"))
 489             s->workaround_bugs|= FF_BUG_AC_VLC;
 490
 491         if(s->avctx->fourcc == ff_get_fourcc("M4S2"))
 492             s->workaround_bugs|= FF_BUG_AC_VLC;
 493 #endif
 494         if(s->avctx->fourcc == ff_get_fourcc("UMP4")){
 495             s->workaround_bugs|= FF_BUG_UMP4;
 496             s->workaround_bugs|= FF_BUG_AC_VLC;
 497         }
 498
 499         if(s->divx_version){
 500             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 501         }
 502
 503         if(s->divx_version>502){
 504             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 505         }
 506
 507         if(s->avctx->fourcc == ff_get_fourcc("XVID") && s->xvid_build==0)
 508             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 509
 510         if(s->avctx->fourcc == ff_get_fourcc("XVID") && s->xvid_build==0)
 511             s->padding_bug_score= 256*256*256*64;
 512
 513         if(s->xvid_build && s->xvid_build<=3)
 514             s->padding_bug_score= 256*256*256*64;
 515
 516         if(s->xvid_build && s->xvid_build<=1)
 517             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 518
 519 #define SET_QPEL_FUNC(postfix1, postfix2) \
 520     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 521     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 522     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 523
 524         if(s->lavc_build && s->lavc_build<4653)
 525             s->workaround_bugs|= FF_BUG_STD_QPEL;
 526
 527         if(s->lavc_build && s->lavc_build<4655)
 528             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 529
 530         if(s->divx_version)
 531             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 532 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 533         if(s->divx_version==501 && s->divx_build==20020416)
 534             s->padding_bug_score= 256*256*256*64;
 535 #if 0
 536         if(s->divx_version==500)
 537             s->padding_bug_score= 256*256*256*64;
 538
 539         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 540          * lets hope this at least works
 541          */
 542         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
 543            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 544             s->workaround_bugs|= FF_BUG_NO_PADDING;
 545
 546         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
 547             s->workaround_bugs|= FF_BUG_NO_PADDING;
 548 #endif
 549     }
 550
 551     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 552         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 553         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 554         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 555         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 556         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 557         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 558
 559         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 560         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 561         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 562         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 563         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 564         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 565     }
 566
 567 #if 0 // dump bits per frame / qp / complexity
 568 {
 569     static FILE *f=NULL;
 570     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 571     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 572 }
 573 #endif
 574
 575         /* After H263 & mpeg4 header decode we have the height, width,*/
 576         /* and other parameters. So then we could init the picture   */
 577         /* FIXME: By the way H263 decoder is evolving it should have */
 578         /* an H263EncContext                                         */
 579     if(s->aspected_height)
 580         new_aspect= s->aspected_width*s->width / (float)(s->height*s->aspected_height);
 581     else
 582         new_aspect=0;
 583
 584     if (   s->width != avctx->width || s->height != avctx->height
 585         || ABS(new_aspect - avctx->aspect_ratio) > 0.001) {
 586         /* H.263 could change picture size any time */
 587         MPV_common_end(s);
 588         s->context_initialized=0;
 589     }
 590     if (!s->context_initialized) {
 591         avctx->width = s->width;
 592         avctx->height = s->height;
 593         avctx->aspect_ratio= new_aspect;
 594
 595         goto retry;
 596     }
 597
 598     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
 599         s->gob_index = ff_h263_get_gob_height(s);
 600
 601     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
 602     /* skip if the header was thrashed */
 603     if (ret < 0){
 604         fprintf(stderr, "header damaged\n");
 605         return -1;
 606     }
 607
 608     // for hurry_up==5
 609     s->current_picture.pict_type= s->pict_type;
 610     s->current_picture.key_frame= s->pict_type == I_TYPE;
 611
 612     /* skip b frames if we dont have reference frames */
 613     if(s->last_picture.data[0]==NULL && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 614     /* skip b frames if we are in a hurry */
 615     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
 616     /* skip everything if we are in a hurry>=5 */
 617     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 618
 619     if(s->next_p_frame_damaged){
 620         if(s->pict_type==B_TYPE)
 621             return get_consumed_bytes(s, buf_size);
 622         else
 623             s->next_p_frame_damaged=0;
 624     }
 625
 626     if(MPV_frame_start(s, avctx) < 0)
 627         return -1;
 628
 629 #ifdef DEBUG
 630     printf("qscale=%d\n", s->qscale);
 631 #endif
 632
 633     if(s->error_resilience)
 634         memset(s->error_status_table, MV_ERROR|AC_ERROR|DC_ERROR|VP_START|AC_END|DC_END|MV_END, s->mb_num*sizeof(uint8_t));
 635
 636     /* decode each macroblock */
 637     s->block_wrap[0]=
 638     s->block_wrap[1]=
 639     s->block_wrap[2]=
 640     s->block_wrap[3]= s->mb_width*2 + 2;
 641     s->block_wrap[4]=
 642     s->block_wrap[5]= s->mb_width + 2;
 643     s->mb_x=0;
 644     s->mb_y=0;
 645
 646     decode_slice(s);
 647     s->error_status_table[0]|= VP_START;
 648     while(s->mb_y<s->mb_height && s->gb.size_in_bits - get_bits_count(&s->gb)>16){
 649         if(s->msmpeg4_version){
 650             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0)
 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         s->error_status_table[s->resync_mb_x + s->resync_mb_y*s->mb_width]|= VP_START;
 663     }
 664
 665     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
 666         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
 667             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 668         }
 669
 670     /* divx 5.01+ bistream reorder stuff */
 671     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_version>=500){
 672         int current_pos= get_bits_count(&s->gb)>>3;
 673
 674         if(   buf_size - current_pos > 5
 675            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
 676             int i;
 677             int startcode_found=0;
 678             for(i=current_pos; i<buf_size-3; i++){
 679                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 680                     startcode_found=1;
 681                     break;
 682                 }
 683             }
 684             if(startcode_found){
 685                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 686                 s->bitstream_buffer_size= buf_size - current_pos;
 687             }
 688         }
 689     }
 690
 691     if(s->error_resilience){
 692         int error=0, num_end_markers=0;
 693         for(i=0; i<s->mb_num; i++){
 694             int status= s->error_status_table[i];
 695 #if 0
 696             if(i%s->mb_width == 0) printf("\n");
 697             printf("%2X ", status);
 698 #endif
 699             if(status==0) continue;
 700
 701             if(status&(DC_ERROR|AC_ERROR|MV_ERROR))
 702                 error=1;
 703             if(status&VP_START){
 704                 if(num_end_markers)
 705                     error=1;
 706                 num_end_markers=3;
 707             }
 708             if(status&AC_END)
 709                 num_end_markers--;
 710             if(status&DC_END)
 711                 num_end_markers--;
 712             if(status&MV_END)
 713                 num_end_markers--;
 714         }
 715         if(num_end_markers || error){
 716             fprintf(stderr, "concealing errors\n");
 717             ff_error_resilience(s);
 718         }
 719     }
 720
 721     MPV_frame_end(s);
 722
 723     if((avctx->debug&FF_DEBUG_VIS_MV) && s->last_picture.data[0]){
 724         const int shift= 1 + s->quarter_sample;
 725         int mb_y;
 726         uint8_t *ptr= s->last_picture.data[0];
 727         s->low_delay=0; //needed to see the vectors without trashing the buffers
 728
 729         for(mb_y=0; mb_y<s->mb_height; mb_y++){
 730             int mb_x;
 731             for(mb_x=0; mb_x<s->mb_width; mb_x++){
 732                 const int mb_index= mb_x + mb_y*s->mb_width;
 733                 if(s->co_located_type_table[mb_index] == MV_TYPE_8X8){
 734                     int i;
 735                     for(i=0; i<4; i++){
 736                         int sx= mb_x*16 + 4 + 8*(i&1);
 737                         int sy= mb_y*16 + 4 + 8*(i>>1);
 738                         int xy= 1 + mb_x*2 + (i&1) + (mb_y*2 + 1 + (i>>1))*(s->mb_width*2 + 2);
 739                         int mx= (s->motion_val[xy][0]>>shift) + sx;
 740                         int my= (s->motion_val[xy][1]>>shift) + sy;
 741                         draw_arrow(ptr, sx, sy, mx, my, s->width, s->height, s->linesize, 100);
 742                     }
 743                 }else{
 744                     int sx= mb_x*16 + 8;
 745                     int sy= mb_y*16 + 8;
 746                     int xy= 1 + mb_x*2 + (mb_y*2 + 1)*(s->mb_width*2 + 2);
 747                     int mx= (s->motion_val[xy][0]>>shift) + sx;
 748                     int my= (s->motion_val[xy][1]>>shift) + sy;
 749                     draw_arrow(ptr, sx, sy, mx, my, s->width, s->height, s->linesize, 100);
 750                 }
 751                 s->mbskip_table[mb_index]=0;
 752             }
 753         }
 754     }
 755
 756
 757     if(s->pict_type==B_TYPE || s->low_delay){
 758         *pict= *(AVFrame*)&s->current_picture;
 759     } else {
 760         *pict= *(AVFrame*)&s->last_picture;
 761     }
 762
 763     if(avctx->debug&FF_DEBUG_QP){
 764         int8_t *qtab= pict->qscale_table;
 765         int x,y;
 766
 767         for(y=0; y<s->mb_height; y++){
 768             for(x=0; x<s->mb_width; x++){
 769                 printf("%2d ", qtab[x + y*s->mb_width]);
 770             }
 771             printf("\n");
 772         }
 773         printf("\n");
 774     }
 775
 776     /* Return the Picture timestamp as the frame number */
 777     /* we substract 1 because it is added on utils.c    */
 778     avctx->frame_number = s->picture_number - 1;
 779
 780     /* dont output the last pic after seeking */
 781     if(s->last_picture.data[0] || s->low_delay)
 782         *data_size = sizeof(AVFrame);
 783 #ifdef PRINT_FRAME_TIME
 784 printf("%Ld\n", rdtsc()-time);
 785 #endif
 786     return get_consumed_bytes(s, buf_size);
 787 }
 788
 789 AVCodec mpeg4_decoder = {
 790     "mpeg4",
 791     CODEC_TYPE_VIDEO,
 792     CODEC_ID_MPEG4,
 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 | CODEC_CAP_TRUNCATED,
 799 };
 800
 801 AVCodec h263_decoder = {
 802     "h263",
 803     CODEC_TYPE_VIDEO,
 804     CODEC_ID_H263,
 805     sizeof(MpegEncContext),
 806     ff_h263_decode_init,
 807     NULL,
 808     ff_h263_decode_end,
 809     ff_h263_decode_frame,
 810     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 811 };
 812
 813 AVCodec msmpeg4v1_decoder = {
 814     "msmpeg4v1",
 815     CODEC_TYPE_VIDEO,
 816     CODEC_ID_MSMPEG4V1,
 817     sizeof(MpegEncContext),
 818     ff_h263_decode_init,
 819     NULL,
 820     ff_h263_decode_end,
 821     ff_h263_decode_frame,
 822     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 823 };
 824
 825 AVCodec msmpeg4v2_decoder = {
 826     "msmpeg4v2",
 827     CODEC_TYPE_VIDEO,
 828     CODEC_ID_MSMPEG4V2,
 829     sizeof(MpegEncContext),
 830     ff_h263_decode_init,
 831     NULL,
 832     ff_h263_decode_end,
 833     ff_h263_decode_frame,
 834     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 835 };
 836
 837 AVCodec msmpeg4v3_decoder = {
 838     "msmpeg4",
 839     CODEC_TYPE_VIDEO,
 840     CODEC_ID_MSMPEG4V3,
 841     sizeof(MpegEncContext),
 842     ff_h263_decode_init,
 843     NULL,
 844     ff_h263_decode_end,
 845     ff_h263_decode_frame,
 846     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 847 };
 848
 849 AVCodec wmv1_decoder = {
 850     "wmv1",
 851     CODEC_TYPE_VIDEO,
 852     CODEC_ID_WMV1,
 853     sizeof(MpegEncContext),
 854     ff_h263_decode_init,
 855     NULL,
 856     ff_h263_decode_end,
 857     ff_h263_decode_frame,
 858     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 859 };
 860
 861 AVCodec h263i_decoder = {
 862     "h263i",
 863     CODEC_TYPE_VIDEO,
 864     CODEC_ID_H263I,
 865     sizeof(MpegEncContext),
 866     ff_h263_decode_init,
 867     NULL,
 868     ff_h263_decode_end,
 869     ff_h263_decode_frame,
 870     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
 871 };
 872