libavcodec/h263dec.c

   1 /*
   2  * H.263 decoder
   3  * Copyright (c) 2001 Fabrice Bellard
   4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file
  25  * H.263 decoder.
  26  */
  27
  28 #include "libavutil/cpu.h"
  29 #include "internal.h"
  30 #include "avcodec.h"
  31 #include "dsputil.h"
  32 #include "mpegvideo.h"
  33 #include "h263.h"
  34 #include "h263_parser.h"
  35 #include "mpeg4video_parser.h"
  36 #include "msmpeg4.h"
  37 #include "vdpau_internal.h"
  38 #include "flv.h"
  39 #include "mpeg4video.h"
  40
  41 //#define DEBUG
  42 //#define PRINT_FRAME_TIME
  43
  44 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
  45 {
  46     MpegEncContext *s = avctx->priv_data;
  47
  48     s->avctx = avctx;
  49     s->out_format = FMT_H263;
  50
  51     s->width  = avctx->coded_width;
  52     s->height = avctx->coded_height;
  53     s->workaround_bugs= avctx->workaround_bugs;
  54
  55     // set defaults
  56     MPV_decode_defaults(s);
  57     s->quant_precision=5;
  58     s->decode_mb= ff_h263_decode_mb;
  59     s->low_delay= 1;
  60     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
  61     s->unrestricted_mv= 1;
  62
  63     /* select sub codec */
  64     switch(avctx->codec->id) {
  65     case CODEC_ID_H263:
  66         s->unrestricted_mv= 0;
  67         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
  68         break;
  69     case CODEC_ID_MPEG4:
  70         break;
  71     case CODEC_ID_MSMPEG4V1:
  72         s->h263_msmpeg4 = 1;
  73         s->h263_pred = 1;
  74         s->msmpeg4_version=1;
  75         break;
  76     case CODEC_ID_MSMPEG4V2:
  77         s->h263_msmpeg4 = 1;
  78         s->h263_pred = 1;
  79         s->msmpeg4_version=2;
  80         break;
  81     case CODEC_ID_MSMPEG4V3:
  82         s->h263_msmpeg4 = 1;
  83         s->h263_pred = 1;
  84         s->msmpeg4_version=3;
  85         break;
  86     case CODEC_ID_WMV1:
  87         s->h263_msmpeg4 = 1;
  88         s->h263_pred = 1;
  89         s->msmpeg4_version=4;
  90         break;
  91     case CODEC_ID_WMV2:
  92         s->h263_msmpeg4 = 1;
  93         s->h263_pred = 1;
  94         s->msmpeg4_version=5;
  95         break;
  96     case CODEC_ID_VC1:
  97     case CODEC_ID_WMV3:
  98         s->h263_msmpeg4 = 1;
  99         s->h263_pred = 1;
 100         s->msmpeg4_version=6;
 101         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
 102         break;
 103     case CODEC_ID_H263I:
 104         break;
 105     case CODEC_ID_FLV1:
 106         s->h263_flv = 1;
 107         break;
 108     default:
 109         return -1;
 110     }
 111     s->codec_id= avctx->codec->id;
 112     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
 113
 114     /* for h263, we allocate the images after having read the header */
 115     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
 116         if (MPV_common_init(s) < 0)
 117             return -1;
 118
 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(CONFIG_MPEG4_DECODER && 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     if(s->codec_id==CODEC_ID_MPEG4
 265        && (s->workaround_bugs&FF_BUG_AUTODETECT)
 266        && get_bits_left(&s->gb) >= 48
 267        && show_bits(&s->gb, 24)==0x4010
 268        && !s->data_partitioning)
 269         s->padding_bug_score+=32;
 270
 271     /* try to detect the padding bug */
 272     if(      s->codec_id==CODEC_ID_MPEG4
 273        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
 274        &&    get_bits_left(&s->gb) >=0
 275        &&    get_bits_left(&s->gb) < 48
 276 //       &&   !s->resync_marker
 277        &&   !s->data_partitioning){
 278
 279         const int bits_count= get_bits_count(&s->gb);
 280         const int bits_left = s->gb.size_in_bits - bits_count;
 281
 282         if(bits_left==0){
 283             s->padding_bug_score+=16;
 284         } else if(bits_left != 1){
 285             int v= show_bits(&s->gb, 8);
 286             v|= 0x7F >> (7-(bits_count&7));
 287
 288             if(v==0x7F && bits_left<=8)
 289                 s->padding_bug_score--;
 290             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
 291                 s->padding_bug_score+= 4;
 292             else
 293                 s->padding_bug_score++;
 294         }
 295     }
 296
 297     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 298         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
 299             s->workaround_bugs |=  FF_BUG_NO_PADDING;
 300         else
 301             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
 302     }
 303
 304     // handle formats which don't have unique end markers
 305     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
 306         int left= get_bits_left(&s->gb);
 307         int max_extra=7;
 308
 309         /* no markers in M$ crap */
 310         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
 311             max_extra+= 17;
 312
 313         /* buggy padding but the frame should still end approximately at the bitstream end */
 314         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
 315             max_extra+= 48;
 316         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
 317             max_extra+= 256*256*256*64;
 318
 319         if(left>max_extra){
 320             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
 321         }
 322         else if(left<0){
 323             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
 324         }else
 325             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
 326
 327         return 0;
 328     }
 329
 330     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
 331             get_bits_left(&s->gb),
 332             show_bits(&s->gb, 24), s->padding_bug_score);
 333
 334     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
 335
 336     return -1;
 337 }
 338
 339 int ff_h263_decode_frame(AVCodecContext *avctx,
 340                              void *data, int *data_size,
 341                              AVPacket *avpkt)
 342 {
 343     const uint8_t *buf = avpkt->data;
 344     int buf_size = avpkt->size;
 345     MpegEncContext *s = avctx->priv_data;
 346     int ret;
 347     AVFrame *pict = data;
 348
 349 #ifdef PRINT_FRAME_TIME
 350 uint64_t time= rdtsc();
 351 #endif
 352     s->flags= avctx->flags;
 353     s->flags2= avctx->flags2;
 354
 355     /* no supplementary picture */
 356     if (buf_size == 0) {
 357         /* special case for last picture */
 358         if (s->low_delay==0 && s->next_picture_ptr) {
 359             *pict= *(AVFrame*)s->next_picture_ptr;
 360             s->next_picture_ptr= NULL;
 361
 362             *data_size = sizeof(AVFrame);
 363         }
 364
 365         return 0;
 366     }
 367
 368     if(s->flags&CODEC_FLAG_TRUNCATED){
 369         int next;
 370
 371         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
 372             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
 373         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
 374             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
 375         }else{
 376             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
 377             return -1;
 378         }
 379
 380         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
 381             return buf_size;
 382     }
 383
 384
 385 retry:
 386
 387     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
 388         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
 389     }else
 390         init_get_bits(&s->gb, buf, buf_size*8);
 391     s->bitstream_buffer_size=0;
 392
 393     if (!s->context_initialized) {
 394         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
 395             return -1;
 396     }
 397
 398     /* We need to set current_picture_ptr before reading the header,
 399      * otherwise we cannot store anyting in there */
 400     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
 401         int i= ff_find_unused_picture(s, 0);
 402         s->current_picture_ptr= &s->picture[i];
 403     }
 404
 405     /* let's go :-) */
 406     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
 407         ret= ff_wmv2_decode_picture_header(s);
 408     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
 409         ret = msmpeg4_decode_picture_header(s);
 410     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
 411         if(s->avctx->extradata_size && s->picture_number==0){
 412             GetBitContext gb;
 413
 414             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
 415             ret = ff_mpeg4_decode_picture_header(s, &gb);
 416         }
 417         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
 418     } else if (CONFIG_H263I_DECODER && s->codec_id == CODEC_ID_H263I) {
 419         ret = ff_intel_h263_decode_picture_header(s);
 420     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
 421         ret = ff_flv_decode_picture_header(s);
 422     } else {
 423         ret = h263_decode_picture_header(s);
 424     }
 425
 426     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
 427
 428     /* skip if the header was thrashed */
 429     if (ret < 0){
 430         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
 431         return -1;
 432     }
 433
 434     avctx->has_b_frames= !s->low_delay;
 435
 436     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 437         if(s->stream_codec_tag == AV_RL32("XVID") ||
 438            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
 439            s->codec_tag == AV_RL32("RMP4") ||
 440            s->codec_tag == AV_RL32("SIPP")
 441            )
 442             s->xvid_build= 0;
 443 #if 0
 444         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
 445            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
 446             s->xvid_build= 0;
 447 #endif
 448     }
 449
 450     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
 451         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
 452             s->divx_version= 400; //divx 4
 453     }
 454
 455     if(s->xvid_build>=0 && s->divx_version>=0){
 456         s->divx_version=
 457         s->divx_build= -1;
 458     }
 459
 460     if(s->workaround_bugs&FF_BUG_AUTODETECT){
 461         if(s->codec_tag == AV_RL32("XVIX"))
 462             s->workaround_bugs|= FF_BUG_XVID_ILACE;
 463
 464         if(s->codec_tag == AV_RL32("UMP4")){
 465             s->workaround_bugs|= FF_BUG_UMP4;
 466         }
 467
 468         if(s->divx_version>=500 && s->divx_build<1814){
 469             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 470         }
 471
 472         if(s->divx_version>502 && s->divx_build<1814){
 473             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
 474         }
 475
 476         if(s->xvid_build<=3U)
 477             s->padding_bug_score= 256*256*256*64;
 478
 479         if(s->xvid_build<=1U)
 480             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
 481
 482         if(s->xvid_build<=12U)
 483             s->workaround_bugs|= FF_BUG_EDGE;
 484
 485         if(s->xvid_build<=32U)
 486             s->workaround_bugs|= FF_BUG_DC_CLIP;
 487
 488 #define SET_QPEL_FUNC(postfix1, postfix2) \
 489     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
 490     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
 491     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
 492
 493         if(s->lavc_build<4653U)
 494             s->workaround_bugs|= FF_BUG_STD_QPEL;
 495
 496         if(s->lavc_build<4655U)
 497             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 498
 499         if(s->lavc_build<4670U){
 500             s->workaround_bugs|= FF_BUG_EDGE;
 501         }
 502
 503         if(s->lavc_build<=4712U)
 504             s->workaround_bugs|= FF_BUG_DC_CLIP;
 505
 506         if(s->divx_version>=0)
 507             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
 508 //printf("padding_bug_score: %d\n", s->padding_bug_score);
 509         if(s->divx_version==501 && s->divx_build==20020416)
 510             s->padding_bug_score= 256*256*256*64;
 511
 512         if(s->divx_version<500U){
 513             s->workaround_bugs|= FF_BUG_EDGE;
 514         }
 515
 516         if(s->divx_version>=0)
 517             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
 518 #if 0
 519         if(s->divx_version==500)
 520             s->padding_bug_score= 256*256*256*64;
 521
 522         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
 523          * Let us hope this at least works.
 524          */
 525         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
 526            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
 527             s->workaround_bugs|= FF_BUG_NO_PADDING;
 528
 529         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
 530             s->workaround_bugs|= FF_BUG_NO_PADDING;
 531 #endif
 532     }
 533
 534     if(s->workaround_bugs& FF_BUG_STD_QPEL){
 535         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
 536         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
 537         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
 538         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
 539         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
 540         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
 541
 542         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
 543         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
 544         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
 545         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
 546         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
 547         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
 548     }
 549
 550     if(avctx->debug & FF_DEBUG_BUGS)
 551         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
 552                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
 553                s->divx_packed ? "p" : "");
 554
 555 #if 0 // dump bits per frame / qp / complexity
 556 {
 557     static FILE *f=NULL;
 558     if(!f) f=fopen("rate_qp_cplx.txt", "w");
 559     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
 560 }
 561 #endif
 562
 563 #if HAVE_MMX
 564     if (s->codec_id == CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
 565         avctx->idct_algo= FF_IDCT_XVIDMMX;
 566         avctx->coded_width= 0; // force reinit
 567 //        dsputil_init(&s->dsp, avctx);
 568         s->picture_number=0;
 569     }
 570 #endif
 571
 572         /* After H263 & mpeg4 header decode we have the height, width,*/
 573         /* and other parameters. So then we could init the picture   */
 574         /* FIXME: By the way H263 decoder is evolving it should have */
 575         /* an H263EncContext                                         */
 576
 577     if (   s->width  != avctx->coded_width
 578         || s->height != avctx->coded_height) {
 579         /* H.263 could change picture size any time */
 580         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
 581         s->parse_context.buffer=0;
 582         MPV_common_end(s);
 583         s->parse_context= pc;
 584     }
 585     if (!s->context_initialized) {
 586         avcodec_set_dimensions(avctx, s->width, s->height);
 587
 588         goto retry;
 589     }
 590
 591     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
 592         s->gob_index = ff_h263_get_gob_height(s);
 593
 594     // for skipping the frame
 595     s->current_picture.pict_type= s->pict_type;
 596     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
 597
 598     /* skip B-frames if we don't have reference frames */
 599     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
 600 #if FF_API_HURRY_UP
 601     /* skip b frames if we are in a hurry */
 602     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
 603 #endif
 604     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
 605        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
 606        ||  avctx->skip_frame >= AVDISCARD_ALL)
 607         return get_consumed_bytes(s, buf_size);
 608 #if FF_API_HURRY_UP
 609     /* skip everything if we are in a hurry>=5 */
 610     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
 611 #endif
 612
 613     if(s->next_p_frame_damaged){
 614         if(s->pict_type==FF_B_TYPE)
 615             return get_consumed_bytes(s, buf_size);
 616         else
 617             s->next_p_frame_damaged=0;
 618     }
 619
 620     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
 621         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
 622         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
 623     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
 624         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
 625         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 626     }else{
 627         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
 628         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
 629     }
 630
 631     if(MPV_frame_start(s, avctx) < 0)
 632         return -1;
 633
 634     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
 635         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
 636         goto frame_end;
 637     }
 638
 639     if (avctx->hwaccel) {
 640         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
 641             return -1;
 642     }
 643
 644     ff_er_frame_start(s);
 645
 646     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
 647     //which is not available before MPV_frame_start()
 648     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
 649         ret = ff_wmv2_decode_secondary_picture_header(s);
 650         if(ret<0) return ret;
 651         if(ret==1) goto intrax8_decoded;
 652     }
 653
 654     /* decode each macroblock */
 655     s->mb_x=0;
 656     s->mb_y=0;
 657
 658     decode_slice(s);
 659     while(s->mb_y<s->mb_height){
 660         if(s->msmpeg4_version){
 661             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)
 662                 break;
 663         }else{
 664             if(ff_h263_resync(s)<0)
 665                 break;
 666         }
 667
 668         if(s->msmpeg4_version<4 && s->h263_pred)
 669             ff_mpeg4_clean_buffers(s);
 670
 671         decode_slice(s);
 672     }
 673
 674     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
 675         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
 676             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
 677         }
 678
 679     assert(s->bitstream_buffer_size==0);
 680 frame_end:
 681     /* divx 5.01+ bistream reorder stuff */
 682     if(s->codec_id==CODEC_ID_MPEG4 && s->divx_packed){
 683         int current_pos= get_bits_count(&s->gb)>>3;
 684         int startcode_found=0;
 685
 686         if(buf_size - current_pos > 5){
 687             int i;
 688             for(i=current_pos; i<buf_size-3; i++){
 689                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
 690                     startcode_found=1;
 691                     break;
 692                 }
 693             }
 694         }
 695         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
 696             startcode_found=1;
 697             current_pos=0;
 698         }
 699
 700         if(startcode_found){
 701             av_fast_malloc(
 702                 &s->bitstream_buffer,
 703                 &s->allocated_bitstream_buffer_size,
 704                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
 705             if (!s->bitstream_buffer)
 706                 return AVERROR(ENOMEM);
 707             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
 708             s->bitstream_buffer_size= buf_size - current_pos;
 709         }
 710     }
 711
 712 intrax8_decoded:
 713     ff_er_frame_end(s);
 714
 715     if (avctx->hwaccel) {
 716         if (avctx->hwaccel->end_frame(avctx) < 0)
 717             return -1;
 718     }
 719
 720     MPV_frame_end(s);
 721
 722 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
 723 assert(s->current_picture.pict_type == s->pict_type);
 724     if (s->pict_type == FF_B_TYPE || s->low_delay) {
 725         *pict= *(AVFrame*)s->current_picture_ptr;
 726     } else if (s->last_picture_ptr != NULL) {
 727         *pict= *(AVFrame*)s->last_picture_ptr;
 728     }
 729
 730     if(s->last_picture_ptr || s->low_delay){
 731         *data_size = sizeof(AVFrame);
 732         ff_print_debug_info(s, pict);
 733     }
 734
 735 #ifdef PRINT_FRAME_TIME
 736 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
 737 #endif
 738
 739     return get_consumed_bytes(s, buf_size);
 740 }
 741
 742 AVCodec ff_h263_decoder = {
 743     "h263",
 744     AVMEDIA_TYPE_VIDEO,
 745     CODEC_ID_H263,
 746     sizeof(MpegEncContext),
 747     ff_h263_decode_init,
 748     NULL,
 749     ff_h263_decode_end,
 750     ff_h263_decode_frame,
 751     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
 752     .flush= ff_mpeg_flush,
 753     .max_lowres= 3,
 754     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
 755     .pix_fmts= ff_hwaccel_pixfmt_list_420,
 756 };