Ministry of English Composition, reporting for duty (and the word is "skipped", not...
[ffmpeg.git] / 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 library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  */
20  
21 /**
22  * @file h263dec.c
23  * H.263 decoder.
24  */
25  
26 #include "avcodec.h"
27 #include "dsputil.h"
28 #include "mpegvideo.h"
29
30 //#define DEBUG
31 //#define PRINT_FRAME_TIME
32
33 int ff_h263_decode_init(AVCodecContext *avctx)
34 {
35     MpegEncContext *s = avctx->priv_data;
36
37     s->avctx = avctx;
38     s->out_format = FMT_H263;
39
40     s->width  = avctx->coded_width;
41     s->height = avctx->coded_height;
42     s->workaround_bugs= avctx->workaround_bugs;
43
44     // set defaults
45     MPV_decode_defaults(s);
46     s->quant_precision=5;
47     s->decode_mb= ff_h263_decode_mb;
48     s->low_delay= 1;
49     avctx->pix_fmt= PIX_FMT_YUV420P;
50     s->unrestricted_mv= 1;
51
52     /* select sub codec */
53     switch(avctx->codec->id) {
54     case CODEC_ID_H263:
55         s->unrestricted_mv= 0;
56         break;
57     case CODEC_ID_MPEG4:
58         s->decode_mb= ff_mpeg4_decode_mb;
59         s->time_increment_bits = 4; /* default value for broken headers */
60         s->h263_pred = 1;
61         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
62         break;
63     case CODEC_ID_MSMPEG4V1:
64         s->h263_msmpeg4 = 1;
65         s->h263_pred = 1;
66         s->msmpeg4_version=1;
67         break;
68     case CODEC_ID_MSMPEG4V2:
69         s->h263_msmpeg4 = 1;
70         s->h263_pred = 1;
71         s->msmpeg4_version=2;
72         break;
73     case CODEC_ID_MSMPEG4V3:
74         s->h263_msmpeg4 = 1;
75         s->h263_pred = 1;
76         s->msmpeg4_version=3;
77         break;
78     case CODEC_ID_WMV1:
79         s->h263_msmpeg4 = 1;
80         s->h263_pred = 1;
81         s->msmpeg4_version=4;
82         break;
83     case CODEC_ID_WMV2:
84         s->h263_msmpeg4 = 1;
85         s->h263_pred = 1;
86         s->msmpeg4_version=5;
87         break;
88     case CODEC_ID_WMV3:
89         s->h263_msmpeg4 = 1;
90         s->h263_pred = 1;
91         s->msmpeg4_version=6;
92         break;
93     case CODEC_ID_H263I:
94         break;
95     case CODEC_ID_FLV1:
96         s->h263_flv = 1;
97         break;
98     default:
99         return -1;
100     }
101     s->codec_id= avctx->codec->id;
102
103     /* for h263, we allocate the images after having read the header */
104     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
105         if (MPV_common_init(s) < 0)
106             return -1;
107
108     if (s->h263_msmpeg4)
109         ff_msmpeg4_decode_init(s);
110     else
111         h263_decode_init_vlc(s);
112     
113     return 0;
114 }
115
116 int ff_h263_decode_end(AVCodecContext *avctx)
117 {
118     MpegEncContext *s = avctx->priv_data;
119
120     MPV_common_end(s);
121     return 0;
122 }
123
124 /**
125  * retunrs the number of bytes consumed for building the current frame
126  */
127 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
128     int pos= (get_bits_count(&s->gb)+7)>>3;
129     
130     if(s->divx_packed){
131         //we would have to scan through the whole buf to handle the weird reordering ...
132         return buf_size; 
133     }else if(s->flags&CODEC_FLAG_TRUNCATED){
134         pos -= s->parse_context.last_index;
135         if(pos<0) pos=0; // padding is not really read so this might be -1
136         return pos;
137     }else{
138         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
139         if(pos+10>buf_size) pos=buf_size; // oops ;)
140
141         return pos;
142     }
143 }
144
145 static int decode_slice(MpegEncContext *s){
146     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
147     const int mb_size= 16>>s->avctx->lowres;
148     s->last_resync_gb= s->gb;
149     s->first_slice_line= 1;
150         
151     s->resync_mb_x= s->mb_x;
152     s->resync_mb_y= s->mb_y;
153
154     ff_set_qscale(s, s->qscale);
155     
156     if(s->partitioned_frame){
157         const int qscale= s->qscale;
158
159         if(s->codec_id==CODEC_ID_MPEG4){
160             if(ff_mpeg4_decode_partitions(s) < 0)
161                 return -1; 
162         }
163         
164         /* restore variables which were modified */
165         s->first_slice_line=1;
166         s->mb_x= s->resync_mb_x;
167         s->mb_y= s->resync_mb_y;
168         ff_set_qscale(s, qscale);
169     }
170
171     for(; s->mb_y < s->mb_height; s->mb_y++) {
172         /* per-row end of slice checks */
173         if(s->msmpeg4_version){
174             if(s->resync_mb_y + s->slice_height == s->mb_y){
175                 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);
176
177                 return 0;
178             }
179         }
180         
181         if(s->msmpeg4_version==1){
182             s->last_dc[0]=
183             s->last_dc[1]=
184             s->last_dc[2]= 128;
185         }
186     
187         ff_init_block_index(s);
188         for(; s->mb_x < s->mb_width; s->mb_x++) {
189             int ret;
190
191             ff_update_block_index(s);
192
193             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
194                 s->first_slice_line=0; 
195             }
196
197             /* DCT & quantize */
198             s->dsp.clear_blocks(s->block[0]);
199             
200             s->mv_dir = MV_DIR_FORWARD;
201             s->mv_type = MV_TYPE_16X16;
202 //            s->mb_skipped = 0;
203 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
204             ret= s->decode_mb(s, s->block);
205
206             if (s->pict_type!=B_TYPE)
207                 ff_h263_update_motion_val(s);
208
209             if(ret<0){
210                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
211                 if(ret==SLICE_END){
212                     MPV_decode_mb(s, s->block);
213                     if(s->loop_filter)
214                         ff_h263_loop_filter(s);
215
216 //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));
217                     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);
218
219                     s->padding_bug_score--;
220                         
221                     if(++s->mb_x >= s->mb_width){
222                         s->mb_x=0;
223                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
224                         s->mb_y++;
225                     }
226                     return 0; 
227                 }else if(ret==SLICE_NOEND){
228                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
229                     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);
230                     return -1;
231                 }
232                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
233                 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);
234     
235                 return -1;
236             }
237
238             MPV_decode_mb(s, s->block);
239             if(s->loop_filter)
240                 ff_h263_loop_filter(s);
241         }
242         
243         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
244         
245         s->mb_x= 0;
246     }
247     
248     assert(s->mb_x==0 && s->mb_y==s->mb_height);
249
250     /* try to detect the padding bug */
251     if(      s->codec_id==CODEC_ID_MPEG4
252        &&   (s->workaround_bugs&FF_BUG_AUTODETECT) 
253        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
254        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
255 //       &&   !s->resync_marker
256        &&   !s->data_partitioning){
257         
258         const int bits_count= get_bits_count(&s->gb);
259         const int bits_left = s->gb.size_in_bits - bits_count;
260         
261         if(bits_left==0){
262             s->padding_bug_score+=16;
263         } else if(bits_left != 1){
264             int v= show_bits(&s->gb, 8);
265             v|= 0x7F >> (7-(bits_count&7));
266
267             if(v==0x7F && bits_left<=8)
268                 s->padding_bug_score--;
269             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
270                 s->padding_bug_score+= 4;
271             else
272                 s->padding_bug_score++;            
273         }                          
274     }
275     
276     if(s->workaround_bugs&FF_BUG_AUTODETECT){
277         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
278             s->workaround_bugs |=  FF_BUG_NO_PADDING;
279         else
280             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
281     }
282
283     // handle formats which dont have unique end markers
284     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
285         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
286         int max_extra=7;
287         
288         /* no markers in M$ crap */
289         if(s->msmpeg4_version && s->pict_type==I_TYPE)
290             max_extra+= 17;
291         
292         /* buggy padding but the frame should still end approximately at the bitstream end */
293         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
294             max_extra+= 48;
295         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
296             max_extra+= 256*256*256*64;
297         
298         if(left>max_extra){
299             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
300         }
301         else if(left<0){
302             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
303         }else
304             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);
305         
306         return 0;
307     }
308
309     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n", 
310             s->gb.size_in_bits - get_bits_count(&s->gb),
311             show_bits(&s->gb, 24), s->padding_bug_score);
312             
313     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);
314
315     return -1;
316 }
317
318 /**
319  * finds the end of the current frame in the bitstream.
320  * @return the position of the first byte of the next frame, or -1
321  */
322 int ff_mpeg4_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
323     int vop_found, i;
324     uint32_t state;
325     
326     vop_found= pc->frame_start_found;
327     state= pc->state;
328     
329     i=0;
330     if(!vop_found){
331         for(i=0; i<buf_size; i++){
332             state= (state<<8) | buf[i];
333             if(state == 0x1B6){
334                 i++;
335                 vop_found=1;
336                 break;
337             }
338         }
339     }
340
341     if(vop_found){
342         /* EOF considered as end of frame */
343         if (buf_size == 0)
344             return 0;
345         for(; i<buf_size; i++){
346             state= (state<<8) | buf[i];
347             if((state&0xFFFFFF00) == 0x100){
348                 pc->frame_start_found=0;
349                 pc->state=-1; 
350                 return i-3;
351             }
352         }
353     }
354     pc->frame_start_found= vop_found;
355     pc->state= state;
356     return END_NOT_FOUND;
357 }
358
359 static int h263_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
360     int vop_found, i;
361     uint32_t state;
362     
363     vop_found= pc->frame_start_found;
364     state= pc->state;
365     
366     i=0;
367     if(!vop_found){
368         for(i=0; i<buf_size; i++){
369             state= (state<<8) | buf[i];
370             if(state>>(32-22) == 0x20){
371                 i++;
372                 vop_found=1;
373                 break;
374             }
375         }
376     }
377
378     if(vop_found){    
379       for(; i<buf_size; i++){
380         state= (state<<8) | buf[i];
381         if(state>>(32-22) == 0x20){
382             pc->frame_start_found=0;
383             pc->state=-1; 
384             return i-3;
385         }
386       }
387     }
388     pc->frame_start_found= vop_found;
389     pc->state= state;
390     
391     return END_NOT_FOUND;
392 }
393
394 static int h263_parse(AVCodecParserContext *s,
395                            AVCodecContext *avctx,
396                            uint8_t **poutbuf, int *poutbuf_size, 
397                            const uint8_t *buf, int buf_size)
398 {
399     ParseContext *pc = s->priv_data;
400     int next;
401     
402     next= h263_find_frame_end(pc, buf, buf_size);
403
404     if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
405         *poutbuf = NULL;
406         *poutbuf_size = 0;
407         return buf_size;
408     }
409
410     *poutbuf = (uint8_t *)buf;
411     *poutbuf_size = buf_size;
412     return next;
413 }
414
415 int ff_h263_decode_frame(AVCodecContext *avctx, 
416                              void *data, int *data_size,
417                              uint8_t *buf, int buf_size)
418 {
419     MpegEncContext *s = avctx->priv_data;
420     int ret;
421     AVFrame *pict = data; 
422     
423 #ifdef PRINT_FRAME_TIME
424 uint64_t time= rdtsc();
425 #endif
426 #ifdef DEBUG
427     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
428     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
429 #endif
430     s->flags= avctx->flags;
431     s->flags2= avctx->flags2;
432
433     /* no supplementary picture */
434     if (buf_size == 0) {
435         /* special case for last picture */
436         if (s->low_delay==0 && s->next_picture_ptr) {
437             *pict= *(AVFrame*)s->next_picture_ptr;
438             s->next_picture_ptr= NULL;
439
440             *data_size = sizeof(AVFrame);
441         }
442
443         return 0;
444     }
445
446     if(s->flags&CODEC_FLAG_TRUNCATED){
447         int next;
448         
449         if(s->codec_id==CODEC_ID_MPEG4){
450             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
451         }else if(s->codec_id==CODEC_ID_H263){
452             next= h263_find_frame_end(&s->parse_context, buf, buf_size);
453         }else{
454             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
455             return -1;
456         }
457         
458         if( ff_combine_frame(&s->parse_context, next, &buf, &buf_size) < 0 )
459             return buf_size;
460     }
461
462     
463 retry:
464     
465     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
466         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
467     }else
468         init_get_bits(&s->gb, buf, buf_size*8);
469     s->bitstream_buffer_size=0;
470
471     if (!s->context_initialized) {
472         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
473             return -1;
474     }
475     
476     //we need to set current_picture_ptr before reading the header, otherwise we cant store anyting im there
477     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
478         int i= ff_find_unused_picture(s, 0);
479         s->current_picture_ptr= &s->picture[i];
480     }
481       
482     /* let's go :-) */
483     if (s->msmpeg4_version==5) {
484         ret= ff_wmv2_decode_picture_header(s);
485     } else if (s->msmpeg4_version) {
486         ret = msmpeg4_decode_picture_header(s);
487     } else if (s->h263_pred) {
488         if(s->avctx->extradata_size && s->picture_number==0){
489             GetBitContext gb;
490             
491             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
492             ret = ff_mpeg4_decode_picture_header(s, &gb);
493         }
494         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
495
496         if(s->flags& CODEC_FLAG_LOW_DELAY)
497             s->low_delay=1;
498     } else if (s->codec_id == CODEC_ID_H263I) {
499         ret = intel_h263_decode_picture_header(s);
500     } else if (s->h263_flv) {
501         ret = flv_h263_decode_picture_header(s);
502     } else {
503         ret = h263_decode_picture_header(s);
504     }
505     
506     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
507
508     /* skip if the header was thrashed */
509     if (ret < 0){
510         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
511         return -1;
512     }
513     
514     avctx->has_b_frames= !s->low_delay;
515     
516     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
517         if(s->avctx->stream_codec_tag == ff_get_fourcc("XVID") || 
518            s->avctx->codec_tag == ff_get_fourcc("XVID") || s->avctx->codec_tag == ff_get_fourcc("XVIX"))
519             s->xvid_build= -1;
520 #if 0
521         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
522            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc 
523             s->xvid_build= -1;
524 #endif
525     }
526
527     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
528         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
529             s->divx_version= 400; //divx 4
530     }
531     
532     if(s->xvid_build && s->divx_version){
533         s->divx_version=
534         s->divx_build= 0;
535     }
536
537     if(s->workaround_bugs&FF_BUG_AUTODETECT){
538         if(s->avctx->codec_tag == ff_get_fourcc("XVIX")) 
539             s->workaround_bugs|= FF_BUG_XVID_ILACE;
540
541         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
542             s->workaround_bugs|= FF_BUG_UMP4;
543         }
544
545         if(s->divx_version>=500){
546             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
547         }
548
549         if(s->divx_version>502){
550             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
551         }
552
553         if(s->xvid_build && s->xvid_build<=3)
554             s->padding_bug_score= 256*256*256*64;
555         
556         if(s->xvid_build && s->xvid_build<=1)
557             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
558
559         if(s->xvid_build && s->xvid_build<=12)
560             s->workaround_bugs|= FF_BUG_EDGE;
561
562         if(s->xvid_build && s->xvid_build<=32)
563             s->workaround_bugs|= FF_BUG_DC_CLIP;
564
565 #define SET_QPEL_FUNC(postfix1, postfix2) \
566     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
567     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
568     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
569
570         if(s->lavc_build && s->lavc_build<4653)
571             s->workaround_bugs|= FF_BUG_STD_QPEL;
572         
573         if(s->lavc_build && s->lavc_build<4655)
574             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
575
576         if(s->lavc_build && s->lavc_build<4670){
577             s->workaround_bugs|= FF_BUG_EDGE;
578         }
579         
580         if(s->lavc_build && s->lavc_build<=4712)
581             s->workaround_bugs|= FF_BUG_DC_CLIP;
582
583         if(s->divx_version)
584             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
585 //printf("padding_bug_score: %d\n", s->padding_bug_score);
586         if(s->divx_version==501 && s->divx_build==20020416)
587             s->padding_bug_score= 256*256*256*64;
588
589         if(s->divx_version && s->divx_version<500){
590             s->workaround_bugs|= FF_BUG_EDGE;
591         }
592         
593         if(s->divx_version)
594             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
595 #if 0
596         if(s->divx_version==500)
597             s->padding_bug_score= 256*256*256*64;
598
599         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
600          * lets hope this at least works
601          */
602         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
603            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
604             s->workaround_bugs|= FF_BUG_NO_PADDING;
605         
606         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
607             s->workaround_bugs|= FF_BUG_NO_PADDING;
608 #endif
609     }
610     
611     if(s->workaround_bugs& FF_BUG_STD_QPEL){
612         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
613         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
614         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
615         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
616         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
617         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
618
619         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
620         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
621         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
622         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
623         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
624         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
625     }
626
627     if(avctx->debug & FF_DEBUG_BUGS)
628         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n", 
629                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
630                s->divx_packed ? "p" : "");
631     
632 #if 0 // dump bits per frame / qp / complexity
633 {
634     static FILE *f=NULL;
635     if(!f) f=fopen("rate_qp_cplx.txt", "w");
636     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
637 }
638 #endif
639
640 #ifdef HAVE_MMX
641     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & MM_MMX) && !(s->flags&CODEC_FLAG_BITEXACT)){
642         avctx->idct_algo= FF_IDCT_LIBMPEG2MMX;
643         avctx->coded_width= 0; // force reinit
644     }
645 #endif
646
647         /* After H263 & mpeg4 header decode we have the height, width,*/
648         /* and other parameters. So then we could init the picture   */
649         /* FIXME: By the way H263 decoder is evolving it should have */
650         /* an H263EncContext                                         */
651     
652     if (   s->width  != avctx->coded_width 
653         || s->height != avctx->coded_height) {
654         /* H.263 could change picture size any time */
655         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
656         s->parse_context.buffer=0;
657         MPV_common_end(s);
658         s->parse_context= pc;
659     }
660     if (!s->context_initialized) {
661         avcodec_set_dimensions(avctx, s->width, s->height);
662
663         goto retry;
664     }
665
666     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
667         s->gob_index = ff_h263_get_gob_height(s);
668     
669     // for hurry_up==5
670     s->current_picture.pict_type= s->pict_type;
671     s->current_picture.key_frame= s->pict_type == I_TYPE;
672
673     /* skip b frames if we dont have reference frames */
674     if(s->last_picture_ptr==NULL && (s->pict_type==B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
675     /* skip b frames if we are in a hurry */
676     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
677     /* skip everything if we are in a hurry>=5 */
678     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
679     
680     if(s->next_p_frame_damaged){
681         if(s->pict_type==B_TYPE)
682             return get_consumed_bytes(s, buf_size);
683         else
684             s->next_p_frame_damaged=0;
685     }
686
687     if(MPV_frame_start(s, avctx) < 0)
688         return -1;
689
690 #ifdef DEBUG
691     printf("qscale=%d\n", s->qscale);
692 #endif
693
694     ff_er_frame_start(s);
695     
696     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
697     //which isnt available before MPV_frame_start()
698     if (s->msmpeg4_version==5){
699         if(ff_wmv2_decode_secondary_picture_header(s) < 0)
700             return -1;
701     }
702
703     /* decode each macroblock */
704     s->mb_x=0; 
705     s->mb_y=0;
706     
707     decode_slice(s);
708     while(s->mb_y<s->mb_height){
709         if(s->msmpeg4_version){
710             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
711                 break;
712         }else{
713             if(ff_h263_resync(s)<0)
714                 break;
715         }
716         
717         if(s->msmpeg4_version<4 && s->h263_pred)
718             ff_mpeg4_clean_buffers(s);
719
720         decode_slice(s);
721     }
722
723     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
724         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
725             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
726         }
727     
728     /* divx 5.01+ bistream reorder stuff */
729     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
730         int current_pos= get_bits_count(&s->gb)>>3;
731         int startcode_found=0;
732         
733         if(buf_size - current_pos > 5){
734             int i;
735             for(i=current_pos; i<buf_size-3; i++){
736                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
737                     startcode_found=1;
738                     break;
739                 }
740             }
741         }
742         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
743             startcode_found=1;
744             current_pos=0;
745         }
746
747         if(startcode_found){
748             s->bitstream_buffer= av_fast_realloc(
749                 s->bitstream_buffer, 
750                 &s->allocated_bitstream_buffer_size, 
751                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
752             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
753             s->bitstream_buffer_size= buf_size - current_pos;
754         }
755     }
756
757     ff_er_frame_end(s);
758
759     MPV_frame_end(s);
760
761 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
762 assert(s->current_picture.pict_type == s->pict_type);
763     if(s->pict_type==B_TYPE || s->low_delay){
764         *pict= *(AVFrame*)&s->current_picture;
765         ff_print_debug_info(s, pict);
766     } else {
767         *pict= *(AVFrame*)&s->last_picture;
768         if(pict)
769             ff_print_debug_info(s, pict);
770     }
771
772     /* Return the Picture timestamp as the frame number */
773     /* we substract 1 because it is added on utils.c    */
774     avctx->frame_number = s->picture_number - 1;
775
776     /* dont output the last pic after seeking */
777     if(s->last_picture_ptr || s->low_delay)
778         *data_size = sizeof(AVFrame);
779 #ifdef PRINT_FRAME_TIME
780 printf("%Ld\n", rdtsc()-time);
781 #endif
782
783     return get_consumed_bytes(s, buf_size);
784 }
785
786 AVCodec mpeg4_decoder = {
787     "mpeg4",
788     CODEC_TYPE_VIDEO,
789     CODEC_ID_MPEG4,
790     sizeof(MpegEncContext),
791     ff_h263_decode_init,
792     NULL,
793     ff_h263_decode_end,
794     ff_h263_decode_frame,
795     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
796     .flush= ff_mpeg_flush,
797 };
798
799 AVCodec h263_decoder = {
800     "h263",
801     CODEC_TYPE_VIDEO,
802     CODEC_ID_H263,
803     sizeof(MpegEncContext),
804     ff_h263_decode_init,
805     NULL,
806     ff_h263_decode_end,
807     ff_h263_decode_frame,
808     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
809     .flush= ff_mpeg_flush,
810 };
811
812 AVCodec msmpeg4v1_decoder = {
813     "msmpeg4v1",
814     CODEC_TYPE_VIDEO,
815     CODEC_ID_MSMPEG4V1,
816     sizeof(MpegEncContext),
817     ff_h263_decode_init,
818     NULL,
819     ff_h263_decode_end,
820     ff_h263_decode_frame,
821     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
822 };
823
824 AVCodec msmpeg4v2_decoder = {
825     "msmpeg4v2",
826     CODEC_TYPE_VIDEO,
827     CODEC_ID_MSMPEG4V2,
828     sizeof(MpegEncContext),
829     ff_h263_decode_init,
830     NULL,
831     ff_h263_decode_end,
832     ff_h263_decode_frame,
833     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
834 };
835
836 AVCodec msmpeg4v3_decoder = {
837     "msmpeg4",
838     CODEC_TYPE_VIDEO,
839     CODEC_ID_MSMPEG4V3,
840     sizeof(MpegEncContext),
841     ff_h263_decode_init,
842     NULL,
843     ff_h263_decode_end,
844     ff_h263_decode_frame,
845     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
846 };
847
848 AVCodec wmv1_decoder = {
849     "wmv1",
850     CODEC_TYPE_VIDEO,
851     CODEC_ID_WMV1,
852     sizeof(MpegEncContext),
853     ff_h263_decode_init,
854     NULL,
855     ff_h263_decode_end,
856     ff_h263_decode_frame,
857     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
858 };
859
860 AVCodec h263i_decoder = {
861     "h263i",
862     CODEC_TYPE_VIDEO,
863     CODEC_ID_H263I,
864     sizeof(MpegEncContext),
865     ff_h263_decode_init,
866     NULL,
867     ff_h263_decode_end,
868     ff_h263_decode_frame,
869     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
870 };
871
872 AVCodec flv_decoder = {
873     "flv",
874     CODEC_TYPE_VIDEO,
875     CODEC_ID_FLV1,
876     sizeof(MpegEncContext),
877     ff_h263_decode_init,
878     NULL,
879     ff_h263_decode_end,
880     ff_h263_decode_frame,
881     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1
882 };
883
884 AVCodecParser h263_parser = {
885     { CODEC_ID_H263 },
886     sizeof(ParseContext),
887     NULL,
888     h263_parse,
889     ff_parse_close,
890 };