AVCodec.flush()
[ffmpeg.git] / libavcodec / h263dec.c
1 /*
2  * H.263 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  
20 /**
21  * @file h263dec.c
22  * H.263 decoder.
23  */
24  
25 #include "avcodec.h"
26 #include "dsputil.h"
27 #include "mpegvideo.h"
28
29 //#define DEBUG
30 //#define PRINT_FRAME_TIME
31 #ifdef PRINT_FRAME_TIME
32 static inline long long rdtsc()
33 {
34         long long l;
35         asm volatile(   "rdtsc\n\t"
36                 : "=A" (l)
37         );
38 //      printf("%d\n", int(l/1000));
39         return l;
40 }
41 #endif
42
43 int ff_h263_decode_init(AVCodecContext *avctx)
44 {
45     MpegEncContext *s = avctx->priv_data;
46
47     s->avctx = avctx;
48     s->out_format = FMT_H263;
49
50     s->width = avctx->width;
51     s->height = avctx->height;
52     s->workaround_bugs= avctx->workaround_bugs;
53
54     // set defaults
55     s->quant_precision=5;
56     s->progressive_sequence=1;
57     s->decode_mb= ff_h263_decode_mb;
58     s->low_delay= 1;
59     avctx->pix_fmt= PIX_FMT_YUV420P;
60
61     /* select sub codec */
62     switch(avctx->codec->id) {
63     case CODEC_ID_H263:
64         s->gob_number = 0;
65         break;
66     case CODEC_ID_MPEG4:
67         s->time_increment_bits = 4; /* default value for broken headers */
68         s->h263_pred = 1;
69         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
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_H263I:
97         s->h263_intel = 1;
98         break;
99     case CODEC_ID_FLV1:
100         s->h263_flv = 1;
101         break;
102     default:
103         return -1;
104     }
105     s->codec_id= avctx->codec->id;
106
107     /* for h263, we allocate the images after having read the header */
108     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
109         if (MPV_common_init(s) < 0)
110             return -1;
111
112     if (s->h263_msmpeg4)
113         ff_msmpeg4_decode_init(s);
114     else
115         h263_decode_init_vlc(s);
116     
117     return 0;
118 }
119
120 int ff_h263_decode_end(AVCodecContext *avctx)
121 {
122     MpegEncContext *s = avctx->priv_data;
123
124     MPV_common_end(s);
125     return 0;
126 }
127
128 /**
129  * retunrs the number of bytes consumed for building the current frame
130  */
131 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
132     int pos= (get_bits_count(&s->gb)+7)>>3;
133     
134     if(s->divx_packed){
135         //we would have to scan through the whole buf to handle the weird reordering ...
136         return buf_size; 
137     }else if(s->flags&CODEC_FLAG_TRUNCATED){
138         pos -= s->parse_context.last_index;
139         if(pos<0) pos=0; // padding is not really read so this might be -1
140         return pos;
141     }else{
142         if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
143         if(pos+10>buf_size) pos=buf_size; // oops ;)
144
145         return pos;
146     }
147 }
148
149 static int decode_slice(MpegEncContext *s){
150     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
151     s->last_resync_gb= s->gb;
152     s->first_slice_line= 1;
153         
154     s->resync_mb_x= s->mb_x;
155     s->resync_mb_y= s->mb_y;
156
157     s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
158     s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
159     
160     if(s->partitioned_frame){
161         const int qscale= s->qscale;
162
163         if(s->codec_id==CODEC_ID_MPEG4){
164             if(ff_mpeg4_decode_partitions(s) < 0)
165                 return -1; 
166         }
167         
168         /* restore variables which where modified */
169         s->first_slice_line=1;
170         s->mb_x= s->resync_mb_x;
171         s->mb_y= s->resync_mb_y;
172         s->qscale= qscale;
173         s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
174         s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
175     }
176
177     for(; s->mb_y < s->mb_height; s->mb_y++) {
178         /* per-row end of slice checks */
179         if(s->msmpeg4_version){
180             if(s->resync_mb_y + s->slice_height == s->mb_y){
181                 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);
182
183                 return 0;
184             }
185         }
186         
187         if(s->msmpeg4_version==1){
188             s->last_dc[0]=
189             s->last_dc[1]=
190             s->last_dc[2]= 128;
191         }
192     
193         ff_init_block_index(s);
194         for(; s->mb_x < s->mb_width; s->mb_x++) {
195             int ret;
196
197             ff_update_block_index(s);
198
199             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
200                 s->first_slice_line=0; 
201             }
202
203             /* DCT & quantize */
204             s->dsp.clear_blocks(s->block[0]);
205             
206             s->mv_dir = MV_DIR_FORWARD;
207             s->mv_type = MV_TYPE_16X16;
208 //            s->mb_skiped = 0;
209 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
210             ret= s->decode_mb(s, s->block);
211
212             if(ret<0){
213                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
214                 if(ret==SLICE_END){
215                     MPV_decode_mb(s, s->block);
216
217 //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));
218                     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);
219
220                     s->padding_bug_score--;
221                         
222                     if(++s->mb_x >= s->mb_width){
223                         s->mb_x=0;
224                         ff_draw_horiz_band(s, s->mb_y*16, 16);
225                         s->mb_y++;
226                     }
227                     return 0; 
228                 }else if(ret==SLICE_NOEND){
229                     fprintf(stderr,"Slice mismatch at MB: %d\n", xy);
230                     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);
231                     return -1;
232                 }
233                 fprintf(stderr,"Error at MB: %d\n", xy);
234                 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);
235     
236                 return -1;
237             }
238
239             MPV_decode_mb(s, s->block);
240         }
241         
242         ff_draw_horiz_band(s, s->mb_y*16, 16);
243         
244         s->mb_x= 0;
245     }
246     
247     assert(s->mb_x==0 && s->mb_y==s->mb_height);
248
249     /* try to detect the padding bug */
250     if(      s->codec_id==CODEC_ID_MPEG4
251        &&   (s->workaround_bugs&FF_BUG_AUTODETECT) 
252        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
253        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
254 //       &&   !s->resync_marker
255        &&   !s->data_partitioning){
256         
257         const int bits_count= get_bits_count(&s->gb);
258         const int bits_left = s->gb.size_in_bits - bits_count;
259         
260         if(bits_left==0){
261             s->padding_bug_score+=16;
262         }else if(bits_left>8){
263             s->padding_bug_score++;
264         } else if(bits_left != 1){
265             int v= show_bits(&s->gb, 8);
266             v|= 0x7F >> (7-(bits_count&7));
267
268             if(v==0x7F)
269                 s->padding_bug_score--;
270             else
271                 s->padding_bug_score++;            
272         }                          
273     }
274
275     // handle formats which dont have unique end markers
276     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
277         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
278         int max_extra=7;
279         
280         /* no markers in M$ crap */
281         if(s->msmpeg4_version && s->pict_type==I_TYPE)
282             max_extra+= 17;
283         
284         /* buggy padding but the frame should still end approximately at the bitstream end */
285         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
286             max_extra+= 48;
287         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
288             max_extra+= 256*256*256*64;
289         
290         if(left>max_extra){
291             fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
292         }
293         else if(left<0){
294             fprintf(stderr, "overreading %d bits\n", -left);
295         }else
296             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);
297         
298         return 0;
299     }
300
301     fprintf(stderr, "slice end not reached but screenspace end (%d left %06X)\n", 
302             s->gb.size_in_bits - get_bits_count(&s->gb),
303             show_bits(&s->gb, 24));
304             
305     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);
306
307     return -1;
308 }
309
310 /**
311  * finds the end of the current frame in the bitstream.
312  * @return the position of the first byte of the next frame, or -1
313  */
314 static int mpeg4_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
315     ParseContext *pc= &s->parse_context;
316     int vop_found, i;
317     uint32_t state;
318     
319     vop_found= pc->frame_start_found;
320     state= pc->state;
321     
322     i=0;
323     if(!vop_found){
324         for(i=0; i<buf_size; i++){
325             state= (state<<8) | buf[i];
326             if(state == 0x1B6){
327                 i++;
328                 vop_found=1;
329                 break;
330             }
331         }
332     }
333
334     if(vop_found){    
335       for(; i<buf_size; i++){
336         state= (state<<8) | buf[i];
337         if((state&0xFFFFFF00) == 0x100){
338             pc->frame_start_found=0;
339             pc->state=-1; 
340             return i-3;
341         }
342       }
343     }
344     pc->frame_start_found= vop_found;
345     pc->state= state;
346     return END_NOT_FOUND;
347 }
348
349 static int h263_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
350     ParseContext *pc= &s->parse_context;
351     int vop_found, i;
352     uint32_t state;
353     
354     vop_found= pc->frame_start_found;
355     state= pc->state;
356     
357     i=0;
358     if(!vop_found){
359         for(i=0; i<buf_size; i++){
360             state= (state<<8) | buf[i];
361             if(state>>(32-22) == 0x20){
362                 i++;
363                 vop_found=1;
364                 break;
365             }
366         }
367     }
368
369     if(vop_found){    
370       for(; i<buf_size; i++){
371         state= (state<<8) | buf[i];
372         if(state>>(32-22) == 0x20){
373             pc->frame_start_found=0;
374             pc->state=-1; 
375             return i-3;
376         }
377       }
378     }
379     pc->frame_start_found= vop_found;
380     pc->state= state;
381     
382     return END_NOT_FOUND;
383 }
384
385 int ff_h263_decode_frame(AVCodecContext *avctx, 
386                              void *data, int *data_size,
387                              uint8_t *buf, int buf_size)
388 {
389     MpegEncContext *s = avctx->priv_data;
390     int ret,i;
391     AVFrame *pict = data; 
392     float new_aspect;
393     
394 #ifdef PRINT_FRAME_TIME
395 uint64_t time= rdtsc();
396 #endif
397 #ifdef DEBUG
398     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
399     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
400 #endif
401     s->flags= avctx->flags;
402
403     *data_size = 0;
404    
405    /* no supplementary picture */
406     if (buf_size == 0) {
407         return 0;
408     }
409
410     if(s->flags&CODEC_FLAG_TRUNCATED){
411         int next;
412         
413         if(s->codec_id==CODEC_ID_MPEG4){
414             next= mpeg4_find_frame_end(s, buf, buf_size);
415         }else if(s->codec_id==CODEC_ID_H263){
416             next= h263_find_frame_end(s, buf, buf_size);
417         }else{
418             fprintf(stderr, "this codec doesnt support truncated bitstreams\n");
419             return -1;
420         }
421         
422         if( ff_combine_frame(s, next, &buf, &buf_size) < 0 )
423             return buf_size;
424     }
425
426 retry:
427     
428     if(s->bitstream_buffer_size && buf_size<20){ //divx 5.01+ frame reorder
429         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
430     }else
431         init_get_bits(&s->gb, buf, buf_size*8);
432     s->bitstream_buffer_size=0;
433
434     if (!s->context_initialized) {
435         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
436             return -1;
437     }
438       
439     /* let's go :-) */
440     if (s->msmpeg4_version==5) {
441         ret= ff_wmv2_decode_picture_header(s);
442     } else if (s->msmpeg4_version) {
443         ret = msmpeg4_decode_picture_header(s);
444     } else if (s->h263_pred) {
445         if(s->avctx->extradata_size && s->picture_number==0){
446             GetBitContext gb;
447             
448             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
449             ret = ff_mpeg4_decode_picture_header(s, &gb);
450         }
451         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
452
453         if(s->flags& CODEC_FLAG_LOW_DELAY)
454             s->low_delay=1;
455     } else if (s->h263_intel) {
456         ret = intel_h263_decode_picture_header(s);
457     } else if (s->h263_flv) {
458         ret = flv_h263_decode_picture_header(s);
459     } else {
460         ret = h263_decode_picture_header(s);
461     }
462     avctx->has_b_frames= !s->low_delay;
463
464     if(s->workaround_bugs&FF_BUG_AUTODETECT){
465         if(s->padding_bug_score > -2 && !s->data_partitioning && !s->resync_marker)
466             s->workaround_bugs |=  FF_BUG_NO_PADDING;
467         else
468             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
469
470         if(s->avctx->codec_tag == ff_get_fourcc("XVIX")) 
471             s->workaround_bugs|= FF_BUG_XVID_ILACE;
472 #if 0
473         if(s->avctx->codec_tag == ff_get_fourcc("MP4S")) 
474             s->workaround_bugs|= FF_BUG_AC_VLC;
475         
476         if(s->avctx->codec_tag == ff_get_fourcc("M4S2")) 
477             s->workaround_bugs|= FF_BUG_AC_VLC;
478 #endif
479         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
480             s->workaround_bugs|= FF_BUG_UMP4;
481             s->workaround_bugs|= FF_BUG_AC_VLC;
482         }
483
484         if(s->divx_version){
485             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
486         }
487
488         if(s->divx_version>502){
489             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
490         }
491
492         if(s->avctx->codec_tag == ff_get_fourcc("XVID") && s->xvid_build==0)
493             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
494         
495         if(s->avctx->codec_tag == ff_get_fourcc("XVID") && s->xvid_build==0)
496             s->padding_bug_score= 256*256*256*64;
497         
498         if(s->xvid_build && s->xvid_build<=3)
499             s->padding_bug_score= 256*256*256*64;
500         
501         if(s->xvid_build && s->xvid_build<=1)
502             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
503
504 #define SET_QPEL_FUNC(postfix1, postfix2) \
505     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
506     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
507     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
508
509         if(s->lavc_build && s->lavc_build<4653)
510             s->workaround_bugs|= FF_BUG_STD_QPEL;
511         
512         if(s->lavc_build && s->lavc_build<4655)
513             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
514
515         if(s->lavc_build && s->lavc_build<4618){
516             s->workaround_bugs|= FF_BUG_EDGE;
517         }
518
519         if(s->divx_version)
520             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
521 //printf("padding_bug_score: %d\n", s->padding_bug_score);
522         if(s->divx_version==501 && s->divx_build==20020416)
523             s->padding_bug_score= 256*256*256*64;
524
525         if(s->divx_version && s->divx_version<500){
526             s->workaround_bugs|= FF_BUG_EDGE;
527         }
528
529 #if 0
530         if(s->divx_version==500)
531             s->padding_bug_score= 256*256*256*64;
532
533         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
534          * lets hope this at least works
535          */
536         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
537            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
538             s->workaround_bugs|= FF_BUG_NO_PADDING;
539         
540         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
541             s->workaround_bugs|= FF_BUG_NO_PADDING;
542 #endif
543     }
544     
545     if(s->workaround_bugs& FF_BUG_STD_QPEL){
546         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
547         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
548         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
549         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
550         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
551         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
552
553         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
554         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
555         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
556         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
557         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
558         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
559     }
560
561 #if 0 // dump bits per frame / qp / complexity
562 {
563     static FILE *f=NULL;
564     if(!f) f=fopen("rate_qp_cplx.txt", "w");
565     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
566 }
567 #endif
568        
569         /* After H263 & mpeg4 header decode we have the height, width,*/
570         /* and other parameters. So then we could init the picture   */
571         /* FIXME: By the way H263 decoder is evolving it should have */
572         /* an H263EncContext                                         */
573     if(s->aspected_height)
574         new_aspect= s->aspected_width*s->width / (float)(s->height*s->aspected_height);
575     else
576         new_aspect=0;
577     
578     if (   s->width != avctx->width || s->height != avctx->height 
579         || ABS(new_aspect - avctx->aspect_ratio) > 0.001) {
580         /* H.263 could change picture size any time */
581         MPV_common_end(s);
582     }
583     if (!s->context_initialized) {
584         avctx->width = s->width;
585         avctx->height = s->height;
586         avctx->aspect_ratio= new_aspect;
587
588         goto retry;
589     }
590
591     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
592         s->gob_index = ff_h263_get_gob_height(s);
593
594     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
595     /* skip if the header was thrashed */
596     if (ret < 0){
597         fprintf(stderr, "header damaged\n");
598         return -1;
599     }
600     
601     // for hurry_up==5
602     s->current_picture.pict_type= s->pict_type;
603     s->current_picture.key_frame= s->pict_type == I_TYPE;
604
605     /* skip b frames if we dont have reference frames */
606     if(s->last_picture_ptr==NULL && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
607     /* skip b frames if we are in a hurry */
608     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
609     /* skip everything if we are in a hurry>=5 */
610     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
611     
612     if(s->next_p_frame_damaged){
613         if(s->pict_type==B_TYPE)
614             return get_consumed_bytes(s, buf_size);
615         else
616             s->next_p_frame_damaged=0;
617     }
618
619     if(MPV_frame_start(s, avctx) < 0)
620         return -1;
621
622 #ifdef DEBUG
623     printf("qscale=%d\n", s->qscale);
624 #endif
625
626     ff_er_frame_start(s);
627     
628     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
629     //which isnt available before MPV_frame_start()
630     if (s->msmpeg4_version==5){
631         if(ff_wmv2_decode_secondary_picture_header(s) < 0)
632             return -1;
633     }
634
635     /* decode each macroblock */
636     s->mb_x=0; 
637     s->mb_y=0;
638     
639     decode_slice(s);
640     while(s->mb_y<s->mb_height){
641         if(s->msmpeg4_version){
642             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
643                 break;
644         }else{
645             if(ff_h263_resync(s)<0)
646                 break;
647         }
648         
649         if(s->msmpeg4_version<4 && s->h263_pred)
650             ff_mpeg4_clean_buffers(s);
651
652         decode_slice(s);
653     }
654
655     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
656         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
657             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
658         }
659     
660     /* divx 5.01+ bistream reorder stuff */
661     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
662         int current_pos= get_bits_count(&s->gb)>>3;
663
664         if(   buf_size - current_pos > 5 
665            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
666             int i;
667             int startcode_found=0;
668             for(i=current_pos; i<buf_size-3; i++){
669                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
670                     startcode_found=1;
671                     break;
672                 }
673             }
674             if(startcode_found){
675                 memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
676                 s->bitstream_buffer_size= buf_size - current_pos;
677             }
678         }
679     }
680
681     ff_er_frame_end(s);
682
683     MPV_frame_end(s);
684
685 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
686 assert(s->current_picture.pict_type == s->pict_type);
687     if(s->pict_type==B_TYPE || s->low_delay){
688         *pict= *(AVFrame*)&s->current_picture;
689         ff_print_debug_info(s, s->current_picture_ptr);
690     } else {
691         *pict= *(AVFrame*)&s->last_picture;
692         ff_print_debug_info(s, s->last_picture_ptr);
693     }
694
695     /* Return the Picture timestamp as the frame number */
696     /* we substract 1 because it is added on utils.c    */
697     avctx->frame_number = s->picture_number - 1;
698
699     /* dont output the last pic after seeking */
700     if(s->last_picture_ptr || s->low_delay)
701         *data_size = sizeof(AVFrame);
702 #ifdef PRINT_FRAME_TIME
703 printf("%Ld\n", rdtsc()-time);
704 #endif
705
706     return get_consumed_bytes(s, buf_size);
707 }
708
709 static const AVOption mpeg4_decoptions[] =
710 {
711     AVOPTION_SUB(avoptions_workaround_bug),
712     AVOPTION_END()
713 };
714
715 AVCodec mpeg4_decoder = {
716     "mpeg4",
717     CODEC_TYPE_VIDEO,
718     CODEC_ID_MPEG4,
719     sizeof(MpegEncContext),
720     ff_h263_decode_init,
721     NULL,
722     ff_h263_decode_end,
723     ff_h263_decode_frame,
724     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
725     .options = mpeg4_decoptions,
726     .flush= ff_mpeg_flush,
727 };
728
729 AVCodec h263_decoder = {
730     "h263",
731     CODEC_TYPE_VIDEO,
732     CODEC_ID_H263,
733     sizeof(MpegEncContext),
734     ff_h263_decode_init,
735     NULL,
736     ff_h263_decode_end,
737     ff_h263_decode_frame,
738     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
739     .flush= ff_mpeg_flush,
740 };
741
742 AVCodec msmpeg4v1_decoder = {
743     "msmpeg4v1",
744     CODEC_TYPE_VIDEO,
745     CODEC_ID_MSMPEG4V1,
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,
752     mpeg4_decoptions,
753 };
754
755 AVCodec msmpeg4v2_decoder = {
756     "msmpeg4v2",
757     CODEC_TYPE_VIDEO,
758     CODEC_ID_MSMPEG4V2,
759     sizeof(MpegEncContext),
760     ff_h263_decode_init,
761     NULL,
762     ff_h263_decode_end,
763     ff_h263_decode_frame,
764     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
765     mpeg4_decoptions,
766 };
767
768 AVCodec msmpeg4v3_decoder = {
769     "msmpeg4",
770     CODEC_TYPE_VIDEO,
771     CODEC_ID_MSMPEG4V3,
772     sizeof(MpegEncContext),
773     ff_h263_decode_init,
774     NULL,
775     ff_h263_decode_end,
776     ff_h263_decode_frame,
777     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
778     .options = mpeg4_decoptions,
779 };
780
781 AVCodec wmv1_decoder = {
782     "wmv1",
783     CODEC_TYPE_VIDEO,
784     CODEC_ID_WMV1,
785     sizeof(MpegEncContext),
786     ff_h263_decode_init,
787     NULL,
788     ff_h263_decode_end,
789     ff_h263_decode_frame,
790     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
791     mpeg4_decoptions,
792 };
793
794 AVCodec h263i_decoder = {
795     "h263i",
796     CODEC_TYPE_VIDEO,
797     CODEC_ID_H263I,
798     sizeof(MpegEncContext),
799     ff_h263_decode_init,
800     NULL,
801     ff_h263_decode_end,
802     ff_h263_decode_frame,
803     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
804     mpeg4_decoptions,
805 };
806
807 AVCodec flv_decoder = {
808     "flv",
809     CODEC_TYPE_VIDEO,
810     CODEC_ID_FLV1,
811     sizeof(MpegEncContext),
812     ff_h263_decode_init,
813     NULL,
814     ff_h263_decode_end,
815     ff_h263_decode_frame,
816     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1
817 };