]> rtime.felk.cvut.cz Git - frescor/ffmpeg.git/blob - libavcodec/h263dec.c
support decoding mpeg4 with buggy dc clipping
[frescor/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->width;
41     s->height = avctx->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_H263I:
89         break;
90     case CODEC_ID_FLV1:
91         s->h263_flv = 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_packed){
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     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
142     s->last_resync_gb= s->gb;
143     s->first_slice_line= 1;
144         
145     s->resync_mb_x= s->mb_x;
146     s->resync_mb_y= s->mb_y;
147
148     ff_set_qscale(s, 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 were modified */
159         s->first_slice_line=1;
160         s->mb_x= s->resync_mb_x;
161         s->mb_y= s->resync_mb_y;
162         ff_set_qscale(s, qscale);
163     }
164
165     for(; s->mb_y < s->mb_height; s->mb_y++) {
166         /* per-row end of slice checks */
167         if(s->msmpeg4_version){
168             if(s->resync_mb_y + s->slice_height == s->mb_y){
169                 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);
170
171                 return 0;
172             }
173         }
174         
175         if(s->msmpeg4_version==1){
176             s->last_dc[0]=
177             s->last_dc[1]=
178             s->last_dc[2]= 128;
179         }
180     
181         ff_init_block_index(s);
182         for(; s->mb_x < s->mb_width; s->mb_x++) {
183             int ret;
184
185             ff_update_block_index(s);
186
187             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
188                 s->first_slice_line=0; 
189             }
190
191             /* DCT & quantize */
192             s->dsp.clear_blocks(s->block[0]);
193             
194             s->mv_dir = MV_DIR_FORWARD;
195             s->mv_type = MV_TYPE_16X16;
196 //            s->mb_skiped = 0;
197 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
198             ret= s->decode_mb(s, s->block);
199
200             if (s->pict_type!=B_TYPE)
201                 ff_h263_update_motion_val(s);
202
203             if(ret<0){
204                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
205                 if(ret==SLICE_END){
206                     MPV_decode_mb(s, s->block);
207                     if(s->loop_filter)
208                         ff_h263_loop_filter(s);
209
210 //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));
211                     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);
212
213                     s->padding_bug_score--;
214                         
215                     if(++s->mb_x >= s->mb_width){
216                         s->mb_x=0;
217                         ff_draw_horiz_band(s, s->mb_y*16, 16);
218                         s->mb_y++;
219                     }
220                     return 0; 
221                 }else if(ret==SLICE_NOEND){
222                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
223                     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);
224                     return -1;
225                 }
226                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
227                 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);
228     
229                 return -1;
230             }
231
232             MPV_decode_mb(s, s->block);
233             if(s->loop_filter)
234                 ff_h263_loop_filter(s);
235         }
236         
237         ff_draw_horiz_band(s, s->mb_y*16, 16);
238         
239         s->mb_x= 0;
240     }
241     
242     assert(s->mb_x==0 && s->mb_y==s->mb_height);
243
244     /* try to detect the padding bug */
245     if(      s->codec_id==CODEC_ID_MPEG4
246        &&   (s->workaround_bugs&FF_BUG_AUTODETECT) 
247        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
248        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
249 //       &&   !s->resync_marker
250        &&   !s->data_partitioning){
251         
252         const int bits_count= get_bits_count(&s->gb);
253         const int bits_left = s->gb.size_in_bits - bits_count;
254         
255         if(bits_left==0){
256             s->padding_bug_score+=16;
257         }else if(bits_left>8){
258             s->padding_bug_score++;
259         } else if(bits_left != 1){
260             int v= show_bits(&s->gb, 8);
261             v|= 0x7F >> (7-(bits_count&7));
262
263             if(v==0x7F)
264                 s->padding_bug_score--;
265             else
266                 s->padding_bug_score++;            
267         }                          
268     }
269
270     // handle formats which dont have unique end markers
271     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
272         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
273         int max_extra=7;
274         
275         /* no markers in M$ crap */
276         if(s->msmpeg4_version && s->pict_type==I_TYPE)
277             max_extra+= 17;
278         
279         /* buggy padding but the frame should still end approximately at the bitstream end */
280         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
281             max_extra+= 48;
282         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
283             max_extra+= 256*256*256*64;
284         
285         if(left>max_extra){
286             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
287         }
288         else if(left<0){
289             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
290         }else
291             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);
292         
293         return 0;
294     }
295
296     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n", 
297             s->gb.size_in_bits - get_bits_count(&s->gb),
298             show_bits(&s->gb, 24), s->padding_bug_score);
299             
300     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);
301
302     return -1;
303 }
304
305 /**
306  * finds the end of the current frame in the bitstream.
307  * @return the position of the first byte of the next frame, or -1
308  */
309 int ff_mpeg4_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
310     int vop_found, i;
311     uint32_t state;
312     
313     vop_found= pc->frame_start_found;
314     state= pc->state;
315     
316     i=0;
317     if(!vop_found){
318         for(i=0; i<buf_size; i++){
319             state= (state<<8) | buf[i];
320             if(state == 0x1B6){
321                 i++;
322                 vop_found=1;
323                 break;
324             }
325         }
326     }
327
328     if(vop_found){
329         /* EOF considered as end of frame */
330         if (buf_size == 0)
331             return 0;
332         for(; i<buf_size; i++){
333             state= (state<<8) | buf[i];
334             if((state&0xFFFFFF00) == 0x100){
335                 pc->frame_start_found=0;
336                 pc->state=-1; 
337                 return i-3;
338             }
339         }
340     }
341     pc->frame_start_found= vop_found;
342     pc->state= state;
343     return END_NOT_FOUND;
344 }
345
346 static int h263_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
347     int vop_found, i;
348     uint32_t state;
349     
350     vop_found= pc->frame_start_found;
351     state= pc->state;
352     
353     i=0;
354     if(!vop_found){
355         for(i=0; i<buf_size; i++){
356             state= (state<<8) | buf[i];
357             if(state>>(32-22) == 0x20){
358                 i++;
359                 vop_found=1;
360                 break;
361             }
362         }
363     }
364
365     if(vop_found){    
366       for(; i<buf_size; i++){
367         state= (state<<8) | buf[i];
368         if(state>>(32-22) == 0x20){
369             pc->frame_start_found=0;
370             pc->state=-1; 
371             return i-3;
372         }
373       }
374     }
375     pc->frame_start_found= vop_found;
376     pc->state= state;
377     
378     return END_NOT_FOUND;
379 }
380
381 static int h263_parse(AVCodecParserContext *s,
382                            AVCodecContext *avctx,
383                            uint8_t **poutbuf, int *poutbuf_size, 
384                            const uint8_t *buf, int buf_size)
385 {
386     ParseContext *pc = s->priv_data;
387     int next;
388     
389     next= h263_find_frame_end(pc, buf, buf_size);
390
391     if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
392         *poutbuf = NULL;
393         *poutbuf_size = 0;
394         return buf_size;
395     }
396
397     *poutbuf = (uint8_t *)buf;
398     *poutbuf_size = buf_size;
399     return next;
400 }
401
402 int ff_h263_decode_frame(AVCodecContext *avctx, 
403                              void *data, int *data_size,
404                              uint8_t *buf, int buf_size)
405 {
406     MpegEncContext *s = avctx->priv_data;
407     int ret;
408     AVFrame *pict = data; 
409     
410 #ifdef PRINT_FRAME_TIME
411 uint64_t time= rdtsc();
412 #endif
413 #ifdef DEBUG
414     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
415     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
416 #endif
417     s->flags= avctx->flags;
418     s->flags2= avctx->flags2;
419
420     *data_size = 0;
421
422     /* no supplementary picture */
423     if (buf_size == 0) {
424         /* special case for last picture */
425         if (s->low_delay==0 && s->next_picture_ptr) {
426             *pict= *(AVFrame*)s->next_picture_ptr;
427             s->next_picture_ptr= NULL;
428
429             *data_size = sizeof(AVFrame);
430         }
431
432         return 0;
433     }
434
435     if(s->flags&CODEC_FLAG_TRUNCATED){
436         int next;
437         
438         if(s->codec_id==CODEC_ID_MPEG4){
439             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
440         }else if(s->codec_id==CODEC_ID_H263){
441             next= h263_find_frame_end(&s->parse_context, buf, buf_size);
442         }else{
443             av_log(s->avctx, AV_LOG_ERROR, "this codec doesnt support truncated bitstreams\n");
444             return -1;
445         }
446         
447         if( ff_combine_frame(&s->parse_context, next, &buf, &buf_size) < 0 )
448             return buf_size;
449     }
450
451     
452 retry:
453     
454     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
455         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
456     }else
457         init_get_bits(&s->gb, buf, buf_size*8);
458     s->bitstream_buffer_size=0;
459
460     if (!s->context_initialized) {
461         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
462             return -1;
463     }
464     
465     //we need to set current_picture_ptr before reading the header, otherwise we cant store anyting im there
466     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
467         int i= ff_find_unused_picture(s, 0);
468         s->current_picture_ptr= &s->picture[i];
469     }
470       
471     /* let's go :-) */
472     if (s->msmpeg4_version==5) {
473         ret= ff_wmv2_decode_picture_header(s);
474     } else if (s->msmpeg4_version) {
475         ret = msmpeg4_decode_picture_header(s);
476     } else if (s->h263_pred) {
477         if(s->avctx->extradata_size && s->picture_number==0){
478             GetBitContext gb;
479             
480             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
481             ret = ff_mpeg4_decode_picture_header(s, &gb);
482         }
483         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
484
485         if(s->flags& CODEC_FLAG_LOW_DELAY)
486             s->low_delay=1;
487     } else if (s->codec_id == CODEC_ID_H263I) {
488         ret = intel_h263_decode_picture_header(s);
489     } else if (s->h263_flv) {
490         ret = flv_h263_decode_picture_header(s);
491     } else {
492         ret = h263_decode_picture_header(s);
493     }
494     
495     if(ret==FRAME_SKIPED) return get_consumed_bytes(s, buf_size);
496
497     /* skip if the header was thrashed */
498     if (ret < 0){
499         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
500         return -1;
501     }
502     
503     avctx->has_b_frames= !s->low_delay;
504     
505     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
506         if(s->avctx->stream_codec_tag == ff_get_fourcc("XVID") || 
507            s->avctx->codec_tag == ff_get_fourcc("XVID") || s->avctx->codec_tag == ff_get_fourcc("XVIX"))
508             s->xvid_build= -1;
509 #if 0
510         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
511            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc 
512             s->xvid_build= -1;
513 #endif
514     }
515
516     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
517         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
518             s->divx_version= 400; //divx 4
519     }
520
521     if(s->workaround_bugs&FF_BUG_AUTODETECT){
522         s->workaround_bugs &= ~FF_BUG_NO_PADDING;
523         
524         if(s->padding_bug_score > -2 && !s->data_partitioning && (s->divx_version || !s->resync_marker))
525             s->workaround_bugs |=  FF_BUG_NO_PADDING;
526
527         if(s->avctx->codec_tag == ff_get_fourcc("XVIX")) 
528             s->workaround_bugs|= FF_BUG_XVID_ILACE;
529
530         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
531             s->workaround_bugs|= FF_BUG_UMP4;
532         }
533
534         if(s->divx_version>=500){
535             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
536         }
537
538         if(s->divx_version>502){
539             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
540         }
541
542         if(s->xvid_build && s->xvid_build<=3)
543             s->padding_bug_score= 256*256*256*64;
544         
545         if(s->xvid_build && s->xvid_build<=1)
546             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
547
548         if(s->xvid_build && s->xvid_build<=12)
549             s->workaround_bugs|= FF_BUG_EDGE;
550
551         if(s->xvid_build && s->xvid_build<=32)
552             s->workaround_bugs|= FF_BUG_DC_CLIP;
553
554 #define SET_QPEL_FUNC(postfix1, postfix2) \
555     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
556     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
557     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
558
559         if(s->lavc_build && s->lavc_build<4653)
560             s->workaround_bugs|= FF_BUG_STD_QPEL;
561         
562         if(s->lavc_build && s->lavc_build<4655)
563             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
564
565         if(s->lavc_build && s->lavc_build<4670){
566             s->workaround_bugs|= FF_BUG_EDGE;
567         }
568         
569         if(s->lavc_build && s->lavc_build<=4712)
570             s->workaround_bugs|= FF_BUG_DC_CLIP;
571
572         if(s->divx_version)
573             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
574 //printf("padding_bug_score: %d\n", s->padding_bug_score);
575         if(s->divx_version==501 && s->divx_build==20020416)
576             s->padding_bug_score= 256*256*256*64;
577
578         if(s->divx_version && s->divx_version<500){
579             s->workaround_bugs|= FF_BUG_EDGE;
580         }
581         
582         if(s->divx_version)
583             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
584 #if 0
585         if(s->divx_version==500)
586             s->padding_bug_score= 256*256*256*64;
587
588         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
589          * lets hope this at least works
590          */
591         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
592            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
593             s->workaround_bugs|= FF_BUG_NO_PADDING;
594         
595         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
596             s->workaround_bugs|= FF_BUG_NO_PADDING;
597 #endif
598     }
599     
600     if(s->workaround_bugs& FF_BUG_STD_QPEL){
601         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
602         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
603         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
604         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
605         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
606         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
607
608         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
609         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
610         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
611         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
612         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
613         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
614     }
615
616     if(avctx->debug & FF_DEBUG_BUGS)
617         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n", 
618                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
619                s->divx_packed ? "p" : "");
620     
621 #if 0 // dump bits per frame / qp / complexity
622 {
623     static FILE *f=NULL;
624     if(!f) f=fopen("rate_qp_cplx.txt", "w");
625     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
626 }
627 #endif
628        
629         /* After H263 & mpeg4 header decode we have the height, width,*/
630         /* and other parameters. So then we could init the picture   */
631         /* FIXME: By the way H263 decoder is evolving it should have */
632         /* an H263EncContext                                         */
633     
634     if (   s->width != avctx->width || s->height != avctx->height) {
635         /* H.263 could change picture size any time */
636         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
637         s->parse_context.buffer=0;
638         MPV_common_end(s);
639         s->parse_context= pc;
640     }
641     if (!s->context_initialized) {
642         avctx->width = s->width;
643         avctx->height = s->height;
644
645         goto retry;
646     }
647
648     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
649         s->gob_index = ff_h263_get_gob_height(s);
650     
651     // for hurry_up==5
652     s->current_picture.pict_type= s->pict_type;
653     s->current_picture.key_frame= s->pict_type == I_TYPE;
654
655     /* skip b frames if we dont have reference frames */
656     if(s->last_picture_ptr==NULL && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
657     /* skip b frames if we are in a hurry */
658     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
659     /* skip everything if we are in a hurry>=5 */
660     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
661     
662     if(s->next_p_frame_damaged){
663         if(s->pict_type==B_TYPE)
664             return get_consumed_bytes(s, buf_size);
665         else
666             s->next_p_frame_damaged=0;
667     }
668
669     if(MPV_frame_start(s, avctx) < 0)
670         return -1;
671
672 #ifdef DEBUG
673     printf("qscale=%d\n", s->qscale);
674 #endif
675
676     ff_er_frame_start(s);
677     
678     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
679     //which isnt available before MPV_frame_start()
680     if (s->msmpeg4_version==5){
681         if(ff_wmv2_decode_secondary_picture_header(s) < 0)
682             return -1;
683     }
684
685     /* decode each macroblock */
686     s->mb_x=0; 
687     s->mb_y=0;
688     
689     decode_slice(s);
690     while(s->mb_y<s->mb_height){
691         if(s->msmpeg4_version){
692             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
693                 break;
694         }else{
695             if(ff_h263_resync(s)<0)
696                 break;
697         }
698         
699         if(s->msmpeg4_version<4 && s->h263_pred)
700             ff_mpeg4_clean_buffers(s);
701
702         decode_slice(s);
703     }
704
705     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
706         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
707             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
708         }
709     
710     /* divx 5.01+ bistream reorder stuff */
711     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
712         int current_pos= get_bits_count(&s->gb)>>3;
713         int startcode_found=0;
714
715         if(   buf_size - current_pos > 5 
716            && buf_size - current_pos < BITSTREAM_BUFFER_SIZE){
717             int i;
718             for(i=current_pos; i<buf_size-3; i++){
719                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
720                     startcode_found=1;
721                     break;
722                 }
723             }
724         }
725         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
726             startcode_found=1;
727             current_pos=0;
728         }
729
730         if(startcode_found){
731             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
732             s->bitstream_buffer_size= buf_size - current_pos;
733         }
734     }
735
736     ff_er_frame_end(s);
737
738     MPV_frame_end(s);
739
740 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
741 assert(s->current_picture.pict_type == s->pict_type);
742     if(s->pict_type==B_TYPE || s->low_delay){
743         *pict= *(AVFrame*)&s->current_picture;
744         ff_print_debug_info(s, pict);
745     } else {
746         *pict= *(AVFrame*)&s->last_picture;
747         if(pict)
748             ff_print_debug_info(s, pict);
749     }
750
751     /* Return the Picture timestamp as the frame number */
752     /* we substract 1 because it is added on utils.c    */
753     avctx->frame_number = s->picture_number - 1;
754
755     /* dont output the last pic after seeking */
756     if(s->last_picture_ptr || s->low_delay)
757         *data_size = sizeof(AVFrame);
758 #ifdef PRINT_FRAME_TIME
759 printf("%Ld\n", rdtsc()-time);
760 #endif
761
762     return get_consumed_bytes(s, buf_size);
763 }
764
765 static const AVOption mpeg4_decoptions[] =
766 {
767     AVOPTION_SUB(avoptions_workaround_bug),
768     AVOPTION_END()
769 };
770
771 AVCodec mpeg4_decoder = {
772     "mpeg4",
773     CODEC_TYPE_VIDEO,
774     CODEC_ID_MPEG4,
775     sizeof(MpegEncContext),
776     ff_h263_decode_init,
777     NULL,
778     ff_h263_decode_end,
779     ff_h263_decode_frame,
780     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
781     .options = mpeg4_decoptions,
782     .flush= ff_mpeg_flush,
783 };
784
785 AVCodec h263_decoder = {
786     "h263",
787     CODEC_TYPE_VIDEO,
788     CODEC_ID_H263,
789     sizeof(MpegEncContext),
790     ff_h263_decode_init,
791     NULL,
792     ff_h263_decode_end,
793     ff_h263_decode_frame,
794     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
795     .flush= ff_mpeg_flush,
796 };
797
798 AVCodec msmpeg4v1_decoder = {
799     "msmpeg4v1",
800     CODEC_TYPE_VIDEO,
801     CODEC_ID_MSMPEG4V1,
802     sizeof(MpegEncContext),
803     ff_h263_decode_init,
804     NULL,
805     ff_h263_decode_end,
806     ff_h263_decode_frame,
807     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
808     mpeg4_decoptions,
809 };
810
811 AVCodec msmpeg4v2_decoder = {
812     "msmpeg4v2",
813     CODEC_TYPE_VIDEO,
814     CODEC_ID_MSMPEG4V2,
815     sizeof(MpegEncContext),
816     ff_h263_decode_init,
817     NULL,
818     ff_h263_decode_end,
819     ff_h263_decode_frame,
820     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
821     mpeg4_decoptions,
822 };
823
824 AVCodec msmpeg4v3_decoder = {
825     "msmpeg4",
826     CODEC_TYPE_VIDEO,
827     CODEC_ID_MSMPEG4V3,
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     .options = mpeg4_decoptions,
835 };
836
837 AVCodec wmv1_decoder = {
838     "wmv1",
839     CODEC_TYPE_VIDEO,
840     CODEC_ID_WMV1,
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     mpeg4_decoptions,
848 };
849
850 AVCodec h263i_decoder = {
851     "h263i",
852     CODEC_TYPE_VIDEO,
853     CODEC_ID_H263I,
854     sizeof(MpegEncContext),
855     ff_h263_decode_init,
856     NULL,
857     ff_h263_decode_end,
858     ff_h263_decode_frame,
859     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
860     mpeg4_decoptions,
861 };
862
863 AVCodec flv_decoder = {
864     "flv",
865     CODEC_TYPE_VIDEO,
866     CODEC_ID_FLV1,
867     sizeof(MpegEncContext),
868     ff_h263_decode_init,
869     NULL,
870     ff_h263_decode_end,
871     ff_h263_decode_frame,
872     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1
873 };
874
875 AVCodecParser h263_parser = {
876     { CODEC_ID_H263 },
877     sizeof(ParseContext),
878     NULL,
879     h263_parse,
880     ff_parse_close,
881 };