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[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  * returns 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            
199             s->mv_dir = MV_DIR_FORWARD;
200             s->mv_type = MV_TYPE_16X16;
201 //            s->mb_skipped = 0;
202 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
203             ret= s->decode_mb(s, s->block);
204
205             if (s->pict_type!=B_TYPE)
206                 ff_h263_update_motion_val(s);
207
208             if(ret<0){
209                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
210                 if(ret==SLICE_END){
211                     MPV_decode_mb(s, s->block);
212                     if(s->loop_filter)
213                         ff_h263_loop_filter(s);
214
215 //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));
216                     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);
217
218                     s->padding_bug_score--;
219                         
220                     if(++s->mb_x >= s->mb_width){
221                         s->mb_x=0;
222                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
223                         s->mb_y++;
224                     }
225                     return 0; 
226                 }else if(ret==SLICE_NOEND){
227                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
228                     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);
229                     return -1;
230                 }
231                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
232                 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);
233     
234                 return -1;
235             }
236
237             MPV_decode_mb(s, s->block);
238             if(s->loop_filter)
239                 ff_h263_loop_filter(s);
240         }
241         
242         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
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 != 1){
263             int v= show_bits(&s->gb, 8);
264             v|= 0x7F >> (7-(bits_count&7));
265
266             if(v==0x7F && bits_left<=8)
267                 s->padding_bug_score--;
268             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
269                 s->padding_bug_score+= 4;
270             else
271                 s->padding_bug_score++;            
272         }                          
273     }
274     
275     if(s->workaround_bugs&FF_BUG_AUTODETECT){
276         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
277             s->workaround_bugs |=  FF_BUG_NO_PADDING;
278         else
279             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
280     }
281
282     // handle formats which don't have unique end markers
283     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
284         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
285         int max_extra=7;
286         
287         /* no markers in M$ crap */
288         if(s->msmpeg4_version && s->pict_type==I_TYPE)
289             max_extra+= 17;
290         
291         /* buggy padding but the frame should still end approximately at the bitstream end */
292         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
293             max_extra+= 48;
294         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
295             max_extra+= 256*256*256*64;
296         
297         if(left>max_extra){
298             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
299         }
300         else if(left<0){
301             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
302         }else
303             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);
304         
305         return 0;
306     }
307
308     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n", 
309             s->gb.size_in_bits - get_bits_count(&s->gb),
310             show_bits(&s->gb, 24), s->padding_bug_score);
311             
312     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);
313
314     return -1;
315 }
316
317 /**
318  * finds the end of the current frame in the bitstream.
319  * @return the position of the first byte of the next frame, or -1
320  */
321 int ff_mpeg4_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
322     int vop_found, i;
323     uint32_t state;
324     
325     vop_found= pc->frame_start_found;
326     state= pc->state;
327     
328     i=0;
329     if(!vop_found){
330         for(i=0; i<buf_size; i++){
331             state= (state<<8) | buf[i];
332             if(state == 0x1B6){
333                 i++;
334                 vop_found=1;
335                 break;
336             }
337         }
338     }
339
340     if(vop_found){
341         /* EOF considered as end of frame */
342         if (buf_size == 0)
343             return 0;
344         for(; i<buf_size; i++){
345             state= (state<<8) | buf[i];
346             if((state&0xFFFFFF00) == 0x100){
347                 pc->frame_start_found=0;
348                 pc->state=-1; 
349                 return i-3;
350             }
351         }
352     }
353     pc->frame_start_found= vop_found;
354     pc->state= state;
355     return END_NOT_FOUND;
356 }
357
358 static int h263_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
359     int vop_found, i;
360     uint32_t state;
361     
362     vop_found= pc->frame_start_found;
363     state= pc->state;
364     
365     i=0;
366     if(!vop_found){
367         for(i=0; i<buf_size; i++){
368             state= (state<<8) | buf[i];
369             if(state>>(32-22) == 0x20){
370                 i++;
371                 vop_found=1;
372                 break;
373             }
374         }
375     }
376
377     if(vop_found){    
378       for(; i<buf_size; i++){
379         state= (state<<8) | buf[i];
380         if(state>>(32-22) == 0x20){
381             pc->frame_start_found=0;
382             pc->state=-1; 
383             return i-3;
384         }
385       }
386     }
387     pc->frame_start_found= vop_found;
388     pc->state= state;
389     
390     return END_NOT_FOUND;
391 }
392
393 static int h263_parse(AVCodecParserContext *s,
394                            AVCodecContext *avctx,
395                            uint8_t **poutbuf, int *poutbuf_size, 
396                            const uint8_t *buf, int buf_size)
397 {
398     ParseContext *pc = s->priv_data;
399     int next;
400     
401     next= h263_find_frame_end(pc, buf, buf_size);
402
403     if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
404         *poutbuf = NULL;
405         *poutbuf_size = 0;
406         return buf_size;
407     }
408
409     *poutbuf = (uint8_t *)buf;
410     *poutbuf_size = buf_size;
411     return next;
412 }
413
414 int ff_h263_decode_frame(AVCodecContext *avctx, 
415                              void *data, int *data_size,
416                              uint8_t *buf, int buf_size)
417 {
418     MpegEncContext *s = avctx->priv_data;
419     int ret;
420     AVFrame *pict = data; 
421     
422 #ifdef PRINT_FRAME_TIME
423 uint64_t time= rdtsc();
424 #endif
425 #ifdef DEBUG
426     printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
427     printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
428 #endif
429     s->flags= avctx->flags;
430     s->flags2= avctx->flags2;
431
432     /* no supplementary picture */
433     if (buf_size == 0) {
434         /* special case for last picture */
435         if (s->low_delay==0 && s->next_picture_ptr) {
436             *pict= *(AVFrame*)s->next_picture_ptr;
437             s->next_picture_ptr= NULL;
438
439             *data_size = sizeof(AVFrame);
440         }
441
442         return 0;
443     }
444
445     if(s->flags&CODEC_FLAG_TRUNCATED){
446         int next;
447         
448         if(s->codec_id==CODEC_ID_MPEG4){
449             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
450         }else if(s->codec_id==CODEC_ID_H263){
451             next= h263_find_frame_end(&s->parse_context, buf, buf_size);
452         }else{
453             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
454             return -1;
455         }
456         
457         if( ff_combine_frame(&s->parse_context, next, &buf, &buf_size) < 0 )
458             return buf_size;
459     }
460
461     
462 retry:
463     
464     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
465         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
466     }else
467         init_get_bits(&s->gb, buf, buf_size*8);
468     s->bitstream_buffer_size=0;
469
470     if (!s->context_initialized) {
471         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
472             return -1;
473     }
474     
475     //we need to set current_picture_ptr before reading the header, otherwise we cant store anyting im there
476     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
477         int i= ff_find_unused_picture(s, 0);
478         s->current_picture_ptr= &s->picture[i];
479     }
480       
481     /* let's go :-) */
482     if (s->msmpeg4_version==5) {
483         ret= ff_wmv2_decode_picture_header(s);
484     } else if (s->msmpeg4_version) {
485         ret = msmpeg4_decode_picture_header(s);
486     } else if (s->h263_pred) {
487         if(s->avctx->extradata_size && s->picture_number==0){
488             GetBitContext gb;
489             
490             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
491             ret = ff_mpeg4_decode_picture_header(s, &gb);
492         }
493         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
494
495         if(s->flags& CODEC_FLAG_LOW_DELAY)
496             s->low_delay=1;
497     } else if (s->codec_id == CODEC_ID_H263I) {
498         ret = intel_h263_decode_picture_header(s);
499     } else if (s->h263_flv) {
500         ret = flv_h263_decode_picture_header(s);
501     } else {
502         ret = h263_decode_picture_header(s);
503     }
504     
505     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
506
507     /* skip if the header was thrashed */
508     if (ret < 0){
509         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
510         return -1;
511     }
512     
513     avctx->has_b_frames= !s->low_delay;
514     
515     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
516         if(s->avctx->stream_codec_tag == ff_get_fourcc("XVID") || 
517            s->avctx->codec_tag == ff_get_fourcc("XVID") || s->avctx->codec_tag == ff_get_fourcc("XVIX"))
518             s->xvid_build= -1;
519 #if 0
520         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
521            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc 
522             s->xvid_build= -1;
523 #endif
524     }
525
526     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
527         if(s->avctx->codec_tag == ff_get_fourcc("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
528             s->divx_version= 400; //divx 4
529     }
530     
531     if(s->xvid_build && s->divx_version){
532         s->divx_version=
533         s->divx_build= 0;
534     }
535
536     if(s->workaround_bugs&FF_BUG_AUTODETECT){
537         if(s->avctx->codec_tag == ff_get_fourcc("XVIX")) 
538             s->workaround_bugs|= FF_BUG_XVID_ILACE;
539
540         if(s->avctx->codec_tag == ff_get_fourcc("UMP4")){
541             s->workaround_bugs|= FF_BUG_UMP4;
542         }
543
544         if(s->divx_version>=500){
545             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
546         }
547
548         if(s->divx_version>502){
549             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
550         }
551
552         if(s->xvid_build && s->xvid_build<=3)
553             s->padding_bug_score= 256*256*256*64;
554         
555         if(s->xvid_build && s->xvid_build<=1)
556             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
557
558         if(s->xvid_build && s->xvid_build<=12)
559             s->workaround_bugs|= FF_BUG_EDGE;
560
561         if(s->xvid_build && s->xvid_build<=32)
562             s->workaround_bugs|= FF_BUG_DC_CLIP;
563
564 #define SET_QPEL_FUNC(postfix1, postfix2) \
565     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
566     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
567     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
568
569         if(s->lavc_build && s->lavc_build<4653)
570             s->workaround_bugs|= FF_BUG_STD_QPEL;
571         
572         if(s->lavc_build && s->lavc_build<4655)
573             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
574
575         if(s->lavc_build && s->lavc_build<4670){
576             s->workaround_bugs|= FF_BUG_EDGE;
577         }
578         
579         if(s->lavc_build && s->lavc_build<=4712)
580             s->workaround_bugs|= FF_BUG_DC_CLIP;
581
582         if(s->divx_version)
583             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
584 //printf("padding_bug_score: %d\n", s->padding_bug_score);
585         if(s->divx_version==501 && s->divx_build==20020416)
586             s->padding_bug_score= 256*256*256*64;
587
588         if(s->divx_version && s->divx_version<500){
589             s->workaround_bugs|= FF_BUG_EDGE;
590         }
591         
592         if(s->divx_version)
593             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
594 #if 0
595         if(s->divx_version==500)
596             s->padding_bug_score= 256*256*256*64;
597
598         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
599          * lets hope this at least works
600          */
601         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
602            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
603             s->workaround_bugs|= FF_BUG_NO_PADDING;
604         
605         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
606             s->workaround_bugs|= FF_BUG_NO_PADDING;
607 #endif
608     }
609     
610     if(s->workaround_bugs& FF_BUG_STD_QPEL){
611         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
612         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
613         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
614         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
615         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
616         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
617
618         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
619         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
620         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
621         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
622         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
623         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
624     }
625
626     if(avctx->debug & FF_DEBUG_BUGS)
627         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n", 
628                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
629                s->divx_packed ? "p" : "");
630     
631 #if 0 // dump bits per frame / qp / complexity
632 {
633     static FILE *f=NULL;
634     if(!f) f=fopen("rate_qp_cplx.txt", "w");
635     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
636 }
637 #endif
638
639 #ifdef HAVE_MMX
640     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)){
641         avctx->idct_algo= FF_IDCT_LIBMPEG2MMX;
642         avctx->coded_width= 0; // force reinit
643     }
644 #endif
645
646         /* After H263 & mpeg4 header decode we have the height, width,*/
647         /* and other parameters. So then we could init the picture   */
648         /* FIXME: By the way H263 decoder is evolving it should have */
649         /* an H263EncContext                                         */
650     
651     if (   s->width  != avctx->coded_width 
652         || s->height != avctx->coded_height) {
653         /* H.263 could change picture size any time */
654         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
655         s->parse_context.buffer=0;
656         MPV_common_end(s);
657         s->parse_context= pc;
658     }
659     if (!s->context_initialized) {
660         avcodec_set_dimensions(avctx, s->width, s->height);
661
662         goto retry;
663     }
664
665     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P))
666         s->gob_index = ff_h263_get_gob_height(s);
667     
668     // for hurry_up==5
669     s->current_picture.pict_type= s->pict_type;
670     s->current_picture.key_frame= s->pict_type == I_TYPE;
671
672     /* skip B-frames if we don't have reference frames */
673     if(s->last_picture_ptr==NULL && (s->pict_type==B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
674     /* skip b frames if we are in a hurry */
675     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
676     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==B_TYPE)
677        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=I_TYPE)
678        ||  avctx->skip_frame >= AVDISCARD_ALL) 
679         return get_consumed_bytes(s, buf_size);
680     /* skip everything if we are in a hurry>=5 */
681     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
682     
683     if(s->next_p_frame_damaged){
684         if(s->pict_type==B_TYPE)
685             return get_consumed_bytes(s, buf_size);
686         else
687             s->next_p_frame_damaged=0;
688     }
689
690     if(MPV_frame_start(s, avctx) < 0)
691         return -1;
692
693 #ifdef DEBUG
694     printf("qscale=%d\n", s->qscale);
695 #endif
696
697     ff_er_frame_start(s);
698     
699     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
700     //which isnt available before MPV_frame_start()
701     if (s->msmpeg4_version==5){
702         if(ff_wmv2_decode_secondary_picture_header(s) < 0)
703             return -1;
704     }
705
706     /* decode each macroblock */
707     s->mb_x=0; 
708     s->mb_y=0;
709     
710     decode_slice(s);
711     while(s->mb_y<s->mb_height){
712         if(s->msmpeg4_version){
713             if(s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
714                 break;
715         }else{
716             if(ff_h263_resync(s)<0)
717                 break;
718         }
719         
720         if(s->msmpeg4_version<4 && s->h263_pred)
721             ff_mpeg4_clean_buffers(s);
722
723         decode_slice(s);
724     }
725
726     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==I_TYPE)
727         if(msmpeg4_decode_ext_header(s, buf_size) < 0){
728             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
729         }
730     
731     /* divx 5.01+ bistream reorder stuff */
732     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
733         int current_pos= get_bits_count(&s->gb)>>3;
734         int startcode_found=0;
735         
736         if(buf_size - current_pos > 5){
737             int i;
738             for(i=current_pos; i<buf_size-3; i++){
739                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
740                     startcode_found=1;
741                     break;
742                 }
743             }
744         }
745         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
746             startcode_found=1;
747             current_pos=0;
748         }
749
750         if(startcode_found){
751             s->bitstream_buffer= av_fast_realloc(
752                 s->bitstream_buffer, 
753                 &s->allocated_bitstream_buffer_size, 
754                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
755             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
756             s->bitstream_buffer_size= buf_size - current_pos;
757         }
758     }
759
760     ff_er_frame_end(s);
761
762     MPV_frame_end(s);
763
764 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
765 assert(s->current_picture.pict_type == s->pict_type);
766     if(s->pict_type==B_TYPE || s->low_delay){
767         *pict= *(AVFrame*)&s->current_picture;
768         ff_print_debug_info(s, pict);
769     } else {
770         *pict= *(AVFrame*)&s->last_picture;
771         if(pict)
772             ff_print_debug_info(s, pict);
773     }
774
775     /* Return the Picture timestamp as the frame number */
776     /* we substract 1 because it is added on utils.c    */
777     avctx->frame_number = s->picture_number - 1;
778
779     /* don't output the last pic after seeking */
780     if(s->last_picture_ptr || s->low_delay)
781         *data_size = sizeof(AVFrame);
782 #ifdef PRINT_FRAME_TIME
783 printf("%Ld\n", rdtsc()-time);
784 #endif
785
786     return get_consumed_bytes(s, buf_size);
787 }
788
789 AVCodec mpeg4_decoder = {
790     "mpeg4",
791     CODEC_TYPE_VIDEO,
792     CODEC_ID_MPEG4,
793     sizeof(MpegEncContext),
794     ff_h263_decode_init,
795     NULL,
796     ff_h263_decode_end,
797     ff_h263_decode_frame,
798     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
799     .flush= ff_mpeg_flush,
800 };
801
802 AVCodec h263_decoder = {
803     "h263",
804     CODEC_TYPE_VIDEO,
805     CODEC_ID_H263,
806     sizeof(MpegEncContext),
807     ff_h263_decode_init,
808     NULL,
809     ff_h263_decode_end,
810     ff_h263_decode_frame,
811     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
812     .flush= ff_mpeg_flush,
813 };
814
815 AVCodec msmpeg4v1_decoder = {
816     "msmpeg4v1",
817     CODEC_TYPE_VIDEO,
818     CODEC_ID_MSMPEG4V1,
819     sizeof(MpegEncContext),
820     ff_h263_decode_init,
821     NULL,
822     ff_h263_decode_end,
823     ff_h263_decode_frame,
824     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
825 };
826
827 AVCodec msmpeg4v2_decoder = {
828     "msmpeg4v2",
829     CODEC_TYPE_VIDEO,
830     CODEC_ID_MSMPEG4V2,
831     sizeof(MpegEncContext),
832     ff_h263_decode_init,
833     NULL,
834     ff_h263_decode_end,
835     ff_h263_decode_frame,
836     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
837 };
838
839 AVCodec msmpeg4v3_decoder = {
840     "msmpeg4",
841     CODEC_TYPE_VIDEO,
842     CODEC_ID_MSMPEG4V3,
843     sizeof(MpegEncContext),
844     ff_h263_decode_init,
845     NULL,
846     ff_h263_decode_end,
847     ff_h263_decode_frame,
848     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
849 };
850
851 AVCodec wmv1_decoder = {
852     "wmv1",
853     CODEC_TYPE_VIDEO,
854     CODEC_ID_WMV1,
855     sizeof(MpegEncContext),
856     ff_h263_decode_init,
857     NULL,
858     ff_h263_decode_end,
859     ff_h263_decode_frame,
860     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
861 };
862
863 AVCodec h263i_decoder = {
864     "h263i",
865     CODEC_TYPE_VIDEO,
866     CODEC_ID_H263I,
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 AVCodec flv_decoder = {
876     "flv",
877     CODEC_TYPE_VIDEO,
878     CODEC_ID_FLV1,
879     sizeof(MpegEncContext),
880     ff_h263_decode_init,
881     NULL,
882     ff_h263_decode_end,
883     ff_h263_decode_frame,
884     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1
885 };
886
887 AVCodecParser h263_parser = {
888     { CODEC_ID_H263 },
889     sizeof(ParseContext),
890     NULL,
891     h263_parse,
892     ff_parse_close,
893 };