Update to MPlayer SVN rev 29473 and FFmpeg SVN rev 19572.
[vaapi:athaifas-mplayer.git] / libavcodec / .svn / text-base / h263dec.c.svn-base
1 /*
2  * H.263 decoder
3  * Copyright (c) 2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 /**
24  * @file libavcodec/h263dec.c
25  * H.263 decoder.
26  */
27
28 #include "internal.h"
29 #include "avcodec.h"
30 #include "dsputil.h"
31 #include "mpegvideo.h"
32 #include "h263_parser.h"
33 #include "mpeg4video_parser.h"
34 #include "msmpeg4.h"
35
36 //#define DEBUG
37 //#define PRINT_FRAME_TIME
38
39 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
40 {
41     MpegEncContext *s = avctx->priv_data;
42
43     s->avctx = avctx;
44     s->out_format = FMT_H263;
45
46     s->width  = avctx->coded_width;
47     s->height = avctx->coded_height;
48     s->workaround_bugs= avctx->workaround_bugs;
49
50     // set defaults
51     MPV_decode_defaults(s);
52     s->quant_precision=5;
53     s->decode_mb= ff_h263_decode_mb;
54     s->low_delay= 1;
55     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
56     s->unrestricted_mv= 1;
57
58     /* select sub codec */
59     switch(avctx->codec->id) {
60     case CODEC_ID_H263:
61         s->unrestricted_mv= 0;
62         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
63         break;
64     case CODEC_ID_MPEG4:
65         s->decode_mb= ff_mpeg4_decode_mb;
66         s->time_increment_bits = 4; /* default value for broken headers */
67         s->h263_pred = 1;
68         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
69         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
70         break;
71     case CODEC_ID_MSMPEG4V1:
72         s->h263_msmpeg4 = 1;
73         s->h263_pred = 1;
74         s->msmpeg4_version=1;
75         break;
76     case CODEC_ID_MSMPEG4V2:
77         s->h263_msmpeg4 = 1;
78         s->h263_pred = 1;
79         s->msmpeg4_version=2;
80         break;
81     case CODEC_ID_MSMPEG4V3:
82         s->h263_msmpeg4 = 1;
83         s->h263_pred = 1;
84         s->msmpeg4_version=3;
85         break;
86     case CODEC_ID_WMV1:
87         s->h263_msmpeg4 = 1;
88         s->h263_pred = 1;
89         s->msmpeg4_version=4;
90         break;
91     case CODEC_ID_WMV2:
92         s->h263_msmpeg4 = 1;
93         s->h263_pred = 1;
94         s->msmpeg4_version=5;
95         break;
96     case CODEC_ID_VC1:
97     case CODEC_ID_WMV3:
98         s->h263_msmpeg4 = 1;
99         s->h263_pred = 1;
100         s->msmpeg4_version=6;
101         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
102         break;
103     case CODEC_ID_H263I:
104         break;
105     case CODEC_ID_FLV1:
106         s->h263_flv = 1;
107         break;
108     default:
109         return -1;
110     }
111     s->codec_id= avctx->codec->id;
112     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
113
114     /* for h263, we allocate the images after having read the header */
115     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
116         if (MPV_common_init(s) < 0)
117             return -1;
118
119     if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
120         ff_msmpeg4_decode_init(s);
121     else
122         h263_decode_init_vlc(s);
123
124     return 0;
125 }
126
127 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
128 {
129     MpegEncContext *s = avctx->priv_data;
130
131     MPV_common_end(s);
132     return 0;
133 }
134
135 /**
136  * returns the number of bytes consumed for building the current frame
137  */
138 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
139     int pos= (get_bits_count(&s->gb)+7)>>3;
140
141     if(s->divx_packed || s->avctx->hwaccel){
142         //we would have to scan through the whole buf to handle the weird reordering ...
143         return buf_size;
144     }else if(s->flags&CODEC_FLAG_TRUNCATED){
145         pos -= s->parse_context.last_index;
146         if(pos<0) pos=0; // padding is not really read so this might be -1
147         return pos;
148     }else{
149         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
150         if(pos+10>buf_size) pos=buf_size; // oops ;)
151
152         return pos;
153     }
154 }
155
156 static int decode_slice(MpegEncContext *s){
157     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
158     const int mb_size= 16>>s->avctx->lowres;
159     s->last_resync_gb= s->gb;
160     s->first_slice_line= 1;
161
162     s->resync_mb_x= s->mb_x;
163     s->resync_mb_y= s->mb_y;
164
165     ff_set_qscale(s, s->qscale);
166
167     if (s->avctx->hwaccel) {
168         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
169         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
170         skip_bits_long(&s->gb, 8*(end - start));
171         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
172     }
173
174     if(s->partitioned_frame){
175         const int qscale= s->qscale;
176
177         if(s->codec_id==CODEC_ID_MPEG4){
178             if(ff_mpeg4_decode_partitions(s) < 0)
179                 return -1;
180         }
181
182         /* restore variables which were modified */
183         s->first_slice_line=1;
184         s->mb_x= s->resync_mb_x;
185         s->mb_y= s->resync_mb_y;
186         ff_set_qscale(s, qscale);
187     }
188
189     for(; s->mb_y < s->mb_height; s->mb_y++) {
190         /* per-row end of slice checks */
191         if(s->msmpeg4_version){
192             if(s->resync_mb_y + s->slice_height == s->mb_y){
193                 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);
194
195                 return 0;
196             }
197         }
198
199         if(s->msmpeg4_version==1){
200             s->last_dc[0]=
201             s->last_dc[1]=
202             s->last_dc[2]= 128;
203         }
204
205         ff_init_block_index(s);
206         for(; s->mb_x < s->mb_width; s->mb_x++) {
207             int ret;
208
209             ff_update_block_index(s);
210
211             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
212                 s->first_slice_line=0;
213             }
214
215             /* DCT & quantize */
216
217             s->mv_dir = MV_DIR_FORWARD;
218             s->mv_type = MV_TYPE_16X16;
219 //            s->mb_skipped = 0;
220 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
221             ret= s->decode_mb(s, s->block);
222
223             if (s->pict_type!=FF_B_TYPE)
224                 ff_h263_update_motion_val(s);
225
226             if(ret<0){
227                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
228                 if(ret==SLICE_END){
229                     MPV_decode_mb(s, s->block);
230                     if(s->loop_filter)
231                         ff_h263_loop_filter(s);
232
233 //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));
234                     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);
235
236                     s->padding_bug_score--;
237
238                     if(++s->mb_x >= s->mb_width){
239                         s->mb_x=0;
240                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
241                         s->mb_y++;
242                     }
243                     return 0;
244                 }else if(ret==SLICE_NOEND){
245                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
246                     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);
247                     return -1;
248                 }
249                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
250                 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);
251
252                 return -1;
253             }
254
255             MPV_decode_mb(s, s->block);
256             if(s->loop_filter)
257                 ff_h263_loop_filter(s);
258         }
259
260         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
261
262         s->mb_x= 0;
263     }
264
265     assert(s->mb_x==0 && s->mb_y==s->mb_height);
266
267     /* try to detect the padding bug */
268     if(      s->codec_id==CODEC_ID_MPEG4
269        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
270        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
271        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
272 //       &&   !s->resync_marker
273        &&   !s->data_partitioning){
274
275         const int bits_count= get_bits_count(&s->gb);
276         const int bits_left = s->gb.size_in_bits - bits_count;
277
278         if(bits_left==0){
279             s->padding_bug_score+=16;
280         } else if(bits_left != 1){
281             int v= show_bits(&s->gb, 8);
282             v|= 0x7F >> (7-(bits_count&7));
283
284             if(v==0x7F && bits_left<=8)
285                 s->padding_bug_score--;
286             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
287                 s->padding_bug_score+= 4;
288             else
289                 s->padding_bug_score++;
290         }
291     }
292
293     if(s->workaround_bugs&FF_BUG_AUTODETECT){
294         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
295             s->workaround_bugs |=  FF_BUG_NO_PADDING;
296         else
297             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
298     }
299
300     // handle formats which don't have unique end markers
301     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
302         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
303         int max_extra=7;
304
305         /* no markers in M$ crap */
306         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
307             max_extra+= 17;
308
309         /* buggy padding but the frame should still end approximately at the bitstream end */
310         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
311             max_extra+= 48;
312         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
313             max_extra+= 256*256*256*64;
314
315         if(left>max_extra){
316             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
317         }
318         else if(left<0){
319             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
320         }else
321             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);
322
323         return 0;
324     }
325
326     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
327             s->gb.size_in_bits - get_bits_count(&s->gb),
328             show_bits(&s->gb, 24), s->padding_bug_score);
329
330     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);
331
332     return -1;
333 }
334
335 int ff_h263_decode_frame(AVCodecContext *avctx,
336                              void *data, int *data_size,
337                              AVPacket *avpkt)
338 {
339     const uint8_t *buf = avpkt->data;
340     int buf_size = avpkt->size;
341     MpegEncContext *s = avctx->priv_data;
342     int ret;
343     AVFrame *pict = data;
344
345 #ifdef PRINT_FRAME_TIME
346 uint64_t time= rdtsc();
347 #endif
348     s->flags= avctx->flags;
349     s->flags2= avctx->flags2;
350
351     /* no supplementary picture */
352     if (buf_size == 0) {
353         /* special case for last picture */
354         if (s->low_delay==0 && s->next_picture_ptr) {
355             *pict= *(AVFrame*)s->next_picture_ptr;
356             s->next_picture_ptr= NULL;
357
358             *data_size = sizeof(AVFrame);
359         }
360
361         return 0;
362     }
363
364     if(s->flags&CODEC_FLAG_TRUNCATED){
365         int next;
366
367         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
368             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
369         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
370             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
371         }else{
372             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
373             return -1;
374         }
375
376         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
377             return buf_size;
378     }
379
380
381 retry:
382
383     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
384         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
385     }else
386         init_get_bits(&s->gb, buf, buf_size*8);
387     s->bitstream_buffer_size=0;
388
389     if (!s->context_initialized) {
390         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
391             return -1;
392     }
393
394     /* We need to set current_picture_ptr before reading the header,
395      * otherwise we cannot store anyting in there */
396     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
397         int i= ff_find_unused_picture(s, 0);
398         s->current_picture_ptr= &s->picture[i];
399     }
400
401     /* let's go :-) */
402     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
403         ret= ff_wmv2_decode_picture_header(s);
404     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
405         ret = msmpeg4_decode_picture_header(s);
406     } else if (s->h263_pred) {
407         if(s->avctx->extradata_size && s->picture_number==0){
408             GetBitContext gb;
409
410             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
411             ret = ff_mpeg4_decode_picture_header(s, &gb);
412         }
413         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
414     } else if (s->codec_id == CODEC_ID_H263I) {
415         ret = intel_h263_decode_picture_header(s);
416     } else if (s->h263_flv) {
417         ret = flv_h263_decode_picture_header(s);
418     } else {
419         ret = h263_decode_picture_header(s);
420     }
421
422     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
423
424     /* skip if the header was thrashed */
425     if (ret < 0){
426         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
427         return -1;
428     }
429
430     avctx->has_b_frames= !s->low_delay;
431
432     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
433         if(s->stream_codec_tag == AV_RL32("XVID") ||
434            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
435            s->codec_tag == AV_RL32("RMP4"))
436             s->xvid_build= -1;
437 #if 0
438         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
439            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
440             s->xvid_build= -1;
441 #endif
442     }
443
444     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
445         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
446             s->divx_version= 400; //divx 4
447     }
448
449     if(s->xvid_build && s->divx_version){
450         s->divx_version=
451         s->divx_build= 0;
452     }
453
454     if(s->workaround_bugs&FF_BUG_AUTODETECT){
455         if(s->codec_tag == AV_RL32("XVIX"))
456             s->workaround_bugs|= FF_BUG_XVID_ILACE;
457
458         if(s->codec_tag == AV_RL32("UMP4")){
459             s->workaround_bugs|= FF_BUG_UMP4;
460         }
461
462         if(s->divx_version>=500 && s->divx_build<1814){
463             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
464         }
465
466         if(s->divx_version>502 && s->divx_build<1814){
467             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
468         }
469
470         if(s->xvid_build && s->xvid_build<=3)
471             s->padding_bug_score= 256*256*256*64;
472
473         if(s->xvid_build && s->xvid_build<=1)
474             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
475
476         if(s->xvid_build && s->xvid_build<=12)
477             s->workaround_bugs|= FF_BUG_EDGE;
478
479         if(s->xvid_build && s->xvid_build<=32)
480             s->workaround_bugs|= FF_BUG_DC_CLIP;
481
482 #define SET_QPEL_FUNC(postfix1, postfix2) \
483     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
484     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
485     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
486
487         if(s->lavc_build && s->lavc_build<4653)
488             s->workaround_bugs|= FF_BUG_STD_QPEL;
489
490         if(s->lavc_build && s->lavc_build<4655)
491             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
492
493         if(s->lavc_build && s->lavc_build<4670){
494             s->workaround_bugs|= FF_BUG_EDGE;
495         }
496
497         if(s->lavc_build && s->lavc_build<=4712)
498             s->workaround_bugs|= FF_BUG_DC_CLIP;
499
500         if(s->divx_version)
501             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
502 //printf("padding_bug_score: %d\n", s->padding_bug_score);
503         if(s->divx_version==501 && s->divx_build==20020416)
504             s->padding_bug_score= 256*256*256*64;
505
506         if(s->divx_version && s->divx_version<500){
507             s->workaround_bugs|= FF_BUG_EDGE;
508         }
509
510         if(s->divx_version)
511             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
512 #if 0
513         if(s->divx_version==500)
514             s->padding_bug_score= 256*256*256*64;
515
516         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
517          * Let us hope this at least works.
518          */
519         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
520            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
521             s->workaround_bugs|= FF_BUG_NO_PADDING;
522
523         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
524             s->workaround_bugs|= FF_BUG_NO_PADDING;
525 #endif
526     }
527
528     if(s->workaround_bugs& FF_BUG_STD_QPEL){
529         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
530         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
531         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
532         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
533         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
534         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
535
536         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
537         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
538         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
539         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
540         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
541         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
542     }
543
544     if(avctx->debug & FF_DEBUG_BUGS)
545         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
546                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
547                s->divx_packed ? "p" : "");
548
549 #if 0 // dump bits per frame / qp / complexity
550 {
551     static FILE *f=NULL;
552     if(!f) f=fopen("rate_qp_cplx.txt", "w");
553     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
554 }
555 #endif
556
557 #if HAVE_MMX
558     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
559         avctx->idct_algo= FF_IDCT_XVIDMMX;
560         avctx->coded_width= 0; // force reinit
561 //        dsputil_init(&s->dsp, avctx);
562         s->picture_number=0;
563     }
564 #endif
565
566         /* After H263 & mpeg4 header decode we have the height, width,*/
567         /* and other parameters. So then we could init the picture   */
568         /* FIXME: By the way H263 decoder is evolving it should have */
569         /* an H263EncContext                                         */
570
571     if (   s->width  != avctx->coded_width
572         || s->height != avctx->coded_height) {
573         /* H.263 could change picture size any time */
574         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
575         s->parse_context.buffer=0;
576         MPV_common_end(s);
577         s->parse_context= pc;
578     }
579     if (!s->context_initialized) {
580         avcodec_set_dimensions(avctx, s->width, s->height);
581
582         goto retry;
583     }
584
585     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
586         s->gob_index = ff_h263_get_gob_height(s);
587
588     // for hurry_up==5
589     s->current_picture.pict_type= s->pict_type;
590     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
591
592     /* skip B-frames if we don't have reference frames */
593     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
594     /* skip b frames if we are in a hurry */
595     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
596     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
597        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
598        ||  avctx->skip_frame >= AVDISCARD_ALL)
599         return get_consumed_bytes(s, buf_size);
600     /* skip everything if we are in a hurry>=5 */
601     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
602
603     if(s->next_p_frame_damaged){
604         if(s->pict_type==FF_B_TYPE)
605             return get_consumed_bytes(s, buf_size);
606         else
607             s->next_p_frame_damaged=0;
608     }
609
610     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
611         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
612         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
613     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
614         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
615         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
616     }else{
617         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
618         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
619     }
620
621     if(MPV_frame_start(s, avctx) < 0)
622         return -1;
623
624     if (avctx->hwaccel) {
625         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
626             return -1;
627     }
628
629     ff_er_frame_start(s);
630
631     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
632     //which is not available before MPV_frame_start()
633     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
634         ret = ff_wmv2_decode_secondary_picture_header(s);
635         if(ret<0) return ret;
636         if(ret==1) goto intrax8_decoded;
637     }
638
639     /* decode each macroblock */
640     s->mb_x=0;
641     s->mb_y=0;
642
643     decode_slice(s);
644     while(s->mb_y<s->mb_height){
645         if(s->msmpeg4_version){
646             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_count(&s->gb) > s->gb.size_in_bits)
647                 break;
648         }else{
649             if(ff_h263_resync(s)<0)
650                 break;
651         }
652
653         if(s->msmpeg4_version<4 && s->h263_pred)
654             ff_mpeg4_clean_buffers(s);
655
656         decode_slice(s);
657     }
658
659     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
660         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
661             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
662         }
663
664     /* divx 5.01+ bistream reorder stuff */
665     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
666         int current_pos= get_bits_count(&s->gb)>>3;
667         int startcode_found=0;
668
669         if(buf_size - current_pos > 5){
670             int i;
671             for(i=current_pos; i<buf_size-3; i++){
672                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
673                     startcode_found=1;
674                     break;
675                 }
676             }
677         }
678         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
679             startcode_found=1;
680             current_pos=0;
681         }
682
683         if(startcode_found){
684             av_fast_malloc(
685                 &s->bitstream_buffer,
686                 &s->allocated_bitstream_buffer_size,
687                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
688             if (!s->bitstream_buffer)
689                 return AVERROR(ENOMEM);
690             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
691             s->bitstream_buffer_size= buf_size - current_pos;
692         }
693     }
694
695 intrax8_decoded:
696     ff_er_frame_end(s);
697
698     if (avctx->hwaccel) {
699         if (avctx->hwaccel->end_frame(avctx) < 0)
700             return -1;
701     }
702
703     MPV_frame_end(s);
704
705 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
706 assert(s->current_picture.pict_type == s->pict_type);
707     if (s->pict_type == FF_B_TYPE || s->low_delay) {
708         *pict= *(AVFrame*)s->current_picture_ptr;
709     } else if (s->last_picture_ptr != NULL) {
710         *pict= *(AVFrame*)s->last_picture_ptr;
711     }
712
713     if(s->last_picture_ptr || s->low_delay){
714         *data_size = sizeof(AVFrame);
715         ff_print_debug_info(s, pict);
716     }
717
718 #ifdef PRINT_FRAME_TIME
719 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
720 #endif
721
722     return get_consumed_bytes(s, buf_size);
723 }
724
725 AVCodec mpeg4_decoder = {
726     "mpeg4",
727     CODEC_TYPE_VIDEO,
728     CODEC_ID_MPEG4,
729     sizeof(MpegEncContext),
730     ff_h263_decode_init,
731     NULL,
732     ff_h263_decode_end,
733     ff_h263_decode_frame,
734     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
735     .flush= ff_mpeg_flush,
736     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
737     .pix_fmts= ff_hwaccel_pixfmt_list_420,
738 };
739
740 AVCodec h263_decoder = {
741     "h263",
742     CODEC_TYPE_VIDEO,
743     CODEC_ID_H263,
744     sizeof(MpegEncContext),
745     ff_h263_decode_init,
746     NULL,
747     ff_h263_decode_end,
748     ff_h263_decode_frame,
749     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
750     .flush= ff_mpeg_flush,
751     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
752     .pix_fmts= ff_hwaccel_pixfmt_list_420,
753 };
754
755 AVCodec msmpeg4v1_decoder = {
756     "msmpeg4v1",
757     CODEC_TYPE_VIDEO,
758     CODEC_ID_MSMPEG4V1,
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     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
766     .pix_fmts= ff_pixfmt_list_420,
767 };
768
769 AVCodec msmpeg4v2_decoder = {
770     "msmpeg4v2",
771     CODEC_TYPE_VIDEO,
772     CODEC_ID_MSMPEG4V2,
773     sizeof(MpegEncContext),
774     ff_h263_decode_init,
775     NULL,
776     ff_h263_decode_end,
777     ff_h263_decode_frame,
778     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
779     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
780     .pix_fmts= ff_pixfmt_list_420,
781 };
782
783 AVCodec msmpeg4v3_decoder = {
784     "msmpeg4",
785     CODEC_TYPE_VIDEO,
786     CODEC_ID_MSMPEG4V3,
787     sizeof(MpegEncContext),
788     ff_h263_decode_init,
789     NULL,
790     ff_h263_decode_end,
791     ff_h263_decode_frame,
792     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
793     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
794     .pix_fmts= ff_pixfmt_list_420,
795 };
796
797 AVCodec wmv1_decoder = {
798     "wmv1",
799     CODEC_TYPE_VIDEO,
800     CODEC_ID_WMV1,
801     sizeof(MpegEncContext),
802     ff_h263_decode_init,
803     NULL,
804     ff_h263_decode_end,
805     ff_h263_decode_frame,
806     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
807     .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
808     .pix_fmts= ff_pixfmt_list_420,
809 };
810
811 AVCodec h263i_decoder = {
812     "h263i",
813     CODEC_TYPE_VIDEO,
814     CODEC_ID_H263I,
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     .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
822     .pix_fmts= ff_pixfmt_list_420,
823 };
824
825 AVCodec flv_decoder = {
826     "flv",
827     CODEC_TYPE_VIDEO,
828     CODEC_ID_FLV1,
829     sizeof(MpegEncContext),
830     ff_h263_decode_init,
831     NULL,
832     ff_h263_decode_end,
833     ff_h263_decode_frame,
834     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
835     .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV)"),
836     .pix_fmts= ff_pixfmt_list_420,
837 };