Merge remote branch 'qatar/master'
[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 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
25  * H.263 decoder.
26  */
27
28 #include "libavutil/cpu.h"
29 #include "internal.h"
30 #include "avcodec.h"
31 #include "dsputil.h"
32 #include "mpegvideo.h"
33 #include "h263.h"
34 #include "h263_parser.h"
35 #include "mpeg4video_parser.h"
36 #include "msmpeg4.h"
37 #include "vdpau_internal.h"
38 #include "thread.h"
39 #include "flv.h"
40 #include "mpeg4video.h"
41
42 //#define DEBUG
43 //#define PRINT_FRAME_TIME
44
45 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
46 {
47     MpegEncContext *s = avctx->priv_data;
48
49     s->avctx = avctx;
50     s->out_format = FMT_H263;
51
52     s->width  = avctx->coded_width;
53     s->height = avctx->coded_height;
54     s->workaround_bugs= avctx->workaround_bugs;
55
56     // set defaults
57     MPV_decode_defaults(s);
58     s->quant_precision=5;
59     s->decode_mb= ff_h263_decode_mb;
60     s->low_delay= 1;
61     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
62     s->unrestricted_mv= 1;
63
64     /* select sub codec */
65     switch(avctx->codec->id) {
66     case CODEC_ID_H263:
67         s->unrestricted_mv= 0;
68         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
69         break;
70     case CODEC_ID_MPEG4:
71         break;
72     case CODEC_ID_MSMPEG4V1:
73         s->h263_msmpeg4 = 1;
74         s->h263_pred = 1;
75         s->msmpeg4_version=1;
76         break;
77     case CODEC_ID_MSMPEG4V2:
78         s->h263_msmpeg4 = 1;
79         s->h263_pred = 1;
80         s->msmpeg4_version=2;
81         break;
82     case CODEC_ID_MSMPEG4V3:
83         s->h263_msmpeg4 = 1;
84         s->h263_pred = 1;
85         s->msmpeg4_version=3;
86         break;
87     case CODEC_ID_WMV1:
88         s->h263_msmpeg4 = 1;
89         s->h263_pred = 1;
90         s->msmpeg4_version=4;
91         break;
92     case CODEC_ID_WMV2:
93         s->h263_msmpeg4 = 1;
94         s->h263_pred = 1;
95         s->msmpeg4_version=5;
96         break;
97     case CODEC_ID_VC1:
98     case CODEC_ID_WMV3:
99         s->h263_msmpeg4 = 1;
100         s->h263_pred = 1;
101         s->msmpeg4_version=6;
102         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
103         break;
104     case CODEC_ID_H263I:
105         break;
106     case CODEC_ID_FLV1:
107         s->h263_flv = 1;
108         break;
109     default:
110         return -1;
111     }
112     s->codec_id= avctx->codec->id;
113     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
114
115     /* for h263, we allocate the images after having read the header */
116     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
117         if (MPV_common_init(s) < 0)
118             return -1;
119
120         h263_decode_init_vlc(s);
121
122     return 0;
123 }
124
125 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
126 {
127     MpegEncContext *s = avctx->priv_data;
128
129     MPV_common_end(s);
130     return 0;
131 }
132
133 /**
134  * returns the number of bytes consumed for building the current frame
135  */
136 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
137     int pos= (get_bits_count(&s->gb)+7)>>3;
138
139     if(s->divx_packed || s->avctx->hwaccel){
140         //we would have to scan through the whole buf to handle the weird reordering ...
141         return buf_size;
142     }else if(s->flags&CODEC_FLAG_TRUNCATED){
143         pos -= s->parse_context.last_index;
144         if(pos<0) pos=0; // padding is not really read so this might be -1
145         return pos;
146     }else{
147         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
148         if(pos+10>buf_size) pos=buf_size; // oops ;)
149
150         return pos;
151     }
152 }
153
154 static int decode_slice(MpegEncContext *s){
155     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
156     const int mb_size= 16>>s->avctx->lowres;
157     s->last_resync_gb= s->gb;
158     s->first_slice_line= 1;
159
160     s->resync_mb_x= s->mb_x;
161     s->resync_mb_y= s->mb_y;
162
163     ff_set_qscale(s, s->qscale);
164
165     if (s->avctx->hwaccel) {
166         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
167         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
168         skip_bits_long(&s->gb, 8*(end - start));
169         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
170     }
171
172     if(s->partitioned_frame){
173         const int qscale= s->qscale;
174
175         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
176             if(ff_mpeg4_decode_partitions(s) < 0)
177                 return -1;
178         }
179
180         /* restore variables which were modified */
181         s->first_slice_line=1;
182         s->mb_x= s->resync_mb_x;
183         s->mb_y= s->resync_mb_y;
184         ff_set_qscale(s, qscale);
185     }
186
187     for(; s->mb_y < s->mb_height; s->mb_y++) {
188         /* per-row end of slice checks */
189         if(s->msmpeg4_version){
190             if(s->resync_mb_y + s->slice_height == s->mb_y){
191                 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);
192
193                 return 0;
194             }
195         }
196
197         if(s->msmpeg4_version==1){
198             s->last_dc[0]=
199             s->last_dc[1]=
200             s->last_dc[2]= 128;
201         }
202
203         ff_init_block_index(s);
204         for(; s->mb_x < s->mb_width; s->mb_x++) {
205             int ret;
206
207             ff_update_block_index(s);
208
209             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
210                 s->first_slice_line=0;
211             }
212
213             /* DCT & quantize */
214
215             s->mv_dir = MV_DIR_FORWARD;
216             s->mv_type = MV_TYPE_16X16;
217 //            s->mb_skipped = 0;
218 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
219             ret= s->decode_mb(s, s->block);
220
221             if (s->pict_type!=FF_B_TYPE)
222                 ff_h263_update_motion_val(s);
223
224             if(ret<0){
225                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
226                 if(ret==SLICE_END){
227                     MPV_decode_mb(s, s->block);
228                     if(s->loop_filter)
229                         ff_h263_loop_filter(s);
230
231 //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));
232                     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);
233
234                     s->padding_bug_score--;
235
236                     if(++s->mb_x >= s->mb_width){
237                         s->mb_x=0;
238                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
239                         MPV_report_decode_progress(s);
240                         s->mb_y++;
241                     }
242                     return 0;
243                 }else if(ret==SLICE_NOEND){
244                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
245                     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);
246                     return -1;
247                 }
248                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
249                 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);
250
251                 return -1;
252             }
253
254             MPV_decode_mb(s, s->block);
255             if(s->loop_filter)
256                 ff_h263_loop_filter(s);
257         }
258
259         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
260         MPV_report_decode_progress(s);
261
262         s->mb_x= 0;
263     }
264
265     assert(s->mb_x==0 && s->mb_y==s->mb_height);
266
267     if(s->codec_id==CODEC_ID_MPEG4
268        && (s->workaround_bugs&FF_BUG_AUTODETECT)
269        && get_bits_left(&s->gb) >= 48
270        && show_bits(&s->gb, 24)==0x4010
271        && !s->data_partitioning)
272         s->padding_bug_score+=32;
273
274     /* try to detect the padding bug */
275     if(      s->codec_id==CODEC_ID_MPEG4
276        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
277        &&    get_bits_left(&s->gb) >=0
278        &&    get_bits_left(&s->gb) < 48
279 //       &&   !s->resync_marker
280        &&   !s->data_partitioning){
281
282         const int bits_count= get_bits_count(&s->gb);
283         const int bits_left = s->gb.size_in_bits - bits_count;
284
285         if(bits_left==0){
286             s->padding_bug_score+=16;
287         } else if(bits_left != 1){
288             int v= show_bits(&s->gb, 8);
289             v|= 0x7F >> (7-(bits_count&7));
290
291             if(v==0x7F && bits_left<=8)
292                 s->padding_bug_score--;
293             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
294                 s->padding_bug_score+= 4;
295             else
296                 s->padding_bug_score++;
297         }
298     }
299
300     if(s->workaround_bugs&FF_BUG_AUTODETECT){
301         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
302             s->workaround_bugs |=  FF_BUG_NO_PADDING;
303         else
304             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
305     }
306
307     // handle formats which don't have unique end markers
308     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
309         int left= get_bits_left(&s->gb);
310         int max_extra=7;
311
312         /* no markers in M$ crap */
313         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
314             max_extra+= 17;
315
316         /* buggy padding but the frame should still end approximately at the bitstream end */
317         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
318             max_extra+= 48;
319         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
320             max_extra+= 256*256*256*64;
321
322         if(left>max_extra){
323             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
324         }
325         else if(left<0){
326             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
327         }else
328             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);
329
330         return 0;
331     }
332
333     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
334             get_bits_left(&s->gb),
335             show_bits(&s->gb, 24), s->padding_bug_score);
336
337     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);
338
339     return -1;
340 }
341
342 int ff_h263_decode_frame(AVCodecContext *avctx,
343                              void *data, int *data_size,
344                              AVPacket *avpkt)
345 {
346     const uint8_t *buf = avpkt->data;
347     int buf_size = avpkt->size;
348     MpegEncContext *s = avctx->priv_data;
349     int ret;
350     AVFrame *pict = data;
351
352 #ifdef PRINT_FRAME_TIME
353 uint64_t time= rdtsc();
354 #endif
355     s->flags= avctx->flags;
356     s->flags2= avctx->flags2;
357
358     /* no supplementary picture */
359     if (buf_size == 0) {
360         /* special case for last picture */
361         if (s->low_delay==0 && s->next_picture_ptr) {
362             *pict= *(AVFrame*)s->next_picture_ptr;
363             s->next_picture_ptr= NULL;
364
365             *data_size = sizeof(AVFrame);
366         }
367
368         return 0;
369     }
370
371     if(s->flags&CODEC_FLAG_TRUNCATED){
372         int next;
373
374         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
375             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
376         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
377             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
378         }else{
379             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
380             return -1;
381         }
382
383         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
384             return buf_size;
385     }
386
387
388 retry:
389     if(s->divx_packed && s->xvid_build>=0 && s->bitstream_buffer_size){
390         int i;
391         for(i=0; i<buf_size-3; i++){
392             if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1){
393                 if(buf[i+3]==0xB0){
394                     av_log(s->avctx, AV_LOG_WARNING, "Discarding excessive bitstream in packed xvid\n");
395                     s->bitstream_buffer_size=0;
396                 }
397                 break;
398             }
399         }
400     }
401
402     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
403         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
404     }else
405         init_get_bits(&s->gb, buf, buf_size*8);
406     s->bitstream_buffer_size=0;
407
408     if (!s->context_initialized) {
409         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
410             return -1;
411     }
412
413     /* We need to set current_picture_ptr before reading the header,
414      * otherwise we cannot store anyting in there */
415     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
416         int i= ff_find_unused_picture(s, 0);
417         s->current_picture_ptr= &s->picture[i];
418     }
419
420     /* let's go :-) */
421     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
422         ret= ff_wmv2_decode_picture_header(s);
423     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
424         ret = msmpeg4_decode_picture_header(s);
425     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
426         if(s->avctx->extradata_size && s->picture_number==0){
427             GetBitContext gb;
428
429             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
430             ret = ff_mpeg4_decode_picture_header(s, &gb);
431         }
432         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
433     } else if (CONFIG_H263I_DECODER && s->codec_id == CODEC_ID_H263I) {
434         ret = ff_intel_h263_decode_picture_header(s);
435     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
436         ret = ff_flv_decode_picture_header(s);
437     } else {
438         ret = h263_decode_picture_header(s);
439     }
440
441     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
442
443     /* skip if the header was thrashed */
444     if (ret < 0){
445         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
446         return -1;
447     }
448
449     avctx->has_b_frames= !s->low_delay;
450
451     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
452         if(s->stream_codec_tag == AV_RL32("XVID") ||
453            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
454            s->codec_tag == AV_RL32("RMP4") ||
455            s->codec_tag == AV_RL32("SIPP")
456            )
457             s->xvid_build= 0;
458 #if 0
459         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
460            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
461             s->xvid_build= 0;
462 #endif
463     }
464
465     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
466         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
467             s->divx_version= 400; //divx 4
468     }
469
470     if(s->xvid_build>=0 && s->divx_version>=0){
471         s->divx_version=
472         s->divx_build= -1;
473     }
474
475     if(s->workaround_bugs&FF_BUG_AUTODETECT){
476         if(s->codec_tag == AV_RL32("XVIX"))
477             s->workaround_bugs|= FF_BUG_XVID_ILACE;
478
479         if(s->codec_tag == AV_RL32("UMP4")){
480             s->workaround_bugs|= FF_BUG_UMP4;
481         }
482
483         if(s->divx_version>=500 && s->divx_build<1814){
484             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
485         }
486
487         if(s->divx_version>502 && s->divx_build<1814){
488             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
489         }
490
491         if(s->xvid_build<=3U)
492             s->padding_bug_score= 256*256*256*64;
493
494         if(s->xvid_build<=1U)
495             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
496
497         if(s->xvid_build<=12U)
498             s->workaround_bugs|= FF_BUG_EDGE;
499
500         if(s->xvid_build<=32U)
501             s->workaround_bugs|= FF_BUG_DC_CLIP;
502
503 #define SET_QPEL_FUNC(postfix1, postfix2) \
504     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
505     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
506     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
507
508         if(s->lavc_build<4653U)
509             s->workaround_bugs|= FF_BUG_STD_QPEL;
510
511         if(s->lavc_build<4655U)
512             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
513
514         if(s->lavc_build<4670U){
515             s->workaround_bugs|= FF_BUG_EDGE;
516         }
517
518         if(s->lavc_build<=4712U)
519             s->workaround_bugs|= FF_BUG_DC_CLIP;
520
521         if(s->divx_version>=0)
522             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
523 //printf("padding_bug_score: %d\n", s->padding_bug_score);
524         if(s->divx_version==501 && s->divx_build==20020416)
525             s->padding_bug_score= 256*256*256*64;
526
527         if(s->divx_version<500U){
528             s->workaround_bugs|= FF_BUG_EDGE;
529         }
530
531         if(s->divx_version>=0)
532             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
533 #if 0
534         if(s->divx_version==500)
535             s->padding_bug_score= 256*256*256*64;
536
537         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
538          * Let us hope this at least works.
539          */
540         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
541            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
542             s->workaround_bugs|= FF_BUG_NO_PADDING;
543
544         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
545             s->workaround_bugs|= FF_BUG_NO_PADDING;
546 #endif
547     }
548
549     if(s->workaround_bugs& FF_BUG_STD_QPEL){
550         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
551         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
552         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
553         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
554         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
555         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
556
557         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
558         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
559         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
560         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
561         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
562         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
563     }
564
565     if(avctx->debug & FF_DEBUG_BUGS)
566         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
567                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
568                s->divx_packed ? "p" : "");
569
570 #if 0 // dump bits per frame / qp / complexity
571 {
572     static FILE *f=NULL;
573     if(!f) f=fopen("rate_qp_cplx.txt", "w");
574     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
575 }
576 #endif
577
578 #if HAVE_MMX
579     if (s->codec_id == CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
580         avctx->idct_algo= FF_IDCT_XVIDMMX;
581         avctx->coded_width= 0; // force reinit
582 //        dsputil_init(&s->dsp, avctx);
583         s->picture_number=0;
584     }
585 #endif
586
587         /* After H263 & mpeg4 header decode we have the height, width,*/
588         /* and other parameters. So then we could init the picture   */
589         /* FIXME: By the way H263 decoder is evolving it should have */
590         /* an H263EncContext                                         */
591
592     if (   s->width  != avctx->coded_width
593         || s->height != avctx->coded_height) {
594         /* H.263 could change picture size any time */
595         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
596         s->parse_context.buffer=0;
597         MPV_common_end(s);
598         s->parse_context= pc;
599     }
600     if (!s->context_initialized) {
601         avcodec_set_dimensions(avctx, s->width, s->height);
602
603         goto retry;
604     }
605
606     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
607         s->gob_index = ff_h263_get_gob_height(s);
608
609     // for skipping the frame
610     s->current_picture.pict_type= s->pict_type;
611     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
612
613     /* skip B-frames if we don't have reference frames */
614     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
615 #if FF_API_HURRY_UP
616     /* skip b frames if we are in a hurry */
617     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
618 #endif
619     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
620        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
621        ||  avctx->skip_frame >= AVDISCARD_ALL)
622         return get_consumed_bytes(s, buf_size);
623 #if FF_API_HURRY_UP
624     /* skip everything if we are in a hurry>=5 */
625     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
626 #endif
627
628     if(s->next_p_frame_damaged){
629         if(s->pict_type==FF_B_TYPE)
630             return get_consumed_bytes(s, buf_size);
631         else
632             s->next_p_frame_damaged=0;
633     }
634
635     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
636         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
637         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
638     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
639         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
640         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
641     }else{
642         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
643         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
644     }
645
646     if(MPV_frame_start(s, avctx) < 0)
647         return -1;
648
649     if (!s->divx_packed) ff_thread_finish_setup(avctx);
650
651     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
652         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
653         goto frame_end;
654     }
655
656     if (avctx->hwaccel) {
657         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
658             return -1;
659     }
660
661     ff_er_frame_start(s);
662
663     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
664     //which is not available before MPV_frame_start()
665     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
666         ret = ff_wmv2_decode_secondary_picture_header(s);
667         if(ret<0) return ret;
668         if(ret==1) goto intrax8_decoded;
669     }
670
671     /* decode each macroblock */
672     s->mb_x=0;
673     s->mb_y=0;
674
675     decode_slice(s);
676     while(s->mb_y<s->mb_height){
677         if(s->msmpeg4_version){
678             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)
679                 break;
680         }else{
681             if(ff_h263_resync(s)<0)
682                 break;
683         }
684
685         if(s->msmpeg4_version<4 && s->h263_pred)
686             ff_mpeg4_clean_buffers(s);
687
688         decode_slice(s);
689     }
690
691     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
692         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
693             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
694         }
695
696     assert(s->bitstream_buffer_size==0);
697 frame_end:
698     /* divx 5.01+ bistream reorder stuff */
699     if(s->codec_id==CODEC_ID_MPEG4 && s->divx_packed){
700         int current_pos= get_bits_count(&s->gb)>>3;
701         int startcode_found=0;
702
703         if(buf_size - current_pos > 5){
704             int i;
705             for(i=current_pos; i<buf_size-3; i++){
706                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
707                     startcode_found=1;
708                     break;
709                 }
710             }
711         }
712         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
713             startcode_found=1;
714             current_pos=0;
715         }
716
717         if(startcode_found){
718             av_fast_malloc(
719                 &s->bitstream_buffer,
720                 &s->allocated_bitstream_buffer_size,
721                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
722             if (!s->bitstream_buffer)
723                 return AVERROR(ENOMEM);
724             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
725             s->bitstream_buffer_size= buf_size - current_pos;
726         }
727     }
728
729 intrax8_decoded:
730     ff_er_frame_end(s);
731
732     if (avctx->hwaccel) {
733         if (avctx->hwaccel->end_frame(avctx) < 0)
734             return -1;
735     }
736
737     MPV_frame_end(s);
738
739 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
740 assert(s->current_picture.pict_type == s->pict_type);
741     if (s->pict_type == FF_B_TYPE || s->low_delay) {
742         *pict= *(AVFrame*)s->current_picture_ptr;
743     } else if (s->last_picture_ptr != NULL) {
744         *pict= *(AVFrame*)s->last_picture_ptr;
745     }
746
747     if(s->last_picture_ptr || s->low_delay){
748         *data_size = sizeof(AVFrame);
749         ff_print_debug_info(s, pict);
750     }
751
752 #ifdef PRINT_FRAME_TIME
753 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
754 #endif
755
756     return get_consumed_bytes(s, buf_size);
757 }
758
759 AVCodec ff_h263_decoder = {
760     "h263",
761     AVMEDIA_TYPE_VIDEO,
762     CODEC_ID_H263,
763     sizeof(MpegEncContext),
764     ff_h263_decode_init,
765     NULL,
766     ff_h263_decode_end,
767     ff_h263_decode_frame,
768     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
769     .flush= ff_mpeg_flush,
770     .max_lowres= 3,
771     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
772     .pix_fmts= ff_hwaccel_pixfmt_list_420,
773 };