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[ffmpeg] / 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 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 #include "vdpau_internal.h"
36 #include "flv.h"
37 #include "mpeg4video.h"
38
39 //#define DEBUG
40 //#define PRINT_FRAME_TIME
41
42 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
43 {
44     MpegEncContext *s = avctx->priv_data;
45
46     s->avctx = avctx;
47     s->out_format = FMT_H263;
48
49     s->width  = avctx->coded_width;
50     s->height = avctx->coded_height;
51     s->workaround_bugs= avctx->workaround_bugs;
52
53     // set defaults
54     MPV_decode_defaults(s);
55     s->quant_precision=5;
56     s->decode_mb= ff_h263_decode_mb;
57     s->low_delay= 1;
58     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
59     s->unrestricted_mv= 1;
60
61     /* select sub codec */
62     switch(avctx->codec->id) {
63     case CODEC_ID_H263:
64         s->unrestricted_mv= 0;
65         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
66         break;
67     case CODEC_ID_MPEG4:
68         break;
69     case CODEC_ID_MSMPEG4V1:
70         s->h263_msmpeg4 = 1;
71         s->h263_pred = 1;
72         s->msmpeg4_version=1;
73         break;
74     case CODEC_ID_MSMPEG4V2:
75         s->h263_msmpeg4 = 1;
76         s->h263_pred = 1;
77         s->msmpeg4_version=2;
78         break;
79     case CODEC_ID_MSMPEG4V3:
80         s->h263_msmpeg4 = 1;
81         s->h263_pred = 1;
82         s->msmpeg4_version=3;
83         break;
84     case CODEC_ID_WMV1:
85         s->h263_msmpeg4 = 1;
86         s->h263_pred = 1;
87         s->msmpeg4_version=4;
88         break;
89     case CODEC_ID_WMV2:
90         s->h263_msmpeg4 = 1;
91         s->h263_pred = 1;
92         s->msmpeg4_version=5;
93         break;
94     case CODEC_ID_VC1:
95     case CODEC_ID_WMV3:
96         s->h263_msmpeg4 = 1;
97         s->h263_pred = 1;
98         s->msmpeg4_version=6;
99         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
100         break;
101     case CODEC_ID_H263I:
102         break;
103     case CODEC_ID_FLV1:
104         s->h263_flv = 1;
105         break;
106     default:
107         return -1;
108     }
109     s->codec_id= avctx->codec->id;
110     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
111
112     /* for h263, we allocate the images after having read the header */
113     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
114         if (MPV_common_init(s) < 0)
115             return -1;
116
117     if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
118         ff_msmpeg4_decode_init(s);
119     else
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                         s->mb_y++;
240                     }
241                     return 0;
242                 }else if(ret==SLICE_NOEND){
243                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
244                     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);
245                     return -1;
246                 }
247                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
248                 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);
249
250                 return -1;
251             }
252
253             MPV_decode_mb(s, s->block);
254             if(s->loop_filter)
255                 ff_h263_loop_filter(s);
256         }
257
258         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
259
260         s->mb_x= 0;
261     }
262
263     assert(s->mb_x==0 && s->mb_y==s->mb_height);
264
265     /* try to detect the padding bug */
266     if(      s->codec_id==CODEC_ID_MPEG4
267        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
268        &&    get_bits_left(&s->gb) >=0
269        &&    get_bits_left(&s->gb) < 48
270 //       &&   !s->resync_marker
271        &&   !s->data_partitioning){
272
273         const int bits_count= get_bits_count(&s->gb);
274         const int bits_left = s->gb.size_in_bits - bits_count;
275
276         if(bits_left==0){
277             s->padding_bug_score+=16;
278         } else if(bits_left != 1){
279             int v= show_bits(&s->gb, 8);
280             v|= 0x7F >> (7-(bits_count&7));
281
282             if(v==0x7F && bits_left<=8)
283                 s->padding_bug_score--;
284             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
285                 s->padding_bug_score+= 4;
286             else
287                 s->padding_bug_score++;
288         }
289     }
290
291     if(s->workaround_bugs&FF_BUG_AUTODETECT){
292         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
293             s->workaround_bugs |=  FF_BUG_NO_PADDING;
294         else
295             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
296     }
297
298     // handle formats which don't have unique end markers
299     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
300         int left= get_bits_left(&s->gb);
301         int max_extra=7;
302
303         /* no markers in M$ crap */
304         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
305             max_extra+= 17;
306
307         /* buggy padding but the frame should still end approximately at the bitstream end */
308         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
309             max_extra+= 48;
310         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
311             max_extra+= 256*256*256*64;
312
313         if(left>max_extra){
314             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
315         }
316         else if(left<0){
317             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
318         }else
319             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);
320
321         return 0;
322     }
323
324     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
325             get_bits_left(&s->gb),
326             show_bits(&s->gb, 24), s->padding_bug_score);
327
328     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);
329
330     return -1;
331 }
332
333 int ff_h263_decode_frame(AVCodecContext *avctx,
334                              void *data, int *data_size,
335                              AVPacket *avpkt)
336 {
337     const uint8_t *buf = avpkt->data;
338     int buf_size = avpkt->size;
339     MpegEncContext *s = avctx->priv_data;
340     int ret;
341     AVFrame *pict = data;
342
343 #ifdef PRINT_FRAME_TIME
344 uint64_t time= rdtsc();
345 #endif
346     s->flags= avctx->flags;
347     s->flags2= avctx->flags2;
348
349     /* no supplementary picture */
350     if (buf_size == 0) {
351         /* special case for last picture */
352         if (s->low_delay==0 && s->next_picture_ptr) {
353             *pict= *(AVFrame*)s->next_picture_ptr;
354             s->next_picture_ptr= NULL;
355
356             *data_size = sizeof(AVFrame);
357         }
358
359         return 0;
360     }
361
362     if(s->flags&CODEC_FLAG_TRUNCATED){
363         int next;
364
365         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
366             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
367         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
368             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
369         }else{
370             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
371             return -1;
372         }
373
374         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
375             return buf_size;
376     }
377
378
379 retry:
380
381     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
382         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
383     }else
384         init_get_bits(&s->gb, buf, buf_size*8);
385     s->bitstream_buffer_size=0;
386
387     if (!s->context_initialized) {
388         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
389             return -1;
390     }
391
392     /* We need to set current_picture_ptr before reading the header,
393      * otherwise we cannot store anyting in there */
394     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
395         int i= ff_find_unused_picture(s, 0);
396         s->current_picture_ptr= &s->picture[i];
397     }
398
399     /* let's go :-) */
400     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
401         ret= ff_wmv2_decode_picture_header(s);
402     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
403         ret = msmpeg4_decode_picture_header(s);
404     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
405         if(s->avctx->extradata_size && s->picture_number==0){
406             GetBitContext gb;
407
408             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
409             ret = ff_mpeg4_decode_picture_header(s, &gb);
410         }
411         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
412     } else if (CONFIG_H263I_DECODER && s->codec_id == CODEC_ID_H263I) {
413         ret = ff_intel_h263_decode_picture_header(s);
414     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
415         ret = ff_flv_decode_picture_header(s);
416     } else {
417         ret = h263_decode_picture_header(s);
418     }
419
420     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
421
422     /* skip if the header was thrashed */
423     if (ret < 0){
424         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
425         return -1;
426     }
427
428     avctx->has_b_frames= !s->low_delay;
429
430     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
431         if(s->stream_codec_tag == AV_RL32("XVID") ||
432            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
433            s->codec_tag == AV_RL32("RMP4"))
434             s->xvid_build= -1;
435 #if 0
436         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
437            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
438             s->xvid_build= -1;
439 #endif
440     }
441
442     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
443         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
444             s->divx_version= 400; //divx 4
445     }
446
447     if(s->xvid_build && s->divx_version){
448         s->divx_version=
449         s->divx_build= 0;
450     }
451
452     if(s->workaround_bugs&FF_BUG_AUTODETECT){
453         if(s->codec_tag == AV_RL32("XVIX"))
454             s->workaround_bugs|= FF_BUG_XVID_ILACE;
455
456         if(s->codec_tag == AV_RL32("UMP4")){
457             s->workaround_bugs|= FF_BUG_UMP4;
458         }
459
460         if(s->divx_version>=500 && s->divx_build<1814){
461             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
462         }
463
464         if(s->divx_version>502 && s->divx_build<1814){
465             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
466         }
467
468         if(s->xvid_build && s->xvid_build<=3)
469             s->padding_bug_score= 256*256*256*64;
470
471         if(s->xvid_build && s->xvid_build<=1)
472             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
473
474         if(s->xvid_build && s->xvid_build<=12)
475             s->workaround_bugs|= FF_BUG_EDGE;
476
477         if(s->xvid_build && s->xvid_build<=32)
478             s->workaround_bugs|= FF_BUG_DC_CLIP;
479
480 #define SET_QPEL_FUNC(postfix1, postfix2) \
481     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
482     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
483     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
484
485         if(s->lavc_build && s->lavc_build<4653)
486             s->workaround_bugs|= FF_BUG_STD_QPEL;
487
488         if(s->lavc_build && s->lavc_build<4655)
489             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
490
491         if(s->lavc_build && s->lavc_build<4670){
492             s->workaround_bugs|= FF_BUG_EDGE;
493         }
494
495         if(s->lavc_build && s->lavc_build<=4712)
496             s->workaround_bugs|= FF_BUG_DC_CLIP;
497
498         if(s->divx_version)
499             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
500 //printf("padding_bug_score: %d\n", s->padding_bug_score);
501         if(s->divx_version==501 && s->divx_build==20020416)
502             s->padding_bug_score= 256*256*256*64;
503
504         if(s->divx_version && s->divx_version<500){
505             s->workaround_bugs|= FF_BUG_EDGE;
506         }
507
508         if(s->divx_version)
509             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
510 #if 0
511         if(s->divx_version==500)
512             s->padding_bug_score= 256*256*256*64;
513
514         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
515          * Let us hope this at least works.
516          */
517         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
518            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
519             s->workaround_bugs|= FF_BUG_NO_PADDING;
520
521         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
522             s->workaround_bugs|= FF_BUG_NO_PADDING;
523 #endif
524     }
525
526     if(s->workaround_bugs& FF_BUG_STD_QPEL){
527         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
528         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
529         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
530         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
531         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
532         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
533
534         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
535         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
536         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
537         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
538         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
539         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
540     }
541
542     if(avctx->debug & FF_DEBUG_BUGS)
543         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
544                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
545                s->divx_packed ? "p" : "");
546
547 #if 0 // dump bits per frame / qp / complexity
548 {
549     static FILE *f=NULL;
550     if(!f) f=fopen("rate_qp_cplx.txt", "w");
551     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
552 }
553 #endif
554
555 #if HAVE_MMX
556     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
557         avctx->idct_algo= FF_IDCT_XVIDMMX;
558         avctx->coded_width= 0; // force reinit
559 //        dsputil_init(&s->dsp, avctx);
560         s->picture_number=0;
561     }
562 #endif
563
564         /* After H263 & mpeg4 header decode we have the height, width,*/
565         /* and other parameters. So then we could init the picture   */
566         /* FIXME: By the way H263 decoder is evolving it should have */
567         /* an H263EncContext                                         */
568
569     if (   s->width  != avctx->coded_width
570         || s->height != avctx->coded_height) {
571         /* H.263 could change picture size any time */
572         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
573         s->parse_context.buffer=0;
574         MPV_common_end(s);
575         s->parse_context= pc;
576     }
577     if (!s->context_initialized) {
578         avcodec_set_dimensions(avctx, s->width, s->height);
579
580         goto retry;
581     }
582
583     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
584         s->gob_index = ff_h263_get_gob_height(s);
585
586     // for hurry_up==5
587     s->current_picture.pict_type= s->pict_type;
588     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
589
590     /* skip B-frames if we don't have reference frames */
591     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
592     /* skip b frames if we are in a hurry */
593     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
594     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
595        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
596        ||  avctx->skip_frame >= AVDISCARD_ALL)
597         return get_consumed_bytes(s, buf_size);
598     /* skip everything if we are in a hurry>=5 */
599     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
600
601     if(s->next_p_frame_damaged){
602         if(s->pict_type==FF_B_TYPE)
603             return get_consumed_bytes(s, buf_size);
604         else
605             s->next_p_frame_damaged=0;
606     }
607
608     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
609         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
610         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
611     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
612         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
613         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
614     }else{
615         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
616         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
617     }
618
619     if(MPV_frame_start(s, avctx) < 0)
620         return -1;
621
622     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
623         ff_vdpau_mpeg4_decode_picture(s, buf, buf_size);
624         goto frame_end;
625     }
626
627     if (avctx->hwaccel) {
628         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
629             return -1;
630     }
631
632     ff_er_frame_start(s);
633
634     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
635     //which is not available before MPV_frame_start()
636     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
637         ret = ff_wmv2_decode_secondary_picture_header(s);
638         if(ret<0) return ret;
639         if(ret==1) goto intrax8_decoded;
640     }
641
642     /* decode each macroblock */
643     s->mb_x=0;
644     s->mb_y=0;
645
646     decode_slice(s);
647     while(s->mb_y<s->mb_height){
648         if(s->msmpeg4_version){
649             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)
650                 break;
651         }else{
652             if(ff_h263_resync(s)<0)
653                 break;
654         }
655
656         if(s->msmpeg4_version<4 && s->h263_pred)
657             ff_mpeg4_clean_buffers(s);
658
659         decode_slice(s);
660     }
661
662     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
663         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
664             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
665         }
666
667     assert(s->bitstream_buffer_size==0);
668     /* divx 5.01+ bistream reorder stuff */
669     if(s->codec_id==CODEC_ID_MPEG4 && s->divx_packed){
670         int current_pos= get_bits_count(&s->gb)>>3;
671         int startcode_found=0;
672
673         if(buf_size - current_pos > 5){
674             int i;
675             for(i=current_pos; i<buf_size-3; i++){
676                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
677                     startcode_found=1;
678                     break;
679                 }
680             }
681         }
682         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build){ //xvid style
683             startcode_found=1;
684             current_pos=0;
685         }
686
687         if(startcode_found){
688             av_fast_malloc(
689                 &s->bitstream_buffer,
690                 &s->allocated_bitstream_buffer_size,
691                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
692             if (!s->bitstream_buffer)
693                 return AVERROR(ENOMEM);
694             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
695             s->bitstream_buffer_size= buf_size - current_pos;
696         }
697     }
698
699 intrax8_decoded:
700     ff_er_frame_end(s);
701
702 frame_end:
703     if (avctx->hwaccel) {
704         if (avctx->hwaccel->end_frame(avctx) < 0)
705             return -1;
706     }
707
708     MPV_frame_end(s);
709
710 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
711 assert(s->current_picture.pict_type == s->pict_type);
712     if (s->pict_type == FF_B_TYPE || s->low_delay) {
713         *pict= *(AVFrame*)s->current_picture_ptr;
714     } else if (s->last_picture_ptr != NULL) {
715         *pict= *(AVFrame*)s->last_picture_ptr;
716     }
717
718     if(s->last_picture_ptr || s->low_delay){
719         *data_size = sizeof(AVFrame);
720         ff_print_debug_info(s, pict);
721     }
722
723 #ifdef PRINT_FRAME_TIME
724 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
725 #endif
726
727     return get_consumed_bytes(s, buf_size);
728 }
729
730 AVCodec h263_decoder = {
731     "h263",
732     CODEC_TYPE_VIDEO,
733     CODEC_ID_H263,
734     sizeof(MpegEncContext),
735     ff_h263_decode_init,
736     NULL,
737     ff_h263_decode_end,
738     ff_h263_decode_frame,
739     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
740     .flush= ff_mpeg_flush,
741     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
742     .pix_fmts= ff_hwaccel_pixfmt_list_420,
743 };
744
745 AVCodec msmpeg4v1_decoder = {
746     "msmpeg4v1",
747     CODEC_TYPE_VIDEO,
748     CODEC_ID_MSMPEG4V1,
749     sizeof(MpegEncContext),
750     ff_h263_decode_init,
751     NULL,
752     ff_h263_decode_end,
753     ff_h263_decode_frame,
754     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
755     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
756     .pix_fmts= ff_pixfmt_list_420,
757 };
758
759 AVCodec msmpeg4v2_decoder = {
760     "msmpeg4v2",
761     CODEC_TYPE_VIDEO,
762     CODEC_ID_MSMPEG4V2,
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,
769     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
770     .pix_fmts= ff_pixfmt_list_420,
771 };
772
773 AVCodec msmpeg4v3_decoder = {
774     "msmpeg4",
775     CODEC_TYPE_VIDEO,
776     CODEC_ID_MSMPEG4V3,
777     sizeof(MpegEncContext),
778     ff_h263_decode_init,
779     NULL,
780     ff_h263_decode_end,
781     ff_h263_decode_frame,
782     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
783     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
784     .pix_fmts= ff_pixfmt_list_420,
785 };
786
787 AVCodec wmv1_decoder = {
788     "wmv1",
789     CODEC_TYPE_VIDEO,
790     CODEC_ID_WMV1,
791     sizeof(MpegEncContext),
792     ff_h263_decode_init,
793     NULL,
794     ff_h263_decode_end,
795     ff_h263_decode_frame,
796     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
797     .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
798     .pix_fmts= ff_pixfmt_list_420,
799 };