Add a av_fast_malloc function and replace several uses of av_fast_realloc,
[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 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         break;
63     case CODEC_ID_MPEG4:
64         s->decode_mb= ff_mpeg4_decode_mb;
65         s->time_increment_bits = 4; /* default value for broken headers */
66         s->h263_pred = 1;
67         s->low_delay = 0; //default, might be overriden in the vol header during header parsing
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         break;
100     case CODEC_ID_H263I:
101         break;
102     case CODEC_ID_FLV1:
103         s->h263_flv = 1;
104         break;
105     default:
106         return -1;
107     }
108     s->codec_id= avctx->codec->id;
109     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
110
111     /* for h263, we allocate the images after having read the header */
112     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
113         if (MPV_common_init(s) < 0)
114             return -1;
115
116     if (CONFIG_MSMPEG4_DECODER && s->h263_msmpeg4)
117         ff_msmpeg4_decode_init(s);
118     else
119         h263_decode_init_vlc(s);
120
121     return 0;
122 }
123
124 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
125 {
126     MpegEncContext *s = avctx->priv_data;
127
128     MPV_common_end(s);
129     return 0;
130 }
131
132 /**
133  * returns the number of bytes consumed for building the current frame
134  */
135 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
136     int pos= (get_bits_count(&s->gb)+7)>>3;
137
138     if(s->divx_packed || s->avctx->hwaccel){
139         //we would have to scan through the whole buf to handle the weird reordering ...
140         return buf_size;
141     }else if(s->flags&CODEC_FLAG_TRUNCATED){
142         pos -= s->parse_context.last_index;
143         if(pos<0) pos=0; // padding is not really read so this might be -1
144         return pos;
145     }else{
146         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
147         if(pos+10>buf_size) pos=buf_size; // oops ;)
148
149         return pos;
150     }
151 }
152
153 static int decode_slice(MpegEncContext *s){
154     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
155     const int mb_size= 16>>s->avctx->lowres;
156     s->last_resync_gb= s->gb;
157     s->first_slice_line= 1;
158
159     s->resync_mb_x= s->mb_x;
160     s->resync_mb_y= s->mb_y;
161
162     ff_set_qscale(s, s->qscale);
163
164     if (s->avctx->hwaccel) {
165         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
166         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
167         skip_bits_long(&s->gb, 8*(end - start));
168         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
169     }
170
171     if(s->partitioned_frame){
172         const int qscale= s->qscale;
173
174         if(s->codec_id==CODEC_ID_MPEG4){
175             if(ff_mpeg4_decode_partitions(s) < 0)
176                 return -1;
177         }
178
179         /* restore variables which were modified */
180         s->first_slice_line=1;
181         s->mb_x= s->resync_mb_x;
182         s->mb_y= s->resync_mb_y;
183         ff_set_qscale(s, qscale);
184     }
185
186     for(; s->mb_y < s->mb_height; s->mb_y++) {
187         /* per-row end of slice checks */
188         if(s->msmpeg4_version){
189             if(s->resync_mb_y + s->slice_height == s->mb_y){
190                 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);
191
192                 return 0;
193             }
194         }
195
196         if(s->msmpeg4_version==1){
197             s->last_dc[0]=
198             s->last_dc[1]=
199             s->last_dc[2]= 128;
200         }
201
202         ff_init_block_index(s);
203         for(; s->mb_x < s->mb_width; s->mb_x++) {
204             int ret;
205
206             ff_update_block_index(s);
207
208             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
209                 s->first_slice_line=0;
210             }
211
212             /* DCT & quantize */
213
214             s->mv_dir = MV_DIR_FORWARD;
215             s->mv_type = MV_TYPE_16X16;
216 //            s->mb_skipped = 0;
217 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
218             ret= s->decode_mb(s, s->block);
219
220             if (s->pict_type!=FF_B_TYPE)
221                 ff_h263_update_motion_val(s);
222
223             if(ret<0){
224                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
225                 if(ret==SLICE_END){
226                     MPV_decode_mb(s, s->block);
227                     if(s->loop_filter)
228                         ff_h263_loop_filter(s);
229
230 //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));
231                     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);
232
233                     s->padding_bug_score--;
234
235                     if(++s->mb_x >= s->mb_width){
236                         s->mb_x=0;
237                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
238                         s->mb_y++;
239                     }
240                     return 0;
241                 }else if(ret==SLICE_NOEND){
242                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
243                     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);
244                     return -1;
245                 }
246                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
247                 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);
248
249                 return -1;
250             }
251
252             MPV_decode_mb(s, s->block);
253             if(s->loop_filter)
254                 ff_h263_loop_filter(s);
255         }
256
257         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
258
259         s->mb_x= 0;
260     }
261
262     assert(s->mb_x==0 && s->mb_y==s->mb_height);
263
264     /* try to detect the padding bug */
265     if(      s->codec_id==CODEC_ID_MPEG4
266        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
267        &&    s->gb.size_in_bits - get_bits_count(&s->gb) >=0
268        &&    s->gb.size_in_bits - get_bits_count(&s->gb) < 48
269 //       &&   !s->resync_marker
270        &&   !s->data_partitioning){
271
272         const int bits_count= get_bits_count(&s->gb);
273         const int bits_left = s->gb.size_in_bits - bits_count;
274
275         if(bits_left==0){
276             s->padding_bug_score+=16;
277         } else if(bits_left != 1){
278             int v= show_bits(&s->gb, 8);
279             v|= 0x7F >> (7-(bits_count&7));
280
281             if(v==0x7F && bits_left<=8)
282                 s->padding_bug_score--;
283             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
284                 s->padding_bug_score+= 4;
285             else
286                 s->padding_bug_score++;
287         }
288     }
289
290     if(s->workaround_bugs&FF_BUG_AUTODETECT){
291         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version || !s->resync_marker)*/)
292             s->workaround_bugs |=  FF_BUG_NO_PADDING;
293         else
294             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
295     }
296
297     // handle formats which don't have unique end markers
298     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
299         int left= s->gb.size_in_bits - get_bits_count(&s->gb);
300         int max_extra=7;
301
302         /* no markers in M$ crap */
303         if(s->msmpeg4_version && s->pict_type==FF_I_TYPE)
304             max_extra+= 17;
305
306         /* buggy padding but the frame should still end approximately at the bitstream end */
307         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
308             max_extra+= 48;
309         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
310             max_extra+= 256*256*256*64;
311
312         if(left>max_extra){
313             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
314         }
315         else if(left<0){
316             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
317         }else
318             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);
319
320         return 0;
321     }
322
323     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
324             s->gb.size_in_bits - get_bits_count(&s->gb),
325             show_bits(&s->gb, 24), s->padding_bug_score);
326
327     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);
328
329     return -1;
330 }
331
332 int ff_h263_decode_frame(AVCodecContext *avctx,
333                              void *data, int *data_size,
334                              AVPacket *avpkt)
335 {
336     const uint8_t *buf = avpkt->data;
337     int buf_size = avpkt->size;
338     MpegEncContext *s = avctx->priv_data;
339     int ret;
340     AVFrame *pict = data;
341
342 #ifdef PRINT_FRAME_TIME
343 uint64_t time= rdtsc();
344 #endif
345 #ifdef DEBUG
346     av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
347     if(buf_size>0)
348         av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
349 #endif
350     s->flags= avctx->flags;
351     s->flags2= avctx->flags2;
352
353     /* no supplementary picture */
354     if (buf_size == 0) {
355         /* special case for last picture */
356         if (s->low_delay==0 && s->next_picture_ptr) {
357             *pict= *(AVFrame*)s->next_picture_ptr;
358             s->next_picture_ptr= NULL;
359
360             *data_size = sizeof(AVFrame);
361         }
362
363         return 0;
364     }
365
366     if(s->flags&CODEC_FLAG_TRUNCATED){
367         int next;
368
369         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
370             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
371         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
372             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
373         }else{
374             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
375             return -1;
376         }
377
378         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
379             return buf_size;
380     }
381
382
383 retry:
384
385     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
386         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
387     }else
388         init_get_bits(&s->gb, buf, buf_size*8);
389     s->bitstream_buffer_size=0;
390
391     if (!s->context_initialized) {
392         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
393             return -1;
394     }
395
396     /* We need to set current_picture_ptr before reading the header,
397      * otherwise we cannot store anyting in there */
398     if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
399         int i= ff_find_unused_picture(s, 0);
400         s->current_picture_ptr= &s->picture[i];
401     }
402
403     /* let's go :-) */
404     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
405         ret= ff_wmv2_decode_picture_header(s);
406     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
407         ret = msmpeg4_decode_picture_header(s);
408     } else if (s->h263_pred) {
409         if(s->avctx->extradata_size && s->picture_number==0){
410             GetBitContext gb;
411
412             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
413             ret = ff_mpeg4_decode_picture_header(s, &gb);
414         }
415         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
416     } else if (s->codec_id == CODEC_ID_H263I) {
417         ret = intel_h263_decode_picture_header(s);
418     } else if (s->h263_flv) {
419         ret = flv_h263_decode_picture_header(s);
420     } else {
421         ret = h263_decode_picture_header(s);
422     }
423
424     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
425
426     /* skip if the header was thrashed */
427     if (ret < 0){
428         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
429         return -1;
430     }
431
432     avctx->has_b_frames= !s->low_delay;
433
434     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
435         if(s->stream_codec_tag == AV_RL32("XVID") ||
436            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
437            s->codec_tag == AV_RL32("RMP4"))
438             s->xvid_build= -1;
439 #if 0
440         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
441            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
442             s->xvid_build= -1;
443 #endif
444     }
445
446     if(s->xvid_build==0 && s->divx_version==0 && s->lavc_build==0){
447         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
448             s->divx_version= 400; //divx 4
449     }
450
451     if(s->xvid_build && s->divx_version){
452         s->divx_version=
453         s->divx_build= 0;
454     }
455
456     if(s->workaround_bugs&FF_BUG_AUTODETECT){
457         if(s->codec_tag == AV_RL32("XVIX"))
458             s->workaround_bugs|= FF_BUG_XVID_ILACE;
459
460         if(s->codec_tag == AV_RL32("UMP4")){
461             s->workaround_bugs|= FF_BUG_UMP4;
462         }
463
464         if(s->divx_version>=500 && s->divx_build<1814){
465             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
466         }
467
468         if(s->divx_version>502 && s->divx_build<1814){
469             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
470         }
471
472         if(s->xvid_build && s->xvid_build<=3)
473             s->padding_bug_score= 256*256*256*64;
474
475         if(s->xvid_build && s->xvid_build<=1)
476             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
477
478         if(s->xvid_build && s->xvid_build<=12)
479             s->workaround_bugs|= FF_BUG_EDGE;
480
481         if(s->xvid_build && s->xvid_build<=32)
482             s->workaround_bugs|= FF_BUG_DC_CLIP;
483
484 #define SET_QPEL_FUNC(postfix1, postfix2) \
485     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
486     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
487     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
488
489         if(s->lavc_build && s->lavc_build<4653)
490             s->workaround_bugs|= FF_BUG_STD_QPEL;
491
492         if(s->lavc_build && s->lavc_build<4655)
493             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
494
495         if(s->lavc_build && s->lavc_build<4670){
496             s->workaround_bugs|= FF_BUG_EDGE;
497         }
498
499         if(s->lavc_build && s->lavc_build<=4712)
500             s->workaround_bugs|= FF_BUG_DC_CLIP;
501
502         if(s->divx_version)
503             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
504 //printf("padding_bug_score: %d\n", s->padding_bug_score);
505         if(s->divx_version==501 && s->divx_build==20020416)
506             s->padding_bug_score= 256*256*256*64;
507
508         if(s->divx_version && s->divx_version<500){
509             s->workaround_bugs|= FF_BUG_EDGE;
510         }
511
512         if(s->divx_version)
513             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
514 #if 0
515         if(s->divx_version==500)
516             s->padding_bug_score= 256*256*256*64;
517
518         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
519          * Let us hope this at least works.
520          */
521         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==0
522            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
523             s->workaround_bugs|= FF_BUG_NO_PADDING;
524
525         if(s->lavc_build && s->lavc_build<4609) //FIXME not sure about the version num but a 4609 file seems ok
526             s->workaround_bugs|= FF_BUG_NO_PADDING;
527 #endif
528     }
529
530     if(s->workaround_bugs& FF_BUG_STD_QPEL){
531         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
532         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
533         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
534         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
535         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
536         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
537
538         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
539         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
540         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
541         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
542         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
543         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
544     }
545
546     if(avctx->debug & FF_DEBUG_BUGS)
547         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
548                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
549                s->divx_packed ? "p" : "");
550
551 #if 0 // dump bits per frame / qp / complexity
552 {
553     static FILE *f=NULL;
554     if(!f) f=fopen("rate_qp_cplx.txt", "w");
555     fprintf(f, "%d %d %f\n", buf_size, s->qscale, buf_size*(double)s->qscale);
556 }
557 #endif
558
559 #if HAVE_MMX
560     if(s->codec_id == CODEC_ID_MPEG4 && s->xvid_build && avctx->idct_algo == FF_IDCT_AUTO && (mm_flags & FF_MM_MMX)){
561         avctx->idct_algo= FF_IDCT_XVIDMMX;
562         avctx->coded_width= 0; // force reinit
563 //        dsputil_init(&s->dsp, avctx);
564         s->picture_number=0;
565     }
566 #endif
567
568         /* After H263 & mpeg4 header decode we have the height, width,*/
569         /* and other parameters. So then we could init the picture   */
570         /* FIXME: By the way H263 decoder is evolving it should have */
571         /* an H263EncContext                                         */
572
573     if (   s->width  != avctx->coded_width
574         || s->height != avctx->coded_height) {
575         /* H.263 could change picture size any time */
576         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
577         s->parse_context.buffer=0;
578         MPV_common_end(s);
579         s->parse_context= pc;
580     }
581     if (!s->context_initialized) {
582         avcodec_set_dimensions(avctx, s->width, s->height);
583
584         goto retry;
585     }
586
587     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
588         s->gob_index = ff_h263_get_gob_height(s);
589
590     // for hurry_up==5
591     s->current_picture.pict_type= s->pict_type;
592     s->current_picture.key_frame= s->pict_type == FF_I_TYPE;
593
594     /* skip B-frames if we don't have reference frames */
595     if(s->last_picture_ptr==NULL && (s->pict_type==FF_B_TYPE || s->dropable)) return get_consumed_bytes(s, buf_size);
596     /* skip b frames if we are in a hurry */
597     if(avctx->hurry_up && s->pict_type==FF_B_TYPE) return get_consumed_bytes(s, buf_size);
598     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==FF_B_TYPE)
599        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=FF_I_TYPE)
600        ||  avctx->skip_frame >= AVDISCARD_ALL)
601         return get_consumed_bytes(s, buf_size);
602     /* skip everything if we are in a hurry>=5 */
603     if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
604
605     if(s->next_p_frame_damaged){
606         if(s->pict_type==FF_B_TYPE)
607             return get_consumed_bytes(s, buf_size);
608         else
609             s->next_p_frame_damaged=0;
610     }
611
612     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==FF_B_TYPE){
613         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
614         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
615     }else if((!s->no_rounding) || s->pict_type==FF_B_TYPE){
616         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
617         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
618     }else{
619         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
620         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
621     }
622
623     if(MPV_frame_start(s, avctx) < 0)
624         return -1;
625
626     if (avctx->hwaccel) {
627         if (avctx->hwaccel->start_frame(avctx, buf, buf_size) < 0)
628             return -1;
629     }
630
631 #ifdef DEBUG
632     av_log(avctx, AV_LOG_DEBUG, "qscale=%d\n", s->qscale);
633 #endif
634
635     ff_er_frame_start(s);
636
637     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
638     //which is not available before MPV_frame_start()
639     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
640         ret = ff_wmv2_decode_secondary_picture_header(s);
641         if(ret<0) return ret;
642         if(ret==1) goto intrax8_decoded;
643     }
644
645     /* decode each macroblock */
646     s->mb_x=0;
647     s->mb_y=0;
648
649     decode_slice(s);
650     while(s->mb_y<s->mb_height){
651         if(s->msmpeg4_version){
652             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)
653                 break;
654         }else{
655             if(ff_h263_resync(s)<0)
656                 break;
657         }
658
659         if(s->msmpeg4_version<4 && s->h263_pred)
660             ff_mpeg4_clean_buffers(s);
661
662         decode_slice(s);
663     }
664
665     if (s->h263_msmpeg4 && s->msmpeg4_version<4 && s->pict_type==FF_I_TYPE)
666         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
667             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
668         }
669
670     /* divx 5.01+ bistream reorder stuff */
671     if(s->codec_id==CODEC_ID_MPEG4 && s->bitstream_buffer_size==0 && s->divx_packed){
672         int current_pos= get_bits_count(&s->gb)>>3;
673         int startcode_found=0;
674
675         if(buf_size - current_pos > 5){
676             int i;
677             for(i=current_pos; i<buf_size-3; i++){
678                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
679                     startcode_found=1;
680                     break;
681                 }
682             }
683         }
684         if(s->gb.buffer == s->bitstream_buffer && buf_size>20){ //xvid style
685             startcode_found=1;
686             current_pos=0;
687         }
688
689         if(startcode_found){
690             av_fast_malloc(
691                 &s->bitstream_buffer,
692                 &s->allocated_bitstream_buffer_size,
693                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
694             if (!s->bitstream_buffer)
695                 return AVERROR(ENOMEM);
696             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
697             s->bitstream_buffer_size= buf_size - current_pos;
698         }
699     }
700
701 intrax8_decoded:
702     ff_er_frame_end(s);
703
704     if (avctx->hwaccel) {
705         if (avctx->hwaccel->end_frame(avctx) < 0)
706             return -1;
707     }
708
709     MPV_frame_end(s);
710
711 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
712 assert(s->current_picture.pict_type == s->pict_type);
713     if (s->pict_type == FF_B_TYPE || s->low_delay) {
714         *pict= *(AVFrame*)s->current_picture_ptr;
715     } else if (s->last_picture_ptr != NULL) {
716         *pict= *(AVFrame*)s->last_picture_ptr;
717     }
718
719     if(s->last_picture_ptr || s->low_delay){
720         *data_size = sizeof(AVFrame);
721         ff_print_debug_info(s, pict);
722     }
723
724     /* Return the Picture timestamp as the frame number */
725     /* we subtract 1 because it is added on utils.c     */
726     avctx->frame_number = s->picture_number - 1;
727
728 #ifdef PRINT_FRAME_TIME
729 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
730 #endif
731
732     return get_consumed_bytes(s, buf_size);
733 }
734
735 AVCodec mpeg4_decoder = {
736     "mpeg4",
737     CODEC_TYPE_VIDEO,
738     CODEC_ID_MPEG4,
739     sizeof(MpegEncContext),
740     ff_h263_decode_init,
741     NULL,
742     ff_h263_decode_end,
743     ff_h263_decode_frame,
744     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
745     .flush= ff_mpeg_flush,
746     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
747     .pix_fmts= ff_hwaccel_pixfmt_list_420,
748 };
749
750 AVCodec h263_decoder = {
751     "h263",
752     CODEC_TYPE_VIDEO,
753     CODEC_ID_H263,
754     sizeof(MpegEncContext),
755     ff_h263_decode_init,
756     NULL,
757     ff_h263_decode_end,
758     ff_h263_decode_frame,
759     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
760     .flush= ff_mpeg_flush,
761     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
762     .pix_fmts= ff_hwaccel_pixfmt_list_420,
763 };
764
765 AVCodec msmpeg4v1_decoder = {
766     "msmpeg4v1",
767     CODEC_TYPE_VIDEO,
768     CODEC_ID_MSMPEG4V1,
769     sizeof(MpegEncContext),
770     ff_h263_decode_init,
771     NULL,
772     ff_h263_decode_end,
773     ff_h263_decode_frame,
774     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
775     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 1"),
776     .pix_fmts= ff_pixfmt_list_420,
777 };
778
779 AVCodec msmpeg4v2_decoder = {
780     "msmpeg4v2",
781     CODEC_TYPE_VIDEO,
782     CODEC_ID_MSMPEG4V2,
783     sizeof(MpegEncContext),
784     ff_h263_decode_init,
785     NULL,
786     ff_h263_decode_end,
787     ff_h263_decode_frame,
788     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
789     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 2"),
790     .pix_fmts= ff_pixfmt_list_420,
791 };
792
793 AVCodec msmpeg4v3_decoder = {
794     "msmpeg4",
795     CODEC_TYPE_VIDEO,
796     CODEC_ID_MSMPEG4V3,
797     sizeof(MpegEncContext),
798     ff_h263_decode_init,
799     NULL,
800     ff_h263_decode_end,
801     ff_h263_decode_frame,
802     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
803     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 Microsoft variant version 3"),
804     .pix_fmts= ff_pixfmt_list_420,
805 };
806
807 AVCodec wmv1_decoder = {
808     "wmv1",
809     CODEC_TYPE_VIDEO,
810     CODEC_ID_WMV1,
811     sizeof(MpegEncContext),
812     ff_h263_decode_init,
813     NULL,
814     ff_h263_decode_end,
815     ff_h263_decode_frame,
816     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
817     .long_name= NULL_IF_CONFIG_SMALL("Windows Media Video 7"),
818     .pix_fmts= ff_pixfmt_list_420,
819 };
820
821 AVCodec h263i_decoder = {
822     "h263i",
823     CODEC_TYPE_VIDEO,
824     CODEC_ID_H263I,
825     sizeof(MpegEncContext),
826     ff_h263_decode_init,
827     NULL,
828     ff_h263_decode_end,
829     ff_h263_decode_frame,
830     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
831     .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"),
832     .pix_fmts= ff_pixfmt_list_420,
833 };
834
835 AVCodec flv_decoder = {
836     "flv",
837     CODEC_TYPE_VIDEO,
838     CODEC_ID_FLV1,
839     sizeof(MpegEncContext),
840     ff_h263_decode_init,
841     NULL,
842     ff_h263_decode_end,
843     ff_h263_decode_frame,
844     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
845     .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV)"),
846     .pix_fmts= ff_pixfmt_list_420,
847 };