avcodec/h263dec: use FF_CEIL_RSHIFT()
[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 #define UNCHECKED_BITSTREAM_READER 1
29
30 #include "libavutil/cpu.h"
31 #include "internal.h"
32 #include "avcodec.h"
33 #include "error_resilience.h"
34 #include "mpegvideo.h"
35 #include "h263.h"
36 #include "h263_parser.h"
37 #include "mpeg4video_parser.h"
38 #include "msmpeg4.h"
39 #include "vdpau_internal.h"
40 #include "thread.h"
41 #include "flv.h"
42 #include "mpeg4video.h"
43
44 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
45 {
46     MpegEncContext *s = avctx->priv_data;
47     int ret;
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     ff_MPV_decode_defaults(s);
58     s->quant_precision=5;
59     s->decode_mb= ff_h263_decode_mb;
60     s->low_delay= 1;
61     if (avctx->codec->id == AV_CODEC_ID_MSS2)
62         avctx->pix_fmt = AV_PIX_FMT_YUV420P;
63     else
64         avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
65     s->unrestricted_mv= 1;
66
67     /* select sub codec */
68     switch(avctx->codec->id) {
69     case AV_CODEC_ID_H263:
70     case AV_CODEC_ID_H263P:
71         s->unrestricted_mv= 0;
72         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
73         break;
74     case AV_CODEC_ID_MPEG4:
75         break;
76     case AV_CODEC_ID_MSMPEG4V1:
77         s->h263_pred = 1;
78         s->msmpeg4_version=1;
79         break;
80     case AV_CODEC_ID_MSMPEG4V2:
81         s->h263_pred = 1;
82         s->msmpeg4_version=2;
83         break;
84     case AV_CODEC_ID_MSMPEG4V3:
85         s->h263_pred = 1;
86         s->msmpeg4_version=3;
87         break;
88     case AV_CODEC_ID_WMV1:
89         s->h263_pred = 1;
90         s->msmpeg4_version=4;
91         break;
92     case AV_CODEC_ID_WMV2:
93         s->h263_pred = 1;
94         s->msmpeg4_version=5;
95         break;
96     case AV_CODEC_ID_VC1:
97     case AV_CODEC_ID_WMV3:
98     case AV_CODEC_ID_VC1IMAGE:
99     case AV_CODEC_ID_WMV3IMAGE:
100     case AV_CODEC_ID_MSS2:
101         s->h263_pred = 1;
102         s->msmpeg4_version=6;
103         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
104         break;
105     case AV_CODEC_ID_H263I:
106         break;
107     case AV_CODEC_ID_FLV1:
108         s->h263_flv = 1;
109         break;
110     default:
111         return AVERROR(EINVAL);
112     }
113     s->codec_id= avctx->codec->id;
114     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
115
116     /* for h263, we allocate the images after having read the header */
117     if (avctx->codec->id != AV_CODEC_ID_H263 && avctx->codec->id != AV_CODEC_ID_H263P && avctx->codec->id != AV_CODEC_ID_MPEG4)
118         if ((ret = ff_MPV_common_init(s)) < 0)
119             return ret;
120
121         ff_h263_decode_init_vlc();
122
123     return 0;
124 }
125
126 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
127 {
128     MpegEncContext *s = avctx->priv_data;
129
130     ff_MPV_common_end(s);
131     return 0;
132 }
133
134 /**
135  * Return the number of bytes consumed for building the current frame.
136  */
137 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
138     int pos= (get_bits_count(&s->gb)+7)>>3;
139
140     if(s->divx_packed || s->avctx->hwaccel){
141         //we would have to scan through the whole buf to handle the weird reordering ...
142         return buf_size;
143     }else if(s->flags&CODEC_FLAG_TRUNCATED){
144         pos -= s->parse_context.last_index;
145         if(pos<0) pos=0; // padding is not really read so this might be -1
146         return pos;
147     }else{
148         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
149         if(pos+10>buf_size) pos=buf_size; // oops ;)
150
151         return pos;
152     }
153 }
154
155 static int decode_slice(MpegEncContext *s){
156     const int part_mask= s->partitioned_frame ? (ER_AC_END|ER_AC_ERROR) : 0x7F;
157     const int mb_size= 16>>s->avctx->lowres;
158     int ret;
159
160     s->last_resync_gb= s->gb;
161     s->first_slice_line= 1;
162
163     s->resync_mb_x= s->mb_x;
164     s->resync_mb_y= s->mb_y;
165
166     ff_set_qscale(s, s->qscale);
167
168     if (s->avctx->hwaccel) {
169         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
170         const uint8_t *end  = ff_h263_find_resync_marker(s, start + 1, s->gb.buffer_end);
171         skip_bits_long(&s->gb, 8*(end - start));
172         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
173     }
174
175     if(s->partitioned_frame){
176         const int qscale= s->qscale;
177
178         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
179             if ((ret = ff_mpeg4_decode_partitions(s)) < 0)
180                 return ret;
181         }
182
183         /* restore variables which were modified */
184         s->first_slice_line=1;
185         s->mb_x= s->resync_mb_x;
186         s->mb_y= s->resync_mb_y;
187         ff_set_qscale(s, qscale);
188     }
189
190     for(; s->mb_y < s->mb_height; s->mb_y++) {
191         /* per-row end of slice checks */
192         if(s->msmpeg4_version){
193             if(s->resync_mb_y + s->slice_height == s->mb_y){
194                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
195
196                 return 0;
197             }
198         }
199
200         if(s->msmpeg4_version==1){
201             s->last_dc[0]=
202             s->last_dc[1]=
203             s->last_dc[2]= 128;
204         }
205
206         ff_init_block_index(s);
207         for(; s->mb_x < s->mb_width; s->mb_x++) {
208             int ret;
209
210             ff_update_block_index(s);
211
212             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
213                 s->first_slice_line=0;
214             }
215
216             /* DCT & quantize */
217
218             s->mv_dir = MV_DIR_FORWARD;
219             s->mv_type = MV_TYPE_16X16;
220 //            s->mb_skipped = 0;
221             av_dlog(s, "%d %d %06X\n",
222                     ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
223             ret= s->decode_mb(s, s->block);
224
225             if (s->pict_type!=AV_PICTURE_TYPE_B)
226                 ff_h263_update_motion_val(s);
227
228             if(ret<0){
229                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
230                 if(ret==SLICE_END){
231                     ff_MPV_decode_mb(s, s->block);
232                     if(s->loop_filter)
233                         ff_h263_loop_filter(s);
234
235                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
236
237                     s->padding_bug_score--;
238
239                     if(++s->mb_x >= s->mb_width){
240                         s->mb_x=0;
241                         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
242                         ff_MPV_report_decode_progress(s);
243                         s->mb_y++;
244                     }
245                     return 0;
246                 }else if(ret==SLICE_NOEND){
247                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
248                     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, ER_MB_END&part_mask);
249                     return AVERROR_INVALIDDATA;
250                 }
251                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
252                 ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR&part_mask);
253
254                 return AVERROR_INVALIDDATA;
255             }
256
257             ff_MPV_decode_mb(s, s->block);
258             if(s->loop_filter)
259                 ff_h263_loop_filter(s);
260         }
261
262         ff_mpeg_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
263         ff_MPV_report_decode_progress(s);
264
265         s->mb_x= 0;
266     }
267
268     av_assert1(s->mb_x==0 && s->mb_y==s->mb_height);
269
270     if(s->codec_id==AV_CODEC_ID_MPEG4
271        && (s->workaround_bugs&FF_BUG_AUTODETECT)
272        && get_bits_left(&s->gb) >= 48
273        && show_bits(&s->gb, 24)==0x4010
274        && !s->data_partitioning)
275         s->padding_bug_score+=32;
276
277     /* try to detect the padding bug */
278     if(      s->codec_id==AV_CODEC_ID_MPEG4
279        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
280        &&    get_bits_left(&s->gb) >=0
281        &&    get_bits_left(&s->gb) < 137
282 //       &&   !s->resync_marker
283        &&   !s->data_partitioning){
284
285         const int bits_count= get_bits_count(&s->gb);
286         const int bits_left = s->gb.size_in_bits - bits_count;
287
288         if(bits_left==0){
289             s->padding_bug_score+=16;
290         } else if(bits_left != 1){
291             int v= show_bits(&s->gb, 8);
292             v|= 0x7F >> (7-(bits_count&7));
293
294             if(v==0x7F && bits_left<=8)
295                 s->padding_bug_score--;
296             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
297                 s->padding_bug_score+= 4;
298             else
299                 s->padding_bug_score++;
300         }
301     }
302
303     if(s->workaround_bugs&FF_BUG_AUTODETECT){
304         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
305             s->workaround_bugs |=  FF_BUG_NO_PADDING;
306         else
307             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
308     }
309
310     // handle formats which don't have unique end markers
311     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
312         int left= get_bits_left(&s->gb);
313         int max_extra=7;
314
315         /* no markers in M$ crap */
316         if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
317             max_extra+= 17;
318
319         /* buggy padding but the frame should still end approximately at the bitstream end */
320         if((s->workaround_bugs&FF_BUG_NO_PADDING) && (s->err_recognition&(AV_EF_BUFFER|AV_EF_AGGRESSIVE)))
321             max_extra+= 48;
322         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
323             max_extra+= 256*256*256*64;
324
325         if(left>max_extra){
326             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
327         }
328         else if(left<0){
329             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
330         }else
331             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, ER_MB_END);
332
333         return 0;
334     }
335
336     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
337             get_bits_left(&s->gb),
338             show_bits(&s->gb, 24), s->padding_bug_score);
339
340     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, ER_MB_END&part_mask);
341
342     return AVERROR_INVALIDDATA;
343 }
344
345 int ff_h263_decode_frame(AVCodecContext *avctx,
346                              void *data, int *got_frame,
347                              AVPacket *avpkt)
348 {
349     const uint8_t *buf = avpkt->data;
350     int buf_size = avpkt->size;
351     MpegEncContext *s = avctx->priv_data;
352     int ret;
353     AVFrame *pict = data;
354
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             if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)
363                 return ret;
364             s->next_picture_ptr= NULL;
365
366             *got_frame = 1;
367         }
368
369         return 0;
370     }
371
372     if(s->flags&CODEC_FLAG_TRUNCATED){
373         int next;
374
375         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){
376             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
377         }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){
378             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
379         }else if(CONFIG_H263P_DECODER && s->codec_id==AV_CODEC_ID_H263P){
380             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
381         }else{
382             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
383             return AVERROR(EINVAL);
384         }
385
386         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
387             return buf_size;
388     }
389
390
391 retry:
392     if(s->divx_packed && s->bitstream_buffer_size){
393         int i;
394         for(i=0; i<buf_size-3; i++){
395             if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1){
396                 if(buf[i+3]==0xB0){
397                     av_log(s->avctx, AV_LOG_WARNING, "Discarding excessive bitstream in packed xvid\n");
398                     s->bitstream_buffer_size=0;
399                 }
400                 break;
401             }
402         }
403     }
404
405     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
406         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
407     }else
408         init_get_bits(&s->gb, buf, buf_size*8);
409     s->bitstream_buffer_size=0;
410
411     if (!s->context_initialized) {
412         if ((ret = ff_MPV_common_init(s)) < 0) //we need the idct permutaton for reading a custom matrix
413             return ret;
414     }
415
416     /* We need to set current_picture_ptr before reading the header,
417      * otherwise we cannot store anyting in there */
418     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
419         int i= ff_find_unused_picture(s, 0);
420         if (i < 0)
421             return i;
422         s->current_picture_ptr= &s->picture[i];
423     }
424
425     /* let's go :-) */
426     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
427         ret= ff_wmv2_decode_picture_header(s);
428     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
429         ret = ff_msmpeg4_decode_picture_header(s);
430     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
431         if(s->avctx->extradata_size && s->picture_number==0){
432             GetBitContext gb;
433
434             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
435             ret = ff_mpeg4_decode_picture_header(s, &gb);
436         }
437         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
438     } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {
439         ret = ff_intel_h263_decode_picture_header(s);
440     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
441         ret = ff_flv_decode_picture_header(s);
442     } else {
443         ret = ff_h263_decode_picture_header(s);
444     }
445
446     if (ret < 0 || ret==FRAME_SKIPPED) {
447         if (   s->width  != avctx->coded_width
448             || s->height != avctx->coded_height) {
449                 av_log(s->avctx, AV_LOG_WARNING, "Reverting picture dimensions change due to header decoding failure\n");
450                 s->width = avctx->coded_width;
451                 s->height= avctx->coded_height;
452         }
453     }
454     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
455
456     /* skip if the header was thrashed */
457     if (ret < 0){
458         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
459         return ret;
460     }
461
462     avctx->has_b_frames= !s->low_delay;
463
464     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
465         if(s->stream_codec_tag == AV_RL32("XVID") ||
466            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
467            s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||
468            s->codec_tag == AV_RL32("SIPP")
469            )
470             s->xvid_build= 0;
471 #if 0
472         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
473            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
474             s->xvid_build= 0;
475 #endif
476     }
477
478     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
479         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
480             s->divx_version= 400; //divx 4
481     }
482
483     if(s->xvid_build>=0 && s->divx_version>=0){
484         s->divx_version=
485         s->divx_build= -1;
486     }
487
488     if(s->workaround_bugs&FF_BUG_AUTODETECT){
489         if(s->codec_tag == AV_RL32("XVIX"))
490             s->workaround_bugs|= FF_BUG_XVID_ILACE;
491
492         if(s->codec_tag == AV_RL32("UMP4")){
493             s->workaround_bugs|= FF_BUG_UMP4;
494         }
495
496         if(s->divx_version>=500 && s->divx_build<1814){
497             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
498         }
499
500         if(s->divx_version>502 && s->divx_build<1814){
501             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
502         }
503
504         if(s->xvid_build<=3U)
505             s->padding_bug_score= 256*256*256*64;
506
507         if(s->xvid_build<=1U)
508             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
509
510         if(s->xvid_build<=12U)
511             s->workaround_bugs|= FF_BUG_EDGE;
512
513         if(s->xvid_build<=32U)
514             s->workaround_bugs|= FF_BUG_DC_CLIP;
515
516 #define SET_QPEL_FUNC(postfix1, postfix2) \
517     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
518     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
519     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
520
521         if(s->lavc_build<4653U)
522             s->workaround_bugs|= FF_BUG_STD_QPEL;
523
524         if(s->lavc_build<4655U)
525             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
526
527         if(s->lavc_build<4670U){
528             s->workaround_bugs|= FF_BUG_EDGE;
529         }
530
531         if(s->lavc_build<=4712U)
532             s->workaround_bugs|= FF_BUG_DC_CLIP;
533
534         if(s->divx_version>=0)
535             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
536         if(s->divx_version==501 && s->divx_build==20020416)
537             s->padding_bug_score= 256*256*256*64;
538
539         if(s->divx_version<500U){
540             s->workaround_bugs|= FF_BUG_EDGE;
541         }
542
543         if(s->divx_version>=0)
544             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
545 #if 0
546         if(s->divx_version==500)
547             s->padding_bug_score= 256*256*256*64;
548
549         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
550          * Let us hope this at least works.
551          */
552         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
553            && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)
554             s->workaround_bugs|= FF_BUG_NO_PADDING;
555
556         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
557             s->workaround_bugs|= FF_BUG_NO_PADDING;
558 #endif
559     }
560
561     if(s->workaround_bugs& FF_BUG_STD_QPEL){
562         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
563         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
564         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
565         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
566         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
567         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
568
569         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
570         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
571         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
572         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
573         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
574         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
575     }
576
577     if(avctx->debug & FF_DEBUG_BUGS)
578         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
579                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
580                s->divx_packed ? "p" : "");
581
582 #if HAVE_MMX
583     if (s->codec_id == AV_CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
584         avctx->idct_algo= FF_IDCT_XVIDMMX;
585         ff_dct_common_init(s);
586         goto retry;
587     }
588 #endif
589
590         /* After H263 & mpeg4 header decode we have the height, width,*/
591         /* and other parameters. So then we could init the picture   */
592         /* FIXME: By the way H263 decoder is evolving it should have */
593         /* an H263EncContext                                         */
594
595     if ((!avctx->coded_width || !avctx->coded_height) && 0) {
596         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
597
598         s->parse_context.buffer=0;
599         ff_MPV_common_end(s);
600         s->parse_context= pc;
601         avcodec_set_dimensions(avctx, s->width, s->height);
602
603         goto retry;
604     }
605
606     if (s->width  != avctx->coded_width  ||
607         s->height != avctx->coded_height ||
608         s->context_reinit) {
609         /* H.263 could change picture size any time */
610         s->context_reinit = 0;
611
612         avcodec_set_dimensions(avctx, s->width, s->height);
613
614         if ((ret = ff_MPV_common_frame_size_change(s)))
615             return ret;
616     }
617
618     if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))
619         s->gob_index = ff_h263_get_gob_height(s);
620
621     // for skipping the frame
622     s->current_picture.f.pict_type = s->pict_type;
623     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
624
625     /* skip B-frames if we don't have reference frames */
626     if (s->last_picture_ptr == NULL &&
627         (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))
628         return get_consumed_bytes(s, buf_size);
629     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
630        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
631        ||  avctx->skip_frame >= AVDISCARD_ALL)
632         return get_consumed_bytes(s, buf_size);
633
634     if(s->next_p_frame_damaged){
635         if(s->pict_type==AV_PICTURE_TYPE_B)
636             return get_consumed_bytes(s, buf_size);
637         else
638             s->next_p_frame_damaged=0;
639     }
640
641     if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
642         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
643         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
644     }else{
645         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
646         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
647     }
648
649     if ((ret = ff_MPV_frame_start(s, avctx)) < 0)
650         return ret;
651
652     if (!s->divx_packed && !avctx->hwaccel)
653         ff_thread_finish_setup(avctx);
654
655     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
656         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
657         goto frame_end;
658     }
659
660     if (avctx->hwaccel) {
661         if ((ret = avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer)) < 0)
662             return ret;
663     }
664
665     ff_mpeg_er_frame_start(s);
666
667     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
668     //which is not available before ff_MPV_frame_start()
669     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
670         ret = ff_wmv2_decode_secondary_picture_header(s);
671         if(ret<0) return ret;
672         if(ret==1) goto intrax8_decoded;
673     }
674
675     /* decode each macroblock */
676     s->mb_x=0;
677     s->mb_y=0;
678
679     ret = decode_slice(s);
680     while(s->mb_y<s->mb_height){
681         if(s->msmpeg4_version){
682             if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)
683                 break;
684         }else{
685             int prev_x=s->mb_x, prev_y=s->mb_y;
686             if(ff_h263_resync(s)<0)
687                 break;
688             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
689                 s->er.error_occurred = 1;
690         }
691
692         if(s->msmpeg4_version<4 && s->h263_pred)
693             ff_mpeg4_clean_buffers(s);
694
695         if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;
696     }
697
698     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
699         if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){
700             s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;
701         }
702
703     av_assert1(s->bitstream_buffer_size==0);
704 frame_end:
705     /* divx 5.01+ bitstream reorder stuff */
706     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){
707         int current_pos= s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb)>>3);
708         int startcode_found=0;
709
710         if(buf_size - current_pos > 7){
711             int i;
712             for(i=current_pos; i<buf_size-4; i++){
713                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
714                     startcode_found=!(buf[i+4]&0x40);
715                     break;
716                 }
717             }
718         }
719
720         if(startcode_found){
721             av_fast_malloc(
722                 &s->bitstream_buffer,
723                 &s->allocated_bitstream_buffer_size,
724                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
725             if (!s->bitstream_buffer)
726                 return AVERROR(ENOMEM);
727             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
728             s->bitstream_buffer_size= buf_size - current_pos;
729         }
730     }
731
732 intrax8_decoded:
733     ff_er_frame_end(&s->er);
734
735     if (avctx->hwaccel) {
736         if ((ret = avctx->hwaccel->end_frame(avctx)) < 0)
737             return ret;
738     }
739
740     ff_MPV_frame_end(s);
741
742     if (!s->divx_packed && avctx->hwaccel)
743         ff_thread_finish_setup(avctx);
744
745     av_assert1(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);
746     av_assert1(s->current_picture.f.pict_type == s->pict_type);
747     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
748         if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)
749             return ret;
750         ff_print_debug_info(s, s->current_picture_ptr, pict);
751         ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG1);
752     } else if (s->last_picture_ptr != NULL) {
753         if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)
754             return ret;
755         ff_print_debug_info(s, s->last_picture_ptr, pict);
756         ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG1);
757     }
758
759     if(s->last_picture_ptr || s->low_delay){
760         if (   pict->format == AV_PIX_FMT_YUV420P
761             && (s->codec_tag == AV_RL32("GEOV") || s->codec_tag == AV_RL32("GEOX"))) {
762             int x, y, p;
763             av_frame_make_writable(pict);
764             for (p=0; p<3; p++) {
765                 int w = FF_CEIL_RSHIFT(pict-> width, !!p);
766                 int h = FF_CEIL_RSHIFT(pict->height, !!p);
767                 int linesize = pict->linesize[p];
768                 for (y=0; y<(h>>1); y++)
769                     for (x=0; x<w; x++)
770                         FFSWAP(int,
771                                pict->data[p][x + y*linesize],
772                                pict->data[p][x + (h-1-y)*linesize]);
773             }
774         }
775         *got_frame = 1;
776     }
777
778     return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);
779 }
780
781 const enum AVPixelFormat ff_h263_hwaccel_pixfmt_list_420[] = {
782 #if CONFIG_VAAPI
783     AV_PIX_FMT_VAAPI_VLD,
784 #endif
785 #if CONFIG_VDPAU
786     AV_PIX_FMT_VDPAU,
787 #endif
788     AV_PIX_FMT_YUV420P,
789     AV_PIX_FMT_NONE
790 };
791
792 AVCodec ff_h263_decoder = {
793     .name           = "h263",
794     .type           = AVMEDIA_TYPE_VIDEO,
795     .id             = AV_CODEC_ID_H263,
796     .priv_data_size = sizeof(MpegEncContext),
797     .init           = ff_h263_decode_init,
798     .close          = ff_h263_decode_end,
799     .decode         = ff_h263_decode_frame,
800     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
801                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
802     .flush          = ff_mpeg_flush,
803     .max_lowres     = 3,
804     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
805     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
806 };
807
808 AVCodec ff_h263p_decoder = {
809     .name           = "h263p",
810     .type           = AVMEDIA_TYPE_VIDEO,
811     .id             = AV_CODEC_ID_H263P,
812     .priv_data_size = sizeof(MpegEncContext),
813     .init           = ff_h263_decode_init,
814     .close          = ff_h263_decode_end,
815     .decode         = ff_h263_decode_frame,
816     .capabilities   = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 |
817                       CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
818     .flush          = ff_mpeg_flush,
819     .max_lowres     = 3,
820     .long_name      = NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
821     .pix_fmts       = ff_h263_hwaccel_pixfmt_list_420,
822 };