Eliminate FF_COMMON_FRAME macro.
[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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 /**
24  * @file
25  * H.263 decoder.
26  */
27
28 #include "libavutil/cpu.h"
29 #include "internal.h"
30 #include "avcodec.h"
31 #include "dsputil.h"
32 #include "mpegvideo.h"
33 #include "h263.h"
34 #include "h263_parser.h"
35 #include "mpeg4video_parser.h"
36 #include "msmpeg4.h"
37 #include "vdpau_internal.h"
38 #include "thread.h"
39 #include "flv.h"
40 #include "mpeg4video.h"
41
42 //#define DEBUG
43 //#define PRINT_FRAME_TIME
44
45 av_cold int ff_h263_decode_init(AVCodecContext *avctx)
46 {
47     MpegEncContext *s = avctx->priv_data;
48
49     s->avctx = avctx;
50     s->out_format = FMT_H263;
51
52     s->width  = avctx->coded_width;
53     s->height = avctx->coded_height;
54     s->workaround_bugs= avctx->workaround_bugs;
55
56     // set defaults
57     MPV_decode_defaults(s);
58     s->quant_precision=5;
59     s->decode_mb= ff_h263_decode_mb;
60     s->low_delay= 1;
61     avctx->pix_fmt= avctx->get_format(avctx, avctx->codec->pix_fmts);
62     s->unrestricted_mv= 1;
63
64     /* select sub codec */
65     switch(avctx->codec->id) {
66     case CODEC_ID_H263:
67         s->unrestricted_mv= 0;
68         avctx->chroma_sample_location = AVCHROMA_LOC_CENTER;
69         break;
70     case CODEC_ID_MPEG4:
71         break;
72     case CODEC_ID_MSMPEG4V1:
73         s->h263_pred = 1;
74         s->msmpeg4_version=1;
75         break;
76     case CODEC_ID_MSMPEG4V2:
77         s->h263_pred = 1;
78         s->msmpeg4_version=2;
79         break;
80     case CODEC_ID_MSMPEG4V3:
81         s->h263_pred = 1;
82         s->msmpeg4_version=3;
83         break;
84     case CODEC_ID_WMV1:
85         s->h263_pred = 1;
86         s->msmpeg4_version=4;
87         break;
88     case CODEC_ID_WMV2:
89         s->h263_pred = 1;
90         s->msmpeg4_version=5;
91         break;
92     case CODEC_ID_VC1:
93     case CODEC_ID_WMV3:
94         s->h263_pred = 1;
95         s->msmpeg4_version=6;
96         avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
97         break;
98     case CODEC_ID_H263I:
99         break;
100     case CODEC_ID_FLV1:
101         s->h263_flv = 1;
102         break;
103     default:
104         return -1;
105     }
106     s->codec_id= avctx->codec->id;
107     avctx->hwaccel= ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
108
109     /* for h263, we allocate the images after having read the header */
110     if (avctx->codec->id != CODEC_ID_H263 && avctx->codec->id != CODEC_ID_MPEG4)
111         if (MPV_common_init(s) < 0)
112             return -1;
113
114         h263_decode_init_vlc(s);
115
116     return 0;
117 }
118
119 av_cold int ff_h263_decode_end(AVCodecContext *avctx)
120 {
121     MpegEncContext *s = avctx->priv_data;
122
123     MPV_common_end(s);
124     return 0;
125 }
126
127 /**
128  * returns the number of bytes consumed for building the current frame
129  */
130 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
131     int pos= (get_bits_count(&s->gb)+7)>>3;
132
133     if(s->divx_packed || s->avctx->hwaccel){
134         //we would have to scan through the whole buf to handle the weird reordering ...
135         return buf_size;
136     }else if(s->flags&CODEC_FLAG_TRUNCATED){
137         pos -= s->parse_context.last_index;
138         if(pos<0) pos=0; // padding is not really read so this might be -1
139         return pos;
140     }else{
141         if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...)
142         if(pos+10>buf_size) pos=buf_size; // oops ;)
143
144         return pos;
145     }
146 }
147
148 static int decode_slice(MpegEncContext *s){
149     const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
150     const int mb_size= 16>>s->avctx->lowres;
151     s->last_resync_gb= s->gb;
152     s->first_slice_line= 1;
153
154     s->resync_mb_x= s->mb_x;
155     s->resync_mb_y= s->mb_y;
156
157     ff_set_qscale(s, s->qscale);
158
159     if (s->avctx->hwaccel) {
160         const uint8_t *start= s->gb.buffer + get_bits_count(&s->gb)/8;
161         const uint8_t *end  = ff_h263_find_resync_marker(start + 1, s->gb.buffer_end);
162         skip_bits_long(&s->gb, 8*(end - start));
163         return s->avctx->hwaccel->decode_slice(s->avctx, start, end - start);
164     }
165
166     if(s->partitioned_frame){
167         const int qscale= s->qscale;
168
169         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
170             if(ff_mpeg4_decode_partitions(s) < 0)
171                 return -1;
172         }
173
174         /* restore variables which were modified */
175         s->first_slice_line=1;
176         s->mb_x= s->resync_mb_x;
177         s->mb_y= s->resync_mb_y;
178         ff_set_qscale(s, qscale);
179     }
180
181     for(; s->mb_y < s->mb_height; s->mb_y++) {
182         /* per-row end of slice checks */
183         if(s->msmpeg4_version){
184             if(s->resync_mb_y + s->slice_height == s->mb_y){
185                 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);
186
187                 return 0;
188             }
189         }
190
191         if(s->msmpeg4_version==1){
192             s->last_dc[0]=
193             s->last_dc[1]=
194             s->last_dc[2]= 128;
195         }
196
197         ff_init_block_index(s);
198         for(; s->mb_x < s->mb_width; s->mb_x++) {
199             int ret;
200
201             ff_update_block_index(s);
202
203             if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
204                 s->first_slice_line=0;
205             }
206
207             /* DCT & quantize */
208
209             s->mv_dir = MV_DIR_FORWARD;
210             s->mv_type = MV_TYPE_16X16;
211 //            s->mb_skipped = 0;
212 //printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
213             ret= s->decode_mb(s, s->block);
214
215             if (s->pict_type!=AV_PICTURE_TYPE_B)
216                 ff_h263_update_motion_val(s);
217
218             if(ret<0){
219                 const int xy= s->mb_x + s->mb_y*s->mb_stride;
220                 if(ret==SLICE_END){
221                     MPV_decode_mb(s, s->block);
222                     if(s->loop_filter)
223                         ff_h263_loop_filter(s);
224
225 //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));
226                     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);
227
228                     s->padding_bug_score--;
229
230                     if(++s->mb_x >= s->mb_width){
231                         s->mb_x=0;
232                         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
233                         MPV_report_decode_progress(s);
234                         s->mb_y++;
235                     }
236                     return 0;
237                 }else if(ret==SLICE_NOEND){
238                     av_log(s->avctx, AV_LOG_ERROR, "Slice mismatch at MB: %d\n", xy);
239                     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);
240                     return -1;
241                 }
242                 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", xy);
243                 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);
244
245                 return -1;
246             }
247
248             MPV_decode_mb(s, s->block);
249             if(s->loop_filter)
250                 ff_h263_loop_filter(s);
251         }
252
253         ff_draw_horiz_band(s, s->mb_y*mb_size, mb_size);
254         MPV_report_decode_progress(s);
255
256         s->mb_x= 0;
257     }
258
259     assert(s->mb_x==0 && s->mb_y==s->mb_height);
260
261     if(s->codec_id==CODEC_ID_MPEG4
262        && (s->workaround_bugs&FF_BUG_AUTODETECT)
263        && get_bits_left(&s->gb) >= 48
264        && show_bits(&s->gb, 24)==0x4010
265        && !s->data_partitioning)
266         s->padding_bug_score+=32;
267
268     /* try to detect the padding bug */
269     if(      s->codec_id==CODEC_ID_MPEG4
270        &&   (s->workaround_bugs&FF_BUG_AUTODETECT)
271        &&    get_bits_left(&s->gb) >=0
272        &&    get_bits_left(&s->gb) < 48
273 //       &&   !s->resync_marker
274        &&   !s->data_partitioning){
275
276         const int bits_count= get_bits_count(&s->gb);
277         const int bits_left = s->gb.size_in_bits - bits_count;
278
279         if(bits_left==0){
280             s->padding_bug_score+=16;
281         } else if(bits_left != 1){
282             int v= show_bits(&s->gb, 8);
283             v|= 0x7F >> (7-(bits_count&7));
284
285             if(v==0x7F && bits_left<=8)
286                 s->padding_bug_score--;
287             else if(v==0x7F && ((get_bits_count(&s->gb)+8)&8) && bits_left<=16)
288                 s->padding_bug_score+= 4;
289             else
290                 s->padding_bug_score++;
291         }
292     }
293
294     if(s->workaround_bugs&FF_BUG_AUTODETECT){
295         if(s->padding_bug_score > -2 && !s->data_partitioning /*&& (s->divx_version>=0 || !s->resync_marker)*/)
296             s->workaround_bugs |=  FF_BUG_NO_PADDING;
297         else
298             s->workaround_bugs &= ~FF_BUG_NO_PADDING;
299     }
300
301     // handle formats which don't have unique end markers
302     if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
303         int left= get_bits_left(&s->gb);
304         int max_extra=7;
305
306         /* no markers in M$ crap */
307         if(s->msmpeg4_version && s->pict_type==AV_PICTURE_TYPE_I)
308             max_extra+= 17;
309
310         /* buggy padding but the frame should still end approximately at the bitstream end */
311         if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_recognition>=3)
312             max_extra+= 48;
313         else if((s->workaround_bugs&FF_BUG_NO_PADDING))
314             max_extra+= 256*256*256*64;
315
316         if(left>max_extra){
317             av_log(s->avctx, AV_LOG_ERROR, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
318         }
319         else if(left<0){
320             av_log(s->avctx, AV_LOG_ERROR, "overreading %d bits\n", -left);
321         }else
322             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);
323
324         return 0;
325     }
326
327     av_log(s->avctx, AV_LOG_ERROR, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
328             get_bits_left(&s->gb),
329             show_bits(&s->gb, 24), s->padding_bug_score);
330
331     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);
332
333     return -1;
334 }
335
336 int ff_h263_decode_frame(AVCodecContext *avctx,
337                              void *data, int *data_size,
338                              AVPacket *avpkt)
339 {
340     const uint8_t *buf = avpkt->data;
341     int buf_size = avpkt->size;
342     MpegEncContext *s = avctx->priv_data;
343     int ret;
344     AVFrame *pict = data;
345
346 #ifdef PRINT_FRAME_TIME
347 uint64_t time= rdtsc();
348 #endif
349     s->flags= avctx->flags;
350     s->flags2= avctx->flags2;
351
352     /* no supplementary picture */
353     if (buf_size == 0) {
354         /* special case for last picture */
355         if (s->low_delay==0 && s->next_picture_ptr) {
356             *pict= *(AVFrame*)s->next_picture_ptr;
357             s->next_picture_ptr= NULL;
358
359             *data_size = sizeof(AVFrame);
360         }
361
362         return 0;
363     }
364
365     if(s->flags&CODEC_FLAG_TRUNCATED){
366         int next;
367
368         if(CONFIG_MPEG4_DECODER && s->codec_id==CODEC_ID_MPEG4){
369             next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);
370         }else if(CONFIG_H263_DECODER && s->codec_id==CODEC_ID_H263){
371             next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);
372         }else{
373             av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");
374             return -1;
375         }
376
377         if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )
378             return buf_size;
379     }
380
381
382 retry:
383
384     if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ //divx 5.01+/xvid frame reorder
385         init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);
386     }else
387         init_get_bits(&s->gb, buf, buf_size*8);
388     s->bitstream_buffer_size=0;
389
390     if (!s->context_initialized) {
391         if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
392             return -1;
393     }
394
395     /* We need to set current_picture_ptr before reading the header,
396      * otherwise we cannot store anyting in there */
397     if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
398         int i= ff_find_unused_picture(s, 0);
399         s->current_picture_ptr= &s->picture[i];
400     }
401
402     /* let's go :-) */
403     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {
404         ret= ff_wmv2_decode_picture_header(s);
405     } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {
406         ret = msmpeg4_decode_picture_header(s);
407     } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {
408         if(s->avctx->extradata_size && s->picture_number==0){
409             GetBitContext gb;
410
411             init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);
412             ret = ff_mpeg4_decode_picture_header(s, &gb);
413         }
414         ret = ff_mpeg4_decode_picture_header(s, &s->gb);
415     } else if (CONFIG_H263I_DECODER && s->codec_id == CODEC_ID_H263I) {
416         ret = ff_intel_h263_decode_picture_header(s);
417     } else if (CONFIG_FLV_DECODER && s->h263_flv) {
418         ret = ff_flv_decode_picture_header(s);
419     } else {
420         ret = h263_decode_picture_header(s);
421     }
422
423     if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);
424
425     /* skip if the header was thrashed */
426     if (ret < 0){
427         av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
428         return -1;
429     }
430
431     avctx->has_b_frames= !s->low_delay;
432
433     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
434         if(s->stream_codec_tag == AV_RL32("XVID") ||
435            s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||
436            s->codec_tag == AV_RL32("RMP4") ||
437            s->codec_tag == AV_RL32("SIPP")
438            )
439             s->xvid_build= 0;
440 #if 0
441         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1
442            && s->padding_bug_score > 0 && s->low_delay) // XVID with modified fourcc
443             s->xvid_build= 0;
444 #endif
445     }
446
447     if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){
448         if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)
449             s->divx_version= 400; //divx 4
450     }
451
452     if(s->xvid_build>=0 && s->divx_version>=0){
453         s->divx_version=
454         s->divx_build= -1;
455     }
456
457     if(s->workaround_bugs&FF_BUG_AUTODETECT){
458         if(s->codec_tag == AV_RL32("XVIX"))
459             s->workaround_bugs|= FF_BUG_XVID_ILACE;
460
461         if(s->codec_tag == AV_RL32("UMP4")){
462             s->workaround_bugs|= FF_BUG_UMP4;
463         }
464
465         if(s->divx_version>=500 && s->divx_build<1814){
466             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
467         }
468
469         if(s->divx_version>502 && s->divx_build<1814){
470             s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;
471         }
472
473         if(s->xvid_build<=3U)
474             s->padding_bug_score= 256*256*256*64;
475
476         if(s->xvid_build<=1U)
477             s->workaround_bugs|= FF_BUG_QPEL_CHROMA;
478
479         if(s->xvid_build<=12U)
480             s->workaround_bugs|= FF_BUG_EDGE;
481
482         if(s->xvid_build<=32U)
483             s->workaround_bugs|= FF_BUG_DC_CLIP;
484
485 #define SET_QPEL_FUNC(postfix1, postfix2) \
486     s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\
487     s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\
488     s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;
489
490         if(s->lavc_build<4653U)
491             s->workaround_bugs|= FF_BUG_STD_QPEL;
492
493         if(s->lavc_build<4655U)
494             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
495
496         if(s->lavc_build<4670U){
497             s->workaround_bugs|= FF_BUG_EDGE;
498         }
499
500         if(s->lavc_build<=4712U)
501             s->workaround_bugs|= FF_BUG_DC_CLIP;
502
503         if(s->divx_version>=0)
504             s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;
505 //printf("padding_bug_score: %d\n", s->padding_bug_score);
506         if(s->divx_version==501 && s->divx_build==20020416)
507             s->padding_bug_score= 256*256*256*64;
508
509         if(s->divx_version<500U){
510             s->workaround_bugs|= FF_BUG_EDGE;
511         }
512
513         if(s->divx_version>=0)
514             s->workaround_bugs|= FF_BUG_HPEL_CHROMA;
515 #if 0
516         if(s->divx_version==500)
517             s->padding_bug_score= 256*256*256*64;
518
519         /* very ugly XVID padding bug detection FIXME/XXX solve this differently
520          * Let us hope this at least works.
521          */
522         if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1
523            && s->codec_id==CODEC_ID_MPEG4 && s->vo_type==0)
524             s->workaround_bugs|= FF_BUG_NO_PADDING;
525
526         if(s->lavc_build<4609U) //FIXME not sure about the version num but a 4609 file seems ok
527             s->workaround_bugs|= FF_BUG_NO_PADDING;
528 #endif
529     }
530
531     if(s->workaround_bugs& FF_BUG_STD_QPEL){
532         SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)
533         SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)
534         SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)
535         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
536         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
537         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
538
539         SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)
540         SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)
541         SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)
542         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
543         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
544         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
545     }
546
547     if(avctx->debug & FF_DEBUG_BUGS)
548         av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
549                s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,
550                s->divx_packed ? "p" : "");
551
552 #if HAVE_MMX
553     if (s->codec_id == CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {
554         avctx->idct_algo= FF_IDCT_XVIDMMX;
555         avctx->coded_width= 0; // force reinit
556 //        dsputil_init(&s->dsp, avctx);
557         s->picture_number=0;
558     }
559 #endif
560
561         /* After H263 & mpeg4 header decode we have the height, width,*/
562         /* and other parameters. So then we could init the picture   */
563         /* FIXME: By the way H263 decoder is evolving it should have */
564         /* an H263EncContext                                         */
565
566     if (   s->width  != avctx->coded_width
567         || s->height != avctx->coded_height) {
568         /* H.263 could change picture size any time */
569         ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
570         s->parse_context.buffer=0;
571         MPV_common_end(s);
572         s->parse_context= pc;
573     }
574     if (!s->context_initialized) {
575         avcodec_set_dimensions(avctx, s->width, s->height);
576
577         goto retry;
578     }
579
580     if((s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P || s->codec_id == CODEC_ID_H263I))
581         s->gob_index = ff_h263_get_gob_height(s);
582
583     // for skipping the frame
584     s->current_picture.f.pict_type = s->pict_type;
585     s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;
586
587     /* skip B-frames if we don't have reference frames */
588     if(s->last_picture_ptr==NULL && (s->pict_type==AV_PICTURE_TYPE_B || s->dropable)) return get_consumed_bytes(s, buf_size);
589     if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)
590        || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)
591        ||  avctx->skip_frame >= AVDISCARD_ALL)
592         return get_consumed_bytes(s, buf_size);
593
594     if(s->next_p_frame_damaged){
595         if(s->pict_type==AV_PICTURE_TYPE_B)
596             return get_consumed_bytes(s, buf_size);
597         else
598             s->next_p_frame_damaged=0;
599     }
600
601     if((s->avctx->flags2 & CODEC_FLAG2_FAST) && s->pict_type==AV_PICTURE_TYPE_B){
602         s->me.qpel_put= s->dsp.put_2tap_qpel_pixels_tab;
603         s->me.qpel_avg= s->dsp.avg_2tap_qpel_pixels_tab;
604     }else if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){
605         s->me.qpel_put= s->dsp.put_qpel_pixels_tab;
606         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
607     }else{
608         s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;
609         s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;
610     }
611
612     if(MPV_frame_start(s, avctx) < 0)
613         return -1;
614
615     if (!s->divx_packed) ff_thread_finish_setup(avctx);
616
617     if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {
618         ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);
619         goto frame_end;
620     }
621
622     if (avctx->hwaccel) {
623         if (avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer) < 0)
624             return -1;
625     }
626
627     ff_er_frame_start(s);
628
629     //the second part of the wmv2 header contains the MB skip bits which are stored in current_picture->mb_type
630     //which is not available before MPV_frame_start()
631     if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){
632         ret = ff_wmv2_decode_secondary_picture_header(s);
633         if(ret<0) return ret;
634         if(ret==1) goto intrax8_decoded;
635     }
636
637     /* decode each macroblock */
638     s->mb_x=0;
639     s->mb_y=0;
640
641     decode_slice(s);
642     while(s->mb_y<s->mb_height){
643         if(s->msmpeg4_version){
644             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)
645                 break;
646         }else{
647             int prev_x=s->mb_x, prev_y=s->mb_y;
648             if(ff_h263_resync(s)<0)
649                 break;
650             if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)
651                 s->error_occurred = 1;
652         }
653
654         if(s->msmpeg4_version<4 && s->h263_pred)
655             ff_mpeg4_clean_buffers(s);
656
657         decode_slice(s);
658     }
659
660     if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)
661         if(!CONFIG_MSMPEG4_DECODER || msmpeg4_decode_ext_header(s, buf_size) < 0){
662             s->error_status_table[s->mb_num-1]= AC_ERROR|DC_ERROR|MV_ERROR;
663         }
664
665     assert(s->bitstream_buffer_size==0);
666 frame_end:
667     /* divx 5.01+ bistream reorder stuff */
668     if(s->codec_id==CODEC_ID_MPEG4 && s->divx_packed){
669         int current_pos= get_bits_count(&s->gb)>>3;
670         int startcode_found=0;
671
672         if(buf_size - current_pos > 5){
673             int i;
674             for(i=current_pos; i<buf_size-3; i++){
675                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){
676                     startcode_found=1;
677                     break;
678                 }
679             }
680         }
681         if(s->gb.buffer == s->bitstream_buffer && buf_size>7 && s->xvid_build>=0){ //xvid style
682             startcode_found=1;
683             current_pos=0;
684         }
685
686         if(startcode_found){
687             av_fast_malloc(
688                 &s->bitstream_buffer,
689                 &s->allocated_bitstream_buffer_size,
690                 buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);
691             if (!s->bitstream_buffer)
692                 return AVERROR(ENOMEM);
693             memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);
694             s->bitstream_buffer_size= buf_size - current_pos;
695         }
696     }
697
698 intrax8_decoded:
699     ff_er_frame_end(s);
700
701     if (avctx->hwaccel) {
702         if (avctx->hwaccel->end_frame(avctx) < 0)
703             return -1;
704     }
705
706     MPV_frame_end(s);
707
708 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
709 assert(s->current_picture.pict_type == s->pict_type);
710     if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
711         *pict= *(AVFrame*)s->current_picture_ptr;
712     } else if (s->last_picture_ptr != NULL) {
713         *pict= *(AVFrame*)s->last_picture_ptr;
714     }
715
716     if(s->last_picture_ptr || s->low_delay){
717         *data_size = sizeof(AVFrame);
718         ff_print_debug_info(s, pict);
719     }
720
721 #ifdef PRINT_FRAME_TIME
722 av_log(avctx, AV_LOG_DEBUG, "%"PRId64"\n", rdtsc()-time);
723 #endif
724
725     return get_consumed_bytes(s, buf_size);
726 }
727
728 AVCodec ff_h263_decoder = {
729     "h263",
730     AVMEDIA_TYPE_VIDEO,
731     CODEC_ID_H263,
732     sizeof(MpegEncContext),
733     ff_h263_decode_init,
734     NULL,
735     ff_h263_decode_end,
736     ff_h263_decode_frame,
737     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
738     .flush= ff_mpeg_flush,
739     .max_lowres= 3,
740     .long_name= NULL_IF_CONFIG_SMALL("H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2"),
741     .pix_fmts= ff_hwaccel_pixfmt_list_420,
742 };