mpeg4video: Add support for MPEG-4 Simple Studio Profile.
[ffmpeg.git] / libavcodec / ituh263dec.c
1 /*
2  * ITU H.263 bitstream decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * H.263+ support.
5  * Copyright (c) 2001 Juan J. Sierralta P
6  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24
25 /**
26  * @file
27  * H.263 decoder.
28  */
29
30 #define UNCHECKED_BITSTREAM_READER 1
31 #include <limits.h>
32
33 #include "libavutil/attributes.h"
34 #include "libavutil/imgutils.h"
35 #include "libavutil/internal.h"
36 #include "libavutil/mathematics.h"
37 #include "avcodec.h"
38 #include "mpegvideo.h"
39 #include "h263.h"
40 #include "h263data.h"
41 #include "internal.h"
42 #include "mathops.h"
43 #include "mpegutils.h"
44 #include "unary.h"
45 #include "flv.h"
46 #include "rv10.h"
47 #include "mpeg4video.h"
48 #include "mpegvideodata.h"
49
50 // The defines below define the number of bits that are read at once for
51 // reading vlc values. Changing these may improve speed and data cache needs
52 // be aware though that decreasing them may need the number of stages that is
53 // passed to get_vlc* to be increased.
54 #define MV_VLC_BITS 9
55 #define H263_MBTYPE_B_VLC_BITS 6
56 #define CBPC_B_VLC_BITS 3
57
58 static const int h263_mb_type_b_map[15]= {
59     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
60     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
61     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
62                       MB_TYPE_L0                                 | MB_TYPE_16x16,
63                       MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
64                       MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
65                       MB_TYPE_L1                                 | MB_TYPE_16x16,
66                       MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
67                       MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
68                       MB_TYPE_L0L1                               | MB_TYPE_16x16,
69                       MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
70                       MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
71     0, //stuffing
72     MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
73     MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
74 };
75
76 void ff_h263_show_pict_info(MpegEncContext *s){
77     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
78     av_log(s->avctx, AV_LOG_DEBUG, "qp:%d %c size:%d rnd:%d%s%s%s%s%s%s%s%s%s %d/%d\n",
79          s->qscale, av_get_picture_type_char(s->pict_type),
80          s->gb.size_in_bits, 1-s->no_rounding,
81          s->obmc ? " AP" : "",
82          s->umvplus ? " UMV" : "",
83          s->h263_long_vectors ? " LONG" : "",
84          s->h263_plus ? " +" : "",
85          s->h263_aic ? " AIC" : "",
86          s->alt_inter_vlc ? " AIV" : "",
87          s->modified_quant ? " MQ" : "",
88          s->loop_filter ? " LOOP" : "",
89          s->h263_slice_structured ? " SS" : "",
90          s->avctx->framerate.num, s->avctx->framerate.den
91     );
92     }
93 }
94
95 /***********************************************/
96 /* decoding */
97
98 VLC ff_h263_intra_MCBPC_vlc;
99 VLC ff_h263_inter_MCBPC_vlc;
100 VLC ff_h263_cbpy_vlc;
101 static VLC mv_vlc;
102 static VLC h263_mbtype_b_vlc;
103 static VLC cbpc_b_vlc;
104
105 /* init vlcs */
106
107 /* XXX: find a better solution to handle static init */
108 av_cold void ff_h263_decode_init_vlc(void)
109 {
110     static volatile int done = 0;
111
112     if (!done) {
113         INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
114                  ff_h263_intra_MCBPC_bits, 1, 1,
115                  ff_h263_intra_MCBPC_code, 1, 1, 72);
116         INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
117                  ff_h263_inter_MCBPC_bits, 1, 1,
118                  ff_h263_inter_MCBPC_code, 1, 1, 198);
119         INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
120                  &ff_h263_cbpy_tab[0][1], 2, 1,
121                  &ff_h263_cbpy_tab[0][0], 2, 1, 64);
122         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
123                  &ff_mvtab[0][1], 2, 1,
124                  &ff_mvtab[0][0], 2, 1, 538);
125         ff_rl_init(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
126         ff_rl_init(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
127         INIT_VLC_RL(ff_h263_rl_inter, 554);
128         INIT_VLC_RL(ff_rl_intra_aic, 554);
129         INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
130                  &ff_h263_mbtype_b_tab[0][1], 2, 1,
131                  &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
132         INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
133                  &ff_cbpc_b_tab[0][1], 2, 1,
134                  &ff_cbpc_b_tab[0][0], 2, 1, 8);
135         done = 1;
136     }
137 }
138
139 int ff_h263_decode_mba(MpegEncContext *s)
140 {
141     int i, mb_pos;
142
143     for (i = 0; i < 6; i++)
144         if (s->mb_num - 1 <= ff_mba_max[i])
145             break;
146     mb_pos  = get_bits(&s->gb, ff_mba_length[i]);
147     s->mb_x = mb_pos % s->mb_width;
148     s->mb_y = mb_pos / s->mb_width;
149
150     return mb_pos;
151 }
152
153 /**
154  * Decode the group of blocks header or slice header.
155  * @return <0 if an error occurred
156  */
157 static int h263_decode_gob_header(MpegEncContext *s)
158 {
159     unsigned int val, gob_number;
160     int left;
161
162     /* Check for GOB Start Code */
163     val = show_bits(&s->gb, 16);
164     if(val)
165         return -1;
166
167         /* We have a GBSC probably with GSTUFF */
168     skip_bits(&s->gb, 16); /* Drop the zeros */
169     left= get_bits_left(&s->gb);
170     left = FFMIN(left, 32);
171     //MN: we must check the bits left or we might end in an infinite loop (or segfault)
172     for(;left>13; left--){
173         if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
174     }
175     if(left<=13)
176         return -1;
177
178     if(s->h263_slice_structured){
179         if(check_marker(s->avctx, &s->gb, "before MBA")==0)
180             return -1;
181
182         ff_h263_decode_mba(s);
183
184         if(s->mb_num > 1583)
185             if(check_marker(s->avctx, &s->gb, "after MBA")==0)
186                 return -1;
187
188         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
189         if(check_marker(s->avctx, &s->gb, "after SQUANT")==0)
190             return -1;
191         skip_bits(&s->gb, 2); /* GFID */
192     }else{
193         gob_number = get_bits(&s->gb, 5); /* GN */
194         s->mb_x= 0;
195         s->mb_y= s->gob_index* gob_number;
196         skip_bits(&s->gb, 2); /* GFID */
197         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
198     }
199
200     if(s->mb_y >= s->mb_height)
201         return -1;
202
203     if(s->qscale==0)
204         return -1;
205
206     return 0;
207 }
208
209 /**
210  * Decode the group of blocks / video packet header / slice header (MPEG-4 Studio).
211  * @return bit position of the resync_marker, or <0 if none was found
212  */
213 int ff_h263_resync(MpegEncContext *s){
214     int left, pos, ret;
215
216     /* In MPEG-4 studio mode look for a new slice startcode
217      * and decode slice header */
218     if(s->codec_id==AV_CODEC_ID_MPEG4 && s->studio_profile) {
219         align_get_bits(&s->gb);
220
221         while (get_bits_left(&s->gb) >= 32 && show_bits_long(&s->gb, 32) != SLICE_START_CODE) {
222             get_bits(&s->gb, 8);
223         }
224
225         if (show_bits_long(&s->gb, 32) == SLICE_START_CODE)
226             return get_bits_count(&s->gb);
227         else
228             return -1;
229     }
230
231     if(s->codec_id==AV_CODEC_ID_MPEG4){
232         skip_bits1(&s->gb);
233         align_get_bits(&s->gb);
234     }
235
236     if(show_bits(&s->gb, 16)==0){
237         pos= get_bits_count(&s->gb);
238         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
239             ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
240         else
241             ret= h263_decode_gob_header(s);
242         if(ret>=0)
243             return pos;
244     }
245     //OK, it's not where it is supposed to be ...
246     s->gb= s->last_resync_gb;
247     align_get_bits(&s->gb);
248     left= get_bits_left(&s->gb);
249
250     for(;left>16+1+5+5; left-=8){
251         if(show_bits(&s->gb, 16)==0){
252             GetBitContext bak= s->gb;
253
254             pos= get_bits_count(&s->gb);
255             if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
256                 ret= ff_mpeg4_decode_video_packet_header(s->avctx->priv_data);
257             else
258                 ret= h263_decode_gob_header(s);
259             if(ret>=0)
260                 return pos;
261
262             s->gb= bak;
263         }
264         skip_bits(&s->gb, 8);
265     }
266
267     return -1;
268 }
269
270 int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
271 {
272     int code, val, sign, shift;
273     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
274
275     if (code == 0)
276         return pred;
277     if (code < 0)
278         return 0xffff;
279
280     sign = get_bits1(&s->gb);
281     shift = f_code - 1;
282     val = code;
283     if (shift) {
284         val = (val - 1) << shift;
285         val |= get_bits(&s->gb, shift);
286         val++;
287     }
288     if (sign)
289         val = -val;
290     val += pred;
291
292     /* modulo decoding */
293     if (!s->h263_long_vectors) {
294         val = sign_extend(val, 5 + f_code);
295     } else {
296         /* horrible H.263 long vector mode */
297         if (pred < -31 && val < -63)
298             val += 64;
299         if (pred > 32 && val > 63)
300             val -= 64;
301
302     }
303     return val;
304 }
305
306
307 /* Decode RVLC of H.263+ UMV */
308 static int h263p_decode_umotion(MpegEncContext * s, int pred)
309 {
310    int code = 0, sign;
311
312    if (get_bits1(&s->gb)) /* Motion difference = 0 */
313       return pred;
314
315    code = 2 + get_bits1(&s->gb);
316
317    while (get_bits1(&s->gb))
318    {
319       code <<= 1;
320       code += get_bits1(&s->gb);
321       if (code >= 32768) {
322           avpriv_request_sample(s->avctx, "Huge DMV");
323           return 0xffff;
324       }
325    }
326    sign = code & 1;
327    code >>= 1;
328
329    code = (sign) ? (pred - code) : (pred + code);
330    ff_tlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
331    return code;
332
333 }
334
335 /**
336  * read the next MVs for OBMC. yes this is an ugly hack, feel free to send a patch :)
337  */
338 static void preview_obmc(MpegEncContext *s){
339     GetBitContext gb= s->gb;
340
341     int cbpc, i, pred_x, pred_y, mx, my;
342     int16_t *mot_val;
343     const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
344     const int stride= s->b8_stride*2;
345
346     for(i=0; i<4; i++)
347         s->block_index[i]+= 2;
348     for(i=4; i<6; i++)
349         s->block_index[i]+= 1;
350     s->mb_x++;
351
352     av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
353
354     do{
355         if (get_bits1(&s->gb)) {
356             /* skip mb */
357             mot_val = s->current_picture.motion_val[0][s->block_index[0]];
358             mot_val[0       ]= mot_val[2       ]=
359             mot_val[0+stride]= mot_val[2+stride]= 0;
360             mot_val[1       ]= mot_val[3       ]=
361             mot_val[1+stride]= mot_val[3+stride]= 0;
362
363             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
364             goto end;
365         }
366         cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
367     }while(cbpc == 20);
368
369     if(cbpc & 4){
370         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
371     }else{
372         get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
373         if (cbpc & 8) {
374             if(s->modified_quant){
375                 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
376                 else                  skip_bits(&s->gb, 5);
377             }else
378                 skip_bits(&s->gb, 2);
379         }
380
381         if ((cbpc & 16) == 0) {
382                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
383                 /* 16x16 motion prediction */
384                 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
385                 if (s->umvplus)
386                     mx = h263p_decode_umotion(s, pred_x);
387                 else
388                     mx = ff_h263_decode_motion(s, pred_x, 1);
389
390                 if (s->umvplus)
391                     my = h263p_decode_umotion(s, pred_y);
392                 else
393                     my = ff_h263_decode_motion(s, pred_y, 1);
394
395                 mot_val[0       ]= mot_val[2       ]=
396                 mot_val[0+stride]= mot_val[2+stride]= mx;
397                 mot_val[1       ]= mot_val[3       ]=
398                 mot_val[1+stride]= mot_val[3+stride]= my;
399         } else {
400             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
401             for(i=0;i<4;i++) {
402                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
403                 if (s->umvplus)
404                     mx = h263p_decode_umotion(s, pred_x);
405                 else
406                     mx = ff_h263_decode_motion(s, pred_x, 1);
407
408                 if (s->umvplus)
409                     my = h263p_decode_umotion(s, pred_y);
410                 else
411                     my = ff_h263_decode_motion(s, pred_y, 1);
412                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
413                     skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
414                 mot_val[0] = mx;
415                 mot_val[1] = my;
416             }
417         }
418     }
419 end:
420
421     for(i=0; i<4; i++)
422         s->block_index[i]-= 2;
423     for(i=4; i<6; i++)
424         s->block_index[i]-= 1;
425     s->mb_x--;
426
427     s->gb= gb;
428 }
429
430 static void h263_decode_dquant(MpegEncContext *s){
431     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
432
433     if(s->modified_quant){
434         if(get_bits1(&s->gb))
435             s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
436         else
437             s->qscale= get_bits(&s->gb, 5);
438     }else
439         s->qscale += quant_tab[get_bits(&s->gb, 2)];
440     ff_set_qscale(s, s->qscale);
441 }
442
443 static int h263_decode_block(MpegEncContext * s, int16_t * block,
444                              int n, int coded)
445 {
446     int level, i, j, run;
447     RLTable *rl = &ff_h263_rl_inter;
448     const uint8_t *scan_table;
449     GetBitContext gb= s->gb;
450
451     scan_table = s->intra_scantable.permutated;
452     if (s->h263_aic && s->mb_intra) {
453         rl = &ff_rl_intra_aic;
454         i = 0;
455         if (s->ac_pred) {
456             if (s->h263_aic_dir)
457                 scan_table = s->intra_v_scantable.permutated; /* left */
458             else
459                 scan_table = s->intra_h_scantable.permutated; /* top */
460         }
461     } else if (s->mb_intra) {
462         /* DC coef */
463         if (CONFIG_RV10_DECODER && s->codec_id == AV_CODEC_ID_RV10) {
464           if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
465             int component, diff;
466             component = (n <= 3 ? 0 : n - 4 + 1);
467             level = s->last_dc[component];
468             if (s->rv10_first_dc_coded[component]) {
469                 diff = ff_rv_decode_dc(s, n);
470                 if (diff == 0xffff)
471                     return -1;
472                 level += diff;
473                 level = level & 0xff; /* handle wrap round */
474                 s->last_dc[component] = level;
475             } else {
476                 s->rv10_first_dc_coded[component] = 1;
477             }
478           } else {
479                 level = get_bits(&s->gb, 8);
480                 if (level == 255)
481                     level = 128;
482           }
483         }else{
484             level = get_bits(&s->gb, 8);
485             if((level&0x7F) == 0){
486                 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
487                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
488                     return -1;
489             }
490             if (level == 255)
491                 level = 128;
492         }
493         block[0] = level;
494         i = 1;
495     } else {
496         i = 0;
497     }
498     if (!coded) {
499         if (s->mb_intra && s->h263_aic)
500             goto not_coded;
501         s->block_last_index[n] = i - 1;
502         return 0;
503     }
504 retry:
505     {
506     OPEN_READER(re, &s->gb);
507     i--; // offset by -1 to allow direct indexing of scan_table
508     for(;;) {
509         UPDATE_CACHE(re, &s->gb);
510         GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2, 0);
511         if (run == 66) {
512             if (level){
513                 CLOSE_READER(re, &s->gb);
514                 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
515                 return -1;
516             }
517             /* escape */
518             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
519                 int is11 = SHOW_UBITS(re, &s->gb, 1);
520                 SKIP_CACHE(re, &s->gb, 1);
521                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
522                 if (is11) {
523                     SKIP_COUNTER(re, &s->gb, 1 + 7);
524                     UPDATE_CACHE(re, &s->gb);
525                     level = SHOW_SBITS(re, &s->gb, 11);
526                     SKIP_COUNTER(re, &s->gb, 11);
527                 } else {
528                     SKIP_CACHE(re, &s->gb, 7);
529                     level = SHOW_SBITS(re, &s->gb, 7);
530                     SKIP_COUNTER(re, &s->gb, 1 + 7 + 7);
531                 }
532             } else {
533                 run = SHOW_UBITS(re, &s->gb, 7) + 1;
534                 SKIP_CACHE(re, &s->gb, 7);
535                 level = (int8_t)SHOW_UBITS(re, &s->gb, 8);
536                 SKIP_COUNTER(re, &s->gb, 7 + 8);
537                 if(level == -128){
538                     UPDATE_CACHE(re, &s->gb);
539                     if (s->codec_id == AV_CODEC_ID_RV10) {
540                         /* XXX: should patch encoder too */
541                         level = SHOW_SBITS(re, &s->gb, 12);
542                         SKIP_COUNTER(re, &s->gb, 12);
543                     }else{
544                         level = SHOW_UBITS(re, &s->gb, 5);
545                         SKIP_CACHE(re, &s->gb, 5);
546                         level |= SHOW_SBITS(re, &s->gb, 6) * (1<<5);
547                         SKIP_COUNTER(re, &s->gb, 5 + 6);
548                     }
549                 }
550             }
551         } else {
552             if (SHOW_UBITS(re, &s->gb, 1))
553                 level = -level;
554             SKIP_COUNTER(re, &s->gb, 1);
555         }
556         i += run;
557         if (i >= 64){
558             CLOSE_READER(re, &s->gb);
559             // redo update without last flag, revert -1 offset
560             i = i - run + ((run-1)&63) + 1;
561             if (i < 64) {
562                 // only last marker, no overrun
563                 block[scan_table[i]] = level;
564                 break;
565             }
566             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
567                 //Looks like a hack but no, it's the way it is supposed to work ...
568                 rl = &ff_rl_intra_aic;
569                 i = 0;
570                 s->gb= gb;
571                 s->bdsp.clear_block(block);
572                 goto retry;
573             }
574             av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
575             return -1;
576         }
577         j = scan_table[i];
578         block[j] = level;
579     }
580     }
581 not_coded:
582     if (s->mb_intra && s->h263_aic) {
583         ff_h263_pred_acdc(s, block, n);
584         i = 63;
585     }
586     s->block_last_index[n] = i;
587     return 0;
588 }
589
590 static int h263_skip_b_part(MpegEncContext *s, int cbp)
591 {
592     LOCAL_ALIGNED_32(int16_t, dblock, [64]);
593     int i, mbi;
594     int bli[6];
595
596     /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
597      * but real value should be restored in order to be used later (in OBMC condition)
598      */
599     mbi = s->mb_intra;
600     memcpy(bli, s->block_last_index, sizeof(bli));
601     s->mb_intra = 0;
602     for (i = 0; i < 6; i++) {
603         if (h263_decode_block(s, dblock, i, cbp&32) < 0)
604             return -1;
605         cbp+=cbp;
606     }
607     s->mb_intra = mbi;
608     memcpy(s->block_last_index, bli, sizeof(bli));
609     return 0;
610 }
611
612 static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
613 {
614     int c, mv = 1;
615
616     if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
617         c = get_bits1(gb);
618         if (pb_frame == 2 && c)
619             mv = !get_bits1(gb);
620     } else { // h.263 Annex M improved PB-frame
621         mv = get_unary(gb, 0, 4) + 1;
622         c = mv & 1;
623         mv = !!(mv & 2);
624     }
625     if(c)
626         *cbpb = get_bits(gb, 6);
627     return mv;
628 }
629
630 #define tab_size ((signed)FF_ARRAY_ELEMS(s->direct_scale_mv[0]))
631 #define tab_bias (tab_size / 2)
632 static inline void set_one_direct_mv(MpegEncContext *s, Picture *p, int i)
633 {
634     int xy           = s->block_index[i];
635     uint16_t time_pp = s->pp_time;
636     uint16_t time_pb = s->pb_time;
637     int p_mx, p_my;
638
639     p_mx = p->motion_val[0][xy][0];
640     if ((unsigned)(p_mx + tab_bias) < tab_size) {
641         s->mv[0][i][0] = s->direct_scale_mv[0][p_mx + tab_bias];
642         s->mv[1][i][0] = s->direct_scale_mv[1][p_mx + tab_bias];
643     } else {
644         s->mv[0][i][0] = p_mx * time_pb / time_pp;
645         s->mv[1][i][0] = p_mx * (time_pb - time_pp) / time_pp;
646     }
647     p_my = p->motion_val[0][xy][1];
648     if ((unsigned)(p_my + tab_bias) < tab_size) {
649         s->mv[0][i][1] = s->direct_scale_mv[0][p_my + tab_bias];
650         s->mv[1][i][1] = s->direct_scale_mv[1][p_my + tab_bias];
651     } else {
652         s->mv[0][i][1] = p_my * time_pb / time_pp;
653         s->mv[1][i][1] = p_my * (time_pb - time_pp) / time_pp;
654     }
655 }
656
657 /**
658  * @return the mb_type
659  */
660 static int set_direct_mv(MpegEncContext *s)
661 {
662     const int mb_index = s->mb_x + s->mb_y * s->mb_stride;
663     Picture *p = &s->next_picture;
664     int colocated_mb_type = p->mb_type[mb_index];
665     int i;
666
667     if (s->codec_tag == AV_RL32("U263") && p->f->pict_type == AV_PICTURE_TYPE_I) {
668         p = &s->last_picture;
669         colocated_mb_type = p->mb_type[mb_index];
670     }
671
672     if (IS_8X8(colocated_mb_type)) {
673         s->mv_type = MV_TYPE_8X8;
674         for (i = 0; i < 4; i++)
675             set_one_direct_mv(s, p, i);
676         return MB_TYPE_DIRECT2 | MB_TYPE_8x8 | MB_TYPE_L0L1;
677     } else {
678         set_one_direct_mv(s, p, 0);
679         s->mv[0][1][0] =
680         s->mv[0][2][0] =
681         s->mv[0][3][0] = s->mv[0][0][0];
682         s->mv[0][1][1] =
683         s->mv[0][2][1] =
684         s->mv[0][3][1] = s->mv[0][0][1];
685         s->mv[1][1][0] =
686         s->mv[1][2][0] =
687         s->mv[1][3][0] = s->mv[1][0][0];
688         s->mv[1][1][1] =
689         s->mv[1][2][1] =
690         s->mv[1][3][1] = s->mv[1][0][1];
691         s->mv_type = MV_TYPE_8X8;
692         // Note see prev line
693         return MB_TYPE_DIRECT2 | MB_TYPE_16x16 | MB_TYPE_L0L1;
694     }
695 }
696
697 int ff_h263_decode_mb(MpegEncContext *s,
698                       int16_t block[6][64])
699 {
700     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
701     int16_t *mot_val;
702     const int xy= s->mb_x + s->mb_y * s->mb_stride;
703     int cbpb = 0, pb_mv_count = 0;
704
705     av_assert2(!s->h263_pred);
706
707     if (s->pict_type == AV_PICTURE_TYPE_P) {
708         do{
709             if (get_bits1(&s->gb)) {
710                 /* skip mb */
711                 s->mb_intra = 0;
712                 for(i=0;i<6;i++)
713                     s->block_last_index[i] = -1;
714                 s->mv_dir = MV_DIR_FORWARD;
715                 s->mv_type = MV_TYPE_16X16;
716                 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
717                 s->mv[0][0][0] = 0;
718                 s->mv[0][0][1] = 0;
719                 s->mb_skipped = !(s->obmc | s->loop_filter);
720                 goto end;
721             }
722             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
723             if (cbpc < 0){
724                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
725                 return SLICE_ERROR;
726             }
727         }while(cbpc == 20);
728
729         s->bdsp.clear_blocks(s->block[0]);
730
731         dquant = cbpc & 8;
732         s->mb_intra = ((cbpc & 4) != 0);
733         if (s->mb_intra) goto intra;
734
735         if(s->pb_frame && get_bits1(&s->gb))
736             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
737         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
738
739         if (cbpy < 0) {
740             av_log(s->avctx, AV_LOG_ERROR, "cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
741             return SLICE_ERROR;
742         }
743
744         if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
745             cbpy ^= 0xF;
746
747         cbp = (cbpc & 3) | (cbpy << 2);
748         if (dquant) {
749             h263_decode_dquant(s);
750         }
751
752         s->mv_dir = MV_DIR_FORWARD;
753         if ((cbpc & 16) == 0) {
754             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
755             /* 16x16 motion prediction */
756             s->mv_type = MV_TYPE_16X16;
757             ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
758             if (s->umvplus)
759                mx = h263p_decode_umotion(s, pred_x);
760             else
761                mx = ff_h263_decode_motion(s, pred_x, 1);
762
763             if (mx >= 0xffff)
764                 return SLICE_ERROR;
765
766             if (s->umvplus)
767                my = h263p_decode_umotion(s, pred_y);
768             else
769                my = ff_h263_decode_motion(s, pred_y, 1);
770
771             if (my >= 0xffff)
772                 return SLICE_ERROR;
773             s->mv[0][0][0] = mx;
774             s->mv[0][0][1] = my;
775
776             if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
777                skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
778         } else {
779             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
780             s->mv_type = MV_TYPE_8X8;
781             for(i=0;i<4;i++) {
782                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
783                 if (s->umvplus)
784                     mx = h263p_decode_umotion(s, pred_x);
785                 else
786                     mx = ff_h263_decode_motion(s, pred_x, 1);
787                 if (mx >= 0xffff)
788                     return SLICE_ERROR;
789
790                 if (s->umvplus)
791                     my = h263p_decode_umotion(s, pred_y);
792                 else
793                     my = ff_h263_decode_motion(s, pred_y, 1);
794                 if (my >= 0xffff)
795                     return SLICE_ERROR;
796                 s->mv[0][i][0] = mx;
797                 s->mv[0][i][1] = my;
798                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
799                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
800                 mot_val[0] = mx;
801                 mot_val[1] = my;
802             }
803         }
804     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
805         int mb_type;
806         const int stride= s->b8_stride;
807         int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
808         int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
809 //        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
810
811         //FIXME ugly
812         mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
813         mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
814         mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
815         mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
816
817         do{
818             mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
819             if (mb_type < 0){
820                 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
821                 return SLICE_ERROR;
822             }
823
824             mb_type= h263_mb_type_b_map[ mb_type ];
825         }while(!mb_type);
826
827         s->mb_intra = IS_INTRA(mb_type);
828         if(HAS_CBP(mb_type)){
829             s->bdsp.clear_blocks(s->block[0]);
830             cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
831             if(s->mb_intra){
832                 dquant = IS_QUANT(mb_type);
833                 goto intra;
834             }
835
836             cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
837
838             if (cbpy < 0){
839                 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
840                 return SLICE_ERROR;
841             }
842
843             if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
844                 cbpy ^= 0xF;
845
846             cbp = (cbpc & 3) | (cbpy << 2);
847         }else
848             cbp=0;
849
850         av_assert2(!s->mb_intra);
851
852         if(IS_QUANT(mb_type)){
853             h263_decode_dquant(s);
854         }
855
856         if(IS_DIRECT(mb_type)){
857             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
858             mb_type |= set_direct_mv(s);
859         }else{
860             s->mv_dir = 0;
861             s->mv_type= MV_TYPE_16X16;
862 //FIXME UMV
863
864             if(USES_LIST(mb_type, 0)){
865                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
866                 s->mv_dir = MV_DIR_FORWARD;
867
868                 if (s->umvplus)
869                     mx = h263p_decode_umotion(s, pred_x);
870                 else
871                     mx = ff_h263_decode_motion(s, pred_x, 1);
872                 if (mx >= 0xffff)
873                     return SLICE_ERROR;
874
875                 if (s->umvplus)
876                     my = h263p_decode_umotion(s, pred_y);
877                 else
878                     my = ff_h263_decode_motion(s, pred_y, 1);
879                 if (my >= 0xffff)
880                     return SLICE_ERROR;
881
882                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
883                     skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
884
885                 s->mv[0][0][0] = mx;
886                 s->mv[0][0][1] = my;
887                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
888                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
889             }
890
891             if(USES_LIST(mb_type, 1)){
892                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &pred_x, &pred_y);
893                 s->mv_dir |= MV_DIR_BACKWARD;
894
895                 if (s->umvplus)
896                     mx = h263p_decode_umotion(s, pred_x);
897                 else
898                     mx = ff_h263_decode_motion(s, pred_x, 1);
899                 if (mx >= 0xffff)
900                     return SLICE_ERROR;
901
902                 if (s->umvplus)
903                     my = h263p_decode_umotion(s, pred_y);
904                 else
905                     my = ff_h263_decode_motion(s, pred_y, 1);
906                 if (my >= 0xffff)
907                     return SLICE_ERROR;
908
909                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
910                     skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
911
912                 s->mv[1][0][0] = mx;
913                 s->mv[1][0][1] = my;
914                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
915                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
916             }
917         }
918
919         s->current_picture.mb_type[xy] = mb_type;
920     } else { /* I-Frame */
921         do{
922             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
923             if (cbpc < 0){
924                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
925                 return SLICE_ERROR;
926             }
927         }while(cbpc == 8);
928
929         s->bdsp.clear_blocks(s->block[0]);
930
931         dquant = cbpc & 4;
932         s->mb_intra = 1;
933 intra:
934         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
935         if (s->h263_aic) {
936             s->ac_pred = get_bits1(&s->gb);
937             if(s->ac_pred){
938                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
939
940                 s->h263_aic_dir = get_bits1(&s->gb);
941             }
942         }else
943             s->ac_pred = 0;
944
945         if(s->pb_frame && get_bits1(&s->gb))
946             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
947         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
948         if(cbpy<0){
949             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
950             return SLICE_ERROR;
951         }
952         cbp = (cbpc & 3) | (cbpy << 2);
953         if (dquant) {
954             h263_decode_dquant(s);
955         }
956
957         pb_mv_count += !!s->pb_frame;
958     }
959
960     while(pb_mv_count--){
961         ff_h263_decode_motion(s, 0, 1);
962         ff_h263_decode_motion(s, 0, 1);
963     }
964
965     /* decode each block */
966     for (i = 0; i < 6; i++) {
967         if (h263_decode_block(s, block[i], i, cbp&32) < 0)
968             return -1;
969         cbp+=cbp;
970     }
971
972     if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
973         return -1;
974     if(s->obmc && !s->mb_intra){
975         if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
976             preview_obmc(s);
977     }
978 end:
979
980     if (get_bits_left(&s->gb) < 0)
981         return AVERROR_INVALIDDATA;
982
983         /* per-MB end of slice check */
984     {
985         int v= show_bits(&s->gb, 16);
986
987         if (get_bits_left(&s->gb) < 16) {
988             v >>= 16 - get_bits_left(&s->gb);
989         }
990
991         if(v==0)
992             return SLICE_END;
993     }
994
995     return SLICE_OK;
996 }
997
998 /* Most is hardcoded; should extend to handle all H.263 streams. */
999 int ff_h263_decode_picture_header(MpegEncContext *s)
1000 {
1001     int format, width, height, i, ret;
1002     uint32_t startcode;
1003
1004     align_get_bits(&s->gb);
1005
1006     if (show_bits(&s->gb, 2) == 2 && s->avctx->frame_number == 0) {
1007          av_log(s->avctx, AV_LOG_WARNING, "Header looks like RTP instead of H.263\n");
1008     }
1009
1010     startcode= get_bits(&s->gb, 22-8);
1011
1012     for(i= get_bits_left(&s->gb); i>24; i-=8) {
1013         startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
1014
1015         if(startcode == 0x20)
1016             break;
1017     }
1018
1019     if (startcode != 0x20) {
1020         av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
1021         return -1;
1022     }
1023     /* temporal reference */
1024     i = get_bits(&s->gb, 8); /* picture timestamp */
1025
1026     i -= (i - (s->picture_number & 0xFF) + 128) & ~0xFF;
1027
1028     s->picture_number= (s->picture_number&~0xFF) + i;
1029
1030     /* PTYPE starts here */
1031     if (check_marker(s->avctx, &s->gb, "in PTYPE") != 1) {
1032         return -1;
1033     }
1034     if (get_bits1(&s->gb) != 0) {
1035         av_log(s->avctx, AV_LOG_ERROR, "Bad H.263 id\n");
1036         return -1;      /* H.263 id */
1037     }
1038     skip_bits1(&s->gb);         /* split screen off */
1039     skip_bits1(&s->gb);         /* camera  off */
1040     skip_bits1(&s->gb);         /* freeze picture release off */
1041
1042     format = get_bits(&s->gb, 3);
1043     /*
1044         0    forbidden
1045         1    sub-QCIF
1046         10   QCIF
1047         7       extended PTYPE (PLUSPTYPE)
1048     */
1049
1050     if (format != 7 && format != 6) {
1051         s->h263_plus = 0;
1052         /* H.263v1 */
1053         width = ff_h263_format[format][0];
1054         height = ff_h263_format[format][1];
1055         if (!width)
1056             return -1;
1057
1058         s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
1059
1060         s->h263_long_vectors = get_bits1(&s->gb);
1061
1062         if (get_bits1(&s->gb) != 0) {
1063             av_log(s->avctx, AV_LOG_ERROR, "H.263 SAC not supported\n");
1064             return -1; /* SAC: off */
1065         }
1066         s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1067         s->unrestricted_mv = s->h263_long_vectors || s->obmc;
1068
1069         s->pb_frame = get_bits1(&s->gb);
1070         s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
1071         skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
1072
1073         s->width = width;
1074         s->height = height;
1075         s->avctx->sample_aspect_ratio= (AVRational){12,11};
1076         s->avctx->framerate = (AVRational){ 30000, 1001 };
1077     } else {
1078         int ufep;
1079
1080         /* H.263v2 */
1081         s->h263_plus = 1;
1082         ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
1083
1084         /* ufep other than 0 and 1 are reserved */
1085         if (ufep == 1) {
1086             /* OPPTYPE */
1087             format = get_bits(&s->gb, 3);
1088             ff_dlog(s->avctx, "ufep=1, format: %d\n", format);
1089             s->custom_pcf= get_bits1(&s->gb);
1090             s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
1091             if (get_bits1(&s->gb) != 0) {
1092                 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
1093             }
1094             s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
1095             s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
1096             s->loop_filter= get_bits1(&s->gb);
1097             s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
1098             if(s->avctx->lowres)
1099                 s->loop_filter = 0;
1100
1101             s->h263_slice_structured= get_bits1(&s->gb);
1102             if (get_bits1(&s->gb) != 0) {
1103                 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
1104             }
1105             if (get_bits1(&s->gb) != 0) {
1106                 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
1107             }
1108             s->alt_inter_vlc= get_bits1(&s->gb);
1109             s->modified_quant= get_bits1(&s->gb);
1110             if(s->modified_quant)
1111                 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
1112
1113             skip_bits(&s->gb, 1); /* Prevent start code emulation */
1114
1115             skip_bits(&s->gb, 3); /* Reserved */
1116         } else if (ufep != 0) {
1117             av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
1118             return -1;
1119         }
1120
1121         /* MPPTYPE */
1122         s->pict_type = get_bits(&s->gb, 3);
1123         switch(s->pict_type){
1124         case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
1125         case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
1126         case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
1127         case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
1128         case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
1129         default:
1130             return -1;
1131         }
1132         skip_bits(&s->gb, 2);
1133         s->no_rounding = get_bits1(&s->gb);
1134         skip_bits(&s->gb, 4);
1135
1136         /* Get the picture dimensions */
1137         if (ufep) {
1138             if (format == 6) {
1139                 /* Custom Picture Format (CPFMT) */
1140                 s->aspect_ratio_info = get_bits(&s->gb, 4);
1141                 ff_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
1142                 /* aspect ratios:
1143                 0 - forbidden
1144                 1 - 1:1
1145                 2 - 12:11 (CIF 4:3)
1146                 3 - 10:11 (525-type 4:3)
1147                 4 - 16:11 (CIF 16:9)
1148                 5 - 40:33 (525-type 16:9)
1149                 6-14 - reserved
1150                 */
1151                 width = (get_bits(&s->gb, 9) + 1) * 4;
1152                 check_marker(s->avctx, &s->gb, "in dimensions");
1153                 height = get_bits(&s->gb, 9) * 4;
1154                 ff_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
1155                 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
1156                     /* expected dimensions */
1157                     s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
1158                     s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
1159                 }else{
1160                     s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
1161                 }
1162             } else {
1163                 width = ff_h263_format[format][0];
1164                 height = ff_h263_format[format][1];
1165                 s->avctx->sample_aspect_ratio= (AVRational){12,11};
1166             }
1167             s->avctx->sample_aspect_ratio.den <<= s->ehc_mode;
1168             if ((width == 0) || (height == 0))
1169                 return -1;
1170             s->width = width;
1171             s->height = height;
1172
1173             if(s->custom_pcf){
1174                 int gcd;
1175                 s->avctx->framerate.num  = 1800000;
1176                 s->avctx->framerate.den  = 1000 + get_bits1(&s->gb);
1177                 s->avctx->framerate.den *= get_bits(&s->gb, 7);
1178                 if(s->avctx->framerate.den == 0){
1179                     av_log(s, AV_LOG_ERROR, "zero framerate\n");
1180                     return -1;
1181                 }
1182                 gcd= av_gcd(s->avctx->framerate.den, s->avctx->framerate.num);
1183                 s->avctx->framerate.den /= gcd;
1184                 s->avctx->framerate.num /= gcd;
1185             }else{
1186                 s->avctx->framerate = (AVRational){ 30000, 1001 };
1187             }
1188         }
1189
1190         if(s->custom_pcf){
1191             skip_bits(&s->gb, 2); //extended Temporal reference
1192         }
1193
1194         if (ufep) {
1195             if (s->umvplus) {
1196                 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
1197                     skip_bits1(&s->gb);
1198             }
1199             if(s->h263_slice_structured){
1200                 if (get_bits1(&s->gb) != 0) {
1201                     av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
1202                 }
1203                 if (get_bits1(&s->gb) != 0) {
1204                     av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
1205                 }
1206             }
1207             if (s->pict_type == AV_PICTURE_TYPE_B) {
1208                 skip_bits(&s->gb, 4); //ELNUM
1209                 if (ufep == 1) {
1210                     skip_bits(&s->gb, 4); // RLNUM
1211                 }
1212             }
1213         }
1214
1215         s->qscale = get_bits(&s->gb, 5);
1216     }
1217
1218     if ((ret = av_image_check_size(s->width, s->height, 0, s)) < 0)
1219         return ret;
1220
1221     s->mb_width = (s->width  + 15) / 16;
1222     s->mb_height = (s->height  + 15) / 16;
1223     s->mb_num = s->mb_width * s->mb_height;
1224
1225     if (s->pb_frame) {
1226         skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
1227         if (s->custom_pcf)
1228             skip_bits(&s->gb, 2); //extended Temporal reference
1229         skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
1230     }
1231
1232     if (s->pict_type!=AV_PICTURE_TYPE_B) {
1233         s->time            = s->picture_number;
1234         s->pp_time         = s->time - s->last_non_b_time;
1235         s->last_non_b_time = s->time;
1236     }else{
1237         s->time    = s->picture_number;
1238         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
1239         if (s->pp_time <=s->pb_time ||
1240             s->pp_time <= s->pp_time - s->pb_time ||
1241             s->pp_time <= 0){
1242             s->pp_time = 2;
1243             s->pb_time = 1;
1244         }
1245         ff_mpeg4_init_direct_mv(s);
1246     }
1247
1248     /* PEI */
1249     if (skip_1stop_8data_bits(&s->gb) < 0)
1250         return AVERROR_INVALIDDATA;
1251
1252     if(s->h263_slice_structured){
1253         if (check_marker(s->avctx, &s->gb, "SEPB1") != 1) {
1254             return -1;
1255         }
1256
1257         ff_h263_decode_mba(s);
1258
1259         if (check_marker(s->avctx, &s->gb, "SEPB2") != 1) {
1260             return -1;
1261         }
1262     }
1263     s->f_code = 1;
1264
1265     if (s->pict_type == AV_PICTURE_TYPE_B)
1266         s->low_delay = 0;
1267
1268     if(s->h263_aic){
1269          s->y_dc_scale_table=
1270          s->c_dc_scale_table= ff_aic_dc_scale_table;
1271     }else{
1272         s->y_dc_scale_table=
1273         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
1274     }
1275
1276         ff_h263_show_pict_info(s);
1277     if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
1278         int i,j;
1279         for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1280         av_log(s->avctx, AV_LOG_DEBUG, "\n");
1281         for(i=0; i<13; i++){
1282             for(j=0; j<3; j++){
1283                 int v= get_bits(&s->gb, 8);
1284                 v |= get_sbits(&s->gb, 8)<<8;
1285                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
1286             }
1287             av_log(s->avctx, AV_LOG_DEBUG, "\n");
1288         }
1289         for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
1290     }
1291
1292     return 0;
1293 }