subtitles (codec tag tables still missing ...)
[ffmpeg.git] / libavformat / nutdec.c
1 /*
2  * "NUT" Container Format demuxer
3  * Copyright (c) 2004-2006 Michael Niedermayer
4  * Copyright (c) 2003 Alex Beregszaszi
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 #include "tree.h"
24 #include "nut.h"
25 #include "avstring.h"
26
27 #undef NDEBUG
28 #include <assert.h>
29
30 static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
31     unsigned int len= ff_get_v(bc);
32
33     if(len && maxlen)
34         get_buffer(bc, string, FFMIN(len, maxlen));
35     while(len > maxlen){
36         get_byte(bc);
37         len--;
38     }
39
40     if(maxlen)
41         string[FFMIN(len, maxlen-1)]= 0;
42
43     if(maxlen == len)
44         return -1;
45     else
46         return 0;
47 }
48
49 static int64_t get_s(ByteIOContext *bc){
50     int64_t v = ff_get_v(bc) + 1;
51
52     if (v&1) return -(v>>1);
53     else     return  (v>>1);
54 }
55
56 static uint64_t get_fourcc(ByteIOContext *bc){
57     unsigned int len= ff_get_v(bc);
58
59     if     (len==2) return get_le16(bc);
60     else if(len==4) return get_le32(bc);
61     else            return -1;
62 }
63
64 #ifdef TRACE
65 static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
66     uint64_t v= ff_get_v(bc);
67
68     av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
69     return v;
70 }
71
72 static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
73     int64_t v= get_s(bc);
74
75     av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
76     return v;
77 }
78
79 static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
80     uint64_t v= get_vb(bc);
81
82     av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
83     return v;
84 }
85 #define ff_get_v(bc)  get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
86 #define get_s(bc)  get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
87 #define get_vb(bc)  get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
88 #endif
89
90 static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum, uint64_t startcode)
91 {
92     int64_t size;
93 //    start= url_ftell(bc) - 8;
94
95     startcode= be2me_64(startcode);
96     startcode= ff_crc04C11DB7_update(0, &startcode, 8);
97
98     init_checksum(bc, ff_crc04C11DB7_update, startcode);
99     size= ff_get_v(bc);
100     if(size > 4096)
101         get_be32(bc);
102     if(get_checksum(bc) && size > 4096)
103         return -1;
104
105     init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
106
107     return size;
108 }
109
110 static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
111     uint64_t state=0;
112
113     if(pos >= 0)
114         url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream is not seekable, but that should not matter, as in this case we simply start where we are currently
115
116     while(!url_feof(bc)){
117         state= (state<<8) | get_byte(bc);
118         if((state>>56) != 'N')
119             continue;
120         switch(state){
121         case MAIN_STARTCODE:
122         case STREAM_STARTCODE:
123         case SYNCPOINT_STARTCODE:
124         case INFO_STARTCODE:
125         case INDEX_STARTCODE:
126             return state;
127         }
128     }
129
130     return 0;
131 }
132
133 /**
134  * Find the given startcode.
135  * @param code the startcode
136  * @param pos the start position of the search, or -1 if the current position
137  * @returns the position of the startcode or -1 if not found
138  */
139 static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
140     for(;;){
141         uint64_t startcode= find_any_startcode(bc, pos);
142         if(startcode == code)
143             return url_ftell(bc) - 8;
144         else if(startcode == 0)
145             return -1;
146         pos=-1;
147     }
148 }
149
150 static int nut_probe(AVProbeData *p){
151     int i;
152     uint64_t code= 0;
153
154     for (i = 0; i < p->buf_size; i++) {
155         code = (code << 8) | p->buf[i];
156         if (code == MAIN_STARTCODE)
157             return AVPROBE_SCORE_MAX;
158     }
159     return 0;
160 }
161
162 #define GET_V(dst, check) \
163     tmp= ff_get_v(bc);\
164     if(!(check)){\
165         av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
166         return -1;\
167     }\
168     dst= tmp;
169
170 static int skip_reserved(ByteIOContext *bc, int64_t pos){
171     pos -= url_ftell(bc);
172     if(pos<0){
173         url_fseek(bc, pos, SEEK_CUR);
174         return -1;
175     }else{
176         while(pos--)
177             get_byte(bc);
178         return 0;
179     }
180 }
181
182 static int decode_main_header(NUTContext *nut){
183     AVFormatContext *s= nut->avf;
184     ByteIOContext *bc = s->pb;
185     uint64_t tmp, end;
186     unsigned int stream_count;
187     int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res, tmp_head_idx;
188     int64_t tmp_match;
189
190     end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
191     end += url_ftell(bc);
192
193     GET_V(tmp              , tmp >=2 && tmp <= 3)
194     GET_V(stream_count     , tmp > 0 && tmp <=MAX_STREAMS)
195
196     nut->max_distance = ff_get_v(bc);
197     if(nut->max_distance > 65536){
198         av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
199         nut->max_distance= 65536;
200     }
201
202     GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
203     nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
204
205     for(i=0; i<nut->time_base_count; i++){
206         GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
207         GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
208         if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
209             av_log(s, AV_LOG_ERROR, "time base invalid\n");
210             return -1;
211         }
212     }
213     tmp_pts=0;
214     tmp_mul=1;
215     tmp_stream=0;
216     tmp_match= 1-(1LL<<62);
217     tmp_head_idx= 0;
218     for(i=0; i<256;){
219         int tmp_flags = ff_get_v(bc);
220         int tmp_fields= ff_get_v(bc);
221         if(tmp_fields>0) tmp_pts   = get_s(bc);
222         if(tmp_fields>1) tmp_mul   = ff_get_v(bc);
223         if(tmp_fields>2) tmp_stream= ff_get_v(bc);
224         if(tmp_fields>3) tmp_size  = ff_get_v(bc);
225         else             tmp_size  = 0;
226         if(tmp_fields>4) tmp_res   = ff_get_v(bc);
227         else             tmp_res   = 0;
228         if(tmp_fields>5) count     = ff_get_v(bc);
229         else             count     = tmp_mul - tmp_size;
230         if(tmp_fields>6) tmp_match = get_s(bc);
231         if(tmp_fields>7) tmp_head_idx= ff_get_v(bc);
232
233         while(tmp_fields-- > 8)
234            ff_get_v(bc);
235
236         if(count == 0 || i+count > 256){
237             av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
238             return -1;
239         }
240         if(tmp_stream >= stream_count){
241             av_log(s, AV_LOG_ERROR, "illegal stream number\n");
242             return -1;
243         }
244
245         for(j=0; j<count; j++,i++){
246             if (i == 'N') {
247                 nut->frame_code[i].flags= FLAG_INVALID;
248                 j--;
249                 continue;
250             }
251             nut->frame_code[i].flags           = tmp_flags ;
252             nut->frame_code[i].pts_delta       = tmp_pts   ;
253             nut->frame_code[i].stream_id       = tmp_stream;
254             nut->frame_code[i].size_mul        = tmp_mul   ;
255             nut->frame_code[i].size_lsb        = tmp_size+j;
256             nut->frame_code[i].reserved_count  = tmp_res   ;
257             nut->frame_code[i].header_idx      = tmp_head_idx;
258         }
259     }
260     assert(nut->frame_code['N'].flags == FLAG_INVALID);
261
262     if(end > url_ftell(bc) + 4){
263         int rem= 1024;
264         GET_V(nut->header_count, tmp<128U)
265         nut->header_count++;
266         for(i=1; i<nut->header_count; i++){
267             GET_V(nut->header_len[i], tmp>0 && tmp<256);
268             rem -= nut->header_len[i];
269             if(rem < 0){
270                 av_log(s, AV_LOG_ERROR, "invalid elision header\n");
271                 return -1;
272             }
273             nut->header[i]= av_malloc(nut->header_len[i]);
274             get_buffer(bc, nut->header[i], nut->header_len[i]);
275         }
276         assert(nut->header_len[0]==0);
277     }
278
279     if(skip_reserved(bc, end) || get_checksum(bc)){
280         av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
281         return -1;
282     }
283
284     nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
285     for(i=0; i<stream_count; i++){
286         av_new_stream(s, i);
287     }
288
289     return 0;
290 }
291
292 static int decode_stream_header(NUTContext *nut){
293     AVFormatContext *s= nut->avf;
294     ByteIOContext *bc = s->pb;
295     StreamContext *stc;
296     int class, stream_id;
297     uint64_t tmp, end;
298     AVStream *st;
299
300     end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
301     end += url_ftell(bc);
302
303     GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
304     stc= &nut->stream[stream_id];
305
306     st = s->streams[stream_id];
307     if (!st)
308         return AVERROR(ENOMEM);
309
310     class = ff_get_v(bc);
311     tmp = get_fourcc(bc);
312     st->codec->codec_tag= tmp;
313     switch(class)
314     {
315         case 0:
316             st->codec->codec_type = CODEC_TYPE_VIDEO;
317             st->codec->codec_id = codec_get_id(codec_bmp_tags, tmp);
318             if (st->codec->codec_id == CODEC_ID_NONE)
319                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
320             break;
321         case 1:
322             st->codec->codec_type = CODEC_TYPE_AUDIO;
323             st->codec->codec_id = codec_get_id(codec_wav_tags, tmp);
324             if (st->codec->codec_id == CODEC_ID_NONE)
325                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
326             break;
327         case 2:
328             st->codec->codec_type = CODEC_TYPE_SUBTITLE;
329 //            st->codec->codec_id = codec_get_id(codec_wav_tags, tmp); FIXME
330             if (st->codec->codec_id == CODEC_ID_NONE)
331                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
332             break;
333         case 3:
334             st->codec->codec_type = CODEC_TYPE_DATA;
335             break;
336         default:
337             av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
338             return -1;
339     }
340     GET_V(stc->time_base_id    , tmp < nut->time_base_count);
341     GET_V(stc->msb_pts_shift   , tmp < 16);
342     stc->max_pts_distance= ff_get_v(bc);
343     GET_V(stc->decode_delay    , tmp < 1000); //sanity limit, raise this if Moore's law is true
344     st->codec->has_b_frames= stc->decode_delay;
345     ff_get_v(bc); //stream flags
346
347     GET_V(st->codec->extradata_size, tmp < (1<<30));
348     if(st->codec->extradata_size){
349         st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
350         get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
351     }
352
353     if (st->codec->codec_type == CODEC_TYPE_VIDEO){
354         GET_V(st->codec->width , tmp > 0)
355         GET_V(st->codec->height, tmp > 0)
356         st->codec->sample_aspect_ratio.num= ff_get_v(bc);
357         st->codec->sample_aspect_ratio.den= ff_get_v(bc);
358         if((!st->codec->sample_aspect_ratio.num) != (!st->codec->sample_aspect_ratio.den)){
359             av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->codec->sample_aspect_ratio.num, st->codec->sample_aspect_ratio.den);
360             return -1;
361         }
362         ff_get_v(bc); /* csp type */
363     }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
364         GET_V(st->codec->sample_rate , tmp > 0)
365         ff_get_v(bc); // samplerate_den
366         GET_V(st->codec->channels, tmp > 0)
367     }
368     if(skip_reserved(bc, end) || get_checksum(bc)){
369         av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
370         return -1;
371     }
372     stc->time_base= &nut->time_base[stc->time_base_id];
373     av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
374     return 0;
375 }
376
377 static int decode_info_header(NUTContext *nut){
378     AVFormatContext *s= nut->avf;
379     ByteIOContext *bc = s->pb;
380     uint64_t tmp;
381     unsigned int stream_id_plus1, chapter_start, chapter_len, count;
382     int chapter_id, i;
383     int64_t value, end;
384     char name[256], str_value[1024], type_str[256];
385     const char *type;
386
387     end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
388     end += url_ftell(bc);
389
390     GET_V(stream_id_plus1, tmp <= s->nb_streams)
391     chapter_id   = get_s(bc);
392     chapter_start= ff_get_v(bc);
393     chapter_len  = ff_get_v(bc);
394     count        = ff_get_v(bc);
395     for(i=0; i<count; i++){
396         get_str(bc, name, sizeof(name));
397         value= get_s(bc);
398         if(value == -1){
399             type= "UTF-8";
400             get_str(bc, str_value, sizeof(str_value));
401         }else if(value == -2){
402             get_str(bc, type_str, sizeof(type_str));
403             type= type_str;
404             get_str(bc, str_value, sizeof(str_value));
405         }else if(value == -3){
406             type= "s";
407             value= get_s(bc);
408         }else if(value == -4){
409             type= "t";
410             value= ff_get_v(bc);
411         }else if(value < -4){
412             type= "r";
413             get_s(bc);
414         }else{
415             type= "v";
416         }
417
418         if(chapter_id==0 && !strcmp(type, "UTF-8")){
419             if     (!strcmp(name, "Author"))
420                 av_strlcpy(s->author   , str_value, sizeof(s->author));
421             else if(!strcmp(name, "Title"))
422                 av_strlcpy(s->title    , str_value, sizeof(s->title));
423             else if(!strcmp(name, "Copyright"))
424                 av_strlcpy(s->copyright, str_value, sizeof(s->copyright));
425             else if(!strcmp(name, "Description"))
426                 av_strlcpy(s->comment  , str_value, sizeof(s->comment));
427         }
428     }
429
430     if(skip_reserved(bc, end) || get_checksum(bc)){
431         av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
432         return -1;
433     }
434     return 0;
435 }
436
437 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
438     AVFormatContext *s= nut->avf;
439     ByteIOContext *bc = s->pb;
440     int64_t end, tmp;
441
442     nut->last_syncpoint_pos= url_ftell(bc)-8;
443
444     end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
445     end += url_ftell(bc);
446
447     tmp= ff_get_v(bc);
448     *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
449     if(*back_ptr < 0)
450         return -1;
451
452     ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
453
454     if(skip_reserved(bc, end) || get_checksum(bc)){
455         av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
456         return -1;
457     }
458
459     *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
460     ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
461
462     return 0;
463 }
464
465 static int find_and_decode_index(NUTContext *nut){
466     AVFormatContext *s= nut->avf;
467     ByteIOContext *bc = s->pb;
468     uint64_t tmp, end;
469     int i, j, syncpoint_count;
470     int64_t filesize= url_fsize(bc);
471     int64_t *syncpoints;
472     int8_t *has_keyframe;
473
474     url_fseek(bc, filesize-12, SEEK_SET);
475     url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
476     if(get_be64(bc) != INDEX_STARTCODE){
477         av_log(s, AV_LOG_ERROR, "no index at the end\n");
478         return -1;
479     }
480
481     end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
482     end += url_ftell(bc);
483
484     ff_get_v(bc); //max_pts
485     GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
486     syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
487     has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
488     for(i=0; i<syncpoint_count; i++){
489         GET_V(syncpoints[i], tmp>0)
490         if(i)
491             syncpoints[i] += syncpoints[i-1];
492     }
493
494     for(i=0; i<s->nb_streams; i++){
495         int64_t last_pts= -1;
496         for(j=0; j<syncpoint_count;){
497             uint64_t x= ff_get_v(bc);
498             int type= x&1;
499             int n= j;
500             x>>=1;
501             if(type){
502                 int flag= x&1;
503                 x>>=1;
504                 if(n+x >= syncpoint_count + 1){
505                     av_log(s, AV_LOG_ERROR, "index overflow A\n");
506                     return -1;
507                 }
508                 while(x--)
509                     has_keyframe[n++]= flag;
510                 has_keyframe[n++]= !flag;
511             }else{
512                 while(x != 1){
513                     if(n>=syncpoint_count + 1){
514                         av_log(s, AV_LOG_ERROR, "index overflow B\n");
515                         return -1;
516                     }
517                     has_keyframe[n++]= x&1;
518                     x>>=1;
519                 }
520             }
521             if(has_keyframe[0]){
522                 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
523                 return -1;
524             }
525             assert(n<=syncpoint_count+1);
526             for(; j<n && j<syncpoint_count; j++){
527                 if(has_keyframe[j]){
528                     uint64_t B, A= ff_get_v(bc);
529                     if(!A){
530                         A= ff_get_v(bc);
531                         B= ff_get_v(bc);
532                         //eor_pts[j][i] = last_pts + A + B
533                     }else
534                         B= 0;
535                     av_add_index_entry(
536                         s->streams[i],
537                         16*syncpoints[j-1],
538                         last_pts + A,
539                         0,
540                         0,
541                         AVINDEX_KEYFRAME);
542                     last_pts += A + B;
543                 }
544             }
545         }
546     }
547
548     if(skip_reserved(bc, end) || get_checksum(bc)){
549         av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
550         return -1;
551     }
552     return 0;
553 }
554
555 static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
556 {
557     NUTContext *nut = s->priv_data;
558     ByteIOContext *bc = s->pb;
559     int64_t pos;
560     int initialized_stream_count;
561
562     nut->avf= s;
563
564     /* main header */
565     pos=0;
566     do{
567         pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
568         if (pos<0+1){
569             av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
570             return -1;
571         }
572     }while(decode_main_header(nut) < 0);
573
574     /* stream headers */
575     pos=0;
576     for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
577         pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
578         if (pos<0+1){
579             av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
580             return -1;
581         }
582         if(decode_stream_header(nut) >= 0)
583             initialized_stream_count++;
584     }
585
586     /* info headers */
587     pos=0;
588     for(;;){
589         uint64_t startcode= find_any_startcode(bc, pos);
590         pos= url_ftell(bc);
591
592         if(startcode==0){
593             av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
594             return -1;
595         }else if(startcode == SYNCPOINT_STARTCODE){
596             nut->next_startcode= startcode;
597             break;
598         }else if(startcode != INFO_STARTCODE){
599             continue;
600         }
601
602         decode_info_header(nut);
603     }
604
605     s->data_offset= pos-8;
606
607     if(!url_is_streamed(bc)){
608         int64_t orig_pos= url_ftell(bc);
609         find_and_decode_index(nut);
610         url_fseek(bc, orig_pos, SEEK_SET);
611     }
612     assert(nut->next_startcode == SYNCPOINT_STARTCODE);
613
614     return 0;
615 }
616
617 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
618     AVFormatContext *s= nut->avf;
619     ByteIOContext *bc = s->pb;
620     StreamContext *stc;
621     int size, flags, size_mul, pts_delta, i, reserved_count;
622     uint64_t tmp;
623
624     if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
625         av_log(s, AV_LOG_ERROR, "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n", url_ftell(bc), nut->last_syncpoint_pos, nut->max_distance);
626         return -1;
627     }
628
629     flags          = nut->frame_code[frame_code].flags;
630     size_mul       = nut->frame_code[frame_code].size_mul;
631     size           = nut->frame_code[frame_code].size_lsb;
632     *stream_id     = nut->frame_code[frame_code].stream_id;
633     pts_delta      = nut->frame_code[frame_code].pts_delta;
634     reserved_count = nut->frame_code[frame_code].reserved_count;
635     *header_idx    = nut->frame_code[frame_code].header_idx;
636
637     if(flags & FLAG_INVALID)
638         return -1;
639     if(flags & FLAG_CODED)
640         flags ^= ff_get_v(bc);
641     if(flags & FLAG_STREAM_ID){
642         GET_V(*stream_id, tmp < s->nb_streams)
643     }
644     stc= &nut->stream[*stream_id];
645     if(flags&FLAG_CODED_PTS){
646         int coded_pts= ff_get_v(bc);
647 //FIXME check last_pts validity?
648         if(coded_pts < (1<<stc->msb_pts_shift)){
649             *pts=ff_lsb2full(stc, coded_pts);
650         }else
651             *pts=coded_pts - (1<<stc->msb_pts_shift);
652     }else
653         *pts= stc->last_pts + pts_delta;
654     if(flags&FLAG_SIZE_MSB){
655         size += size_mul*ff_get_v(bc);
656     }
657     if(flags&FLAG_MATCH_TIME)
658         get_s(bc);
659     if(flags&FLAG_HEADER_IDX)
660         *header_idx= ff_get_v(bc);
661     if(flags&FLAG_RESERVED)
662         reserved_count= ff_get_v(bc);
663     for(i=0; i<reserved_count; i++)
664         ff_get_v(bc);
665
666     if(*header_idx >= (unsigned)nut->header_count){
667         av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
668         return -1;
669     }
670     if(size > 4096)
671         *header_idx=0;
672     size -= nut->header_len[*header_idx];
673
674     if(flags&FLAG_CHECKSUM){
675         get_be32(bc); //FIXME check this
676     }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
677         av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
678         return -1;
679     }
680
681     stc->last_pts= *pts;
682     stc->last_flags= flags;
683
684     return size;
685 }
686
687 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
688     AVFormatContext *s= nut->avf;
689     ByteIOContext *bc = s->pb;
690     int size, stream_id, discard;
691     int64_t pts, last_IP_pts;
692     StreamContext *stc;
693     uint8_t header_idx;
694
695     size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
696     if(size < 0)
697         return -1;
698
699     stc= &nut->stream[stream_id];
700
701     if (stc->last_flags & FLAG_KEY)
702         stc->skip_until_key_frame=0;
703
704     discard= s->streams[ stream_id ]->discard;
705     last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
706     if(  (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
707        ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
708        || discard >= AVDISCARD_ALL
709        || stc->skip_until_key_frame){
710         url_fskip(bc, size);
711         return 1;
712     }
713
714     av_new_packet(pkt, size + nut->header_len[header_idx]);
715     memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
716     pkt->pos= url_ftell(bc); //FIXME
717     get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
718
719     pkt->stream_index = stream_id;
720     if (stc->last_flags & FLAG_KEY)
721         pkt->flags |= PKT_FLAG_KEY;
722     pkt->pts = pts;
723
724     return 0;
725 }
726
727 static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
728 {
729     NUTContext *nut = s->priv_data;
730     ByteIOContext *bc = s->pb;
731     int i, frame_code=0, ret, skip;
732     int64_t ts, back_ptr;
733
734     for(;;){
735         int64_t pos= url_ftell(bc);
736         uint64_t tmp= nut->next_startcode;
737         nut->next_startcode=0;
738
739         if(tmp){
740             pos-=8;
741         }else{
742             frame_code = get_byte(bc);
743             if(url_feof(bc))
744                 return -1;
745             if(frame_code == 'N'){
746                 tmp= frame_code;
747                 for(i=1; i<8; i++)
748                     tmp = (tmp<<8) + get_byte(bc);
749             }
750         }
751         switch(tmp){
752         case MAIN_STARTCODE:
753         case STREAM_STARTCODE:
754         case INDEX_STARTCODE:
755             skip= get_packetheader(nut, bc, 0, tmp);
756             url_fseek(bc, skip, SEEK_CUR);
757             break;
758         case INFO_STARTCODE:
759             if(decode_info_header(nut)<0)
760                 goto resync;
761             break;
762         case SYNCPOINT_STARTCODE:
763             if(decode_syncpoint(nut, &ts, &back_ptr)<0)
764                 goto resync;
765             frame_code = get_byte(bc);
766         case 0:
767             ret= decode_frame(nut, pkt, frame_code);
768             if(ret==0)
769                 return 0;
770             else if(ret==1) //ok but discard packet
771                 break;
772         default:
773 resync:
774 av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
775             tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
776             if(tmp==0)
777                 return -1;
778 av_log(s, AV_LOG_DEBUG, "sync\n");
779             nut->next_startcode= tmp;
780         }
781     }
782 }
783
784 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
785     NUTContext *nut = s->priv_data;
786     ByteIOContext *bc = s->pb;
787     int64_t pos, pts, back_ptr;
788 av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
789
790     pos= *pos_arg;
791     do{
792         pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
793         if(pos < 1){
794             assert(nut->next_startcode == 0);
795             av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
796             return AV_NOPTS_VALUE;
797         }
798     }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
799     *pos_arg = pos-1;
800     assert(nut->last_syncpoint_pos == *pos_arg);
801
802     av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
803     if     (stream_index == -1) return pts;
804     else if(stream_index == -2) return back_ptr;
805
806 assert(0);
807 }
808
809 static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
810     NUTContext *nut = s->priv_data;
811     AVStream *st= s->streams[stream_index];
812     syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
813     syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
814     syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
815     int64_t pos, pos2, ts;
816     int i;
817
818     if(st->index_entries){
819         int index= av_index_search_timestamp(st, pts, flags);
820         if(index<0)
821             return -1;
822
823         pos2= st->index_entries[index].pos;
824         ts  = st->index_entries[index].timestamp;
825     }else{
826         av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
827         av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
828                                                     next_node[0]->ts , next_node[1]->ts);
829         pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
830                                             next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
831
832         if(!(flags & AVSEEK_FLAG_BACKWARD)){
833             dummy.pos= pos+16;
834             next_node[1]= &nopts_sp;
835             av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
836             pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos     , next_node[1]->pos, next_node[1]->pos,
837                                                 next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
838             if(pos2>=0)
839                 pos= pos2;
840             //FIXME dir but i think it does not matter
841         }
842         dummy.pos= pos;
843         sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
844
845         assert(sp);
846         pos2= sp->back_ptr  - 15;
847     }
848     av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
849     pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
850     url_fseek(s->pb, pos, SEEK_SET);
851     av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
852     if(pos2 > pos || pos2 + 15 < pos){
853         av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
854     }
855     for(i=0; i<s->nb_streams; i++)
856         nut->stream[i].skip_until_key_frame=1;
857
858     return 0;
859 }
860
861 static int nut_read_close(AVFormatContext *s)
862 {
863     NUTContext *nut = s->priv_data;
864
865     av_freep(&nut->time_base);
866     av_freep(&nut->stream);
867
868     return 0;
869 }
870
871 #ifdef CONFIG_NUT_DEMUXER
872 AVInputFormat nut_demuxer = {
873     "nut",
874     "nut format",
875     sizeof(NUTContext),
876     nut_probe,
877     nut_read_header,
878     nut_read_packet,
879     nut_read_close,
880     read_seek,
881     .extensions = "nut",
882 };
883 #endif