b637bb4f4b23c401527339d1a74bea03a89e51e6
[libav.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;
188
189 end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
190 end += url_ftell(bc);
191
192 GET_V(tmp , tmp >=2 && tmp <= 3)
193 GET_V(stream_count , tmp > 0 && tmp <=MAX_STREAMS)
194
195 nut->max_distance = ff_get_v(bc);
196 if(nut->max_distance > 65536){
197 av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
198 nut->max_distance= 65536;
199 }
200
201 GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
202 nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
203
204 for(i=0; i<nut->time_base_count; i++){
205 GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
206 GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
207 if(ff_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
208 av_log(s, AV_LOG_ERROR, "time base invalid\n");
209 return -1;
210 }
211 }
212 tmp_pts=0;
213 tmp_mul=1;
214 tmp_stream=0;
215 for(i=0; i<256;){
216 int tmp_flags = ff_get_v(bc);
217 int tmp_fields= ff_get_v(bc);
218 if(tmp_fields>0) tmp_pts = get_s(bc);
219 if(tmp_fields>1) tmp_mul = ff_get_v(bc);
220 if(tmp_fields>2) tmp_stream= ff_get_v(bc);
221 if(tmp_fields>3) tmp_size = ff_get_v(bc);
222 else tmp_size = 0;
223 if(tmp_fields>4) tmp_res = ff_get_v(bc);
224 else tmp_res = 0;
225 if(tmp_fields>5) count = ff_get_v(bc);
226 else count = tmp_mul - tmp_size;
227
228 while(tmp_fields-- > 6)
229 ff_get_v(bc);
230
231 if(count == 0 || i+count > 256){
232 av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
233 return -1;
234 }
235 if(tmp_stream >= stream_count){
236 av_log(s, AV_LOG_ERROR, "illegal stream number\n");
237 return -1;
238 }
239
240 for(j=0; j<count; j++,i++){
241 if (i == 'N') {
242 nut->frame_code[i].flags= FLAG_INVALID;
243 j--;
244 continue;
245 }
246 nut->frame_code[i].flags = tmp_flags ;
247 nut->frame_code[i].pts_delta = tmp_pts ;
248 nut->frame_code[i].stream_id = tmp_stream;
249 nut->frame_code[i].size_mul = tmp_mul ;
250 nut->frame_code[i].size_lsb = tmp_size+j;
251 nut->frame_code[i].reserved_count = tmp_res ;
252 }
253 }
254 assert(nut->frame_code['N'].flags == FLAG_INVALID);
255
256 if(skip_reserved(bc, end) || get_checksum(bc)){
257 av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
258 return -1;
259 }
260
261 nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
262 for(i=0; i<stream_count; i++){
263 av_new_stream(s, i);
264 }
265
266 return 0;
267 }
268
269 static int decode_stream_header(NUTContext *nut){
270 AVFormatContext *s= nut->avf;
271 ByteIOContext *bc = s->pb;
272 StreamContext *stc;
273 int class, stream_id;
274 uint64_t tmp, end;
275 AVStream *st;
276
277 end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
278 end += url_ftell(bc);
279
280 GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
281 stc= &nut->stream[stream_id];
282
283 st = s->streams[stream_id];
284 if (!st)
285 return AVERROR(ENOMEM);
286
287 class = ff_get_v(bc);
288 tmp = get_fourcc(bc);
289 st->codec->codec_tag= tmp;
290 switch(class)
291 {
292 case 0:
293 st->codec->codec_type = CODEC_TYPE_VIDEO;
294 st->codec->codec_id = codec_get_id(codec_bmp_tags, tmp);
295 if (st->codec->codec_id == CODEC_ID_NONE)
296 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
297 break;
298 case 1:
299 st->codec->codec_type = CODEC_TYPE_AUDIO;
300 st->codec->codec_id = codec_get_id(codec_wav_tags, tmp);
301 if (st->codec->codec_id == CODEC_ID_NONE)
302 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
303 break;
304 case 2:
305 // st->codec->codec_type = CODEC_TYPE_TEXT;
306 // break;
307 case 3:
308 st->codec->codec_type = CODEC_TYPE_DATA;
309 break;
310 default:
311 av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
312 return -1;
313 }
314 GET_V(stc->time_base_id , tmp < nut->time_base_count);
315 GET_V(stc->msb_pts_shift , tmp < 16);
316 stc->max_pts_distance= ff_get_v(bc);
317 GET_V(stc->decode_delay , tmp < 1000); //sanity limit, raise this if Moore's law is true
318 st->codec->has_b_frames= stc->decode_delay;
319 ff_get_v(bc); //stream flags
320
321 GET_V(st->codec->extradata_size, tmp < (1<<30));
322 if(st->codec->extradata_size){
323 st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
324 get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
325 }
326
327 if (st->codec->codec_type == CODEC_TYPE_VIDEO){
328 GET_V(st->codec->width , tmp > 0)
329 GET_V(st->codec->height, tmp > 0)
330 st->codec->sample_aspect_ratio.num= ff_get_v(bc);
331 st->codec->sample_aspect_ratio.den= ff_get_v(bc);
332 if((!st->codec->sample_aspect_ratio.num) != (!st->codec->sample_aspect_ratio.den)){
333 av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->codec->sample_aspect_ratio.num, st->codec->sample_aspect_ratio.den);
334 return -1;
335 }
336 ff_get_v(bc); /* csp type */
337 }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
338 GET_V(st->codec->sample_rate , tmp > 0)
339 ff_get_v(bc); // samplerate_den
340 GET_V(st->codec->channels, tmp > 0)
341 }
342 if(skip_reserved(bc, end) || get_checksum(bc)){
343 av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
344 return -1;
345 }
346 stc->time_base= &nut->time_base[stc->time_base_id];
347 av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
348 return 0;
349 }
350
351 static int decode_info_header(NUTContext *nut){
352 AVFormatContext *s= nut->avf;
353 ByteIOContext *bc = s->pb;
354 uint64_t tmp;
355 unsigned int stream_id_plus1, chapter_start, chapter_len, count;
356 int chapter_id, i;
357 int64_t value, end;
358 char name[256], str_value[1024], type_str[256];
359 const char *type;
360
361 end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
362 end += url_ftell(bc);
363
364 GET_V(stream_id_plus1, tmp <= s->nb_streams)
365 chapter_id = get_s(bc);
366 chapter_start= ff_get_v(bc);
367 chapter_len = ff_get_v(bc);
368 count = ff_get_v(bc);
369 for(i=0; i<count; i++){
370 get_str(bc, name, sizeof(name));
371 value= get_s(bc);
372 if(value == -1){
373 type= "UTF-8";
374 get_str(bc, str_value, sizeof(str_value));
375 }else if(value == -2){
376 get_str(bc, type_str, sizeof(type_str));
377 type= type_str;
378 get_str(bc, str_value, sizeof(str_value));
379 }else if(value == -3){
380 type= "s";
381 value= get_s(bc);
382 }else if(value == -4){
383 type= "t";
384 value= ff_get_v(bc);
385 }else if(value < -4){
386 type= "r";
387 get_s(bc);
388 }else{
389 type= "v";
390 }
391
392 if(chapter_id==0 && !strcmp(type, "UTF-8")){
393 if (!strcmp(name, "Author"))
394 av_strlcpy(s->author , str_value, sizeof(s->author));
395 else if(!strcmp(name, "Title"))
396 av_strlcpy(s->title , str_value, sizeof(s->title));
397 else if(!strcmp(name, "Copyright"))
398 av_strlcpy(s->copyright, str_value, sizeof(s->copyright));
399 else if(!strcmp(name, "Description"))
400 av_strlcpy(s->comment , str_value, sizeof(s->comment));
401 }
402 }
403
404 if(skip_reserved(bc, end) || get_checksum(bc)){
405 av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
406 return -1;
407 }
408 return 0;
409 }
410
411 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
412 AVFormatContext *s= nut->avf;
413 ByteIOContext *bc = s->pb;
414 int64_t end, tmp;
415
416 nut->last_syncpoint_pos= url_ftell(bc)-8;
417
418 end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
419 end += url_ftell(bc);
420
421 tmp= ff_get_v(bc);
422 *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
423 if(*back_ptr < 0)
424 return -1;
425
426 ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
427
428 if(skip_reserved(bc, end) || get_checksum(bc)){
429 av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
430 return -1;
431 }
432
433 *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
434 ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
435
436 return 0;
437 }
438
439 static int find_and_decode_index(NUTContext *nut){
440 AVFormatContext *s= nut->avf;
441 ByteIOContext *bc = s->pb;
442 uint64_t tmp, end;
443 int i, j, syncpoint_count;
444 int64_t filesize= url_fsize(bc);
445 int64_t *syncpoints;
446 int8_t *has_keyframe;
447
448 url_fseek(bc, filesize-12, SEEK_SET);
449 url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
450 if(get_be64(bc) != INDEX_STARTCODE){
451 av_log(s, AV_LOG_ERROR, "no index at the end\n");
452 return -1;
453 }
454
455 end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
456 end += url_ftell(bc);
457
458 ff_get_v(bc); //max_pts
459 GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
460 syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
461 has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
462 for(i=0; i<syncpoint_count; i++){
463 GET_V(syncpoints[i], tmp>0)
464 if(i)
465 syncpoints[i] += syncpoints[i-1];
466 }
467
468 for(i=0; i<s->nb_streams; i++){
469 int64_t last_pts= -1;
470 for(j=0; j<syncpoint_count;){
471 uint64_t x= ff_get_v(bc);
472 int type= x&1;
473 int n= j;
474 x>>=1;
475 if(type){
476 int flag= x&1;
477 x>>=1;
478 if(n+x >= syncpoint_count + 1){
479 av_log(s, AV_LOG_ERROR, "index overflow A\n");
480 return -1;
481 }
482 while(x--)
483 has_keyframe[n++]= flag;
484 has_keyframe[n++]= !flag;
485 }else{
486 while(x != 1){
487 if(n>=syncpoint_count + 1){
488 av_log(s, AV_LOG_ERROR, "index overflow B\n");
489 return -1;
490 }
491 has_keyframe[n++]= x&1;
492 x>>=1;
493 }
494 }
495 if(has_keyframe[0]){
496 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
497 return -1;
498 }
499 assert(n<=syncpoint_count+1);
500 for(; j<n && j<syncpoint_count; j++){
501 if(has_keyframe[j]){
502 uint64_t B, A= ff_get_v(bc);
503 if(!A){
504 A= ff_get_v(bc);
505 B= ff_get_v(bc);
506 //eor_pts[j][i] = last_pts + A + B
507 }else
508 B= 0;
509 av_add_index_entry(
510 s->streams[i],
511 16*syncpoints[j-1],
512 last_pts + A,
513 0,
514 0,
515 AVINDEX_KEYFRAME);
516 last_pts += A + B;
517 }
518 }
519 }
520 }
521
522 if(skip_reserved(bc, end) || get_checksum(bc)){
523 av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
524 return -1;
525 }
526 return 0;
527 }
528
529 static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
530 {
531 NUTContext *nut = s->priv_data;
532 ByteIOContext *bc = s->pb;
533 int64_t pos;
534 int initialized_stream_count;
535
536 nut->avf= s;
537
538 /* main header */
539 pos=0;
540 do{
541 pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
542 if (pos<0+1){
543 av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
544 return -1;
545 }
546 }while(decode_main_header(nut) < 0);
547
548 /* stream headers */
549 pos=0;
550 for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
551 pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
552 if (pos<0+1){
553 av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
554 return -1;
555 }
556 if(decode_stream_header(nut) >= 0)
557 initialized_stream_count++;
558 }
559
560 /* info headers */
561 pos=0;
562 for(;;){
563 uint64_t startcode= find_any_startcode(bc, pos);
564 pos= url_ftell(bc);
565
566 if(startcode==0){
567 av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
568 return -1;
569 }else if(startcode == SYNCPOINT_STARTCODE){
570 nut->next_startcode= startcode;
571 break;
572 }else if(startcode != INFO_STARTCODE){
573 continue;
574 }
575
576 decode_info_header(nut);
577 }
578
579 s->data_offset= pos-8;
580
581 if(!url_is_streamed(bc)){
582 int64_t orig_pos= url_ftell(bc);
583 find_and_decode_index(nut);
584 url_fseek(bc, orig_pos, SEEK_SET);
585 }
586 assert(nut->next_startcode == SYNCPOINT_STARTCODE);
587
588 return 0;
589 }
590
591 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, int frame_code){
592 AVFormatContext *s= nut->avf;
593 ByteIOContext *bc = s->pb;
594 StreamContext *stc;
595 int size, flags, size_mul, pts_delta, i, reserved_count;
596 uint64_t tmp;
597
598 if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
599 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);
600 return -1;
601 }
602
603 flags = nut->frame_code[frame_code].flags;
604 size_mul = nut->frame_code[frame_code].size_mul;
605 size = nut->frame_code[frame_code].size_lsb;
606 *stream_id = nut->frame_code[frame_code].stream_id;
607 pts_delta = nut->frame_code[frame_code].pts_delta;
608 reserved_count = nut->frame_code[frame_code].reserved_count;
609
610 if(flags & FLAG_INVALID)
611 return -1;
612 if(flags & FLAG_CODED)
613 flags ^= ff_get_v(bc);
614 if(flags & FLAG_STREAM_ID){
615 GET_V(*stream_id, tmp < s->nb_streams)
616 }
617 stc= &nut->stream[*stream_id];
618 if(flags&FLAG_CODED_PTS){
619 int coded_pts= ff_get_v(bc);
620 //FIXME check last_pts validity?
621 if(coded_pts < (1<<stc->msb_pts_shift)){
622 *pts=ff_lsb2full(stc, coded_pts);
623 }else
624 *pts=coded_pts - (1<<stc->msb_pts_shift);
625 }else
626 *pts= stc->last_pts + pts_delta;
627 if(flags&FLAG_SIZE_MSB){
628 size += size_mul*ff_get_v(bc);
629 }
630 if(flags&FLAG_RESERVED)
631 reserved_count= ff_get_v(bc);
632 for(i=0; i<reserved_count; i++)
633 ff_get_v(bc);
634 if(flags&FLAG_CHECKSUM){
635 get_be32(bc); //FIXME check this
636 }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
637 av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
638 return -1;
639 }
640
641 stc->last_pts= *pts;
642 stc->last_flags= flags;
643
644 return size;
645 }
646
647 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
648 AVFormatContext *s= nut->avf;
649 ByteIOContext *bc = s->pb;
650 int size, stream_id, discard;
651 int64_t pts, last_IP_pts;
652 StreamContext *stc;
653
654 size= decode_frame_header(nut, &pts, &stream_id, frame_code);
655 if(size < 0)
656 return -1;
657
658 stc= &nut->stream[stream_id];
659
660 if (stc->last_flags & FLAG_KEY)
661 stc->skip_until_key_frame=0;
662
663 discard= s->streams[ stream_id ]->discard;
664 last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
665 if( (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
666 ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
667 || discard >= AVDISCARD_ALL
668 || stc->skip_until_key_frame){
669 url_fskip(bc, size);
670 return 1;
671 }
672
673 av_get_packet(bc, pkt, size);
674 pkt->stream_index = stream_id;
675 if (stc->last_flags & FLAG_KEY)
676 pkt->flags |= PKT_FLAG_KEY;
677 pkt->pts = pts;
678
679 return 0;
680 }
681
682 static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
683 {
684 NUTContext *nut = s->priv_data;
685 ByteIOContext *bc = s->pb;
686 int i, frame_code=0, ret, skip;
687 int64_t ts, back_ptr;
688
689 for(;;){
690 int64_t pos= url_ftell(bc);
691 uint64_t tmp= nut->next_startcode;
692 nut->next_startcode=0;
693
694 if(tmp){
695 pos-=8;
696 }else{
697 frame_code = get_byte(bc);
698 if(url_feof(bc))
699 return -1;
700 if(frame_code == 'N'){
701 tmp= frame_code;
702 for(i=1; i<8; i++)
703 tmp = (tmp<<8) + get_byte(bc);
704 }
705 }
706 switch(tmp){
707 case MAIN_STARTCODE:
708 case STREAM_STARTCODE:
709 case INDEX_STARTCODE:
710 skip= get_packetheader(nut, bc, 0, tmp);
711 url_fseek(bc, skip, SEEK_CUR);
712 break;
713 case INFO_STARTCODE:
714 if(decode_info_header(nut)<0)
715 goto resync;
716 break;
717 case SYNCPOINT_STARTCODE:
718 if(decode_syncpoint(nut, &ts, &back_ptr)<0)
719 goto resync;
720 frame_code = get_byte(bc);
721 case 0:
722 ret= decode_frame(nut, pkt, frame_code);
723 if(ret==0)
724 return 0;
725 else if(ret==1) //ok but discard packet
726 break;
727 default:
728 resync:
729 av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
730 tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
731 if(tmp==0)
732 return -1;
733 av_log(s, AV_LOG_DEBUG, "sync\n");
734 nut->next_startcode= tmp;
735 }
736 }
737 }
738
739 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
740 NUTContext *nut = s->priv_data;
741 ByteIOContext *bc = s->pb;
742 int64_t pos, pts, back_ptr;
743 av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
744
745 pos= *pos_arg;
746 do{
747 pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
748 if(pos < 1){
749 assert(nut->next_startcode == 0);
750 av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
751 return AV_NOPTS_VALUE;
752 }
753 }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
754 *pos_arg = pos-1;
755 assert(nut->last_syncpoint_pos == *pos_arg);
756
757 av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
758 if (stream_index == -1) return pts;
759 else if(stream_index == -2) return back_ptr;
760
761 assert(0);
762 }
763
764 static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
765 NUTContext *nut = s->priv_data;
766 AVStream *st= s->streams[stream_index];
767 syncpoint_t dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
768 syncpoint_t nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
769 syncpoint_t *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
770 int64_t pos, pos2, ts;
771 int i;
772
773 if(st->index_entries){
774 int index= av_index_search_timestamp(st, pts, flags);
775 if(index<0)
776 return -1;
777
778 pos2= st->index_entries[index].pos;
779 ts = st->index_entries[index].timestamp;
780 }else{
781 av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
782 av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
783 next_node[0]->ts , next_node[1]->ts);
784 pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
785 next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
786
787 if(!(flags & AVSEEK_FLAG_BACKWARD)){
788 dummy.pos= pos+16;
789 next_node[1]= &nopts_sp;
790 av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
791 pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos , next_node[1]->pos, next_node[1]->pos,
792 next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
793 if(pos2>=0)
794 pos= pos2;
795 //FIXME dir but i think it does not matter
796 }
797 dummy.pos= pos;
798 sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
799
800 assert(sp);
801 pos2= sp->back_ptr - 15;
802 }
803 av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
804 pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
805 url_fseek(s->pb, pos, SEEK_SET);
806 av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
807 if(pos2 > pos || pos2 + 15 < pos){
808 av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
809 }
810 for(i=0; i<s->nb_streams; i++)
811 nut->stream[i].skip_until_key_frame=1;
812
813 return 0;
814 }
815
816 static int nut_read_close(AVFormatContext *s)
817 {
818 NUTContext *nut = s->priv_data;
819
820 av_freep(&nut->time_base);
821 av_freep(&nut->stream);
822
823 return 0;
824 }
825
826 #ifdef CONFIG_NUT_DEMUXER
827 AVInputFormat nut_demuxer = {
828 "nut",
829 "nut format",
830 sizeof(NUTContext),
831 nut_probe,
832 nut_read_header,
833 nut_read_packet,
834 nut_read_close,
835 read_seek,
836 .extensions = "nut",
837 };
838 #endif