2 * "NUT" Container Format demuxer
3 * Copyright (c) 2004-2006 Michael Niedermayer
4 * Copyright (c) 2003 Alex Beregszaszi
6 * This file is part of FFmpeg.
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.
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.
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
23 #include "libavutil/avstring.h"
24 #include "libavutil/bswap.h"
25 #include "libavutil/tree.h"
31 static int get_str(ByteIOContext *bc, char *string, unsigned int maxlen){
32 unsigned int len= ff_get_v(bc);
35 get_buffer(bc, string, FFMIN(len, maxlen));
42 string[FFMIN(len, maxlen-1)]= 0;
50 static int64_t get_s(ByteIOContext *bc){
51 int64_t v = ff_get_v(bc) + 1;
53 if (v&1) return -(v>>1);
57 static uint64_t get_fourcc(ByteIOContext *bc){
58 unsigned int len= ff_get_v(bc);
60 if (len==2) return get_le16(bc);
61 else if(len==4) return get_le32(bc);
66 static inline uint64_t get_v_trace(ByteIOContext *bc, char *file, char *func, int line){
67 uint64_t v= ff_get_v(bc);
69 av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
73 static inline int64_t get_s_trace(ByteIOContext *bc, char *file, char *func, int line){
76 av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
80 static inline uint64_t get_vb_trace(ByteIOContext *bc, char *file, char *func, int line){
81 uint64_t v= get_vb(bc);
83 av_log(NULL, AV_LOG_DEBUG, "get_vb %5"PRId64" / %"PRIX64" in %s %s:%d\n", v, v, file, func, line);
86 #define ff_get_v(bc) get_v_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
87 #define get_s(bc) get_s_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
88 #define get_vb(bc) get_vb_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)
91 static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int calculate_checksum, uint64_t startcode)
94 // start= url_ftell(bc) - 8;
96 startcode= be2me_64(startcode);
97 startcode= ff_crc04C11DB7_update(0, &startcode, 8);
99 init_checksum(bc, ff_crc04C11DB7_update, startcode);
103 if(get_checksum(bc) && size > 4096)
106 init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);
111 static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){
115 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 currently are
117 while(!url_feof(bc)){
118 state= (state<<8) | get_byte(bc);
119 if((state>>56) != 'N')
123 case STREAM_STARTCODE:
124 case SYNCPOINT_STARTCODE:
126 case INDEX_STARTCODE:
135 * Find the given startcode.
136 * @param code the startcode
137 * @param pos the start position of the search, or -1 if the current position
138 * @returns the position of the startcode or -1 if not found
140 static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){
142 uint64_t startcode= find_any_startcode(bc, pos);
143 if(startcode == code)
144 return url_ftell(bc) - 8;
145 else if(startcode == 0)
151 static int nut_probe(AVProbeData *p){
155 for (i = 0; i < p->buf_size; i++) {
156 code = (code << 8) | p->buf[i];
157 if (code == MAIN_STARTCODE)
158 return AVPROBE_SCORE_MAX;
163 #define GET_V(dst, check) \
166 av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);\
171 static int skip_reserved(ByteIOContext *bc, int64_t pos){
172 pos -= url_ftell(bc);
174 url_fseek(bc, pos, SEEK_CUR);
183 static int decode_main_header(NUTContext *nut){
184 AVFormatContext *s= nut->avf;
185 ByteIOContext *bc = s->pb;
187 unsigned int stream_count;
188 int i, j, tmp_stream, tmp_mul, tmp_pts, tmp_size, count, tmp_res, tmp_head_idx;
191 end= get_packetheader(nut, bc, 1, MAIN_STARTCODE);
192 end += url_ftell(bc);
194 GET_V(tmp , tmp >=2 && tmp <= 3)
195 GET_V(stream_count , tmp > 0 && tmp <=MAX_STREAMS)
197 nut->max_distance = ff_get_v(bc);
198 if(nut->max_distance > 65536){
199 av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);
200 nut->max_distance= 65536;
203 GET_V(nut->time_base_count, tmp>0 && tmp<INT_MAX / sizeof(AVRational))
204 nut->time_base= av_malloc(nut->time_base_count * sizeof(AVRational));
206 for(i=0; i<nut->time_base_count; i++){
207 GET_V(nut->time_base[i].num, tmp>0 && tmp<(1ULL<<31))
208 GET_V(nut->time_base[i].den, tmp>0 && tmp<(1ULL<<31))
209 if(av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1){
210 av_log(s, AV_LOG_ERROR, "time base invalid\n");
217 tmp_match= 1-(1LL<<62);
220 int tmp_flags = ff_get_v(bc);
221 int tmp_fields= ff_get_v(bc);
222 if(tmp_fields>0) tmp_pts = get_s(bc);
223 if(tmp_fields>1) tmp_mul = ff_get_v(bc);
224 if(tmp_fields>2) tmp_stream= ff_get_v(bc);
225 if(tmp_fields>3) tmp_size = ff_get_v(bc);
227 if(tmp_fields>4) tmp_res = ff_get_v(bc);
229 if(tmp_fields>5) count = ff_get_v(bc);
230 else count = tmp_mul - tmp_size;
231 if(tmp_fields>6) tmp_match = get_s(bc);
232 if(tmp_fields>7) tmp_head_idx= ff_get_v(bc);
234 while(tmp_fields-- > 8)
237 if(count == 0 || i+count > 256){
238 av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);
241 if(tmp_stream >= stream_count){
242 av_log(s, AV_LOG_ERROR, "illegal stream number\n");
246 for(j=0; j<count; j++,i++){
248 nut->frame_code[i].flags= FLAG_INVALID;
252 nut->frame_code[i].flags = tmp_flags ;
253 nut->frame_code[i].pts_delta = tmp_pts ;
254 nut->frame_code[i].stream_id = tmp_stream;
255 nut->frame_code[i].size_mul = tmp_mul ;
256 nut->frame_code[i].size_lsb = tmp_size+j;
257 nut->frame_code[i].reserved_count = tmp_res ;
258 nut->frame_code[i].header_idx = tmp_head_idx;
261 assert(nut->frame_code['N'].flags == FLAG_INVALID);
263 if(end > url_ftell(bc) + 4){
265 GET_V(nut->header_count, tmp<128U)
267 for(i=1; i<nut->header_count; i++){
268 GET_V(nut->header_len[i], tmp>0 && tmp<256);
269 rem -= nut->header_len[i];
271 av_log(s, AV_LOG_ERROR, "invalid elision header\n");
274 nut->header[i]= av_malloc(nut->header_len[i]);
275 get_buffer(bc, nut->header[i], nut->header_len[i]);
277 assert(nut->header_len[0]==0);
280 if(skip_reserved(bc, end) || get_checksum(bc)){
281 av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");
285 nut->stream = av_mallocz(sizeof(StreamContext)*stream_count);
286 for(i=0; i<stream_count; i++){
293 static int decode_stream_header(NUTContext *nut){
294 AVFormatContext *s= nut->avf;
295 ByteIOContext *bc = s->pb;
297 int class, stream_id;
301 end= get_packetheader(nut, bc, 1, STREAM_STARTCODE);
302 end += url_ftell(bc);
304 GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);
305 stc= &nut->stream[stream_id];
307 st = s->streams[stream_id];
309 return AVERROR(ENOMEM);
311 class = ff_get_v(bc);
312 tmp = get_fourcc(bc);
313 st->codec->codec_tag= tmp;
317 st->codec->codec_type = CODEC_TYPE_VIDEO;
318 st->codec->codec_id = codec_get_id(codec_bmp_tags, tmp);
321 st->codec->codec_type = CODEC_TYPE_AUDIO;
322 st->codec->codec_id = codec_get_id(codec_wav_tags, tmp);
325 st->codec->codec_type = CODEC_TYPE_SUBTITLE;
326 st->codec->codec_id = codec_get_id(ff_nut_subtitle_tags, tmp);
329 st->codec->codec_type = CODEC_TYPE_DATA;
332 av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);
335 if(class<3 && st->codec->codec_id == CODEC_ID_NONE)
336 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");
338 GET_V(stc->time_base_id , tmp < nut->time_base_count);
339 GET_V(stc->msb_pts_shift , tmp < 16);
340 stc->max_pts_distance= ff_get_v(bc);
341 GET_V(stc->decode_delay , tmp < 1000); //sanity limit, raise this if Moore's law is true
342 st->codec->has_b_frames= stc->decode_delay;
343 ff_get_v(bc); //stream flags
345 GET_V(st->codec->extradata_size, tmp < (1<<30));
346 if(st->codec->extradata_size){
347 st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
348 get_buffer(bc, st->codec->extradata, st->codec->extradata_size);
351 if (st->codec->codec_type == CODEC_TYPE_VIDEO){
352 GET_V(st->codec->width , tmp > 0)
353 GET_V(st->codec->height, tmp > 0)
354 st->sample_aspect_ratio.num= ff_get_v(bc);
355 st->sample_aspect_ratio.den= ff_get_v(bc);
356 if((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)){
357 av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n", st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
360 ff_get_v(bc); /* csp type */
361 }else if (st->codec->codec_type == CODEC_TYPE_AUDIO){
362 GET_V(st->codec->sample_rate , tmp > 0)
363 ff_get_v(bc); // samplerate_den
364 GET_V(st->codec->channels, tmp > 0)
366 if(skip_reserved(bc, end) || get_checksum(bc)){
367 av_log(s, AV_LOG_ERROR, "stream header %d checksum mismatch\n", stream_id);
370 stc->time_base= &nut->time_base[stc->time_base_id];
371 av_set_pts_info(s->streams[stream_id], 63, stc->time_base->num, stc->time_base->den);
375 static void set_disposition_bits(AVFormatContext* avf, char* value, int stream_id){
377 for (i=0; ff_nut_dispositions[i].flag; ++i) {
378 if (!strcmp(ff_nut_dispositions[i].str, value))
379 flag = ff_nut_dispositions[i].flag;
382 av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);
383 for (i = 0; i < avf->nb_streams; ++i)
384 if (stream_id == i || stream_id == -1)
385 avf->streams[i]->disposition |= flag;
388 static int decode_info_header(NUTContext *nut){
389 AVFormatContext *s= nut->avf;
390 ByteIOContext *bc = s->pb;
392 unsigned int stream_id_plus1, chapter_start, chapter_len, count;
395 char name[256], str_value[1024], type_str[256];
397 AVChapter *chapter= NULL;
399 end= get_packetheader(nut, bc, 1, INFO_STARTCODE);
400 end += url_ftell(bc);
402 GET_V(stream_id_plus1, tmp <= s->nb_streams)
403 chapter_id = get_s(bc);
404 chapter_start= ff_get_v(bc);
405 chapter_len = ff_get_v(bc);
406 count = ff_get_v(bc);
408 if(chapter_id && !stream_id_plus1){
409 int64_t start= chapter_start / nut->time_base_count;
410 chapter= ff_new_chapter(s, chapter_id,
411 nut->time_base[chapter_start % nut->time_base_count],
412 start, start + chapter_len, NULL);
415 for(i=0; i<count; i++){
416 get_str(bc, name, sizeof(name));
420 get_str(bc, str_value, sizeof(str_value));
421 }else if(value == -2){
422 get_str(bc, type_str, sizeof(type_str));
424 get_str(bc, str_value, sizeof(str_value));
425 }else if(value == -3){
428 }else if(value == -4){
431 }else if(value < -4){
438 if (stream_id_plus1 > s->nb_streams) {
439 av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");
443 if(chapter_id==0 && !strcmp(type, "UTF-8")){
444 if (!strcmp(name, "Author"))
445 av_strlcpy(s->author , str_value, sizeof(s->author));
446 else if(!strcmp(name, "Title"))
447 av_strlcpy(s->title , str_value, sizeof(s->title));
448 else if(!strcmp(name, "Copyright"))
449 av_strlcpy(s->copyright, str_value, sizeof(s->copyright));
450 else if(!strcmp(name, "Description"))
451 av_strlcpy(s->comment , str_value, sizeof(s->comment));
452 else if(!strcmp(name, "Disposition"))
453 set_disposition_bits(s, str_value, stream_id_plus1 - 1);
455 if(chapter && !strcmp(type, "UTF-8")){
456 if(!strcmp(name, "Title"))
457 chapter->title= av_strdup(str_value);
461 if(skip_reserved(bc, end) || get_checksum(bc)){
462 av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");
468 static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr){
469 AVFormatContext *s= nut->avf;
470 ByteIOContext *bc = s->pb;
473 nut->last_syncpoint_pos= url_ftell(bc)-8;
475 end= get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);
476 end += url_ftell(bc);
479 *back_ptr= nut->last_syncpoint_pos - 16*ff_get_v(bc);
483 ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count], tmp / nut->time_base_count);
485 if(skip_reserved(bc, end) || get_checksum(bc)){
486 av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");
490 *ts= tmp / s->nb_streams * av_q2d(nut->time_base[tmp % s->nb_streams])*AV_TIME_BASE;
491 ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts);
496 static int find_and_decode_index(NUTContext *nut){
497 AVFormatContext *s= nut->avf;
498 ByteIOContext *bc = s->pb;
500 int i, j, syncpoint_count;
501 int64_t filesize= url_fsize(bc);
503 int8_t *has_keyframe;
506 url_fseek(bc, filesize-12, SEEK_SET);
507 url_fseek(bc, filesize-get_be64(bc), SEEK_SET);
508 if(get_be64(bc) != INDEX_STARTCODE){
509 av_log(s, AV_LOG_ERROR, "no index at the end\n");
513 end= get_packetheader(nut, bc, 1, INDEX_STARTCODE);
514 end += url_ftell(bc);
516 ff_get_v(bc); //max_pts
517 GET_V(syncpoint_count, tmp < INT_MAX/8 && tmp > 0)
518 syncpoints= av_malloc(sizeof(int64_t)*syncpoint_count);
519 has_keyframe= av_malloc(sizeof(int8_t)*(syncpoint_count+1));
520 for(i=0; i<syncpoint_count; i++){
521 syncpoints[i] = ff_get_v(bc);
522 if(syncpoints[i] <= 0)
525 syncpoints[i] += syncpoints[i-1];
528 for(i=0; i<s->nb_streams; i++){
529 int64_t last_pts= -1;
530 for(j=0; j<syncpoint_count;){
531 uint64_t x= ff_get_v(bc);
538 if(n+x >= syncpoint_count + 1){
539 av_log(s, AV_LOG_ERROR, "index overflow A\n");
543 has_keyframe[n++]= flag;
544 has_keyframe[n++]= !flag;
547 if(n>=syncpoint_count + 1){
548 av_log(s, AV_LOG_ERROR, "index overflow B\n");
551 has_keyframe[n++]= x&1;
556 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");
559 assert(n<=syncpoint_count+1);
560 for(; j<n && j<syncpoint_count; j++){
562 uint64_t B, A= ff_get_v(bc);
566 //eor_pts[j][i] = last_pts + A + B
582 if(skip_reserved(bc, end) || get_checksum(bc)){
583 av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");
589 av_free(has_keyframe);
593 static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)
595 NUTContext *nut = s->priv_data;
596 ByteIOContext *bc = s->pb;
598 int initialized_stream_count;
605 pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;
607 av_log(s, AV_LOG_ERROR, "No main startcode found.\n");
610 }while(decode_main_header(nut) < 0);
614 for(initialized_stream_count=0; initialized_stream_count < s->nb_streams;){
615 pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;
617 av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");
620 if(decode_stream_header(nut) >= 0)
621 initialized_stream_count++;
627 uint64_t startcode= find_any_startcode(bc, pos);
631 av_log(s, AV_LOG_ERROR, "EOF before video frames\n");
633 }else if(startcode == SYNCPOINT_STARTCODE){
634 nut->next_startcode= startcode;
636 }else if(startcode != INFO_STARTCODE){
640 decode_info_header(nut);
643 s->data_offset= pos-8;
645 if(!url_is_streamed(bc)){
646 int64_t orig_pos= url_ftell(bc);
647 find_and_decode_index(nut);
648 url_fseek(bc, orig_pos, SEEK_SET);
650 assert(nut->next_startcode == SYNCPOINT_STARTCODE);
655 static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id, uint8_t *header_idx, int frame_code){
656 AVFormatContext *s= nut->avf;
657 ByteIOContext *bc = s->pb;
659 int size, flags, size_mul, pts_delta, i, reserved_count;
662 if(url_ftell(bc) > nut->last_syncpoint_pos + nut->max_distance){
663 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);
667 flags = nut->frame_code[frame_code].flags;
668 size_mul = nut->frame_code[frame_code].size_mul;
669 size = nut->frame_code[frame_code].size_lsb;
670 *stream_id = nut->frame_code[frame_code].stream_id;
671 pts_delta = nut->frame_code[frame_code].pts_delta;
672 reserved_count = nut->frame_code[frame_code].reserved_count;
673 *header_idx = nut->frame_code[frame_code].header_idx;
675 if(flags & FLAG_INVALID)
677 if(flags & FLAG_CODED)
678 flags ^= ff_get_v(bc);
679 if(flags & FLAG_STREAM_ID){
680 GET_V(*stream_id, tmp < s->nb_streams)
682 stc= &nut->stream[*stream_id];
683 if(flags&FLAG_CODED_PTS){
684 int coded_pts= ff_get_v(bc);
685 //FIXME check last_pts validity?
686 if(coded_pts < (1<<stc->msb_pts_shift)){
687 *pts=ff_lsb2full(stc, coded_pts);
689 *pts=coded_pts - (1<<stc->msb_pts_shift);
691 *pts= stc->last_pts + pts_delta;
692 if(flags&FLAG_SIZE_MSB){
693 size += size_mul*ff_get_v(bc);
695 if(flags&FLAG_MATCH_TIME)
697 if(flags&FLAG_HEADER_IDX)
698 *header_idx= ff_get_v(bc);
699 if(flags&FLAG_RESERVED)
700 reserved_count= ff_get_v(bc);
701 for(i=0; i<reserved_count; i++)
704 if(*header_idx >= (unsigned)nut->header_count){
705 av_log(s, AV_LOG_ERROR, "header_idx invalid\n");
710 size -= nut->header_len[*header_idx];
712 if(flags&FLAG_CHECKSUM){
713 get_be32(bc); //FIXME check this
714 }else if(size > 2*nut->max_distance || FFABS(stc->last_pts - *pts) > stc->max_pts_distance){
715 av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");
720 stc->last_flags= flags;
725 static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code){
726 AVFormatContext *s= nut->avf;
727 ByteIOContext *bc = s->pb;
728 int size, stream_id, discard;
729 int64_t pts, last_IP_pts;
733 size= decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);
737 stc= &nut->stream[stream_id];
739 if (stc->last_flags & FLAG_KEY)
740 stc->skip_until_key_frame=0;
742 discard= s->streams[ stream_id ]->discard;
743 last_IP_pts= s->streams[ stream_id ]->last_IP_pts;
744 if( (discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY))
745 ||(discard >= AVDISCARD_BIDIR && last_IP_pts != AV_NOPTS_VALUE && last_IP_pts > pts)
746 || discard >= AVDISCARD_ALL
747 || stc->skip_until_key_frame){
752 av_new_packet(pkt, size + nut->header_len[header_idx]);
753 memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);
754 pkt->pos= url_ftell(bc); //FIXME
755 get_buffer(bc, pkt->data + nut->header_len[header_idx], size);
757 pkt->stream_index = stream_id;
758 if (stc->last_flags & FLAG_KEY)
759 pkt->flags |= PKT_FLAG_KEY;
765 static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)
767 NUTContext *nut = s->priv_data;
768 ByteIOContext *bc = s->pb;
769 int i, frame_code=0, ret, skip;
770 int64_t ts, back_ptr;
773 int64_t pos= url_ftell(bc);
774 uint64_t tmp= nut->next_startcode;
775 nut->next_startcode=0;
780 frame_code = get_byte(bc);
783 if(frame_code == 'N'){
786 tmp = (tmp<<8) + get_byte(bc);
791 case STREAM_STARTCODE:
792 case INDEX_STARTCODE:
793 skip= get_packetheader(nut, bc, 0, tmp);
794 url_fseek(bc, skip, SEEK_CUR);
797 if(decode_info_header(nut)<0)
800 case SYNCPOINT_STARTCODE:
801 if(decode_syncpoint(nut, &ts, &back_ptr)<0)
803 frame_code = get_byte(bc);
805 ret= decode_frame(nut, pkt, frame_code);
808 else if(ret==1) //ok but discard packet
812 av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);
813 tmp= find_any_startcode(bc, nut->last_syncpoint_pos+1);
816 av_log(s, AV_LOG_DEBUG, "sync\n");
817 nut->next_startcode= tmp;
822 static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){
823 NUTContext *nut = s->priv_data;
824 ByteIOContext *bc = s->pb;
825 int64_t pos, pts, back_ptr;
826 av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n", stream_index, *pos_arg, pos_limit);
830 pos= find_startcode(bc, SYNCPOINT_STARTCODE, pos)+1;
832 assert(nut->next_startcode == 0);
833 av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");
834 return AV_NOPTS_VALUE;
836 }while(decode_syncpoint(nut, &pts, &back_ptr) < 0);
838 assert(nut->last_syncpoint_pos == *pos_arg);
840 av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts,back_ptr );
841 if (stream_index == -1) return pts;
842 else if(stream_index == -2) return back_ptr;
847 static int read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags){
848 NUTContext *nut = s->priv_data;
849 AVStream *st= s->streams[stream_index];
850 Syncpoint dummy={.ts= pts*av_q2d(st->time_base)*AV_TIME_BASE};
851 Syncpoint nopts_sp= {.ts= AV_NOPTS_VALUE, .back_ptr= AV_NOPTS_VALUE};
852 Syncpoint *sp, *next_node[2]= {&nopts_sp, &nopts_sp};
853 int64_t pos, pos2, ts;
856 if(st->index_entries){
857 int index= av_index_search_timestamp(st, pts, flags);
861 pos2= st->index_entries[index].pos;
862 ts = st->index_entries[index].timestamp;
864 av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pts_cmp, next_node);
865 av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n", next_node[0]->pos, next_node[1]->pos,
866 next_node[0]->ts , next_node[1]->ts);
867 pos= av_gen_search(s, -1, dummy.ts, next_node[0]->pos, next_node[1]->pos, next_node[1]->pos,
868 next_node[0]->ts , next_node[1]->ts, AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);
870 if(!(flags & AVSEEK_FLAG_BACKWARD)){
872 next_node[1]= &nopts_sp;
873 av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, next_node);
874 pos2= av_gen_search(s, -2, dummy.pos, next_node[0]->pos , next_node[1]->pos, next_node[1]->pos,
875 next_node[0]->back_ptr, next_node[1]->back_ptr, flags, &ts, nut_read_timestamp);
878 //FIXME dir but I think it does not matter
881 sp= av_tree_find(nut->syncpoints, &dummy, ff_nut_sp_pos_cmp, NULL);
884 pos2= sp->back_ptr - 15;
886 av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);
887 pos= find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);
888 url_fseek(s->pb, pos, SEEK_SET);
889 av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);
890 if(pos2 > pos || pos2 + 15 < pos){
891 av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");
893 for(i=0; i<s->nb_streams; i++)
894 nut->stream[i].skip_until_key_frame=1;
899 static int nut_read_close(AVFormatContext *s)
901 NUTContext *nut = s->priv_data;
903 av_freep(&nut->time_base);
904 av_freep(&nut->stream);
909 #if CONFIG_NUT_DEMUXER
910 AVInputFormat nut_demuxer = {
912 NULL_IF_CONFIG_SMALL("NUT format"),