2 * "Real" compatible demuxer.
3 * Copyright (c) 2000, 2001 Fabrice Bellard.
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/avstring.h"
26 static inline void get_strl(ByteIOContext *pb, char *buf, int buf_size, int len)
37 if (buf_size > 0) *q = '\0';
40 static void get_str16(ByteIOContext *pb, char *buf, int buf_size)
42 get_strl(pb, buf, buf_size, get_be16(pb));
45 static void get_str8(ByteIOContext *pb, char *buf, int buf_size)
47 get_strl(pb, buf, buf_size, get_byte(pb));
50 static int rm_read_audio_stream_info(AVFormatContext *s, AVStream *st,
53 RMContext *rm = s->priv_data;
54 ByteIOContext *pb = s->pb;
60 version = get_be32(pb); /* version */
61 if (((version >> 16) & 0xff) == 3) {
62 int64_t startpos = url_ftell(pb);
63 /* very old version */
64 for(i = 0; i < 14; i++)
66 get_str8(pb, s->title, sizeof(s->title));
67 get_str8(pb, s->author, sizeof(s->author));
68 get_str8(pb, s->copyright, sizeof(s->copyright));
69 get_str8(pb, s->comment, sizeof(s->comment));
70 if ((startpos + (version & 0xffff)) >= url_ftell(pb) + 2) {
71 // fourcc (should always be "lpcJ")
73 get_str8(pb, buf, sizeof(buf));
75 // Skip extra header crap (this should never happen)
76 if ((startpos + (version & 0xffff)) > url_ftell(pb))
77 url_fskip(pb, (version & 0xffff) + startpos - url_ftell(pb));
78 st->codec->sample_rate = 8000;
79 st->codec->channels = 1;
80 st->codec->codec_type = CODEC_TYPE_AUDIO;
81 st->codec->codec_id = CODEC_ID_RA_144;
83 int flavor, sub_packet_h, coded_framesize, sub_packet_size;
85 get_be32(pb); /* .ra4 */
86 get_be32(pb); /* data size */
87 get_be16(pb); /* version2 */
88 get_be32(pb); /* header size */
89 flavor= get_be16(pb); /* add codec info / flavor */
90 rm->coded_framesize = coded_framesize = get_be32(pb); /* coded frame size */
91 get_be32(pb); /* ??? */
92 get_be32(pb); /* ??? */
93 get_be32(pb); /* ??? */
94 rm->sub_packet_h = sub_packet_h = get_be16(pb); /* 1 */
95 st->codec->block_align= get_be16(pb); /* frame size */
96 rm->sub_packet_size = sub_packet_size = get_be16(pb); /* sub packet size */
97 get_be16(pb); /* ??? */
98 if (((version >> 16) & 0xff) == 5) {
99 get_be16(pb); get_be16(pb); get_be16(pb); }
100 st->codec->sample_rate = get_be16(pb);
102 st->codec->channels = get_be16(pb);
103 if (((version >> 16) & 0xff) == 5) {
105 buf[0] = get_byte(pb);
106 buf[1] = get_byte(pb);
107 buf[2] = get_byte(pb);
108 buf[3] = get_byte(pb);
111 get_str8(pb, buf, sizeof(buf)); /* desc */
112 get_str8(pb, buf, sizeof(buf)); /* desc */
114 st->codec->codec_type = CODEC_TYPE_AUDIO;
115 if (!strcmp(buf, "dnet")) {
116 st->codec->codec_id = CODEC_ID_AC3;
117 st->need_parsing = AVSTREAM_PARSE_FULL;
118 } else if (!strcmp(buf, "28_8")) {
119 st->codec->codec_id = CODEC_ID_RA_288;
120 st->codec->extradata_size= 0;
121 rm->audio_framesize = st->codec->block_align;
122 st->codec->block_align = coded_framesize;
124 if(rm->audio_framesize >= UINT_MAX / sub_packet_h){
125 av_log(s, AV_LOG_ERROR, "rm->audio_framesize * sub_packet_h too large\n");
129 rm->audiobuf = av_malloc(rm->audio_framesize * sub_packet_h);
130 } else if ((!strcmp(buf, "cook")) || (!strcmp(buf, "atrc"))) {
131 int codecdata_length, i;
132 get_be16(pb); get_byte(pb);
133 if (((version >> 16) & 0xff) == 5)
135 codecdata_length = get_be32(pb);
136 if(codecdata_length + FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)codecdata_length){
137 av_log(s, AV_LOG_ERROR, "codecdata_length too large\n");
141 if (!strcmp(buf, "cook")) st->codec->codec_id = CODEC_ID_COOK;
142 else st->codec->codec_id = CODEC_ID_ATRAC3;
143 st->codec->extradata_size= codecdata_length;
144 st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
145 for(i = 0; i < codecdata_length; i++)
146 ((uint8_t*)st->codec->extradata)[i] = get_byte(pb);
147 rm->audio_framesize = st->codec->block_align;
148 st->codec->block_align = rm->sub_packet_size;
150 if(rm->audio_framesize >= UINT_MAX / sub_packet_h){
151 av_log(s, AV_LOG_ERROR, "rm->audio_framesize * sub_packet_h too large\n");
155 rm->audiobuf = av_malloc(rm->audio_framesize * sub_packet_h);
156 } else if (!strcmp(buf, "raac") || !strcmp(buf, "racp")) {
157 int codecdata_length, i;
158 get_be16(pb); get_byte(pb);
159 if (((version >> 16) & 0xff) == 5)
161 st->codec->codec_id = CODEC_ID_AAC;
162 codecdata_length = get_be32(pb);
163 if(codecdata_length + FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)codecdata_length){
164 av_log(s, AV_LOG_ERROR, "codecdata_length too large\n");
167 if (codecdata_length >= 1) {
168 st->codec->extradata_size = codecdata_length - 1;
169 st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
171 for(i = 0; i < st->codec->extradata_size; i++)
172 ((uint8_t*)st->codec->extradata)[i] = get_byte(pb);
175 st->codec->codec_id = CODEC_ID_NONE;
176 av_strlcpy(st->codec->codec_name, buf, sizeof(st->codec->codec_name));
183 get_str8(pb, s->title, sizeof(s->title));
184 get_str8(pb, s->author, sizeof(s->author));
185 get_str8(pb, s->copyright, sizeof(s->copyright));
186 get_str8(pb, s->comment, sizeof(s->comment));
193 ff_rm_read_mdpr_codecdata (AVFormatContext *s, AVStream *st)
195 ByteIOContext *pb = s->pb;
197 int codec_data_size, size;
200 codec_data_size = get_be32(pb);
201 codec_pos = url_ftell(pb);
203 if (v == MKTAG(0xfd, 'a', 'r', '.')) {
205 if (rm_read_audio_stream_info(s, st, 0))
209 if (get_le32(pb) != MKTAG('V', 'I', 'D', 'O')) {
211 av_log(st->codec, AV_LOG_ERROR, "Unsupported video codec\n");
214 st->codec->codec_tag = get_le32(pb);
215 // av_log(NULL, AV_LOG_DEBUG, "%X %X\n", st->codec->codec_tag, MKTAG('R', 'V', '2', '0'));
216 if ( st->codec->codec_tag != MKTAG('R', 'V', '1', '0')
217 && st->codec->codec_tag != MKTAG('R', 'V', '2', '0')
218 && st->codec->codec_tag != MKTAG('R', 'V', '3', '0')
219 && st->codec->codec_tag != MKTAG('R', 'V', '4', '0'))
221 st->codec->width = get_be16(pb);
222 st->codec->height = get_be16(pb);
223 st->codec->time_base.num= 1;
225 st->codec->codec_type = CODEC_TYPE_VIDEO;
230 st->codec->extradata_size= codec_data_size - (url_ftell(pb) - codec_pos);
232 if(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)st->codec->extradata_size){
233 //check is redundant as get_buffer() will catch this
234 av_log(s, AV_LOG_ERROR, "st->codec->extradata_size too large\n");
237 st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
238 if (!st->codec->extradata)
239 return AVERROR(ENOMEM);
240 get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
242 // av_log(NULL, AV_LOG_DEBUG, "fps= %d fps2= %d\n", fps, fps2);
243 st->codec->time_base.den = fps * st->codec->time_base.num;
244 switch(((uint8_t*)st->codec->extradata)[4]>>4){
245 case 1: st->codec->codec_id = CODEC_ID_RV10; break;
246 case 2: st->codec->codec_id = CODEC_ID_RV20; break;
247 case 3: st->codec->codec_id = CODEC_ID_RV30; break;
248 case 4: st->codec->codec_id = CODEC_ID_RV40; break;
254 /* skip codec info */
255 size = url_ftell(pb) - codec_pos;
256 url_fskip(pb, codec_data_size - size);
262 static int rm_read_header_old(AVFormatContext *s, AVFormatParameters *ap)
264 RMContext *rm = s->priv_data;
268 st = av_new_stream(s, 0);
271 return rm_read_audio_stream_info(s, st, 1);
274 static int rm_read_header(AVFormatContext *s, AVFormatParameters *ap)
276 RMContext *rm = s->priv_data;
278 ByteIOContext *pb = s->pb;
281 unsigned int start_time, duration;
286 if (tag == MKTAG('.', 'r', 'a', 0xfd)) {
287 /* very old .ra format */
288 return rm_read_header_old(s, ap);
289 } else if (tag != MKTAG('.', 'R', 'M', 'F')) {
293 get_be32(pb); /* header size */
296 get_be32(pb); /* number of headers */
302 tag_size = get_be32(pb);
305 printf("tag=%c%c%c%c (%08x) size=%d\n",
313 if (tag_size < 10 && tag != MKTAG('D', 'A', 'T', 'A'))
316 case MKTAG('P', 'R', 'O', 'P'):
318 get_be32(pb); /* max bit rate */
319 get_be32(pb); /* avg bit rate */
320 get_be32(pb); /* max packet size */
321 get_be32(pb); /* avg packet size */
322 get_be32(pb); /* nb packets */
323 get_be32(pb); /* duration */
324 get_be32(pb); /* preroll */
325 get_be32(pb); /* index offset */
326 get_be32(pb); /* data offset */
327 get_be16(pb); /* nb streams */
328 flags = get_be16(pb); /* flags */
330 case MKTAG('C', 'O', 'N', 'T'):
331 get_str16(pb, s->title, sizeof(s->title));
332 get_str16(pb, s->author, sizeof(s->author));
333 get_str16(pb, s->copyright, sizeof(s->copyright));
334 get_str16(pb, s->comment, sizeof(s->comment));
336 case MKTAG('M', 'D', 'P', 'R'):
337 st = av_new_stream(s, 0);
340 st->id = get_be16(pb);
341 get_be32(pb); /* max bit rate */
342 st->codec->bit_rate = get_be32(pb); /* bit rate */
343 get_be32(pb); /* max packet size */
344 get_be32(pb); /* avg packet size */
345 start_time = get_be32(pb); /* start time */
346 get_be32(pb); /* preroll */
347 duration = get_be32(pb); /* duration */
348 st->start_time = start_time;
349 st->duration = duration;
350 get_str8(pb, buf, sizeof(buf)); /* desc */
351 get_str8(pb, buf, sizeof(buf)); /* mimetype */
352 st->codec->codec_type = CODEC_TYPE_DATA;
353 av_set_pts_info(st, 64, 1, 1000);
354 if (ff_rm_read_mdpr_codecdata(s, st) < 0)
357 case MKTAG('D', 'A', 'T', 'A'):
360 /* unknown tag: skip it */
361 url_fskip(pb, tag_size - 10);
366 rm->nb_packets = get_be32(pb); /* number of packets */
367 if (!rm->nb_packets && (flags & 4))
368 rm->nb_packets = 3600 * 25;
369 get_be32(pb); /* next data header */
374 for(i=0;i<s->nb_streams;i++) {
375 av_free(s->streams[i]);
380 static int get_num(ByteIOContext *pb, int *len)
392 return (n << 16) | n1;
396 /* multiple of 20 bytes for ra144 (ugly) */
397 #define RAW_PACKET_SIZE 1000
399 static int sync(AVFormatContext *s, int64_t *timestamp, int *flags, int *stream_index, int64_t *pos){
400 RMContext *rm = s->priv_data;
401 ByteIOContext *pb = s->pb;
402 int len, num, res, i;
404 uint32_t state=0xFFFFFFFF;
406 while(!url_feof(pb)){
407 *pos= url_ftell(pb) - 3;
408 if(rm->remaining_len > 0){
409 num= rm->current_stream;
410 len= rm->remaining_len;
411 *timestamp = AV_NOPTS_VALUE;
414 state= (state<<8) + get_byte(pb);
416 if(state == MKBETAG('I', 'N', 'D', 'X')){
417 len = get_be16(pb) - 6;
423 if(state > (unsigned)0xFFFF || state < 12)
429 *timestamp = get_be32(pb);
430 res= get_byte(pb); /* reserved */
431 *flags = get_byte(pb); /* flags */
436 for(i=0;i<s->nb_streams;i++) {
441 if (i == s->nb_streams) {
443 /* skip packet if unknown number */
445 rm->remaining_len -= len;
455 static int rm_assemble_video_frame(AVFormatContext *s, RMContext *rm, AVPacket *pkt, int len)
457 ByteIOContext *pb = s->pb;
458 int hdr, seq, pic_num, len2, pos;
461 hdr = get_byte(pb); len--;
465 case 2: // last slice
466 seq = get_byte(pb); len--;
467 len2 = get_num(pb, &len);
468 pos = get_num(pb, &len);
469 pic_num = get_byte(pb); len--;
470 rm->remaining_len = len;
472 case 1: //whole frame
473 seq = get_byte(pb); len--;
474 if(av_new_packet(pkt, len + 9) < 0)
477 AV_WL32(pkt->data + 1, 1);
478 AV_WL32(pkt->data + 5, 0);
479 get_buffer(pb, pkt->data + 9, len);
480 rm->remaining_len = 0;
482 case 3: //frame as a part of packet
483 len2 = get_num(pb, &len);
484 pos = get_num(pb, &len);
485 pic_num = get_byte(pb); len--;
486 rm->remaining_len = len - len2;
487 if(av_new_packet(pkt, len2 + 9) < 0)
490 AV_WL32(pkt->data + 1, 1);
491 AV_WL32(pkt->data + 5, 0);
492 get_buffer(pb, pkt->data + 9, len2);
495 //now we have to deal with single slice
497 if((seq & 0x7F) == 1 || rm->curpic_num != pic_num){
498 rm->slices = ((hdr & 0x3F) << 1) + 1;
499 rm->videobufsize = len2 + 8*rm->slices + 1;
500 av_free(rm->videobuf);
501 if(!(rm->videobuf = av_malloc(rm->videobufsize)))
502 return AVERROR(ENOMEM);
503 rm->videobufpos = 8*rm->slices + 1;
505 rm->curpic_num = pic_num;
506 rm->pktpos = url_ftell(pb);
509 len = FFMIN(len, pos);
511 if(++rm->cur_slice > rm->slices)
513 AV_WL32(rm->videobuf - 7 + 8*rm->cur_slice, 1);
514 AV_WL32(rm->videobuf - 3 + 8*rm->cur_slice, rm->videobufpos - 8*rm->slices - 1);
515 if(rm->videobufpos + len > rm->videobufsize)
517 if (get_buffer(pb, rm->videobuf + rm->videobufpos, len) != len)
519 rm->videobufpos += len;
520 rm->remaining_len-= len;
522 if(type == 2 || (rm->videobufpos) == rm->videobufsize){
523 rm->videobuf[0] = rm->cur_slice-1;
524 if(av_new_packet(pkt, rm->videobufpos - 8*(rm->slices - rm->cur_slice)) < 0)
525 return AVERROR(ENOMEM);
526 memcpy(pkt->data, rm->videobuf, 1 + 8*rm->cur_slice);
527 memcpy(pkt->data + 1 + 8*rm->cur_slice, rm->videobuf + 1 + 8*rm->slices,
528 rm->videobufpos - 1 - 8*rm->slices);
529 pkt->pts = AV_NOPTS_VALUE;
530 pkt->pos = rm->pktpos;
538 rm_ac3_swap_bytes (AVStream *st, AVPacket *pkt)
543 if (st->codec->codec_id == CODEC_ID_AC3) {
545 for (j=0;j<pkt->size;j+=2) {
546 FFSWAP(int, ptr[0], ptr[1]);
553 ff_rm_parse_packet (AVFormatContext *s, AVStream *st, int len, AVPacket *pkt,
554 int *seq, int *flags, int64_t *timestamp)
556 ByteIOContext *pb = s->pb;
557 RMContext *rm = s->priv_data;
559 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
560 rm->current_stream= st->id;
561 if(rm_assemble_video_frame(s, rm, pkt, len) == 1)
562 return -1; //got partial frame
563 } else if (st->codec->codec_type == CODEC_TYPE_AUDIO) {
564 if ((st->codec->codec_id == CODEC_ID_RA_288) ||
565 (st->codec->codec_id == CODEC_ID_COOK) ||
566 (st->codec->codec_id == CODEC_ID_ATRAC3)) {
568 int sps = rm->sub_packet_size;
569 int cfs = rm->coded_framesize;
570 int h = rm->sub_packet_h;
571 int y = rm->sub_packet_cnt;
572 int w = rm->audio_framesize;
575 y = rm->sub_packet_cnt = 0;
577 rm->audiotimestamp = *timestamp;
579 switch(st->codec->codec_id) {
580 case CODEC_ID_RA_288:
581 for (x = 0; x < h/2; x++)
582 get_buffer(pb, rm->audiobuf+x*2*w+y*cfs, cfs);
584 case CODEC_ID_ATRAC3:
586 for (x = 0; x < w/sps; x++)
587 get_buffer(pb, rm->audiobuf+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), sps);
591 if (++(rm->sub_packet_cnt) < h)
594 rm->sub_packet_cnt = 0;
595 rm->audio_stream_num = st->index;
596 rm->audio_pkt_cnt = h * w / st->codec->block_align - 1;
597 // Release first audio packet
598 av_new_packet(pkt, st->codec->block_align);
599 memcpy(pkt->data, rm->audiobuf, st->codec->block_align);
600 *timestamp = rm->audiotimestamp;
601 *flags = 2; // Mark first packet as keyframe
603 } else if (st->codec->codec_id == CODEC_ID_AAC) {
605 rm->audio_stream_num = st->index;
606 rm->sub_packet_cnt = (get_be16(pb) & 0xf0) >> 4;
607 if (rm->sub_packet_cnt) {
608 for (x = 0; x < rm->sub_packet_cnt; x++)
609 rm->sub_packet_lengths[x] = get_be16(pb);
610 // Release first audio packet
611 rm->audio_pkt_cnt = rm->sub_packet_cnt - 1;
612 av_get_packet(pb, pkt, rm->sub_packet_lengths[0]);
613 *flags = 2; // Mark first packet as keyframe
616 av_get_packet(pb, pkt, len);
617 rm_ac3_swap_bytes(st, pkt);
620 av_get_packet(pb, pkt, len);
622 if( (st->discard >= AVDISCARD_NONKEY && !(*flags&2))
623 || st->discard >= AVDISCARD_ALL){
628 pkt->stream_index = st->index;
631 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
632 if(st->codec->codec_id == CODEC_ID_RV20){
633 int seq= 128*(pkt->data[2]&0x7F) + (pkt->data[3]>>1);
634 av_log(NULL, AV_LOG_DEBUG, "%d %"PRId64" %d\n", *timestamp, *timestamp*512LL/25, seq);
636 seq |= (*timestamp&~0x3FFF);
637 if(seq - *timestamp > 0x2000) seq -= 0x4000;
638 if(seq - *timestamp < -0x2000) seq += 0x4000;
643 pkt->pts= *timestamp;
645 pkt->flags |= PKT_FLAG_KEY;
651 ff_rm_retrieve_cache (AVFormatContext *s, AVStream *st, AVPacket *pkt)
653 ByteIOContext *pb = s->pb;
654 RMContext *rm = s->priv_data;
656 assert (rm->audio_pkt_cnt > 0);
658 if (st->codec->codec_id == CODEC_ID_AAC)
659 av_get_packet(pb, pkt, rm->sub_packet_lengths[rm->sub_packet_cnt - rm->audio_pkt_cnt]);
661 av_new_packet(pkt, st->codec->block_align);
662 memcpy(pkt->data, rm->audiobuf + st->codec->block_align *
663 (rm->sub_packet_h * rm->audio_framesize / st->codec->block_align - rm->audio_pkt_cnt),
664 st->codec->block_align);
668 pkt->stream_index = st->index;
671 static int rm_read_packet(AVFormatContext *s, AVPacket *pkt)
673 RMContext *rm = s->priv_data;
674 ByteIOContext *pb = s->pb;
677 int64_t timestamp, pos;
680 if (rm->audio_pkt_cnt) {
681 // If there are queued audio packet return them first
682 st = s->streams[rm->audio_stream_num];
683 ff_rm_retrieve_cache(s, st, pkt);
684 } else if (rm->old_format) {
686 if (st->codec->codec_id == CODEC_ID_RA_288) {
689 for (y = 0; y < rm->sub_packet_h; y++)
690 for (x = 0; x < rm->sub_packet_h/2; x++)
691 if (get_buffer(pb, rm->audiobuf+x*2*rm->audio_framesize+y*rm->coded_framesize, rm->coded_framesize) <= 0)
693 rm->audio_stream_num = 0;
694 rm->audio_pkt_cnt = rm->sub_packet_h * rm->audio_framesize / st->codec->block_align - 1;
695 // Release first audio packet
696 av_new_packet(pkt, st->codec->block_align);
697 memcpy(pkt->data, rm->audiobuf, st->codec->block_align);
698 pkt->flags |= PKT_FLAG_KEY; // Mark first packet as keyframe
699 pkt->stream_index = 0;
701 /* just read raw bytes */
702 len = RAW_PACKET_SIZE;
703 len= av_get_packet(pb, pkt, len);
704 pkt->stream_index = 0;
710 rm_ac3_swap_bytes(st, pkt);
714 len=sync(s, ×tamp, &flags, &i, &pos);
719 if (ff_rm_parse_packet (s, st, len, pkt, &seq, &flags, ×tamp) < 0)
722 if((flags&2) && (seq&0x7F) == 1)
723 av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);
729 static int rm_read_close(AVFormatContext *s)
731 RMContext *rm = s->priv_data;
733 av_free(rm->audiobuf);
734 av_free(rm->videobuf);
738 static int rm_probe(AVProbeData *p)
740 /* check file header */
741 if ((p->buf[0] == '.' && p->buf[1] == 'R' &&
742 p->buf[2] == 'M' && p->buf[3] == 'F' &&
743 p->buf[4] == 0 && p->buf[5] == 0) ||
744 (p->buf[0] == '.' && p->buf[1] == 'r' &&
745 p->buf[2] == 'a' && p->buf[3] == 0xfd))
746 return AVPROBE_SCORE_MAX;
751 static int64_t rm_read_dts(AVFormatContext *s, int stream_index,
752 int64_t *ppos, int64_t pos_limit)
754 RMContext *rm = s->priv_data;
756 int stream_index2, flags, len, h;
761 return AV_NOPTS_VALUE;
763 url_fseek(s->pb, pos, SEEK_SET);
769 len=sync(s, &dts, &flags, &stream_index2, &pos);
771 return AV_NOPTS_VALUE;
773 st = s->streams[stream_index2];
774 if (st->codec->codec_type == CODEC_TYPE_VIDEO) {
775 h= get_byte(s->pb); len--;
777 seq = get_byte(s->pb); len--;
781 if((flags&2) && (seq&0x7F) == 1){
782 // av_log(s, AV_LOG_DEBUG, "%d %d-%d %"PRId64" %d\n", flags, stream_index2, stream_index, dts, seq);
783 av_add_index_entry(st, pos, dts, 0, 0, AVINDEX_KEYFRAME);
784 if(stream_index2 == stream_index)
788 url_fskip(s->pb, len);
794 AVInputFormat rm_demuxer = {