3 * Copyright (c) 2000, 2001, 2002 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
26 #if CONFIG_VOBSUB_DEMUXER
27 # include "subtitles.h"
28 # include "libavutil/bprint.h"
34 /*********************************************/
37 #define MAX_SYNC_SIZE 100000
39 static int check_pes(const uint8_t *p, const uint8_t *end){
41 int pes2= (p[3] & 0xC0) == 0x80
42 && (p[4] & 0xC0) != 0x40
43 &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0));
45 for(p+=3; p<end && *p == 0xFF; p++);
46 if((*p&0xC0) == 0x40) p+=2;
47 if((*p&0xF0) == 0x20){
48 pes1= p[0]&p[2]&p[4]&1;
49 }else if((*p&0xF0) == 0x30){
50 pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1;
57 static int check_pack_header(const uint8_t *buf) {
58 return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20;
61 static int mpegps_probe(AVProbeData *p)
64 int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0;
68 for(i=0; i<p->buf_size; i++){
69 code = (code<<8) + p->buf[i];
70 if ((code & 0xffffff00) == 0x100) {
71 int len= p->buf[i+1] << 8 | p->buf[i+2];
72 int pes= check_pes(p->buf+i, p->buf+p->buf_size);
73 int pack = check_pack_header(p->buf+i);
75 if(code == SYSTEM_HEADER_START_CODE) sys++;
76 else if(code == PACK_START_CODE && pack) pspack++;
77 else if((code & 0xf0) == VIDEO_ID && pes) vid++;
78 // skip pes payload to avoid start code emulation for private
80 else if((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;}
81 else if(code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;}
82 else if(code == 0x1fd && pes) vid++; //VC1
84 else if((code & 0xf0) == VIDEO_ID && !pes) invalid++;
85 else if((code & 0xe0) == AUDIO_ID && !pes) invalid++;
86 else if(code == PRIVATE_STREAM_1 && !pes) invalid++;
90 if(vid+audio > invalid+1) /* invalid VDR files nd short PES streams */
91 score= AVPROBE_SCORE_MAX/4;
93 if(sys>invalid && sys*9 <= pspack*10)
94 return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
95 if(pspack > invalid && (priv1+vid+audio)*10 >= pspack*9)
96 return pspack > 2 ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg
97 if((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys && !pspack && p->buf_size>2048 && vid + audio > invalid) /* PES stream */
98 return (audio > 12 || vid > 3 + 2*invalid) ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4;
100 //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1
101 //mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6
102 //Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
107 typedef struct MpegDemuxContext {
108 int32_t header_state;
109 unsigned char psm_es_type[256];
111 #if CONFIG_VOBSUB_DEMUXER
112 AVFormatContext *sub_ctx;
113 FFDemuxSubtitlesQueue q;
117 static int mpegps_read_header(AVFormatContext *s)
119 MpegDemuxContext *m = s->priv_data;
120 const char *sofdec = "Sofdec";
122 int64_t last_pos = avio_tell(s->pb);
124 m->header_state = 0xff;
125 s->ctx_flags |= AVFMTCTX_NOHEADER;
131 } while (v == sofdec[i] && i++ < 6);
133 m->sofdec = (m->sofdec == 6) ? 1 : 0;
136 avio_seek(s->pb, last_pos, SEEK_SET);
138 /* no need to do more */
142 static int64_t get_pts(AVIOContext *pb, int c)
146 buf[0] = c<0 ? avio_r8(pb) : c;
147 avio_read(pb, buf+1, 4);
149 return ff_parse_pes_pts(buf);
152 static int find_next_start_code(AVIOContext *pb, int *size_ptr,
153 int32_t *header_state)
155 unsigned int state, v;
158 state = *header_state;
165 if (state == 0x000001) {
166 state = ((state << 8) | v) & 0xffffff;
170 state = ((state << 8) | v) & 0xffffff;
174 *header_state = state;
180 * Extract stream types from a program stream map
181 * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35
183 * @return number of bytes occupied by PSM in the bitstream
185 static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb)
187 int psm_length, ps_info_length, es_map_length;
189 psm_length = avio_rb16(pb);
192 ps_info_length = avio_rb16(pb);
194 /* skip program_stream_info */
195 avio_skip(pb, ps_info_length);
196 es_map_length = avio_rb16(pb);
198 /* at least one es available? */
199 while (es_map_length >= 4){
200 unsigned char type = avio_r8(pb);
201 unsigned char es_id = avio_r8(pb);
202 uint16_t es_info_length = avio_rb16(pb);
203 /* remember mapping from stream id to stream type */
204 m->psm_es_type[es_id] = type;
205 /* skip program_stream_info */
206 avio_skip(pb, es_info_length);
207 es_map_length -= 4 + es_info_length;
209 avio_rb32(pb); /* crc32 */
210 return 2 + psm_length;
213 /* read the next PES header. Return its position in ppos
214 (if not NULL), and its start code, pts and dts.
216 static int mpegps_read_pes_header(AVFormatContext *s,
217 int64_t *ppos, int *pstart_code,
218 int64_t *ppts, int64_t *pdts)
220 MpegDemuxContext *m = s->priv_data;
221 int len, size, startcode, c, flags, header_len;
222 int pes_ext, ext2_len, id_ext, skip;
224 int64_t last_sync= avio_tell(s->pb);
227 avio_seek(s->pb, last_sync, SEEK_SET);
229 /* next start code (should be immediately after) */
230 m->header_state = 0xff;
231 size = MAX_SYNC_SIZE;
232 startcode = find_next_start_code(s->pb, &size, &m->header_state);
233 last_sync = avio_tell(s->pb);
237 //FIXME we should remember header_state
238 return AVERROR(EAGAIN);
241 if (startcode == PACK_START_CODE)
243 if (startcode == SYSTEM_HEADER_START_CODE)
245 if (startcode == PADDING_STREAM) {
246 avio_skip(s->pb, avio_rb16(s->pb));
249 if (startcode == PRIVATE_STREAM_2) {
250 len = avio_rb16(s->pb);
253 if (avio_r8(s->pb) == 'S') {
255 avio_read(s->pb, buf, sizeof(buf));
256 m->sofdec = !memcmp(buf, "ofdec", 5);
261 m->sofdec -= !m->sofdec;
263 avio_skip(s->pb, len);
266 if (startcode == PROGRAM_STREAM_MAP) {
267 mpegps_psm_parse(m, s->pb);
271 /* find matching stream */
272 if (!((startcode >= 0x1c0 && startcode <= 0x1df) ||
273 (startcode >= 0x1e0 && startcode <= 0x1ef) ||
274 (startcode == 0x1bd) || (startcode == 0x1fd)))
277 *ppos = avio_tell(s->pb) - 4;
279 len = avio_rb16(s->pb);
281 dts = AV_NOPTS_VALUE;
288 /* XXX: for mpeg1, should test only bit 7 */
292 if ((c & 0xc0) == 0x40) {
293 /* buffer scale & size */
298 if ((c & 0xe0) == 0x20) {
299 dts = pts = get_pts(s->pb, c);
302 dts = get_pts(s->pb, -1);
305 } else if ((c & 0xc0) == 0x80) {
307 flags = avio_r8(s->pb);
308 header_len = avio_r8(s->pb);
310 if (header_len > len)
314 dts = pts = get_pts(s->pb, -1);
317 dts = get_pts(s->pb, -1);
321 if (flags & 0x3f && header_len == 0){
323 av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n");
325 if (flags & 0x01) { /* PES extension */
326 pes_ext = avio_r8(s->pb);
328 /* Skip PES private data, program packet sequence counter and P-STD buffer */
329 skip = (pes_ext >> 4) & 0xb;
331 if (pes_ext & 0x40 || skip > header_len){
332 av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext);
335 avio_skip(s->pb, skip);
338 if (pes_ext & 0x01) { /* PES extension 2 */
339 ext2_len = avio_r8(s->pb);
341 if ((ext2_len & 0x7f) > 0) {
342 id_ext = avio_r8(s->pb);
343 if ((id_ext & 0x80) == 0)
344 startcode = ((startcode & 0xff) << 8) | id_ext;
351 avio_skip(s->pb, header_len);
356 if (startcode == PRIVATE_STREAM_1) {
357 startcode = avio_r8(s->pb);
362 if(dts != AV_NOPTS_VALUE && ppos){
364 for(i=0; i<s->nb_streams; i++){
365 if(startcode == s->streams[i]->id &&
366 s->pb->seekable /* index useless on streams anyway */) {
367 ff_reduce_index(s, i);
368 av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */);
373 *pstart_code = startcode;
379 static int mpegps_read_packet(AVFormatContext *s,
382 MpegDemuxContext *m = s->priv_data;
384 int len, startcode, i, es_type, ret;
385 int lpcm_header_len = -1; //Init to supress warning
386 int request_probe= 0;
387 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
388 enum AVMediaType type;
389 int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work
392 len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts);
396 if (startcode >= 0x80 && startcode <= 0xcf) {
400 /* audio: skip header */
402 lpcm_header_len = avio_rb16(s->pb);
404 if (startcode >= 0xb0 && startcode <= 0xbf) {
405 /* MLP/TrueHD audio has a 4-byte header */
411 /* now find stream */
412 for(i=0;i<s->nb_streams;i++) {
414 if (st->id == startcode)
418 es_type = m->psm_es_type[startcode & 0xff];
419 if(es_type == STREAM_TYPE_VIDEO_MPEG1){
420 codec_id = AV_CODEC_ID_MPEG2VIDEO;
421 type = AVMEDIA_TYPE_VIDEO;
422 } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){
423 codec_id = AV_CODEC_ID_MPEG2VIDEO;
424 type = AVMEDIA_TYPE_VIDEO;
425 } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 ||
426 es_type == STREAM_TYPE_AUDIO_MPEG2){
427 codec_id = AV_CODEC_ID_MP3;
428 type = AVMEDIA_TYPE_AUDIO;
429 } else if(es_type == STREAM_TYPE_AUDIO_AAC){
430 codec_id = AV_CODEC_ID_AAC;
431 type = AVMEDIA_TYPE_AUDIO;
432 } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){
433 codec_id = AV_CODEC_ID_MPEG4;
434 type = AVMEDIA_TYPE_VIDEO;
435 } else if(es_type == STREAM_TYPE_VIDEO_H264){
436 codec_id = AV_CODEC_ID_H264;
437 type = AVMEDIA_TYPE_VIDEO;
438 } else if(es_type == STREAM_TYPE_AUDIO_AC3){
439 codec_id = AV_CODEC_ID_AC3;
440 type = AVMEDIA_TYPE_AUDIO;
441 } else if (startcode >= 0x1e0 && startcode <= 0x1ef) {
442 static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 };
443 unsigned char buf[8];
444 avio_read(s->pb, buf, 8);
445 avio_seek(s->pb, -8, SEEK_CUR);
446 if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1))
447 codec_id = AV_CODEC_ID_CAVS;
450 type = AVMEDIA_TYPE_VIDEO;
451 } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
452 type = AVMEDIA_TYPE_AUDIO;
453 codec_id = m->sofdec > 0 ? AV_CODEC_ID_ADPCM_ADX : AV_CODEC_ID_MP2;
454 } else if (startcode >= 0x80 && startcode <= 0x87) {
455 type = AVMEDIA_TYPE_AUDIO;
456 codec_id = AV_CODEC_ID_AC3;
457 } else if ( ( startcode >= 0x88 && startcode <= 0x8f)
458 ||( startcode >= 0x98 && startcode <= 0x9f)) {
459 /* 0x90 - 0x97 is reserved for SDDS in DVD specs */
460 type = AVMEDIA_TYPE_AUDIO;
461 codec_id = AV_CODEC_ID_DTS;
462 } else if (startcode >= 0xa0 && startcode <= 0xaf) {
463 type = AVMEDIA_TYPE_AUDIO;
464 if(lpcm_header_len == 6) {
465 codec_id = AV_CODEC_ID_MLP;
467 /* 16 bit form will be handled as AV_CODEC_ID_PCM_S16BE */
468 codec_id = AV_CODEC_ID_PCM_DVD;
470 } else if (startcode >= 0xb0 && startcode <= 0xbf) {
471 type = AVMEDIA_TYPE_AUDIO;
472 codec_id = AV_CODEC_ID_TRUEHD;
473 } else if (startcode >= 0xc0 && startcode <= 0xcf) {
474 /* Used for both AC-3 and E-AC-3 in EVOB files */
475 type = AVMEDIA_TYPE_AUDIO;
476 codec_id = AV_CODEC_ID_AC3;
477 } else if (startcode >= 0x20 && startcode <= 0x3f) {
478 type = AVMEDIA_TYPE_SUBTITLE;
479 codec_id = AV_CODEC_ID_DVD_SUBTITLE;
480 } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
481 type = AVMEDIA_TYPE_VIDEO;
482 codec_id = AV_CODEC_ID_VC1;
486 avio_skip(s->pb, len);
489 /* no stream found: add a new stream */
490 st = avformat_new_stream(s, NULL);
494 st->codec->codec_type = type;
495 st->codec->codec_id = codec_id;
496 st->request_probe = request_probe;
497 if (codec_id != AV_CODEC_ID_PCM_S16BE)
498 st->need_parsing = AVSTREAM_PARSE_FULL;
500 if(st->discard >= AVDISCARD_ALL)
502 if (startcode >= 0xa0 && startcode <= 0xaf) {
503 if (lpcm_header_len == 6 && st->codec->codec_id == AV_CODEC_ID_MLP) {
511 /* for LPCM, we just skip the header and consider it is raw
515 avio_r8(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */
516 b1 = avio_r8(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */
517 avio_r8(s->pb); /* dynamic range control (0x80 = off) */
519 freq = (b1 >> 4) & 3;
520 st->codec->sample_rate = lpcm_freq_tab[freq];
521 st->codec->channels = 1 + (b1 & 7);
522 st->codec->bits_per_coded_sample = 16 + ((b1 >> 6) & 3) * 4;
523 st->codec->bit_rate = st->codec->channels *
524 st->codec->sample_rate *
525 st->codec->bits_per_coded_sample;
526 if (st->codec->bits_per_coded_sample == 16)
527 st->codec->codec_id = AV_CODEC_ID_PCM_S16BE;
528 else if (st->codec->bits_per_coded_sample == 28)
529 return AVERROR(EINVAL);
532 ret = av_get_packet(s->pb, pkt, len);
535 pkt->pos = dummy_pos;
536 pkt->stream_index = st->index;
537 av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n",
538 pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0,
541 return (ret < 0) ? ret : 0;
544 static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index,
545 int64_t *ppos, int64_t pos_limit)
548 int64_t pos, pts, dts;
551 if (avio_seek(s->pb, pos, SEEK_SET) < 0)
552 return AV_NOPTS_VALUE;
555 len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts);
557 av_dlog(s, "none (ret=%d)\n", len);
558 return AV_NOPTS_VALUE;
560 if (startcode == s->streams[stream_index]->id &&
561 dts != AV_NOPTS_VALUE) {
564 avio_skip(s->pb, len);
566 av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n",
567 pos, dts, dts / 90000.0);
572 AVInputFormat ff_mpegps_demuxer = {
574 .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS (MPEG-2 Program Stream)"),
575 .priv_data_size = sizeof(MpegDemuxContext),
576 .read_probe = mpegps_probe,
577 .read_header = mpegps_read_header,
578 .read_packet = mpegps_read_packet,
579 .read_timestamp = mpegps_read_dts,
580 .flags = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT,
583 #if CONFIG_VOBSUB_DEMUXER
585 #define REF_STRING "# VobSub index file,"
587 static int vobsub_probe(AVProbeData *p)
589 if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
590 return AVPROBE_SCORE_MAX;
594 static int vobsub_read_header(AVFormatContext *s)
596 int i, ret = 0, header_parsed = 0, langidx = 0;
597 MpegDemuxContext *vobsub = s->priv_data;
598 char *sub_name = NULL;
600 char *ext, *header_str;
605 sub_name = av_strdup(s->filename);
606 fname_len = strlen(sub_name);
607 ext = sub_name - 3 + fname_len;
608 if (fname_len < 4 || *(ext - 1) != '.') {
609 av_log(s, AV_LOG_ERROR, "The input index filename is too short "
610 "to guess the associated .SUB file\n");
611 ret = AVERROR_INVALIDDATA;
614 memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
615 av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->filename, sub_name);
616 ret = avformat_open_input(&vobsub->sub_ctx, sub_name, &ff_mpegps_demuxer, NULL);
618 av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", sub_name);
622 av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED);
623 while (!url_feof(s->pb)) {
625 int len = ff_get_line(s->pb, line, sizeof(line));
630 line[strcspn(line, "\r\n")] = 0;
632 if (!strncmp(line, "id:", 3)) {
633 int n, stream_id = 0;
636 n = sscanf(line, "id: %63[^,], index: %u", id, &stream_id);
638 av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
639 "assuming 'id: und, index: 0'\n", line);
644 st = avformat_new_stream(s, NULL);
646 ret = AVERROR(ENOMEM);
650 st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
651 st->codec->codec_id = AV_CODEC_ID_DVD_SUBTITLE;
652 av_dict_set(&st->metadata, "language", id, 0);
653 av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
656 } else if (st && !strncmp(line, "timestamp:", 10)) {
659 int64_t pos, timestamp;
660 const char *p = line + 10;
662 if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"PRIx64,
663 &hh, &mm, &ss, &ms, &pos) != 5) {
664 av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
665 "abort parsing\n", line);
668 timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
669 timestamp = av_rescale_q(timestamp, (AVRational){1,1000}, st->time_base);
671 sub = ff_subtitles_queue_insert(&vobsub->q, "", 0, 0);
673 ret = AVERROR(ENOMEM);
677 sub->pts = timestamp;
678 sub->stream_index = s->nb_streams - 1;
680 } else if (st && !strncmp(line, "alt:", 4)) {
681 const char *p = line + 4;
685 av_dict_set(&st->metadata, "title", p, 0);
686 av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", st->id, p);
689 } else if (!strncmp(line, "delay:", 6)) {
690 int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
691 const char *p = line + 6;
695 if (*p == '-' || *p == '+') {
696 sign = *p == '-' ? -1 : 1;
699 sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
700 delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
702 } else if (!strncmp(line, "langidx:", 8)) {
703 const char *p = line + 8;
705 if (sscanf(p, "%d", &langidx) != 1)
706 av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
708 } else if (!header_parsed) {
709 if (line[0] && line[0] != '#')
710 av_bprintf(&header, "%s\n", line);
714 if (langidx < s->nb_streams)
715 s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;
717 ff_subtitles_queue_finalize(&vobsub->q);
719 if (!av_bprint_is_complete(&header)) {
720 av_bprint_finalize(&header, NULL);
721 ret = AVERROR(ENOMEM);
724 av_bprint_finalize(&header, &header_str);
725 for (i = 0; i < s->nb_streams; i++) {
726 AVStream *sub_st = s->streams[i];
727 sub_st->codec->extradata = av_strdup(header_str);
728 sub_st->codec->extradata_size = header.len;
737 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
739 MpegDemuxContext *vobsub = s->priv_data;
740 FFDemuxSubtitlesQueue *q = &vobsub->q;
741 AVIOContext *pb = vobsub->sub_ctx->pb;
742 int ret, psize, len16 = -1;
745 ret = ff_subtitles_queue_read_packet(q, &idx_pkt);
749 /* compute maximum packet size using the next packet position. This is
750 * useful when the len in the header is non-sense */
751 if (q->current_sub_idx < q->nb_subs) {
752 psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos;
754 int64_t fsize = avio_size(pb);
755 psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos;
758 avio_seek(pb, idx_pkt.pos, SEEK_SET);
765 int n, to_read, startcode;
768 ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
771 to_read = ret & 0xffff;
773 /* this prevents reads above the current packet */
774 if (pkt->size + to_read > psize)
777 /* if the len is computed, we check for overread */
778 if (len16 != -1 && pkt->size + to_read > len16)
781 /* the current chunk doesn't match the stream index (unlikely) */
782 if ((startcode & 0x1f) != idx_pkt.stream_index)
785 ret = av_grow_packet(pkt, to_read);
789 n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
791 pkt->size -= to_read - n;
793 /* first chunk contains the total len of the packet to raise */
794 if (len16 == -1 && n > 2)
795 len16 = AV_RB16(pkt->data);
796 } while (len16 != -1 && pkt->size != len16);
798 pkt->pts = pkt->dts = idx_pkt.pts;
799 pkt->pos = idx_pkt.pos;
800 pkt->stream_index = idx_pkt.stream_index;
805 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
806 int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
808 MpegDemuxContext *vobsub = s->priv_data;
809 return ff_subtitles_queue_seek(&vobsub->q, s, stream_index,
810 min_ts, ts, max_ts, flags);
813 static int vobsub_read_close(AVFormatContext *s)
815 MpegDemuxContext *vobsub = s->priv_data;
816 ff_subtitles_queue_clean(&vobsub->q);
818 avformat_close_input(&vobsub->sub_ctx);
822 AVInputFormat ff_vobsub_demuxer = {
824 .long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
825 .priv_data_size = sizeof(MpegDemuxContext),
826 .read_probe = vobsub_probe,
827 .read_header = vobsub_read_header,
828 .read_packet = vobsub_read_packet,
829 .read_seek2 = vobsub_read_seek,
830 .read_close = vobsub_read_close,
831 .flags = AVFMT_SHOW_IDS,