2 * LOAS AudioSyncStream demuxer
3 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
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/intreadwrite.h"
23 #include "libavutil/internal.h"
27 static int loas_probe(AVProbeData *p)
29 int max_frames = 0, first_frames = 0;
31 uint8_t *buf0 = p->buf;
34 uint8_t *end = buf0 + p->buf_size - 3;
37 for(; buf < end; buf= buf2+1) {
40 for(frames = 0; buf2 < end; frames++) {
41 uint32_t header = AV_RB24(buf2);
42 if((header >> 13) != 0x2B7)
44 fsize = (header & 0x1FFF) + 3;
47 fsize = FFMIN(fsize, end - buf2);
50 max_frames = FFMAX(max_frames, frames);
54 if (first_frames>=3) return AVPROBE_SCORE_MAX/2+1;
55 else if(max_frames>100)return AVPROBE_SCORE_MAX/2;
56 else if(max_frames>=3) return AVPROBE_SCORE_MAX/4;
57 else if(max_frames>=1) return 1;
61 static int loas_read_header(AVFormatContext *s,
62 AVFormatParameters *ap)
66 st = av_new_stream(s, 0);
68 return AVERROR(ENOMEM);
70 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
71 st->codec->codec_id = s->iformat->value;
72 st->need_parsing = AVSTREAM_PARSE_FULL;
74 //LCM of all possible AAC sample rates
75 av_set_pts_info(st, 64, 1, 28224000);
80 AVInputFormat ff_loas_demuxer = {
82 .long_name = NULL_IF_CONFIG_SMALL("LOAS AudioSyncStream"),
83 .read_probe = loas_probe,
84 .read_header = loas_read_header,
85 .read_packet = ff_raw_read_partial_packet,
86 .flags= AVFMT_GENERIC_INDEX,
87 .value = CODEC_ID_AAC_LATM,