3 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2009 Robert Swain ( rob opendot cl )
6 * This file is part of Libav.
8 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavutil/intreadwrite.h"
29 static int adts_aac_probe(AVProbeData *p)
31 int max_frames = 0, first_frames = 0;
33 uint8_t *buf0 = p->buf;
36 uint8_t *end = buf0 + p->buf_size - 7;
40 for (; buf < end; buf = buf2 + 1) {
43 for (frames = 0; buf2 < end; frames++) {
44 uint32_t header = AV_RB16(buf2);
45 if ((header & 0xFFF6) != 0xFFF0) {
47 // Found something that isn't an ADTS header, starting
48 // from a position other than the start of the buffer.
49 // Discard the count we've accumulated so far since it
50 // probably was a false positive.
55 fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
60 max_frames = FFMAX(max_frames, frames);
62 first_frames = frames;
65 if (first_frames >= 3)
66 return AVPROBE_SCORE_EXTENSION + 1;
67 else if (max_frames > 100)
68 return AVPROBE_SCORE_EXTENSION;
69 else if (max_frames >= 3)
70 return AVPROBE_SCORE_EXTENSION / 2;
71 else if (max_frames >= 1)
77 static int adts_aac_read_header(AVFormatContext *s)
81 st = avformat_new_stream(s, NULL);
83 return AVERROR(ENOMEM);
85 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
86 st->codecpar->codec_id = s->iformat->raw_codec_id;
87 st->need_parsing = AVSTREAM_PARSE_FULL;
91 // LCM of all possible ADTS sample rates
92 avpriv_set_pts_info(st, 64, 1, 28224000);
97 AVInputFormat ff_aac_demuxer = {
99 .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
100 .read_probe = adts_aac_probe,
101 .read_header = adts_aac_read_header,
102 .read_packet = ff_raw_read_partial_packet,
103 .flags = AVFMT_GENERIC_INDEX,
105 .mime_type = "audio/aac,audio/aacp,audio/x-aac",
106 .raw_codec_id = AV_CODEC_ID_AAC,