3 * Copyright (c) 2012 Paul B Mahol
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/channel_layout.h"
23 #include "libavutil/intreadwrite.h"
28 static int ast_probe(AVProbeData *p)
30 if (AV_RL32(p->buf) == MKTAG('S','T','R','M') &&
31 AV_RB16(p->buf + 10) &&
32 AV_RB16(p->buf + 12) &&
34 return AVPROBE_SCORE_MAX / 3 * 2;
38 static int ast_read_header(AVFormatContext *s)
43 st = avformat_new_stream(s, NULL);
45 return AVERROR(ENOMEM);
48 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
49 st->codec->codec_id = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb));
51 depth = avio_rb16(s->pb);
53 avpriv_request_sample(s, "depth %d", depth);
54 return AVERROR_INVALIDDATA;
57 st->codec->channels = avio_rb16(s->pb);
58 if (!st->codec->channels)
59 return AVERROR_INVALIDDATA;
61 if (st->codec->channels == 2)
62 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
63 else if (st->codec->channels == 4)
64 st->codec->channel_layout = AV_CH_LAYOUT_4POINT0;
67 st->codec->sample_rate = avio_rb32(s->pb);
68 if (st->codec->sample_rate <= 0)
69 return AVERROR_INVALIDDATA;
71 st->duration = avio_rb32(s->pb);
73 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
78 static int ast_read_packet(AVFormatContext *s, AVPacket *pkt)
87 pos = avio_tell(s->pb);
88 type = avio_rl32(s->pb);
89 size = avio_rb32(s->pb);
90 if (size > INT_MAX / s->streams[0]->codec->channels)
91 return AVERROR_INVALIDDATA;
93 size *= s->streams[0]->codec->channels;
94 if ((ret = avio_skip(s->pb, 24)) < 0) // padding
97 if (type == MKTAG('B','L','C','K')) {
98 ret = av_get_packet(s->pb, pkt, size);
99 pkt->stream_index = 0;
102 av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", type);
103 avio_skip(s->pb, size);
104 ret = AVERROR_INVALIDDATA;
110 AVInputFormat ff_ast_demuxer = {
112 .long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
113 .read_probe = ast_probe,
114 .read_header = ast_read_header,
115 .read_packet = ast_read_packet,
117 .flags = AVFMT_GENERIC_INDEX,
118 .codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0},