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"
27 static int ast_probe(AVProbeData *p)
29 if (AV_RL32(p->buf) == MKTAG('S','T','R','M') &&
30 AV_RB16(p->buf + 10) &&
31 AV_RB16(p->buf + 12) &&
33 return AVPROBE_SCORE_MAX / 3 * 2;
37 static int ast_read_header(AVFormatContext *s)
42 st = avformat_new_stream(s, NULL);
44 return AVERROR(ENOMEM);
47 codec = avio_rb16(s->pb);
50 st->codec->codec_id = AV_CODEC_ID_ADPCM_AFC;
53 st->codec->codec_id = AV_CODEC_ID_PCM_S16BE_PLANAR;
56 av_log(s, AV_LOG_ERROR, "unsupported codec %d\n", codec);
59 depth = avio_rb16(s->pb);
61 av_log_ask_for_sample(s, "unsupported depth %d\n", depth);
62 return AVERROR_INVALIDDATA;
65 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
66 st->codec->channels = avio_rb16(s->pb);
67 if (!st->codec->channels)
68 return AVERROR_INVALIDDATA;
70 if (st->codec->channels == 2)
71 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
72 else if (st->codec->channels == 4)
73 st->codec->channel_layout = AV_CH_LAYOUT_4POINT0;
76 st->codec->sample_rate = avio_rb32(s->pb);
77 if (st->codec->sample_rate <= 0)
78 return AVERROR_INVALIDDATA;
80 st->duration = avio_rb32(s->pb);
82 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
87 static int ast_read_packet(AVFormatContext *s, AVPacket *pkt)
96 pos = avio_tell(s->pb);
97 type = avio_rl32(s->pb);
98 size = avio_rb32(s->pb);
99 if (size > INT_MAX / s->streams[0]->codec->channels)
100 return AVERROR_INVALIDDATA;
102 size *= s->streams[0]->codec->channels;
103 if ((ret = avio_skip(s->pb, 24)) < 0) // padding
106 if (type == MKTAG('B','L','C','K')) {
107 ret = av_get_packet(s->pb, pkt, size);
108 pkt->stream_index = 0;
111 av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", type);
112 avio_skip(s->pb, size);
113 ret = AVERROR_INVALIDDATA;
119 AVInputFormat ff_ast_demuxer = {
121 .long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
122 .read_probe = ast_probe,
123 .read_header = ast_read_header,
124 .read_packet = ast_read_packet,
126 .flags = AVFMT_GENERIC_INDEX,