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'))
33 if (!AV_RB16(p
->buf
+ 10) ||
34 !AV_RB16(p
->buf
+ 12) || AV_RB16(p
->buf
+ 12) > 256 ||
35 !AV_RB32(p
->buf
+ 16) || AV_RB32(p
->buf
+ 16) > 8*48000)
36 return AVPROBE_SCORE_MAX
/ 8;
38 return AVPROBE_SCORE_MAX
/ 3 * 2;
41 static int ast_read_header(AVFormatContext
*s
)
46 st
= avformat_new_stream(s
, NULL
);
48 return AVERROR(ENOMEM
);
51 st
->codec
->codec_type
= AVMEDIA_TYPE_AUDIO
;
52 st
->codec
->codec_id
= ff_codec_get_id(ff_codec_ast_tags
, avio_rb16(s
->pb
));
54 depth
= avio_rb16(s
->pb
);
56 avpriv_request_sample(s
, "depth %d", depth
);
57 return AVERROR_INVALIDDATA
;
60 st
->codec
->channels
= avio_rb16(s
->pb
);
61 if (!st
->codec
->channels
)
62 return AVERROR_INVALIDDATA
;
64 if (st
->codec
->channels
== 2)
65 st
->codec
->channel_layout
= AV_CH_LAYOUT_STEREO
;
66 else if (st
->codec
->channels
== 4)
67 st
->codec
->channel_layout
= AV_CH_LAYOUT_4POINT0
;
70 st
->codec
->sample_rate
= avio_rb32(s
->pb
);
71 if (st
->codec
->sample_rate
<= 0)
72 return AVERROR_INVALIDDATA
;
74 st
->duration
= avio_rb32(s
->pb
);
76 avpriv_set_pts_info(st
, 64, 1, st
->codec
->sample_rate
);
81 static int ast_read_packet(AVFormatContext
*s
, AVPacket
*pkt
)
90 pos
= avio_tell(s
->pb
);
91 type
= avio_rl32(s
->pb
);
92 size
= avio_rb32(s
->pb
);
93 if (size
> INT_MAX
/ s
->streams
[0]->codec
->channels
)
94 return AVERROR_INVALIDDATA
;
96 size
*= s
->streams
[0]->codec
->channels
;
97 if ((ret
= avio_skip(s
->pb
, 24)) < 0) // padding
100 if (type
== MKTAG('B','L','C','K')) {
101 ret
= av_get_packet(s
->pb
, pkt
, size
);
102 pkt
->stream_index
= 0;
105 av_log(s
, AV_LOG_ERROR
, "unknown chunk %x\n", type
);
106 avio_skip(s
->pb
, size
);
107 ret
= AVERROR_INVALIDDATA
;
113 AVInputFormat ff_ast_demuxer
= {
115 .long_name
= NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
116 .read_probe
= ast_probe
,
117 .read_header
= ast_read_header
,
118 .read_packet
= ast_read_packet
,
120 .flags
= AVFMT_GENERIC_INDEX
,
121 .codec_tag
= (const AVCodecTag
* const []){ff_codec_ast_tags
, 0},