3 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2009 Robert Swain ( rob opendot cl )
6 * This file is part of FFmpeg.
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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"
30 static int adts_aac_probe(AVProbeData
*p
)
32 int max_frames
= 0, first_frames
= 0;
34 const uint8_t *buf0
= p
->buf
;
37 const uint8_t *end
= buf0
+ p
->buf_size
- 7;
41 for (; buf
< end
; buf
= buf2
+ 1) {
44 for (frames
= 0; buf2
< end
; frames
++) {
45 uint32_t header
= AV_RB16(buf2
);
46 if ((header
& 0xFFF6) != 0xFFF0) {
48 // Found something that isn't an ADTS header, starting
49 // from a position other than the start of the buffer.
50 // Discard the count we've accumulated so far since it
51 // probably was a false positive.
56 fsize
= (AV_RB32(buf2
+ 3) >> 13) & 0x1FFF;
59 fsize
= FFMIN(fsize
, end
- buf2
);
62 max_frames
= FFMAX(max_frames
, frames
);
64 first_frames
= frames
;
67 if (first_frames
>= 3)
68 return AVPROBE_SCORE_EXTENSION
+ 1;
69 else if (max_frames
> 100)
70 return AVPROBE_SCORE_EXTENSION
;
71 else if (max_frames
>= 3)
72 return AVPROBE_SCORE_EXTENSION
/ 2;
73 else if (max_frames
>= 1)
79 static int adts_aac_read_header(AVFormatContext
*s
)
83 st
= avformat_new_stream(s
, NULL
);
85 return AVERROR(ENOMEM
);
87 st
->codec
->codec_type
= AVMEDIA_TYPE_AUDIO
;
88 st
->codec
->codec_id
= s
->iformat
->raw_codec_id
;
89 st
->need_parsing
= AVSTREAM_PARSE_FULL_RAW
;
92 if (s
->pb
->seekable
&&
93 !av_dict_get(s
->metadata
, "", NULL
, AV_DICT_IGNORE_SUFFIX
)) {
94 int64_t cur
= avio_tell(s
->pb
);
96 avio_seek(s
->pb
, cur
, SEEK_SET
);
99 // LCM of all possible ADTS sample rates
100 avpriv_set_pts_info(st
, 64, 1, 28224000);
105 AVInputFormat ff_aac_demuxer
= {
107 .long_name
= NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
108 .read_probe
= adts_aac_probe
,
109 .read_header
= adts_aac_read_header
,
110 .read_packet
= ff_raw_read_partial_packet
,
111 .flags
= AVFMT_GENERIC_INDEX
,
113 .mime_type
= "audio/aac,audio/aacp,audio/x-aac",
114 .raw_codec_id
= AV_CODEC_ID_AAC
,