blob: 5ab5197e3388e06789458a322e292d812673ee76
1 | /* |
2 | * raw ADTS AAC demuxer |
3 | * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> |
4 | * Copyright (c) 2009 Robert Swain ( rob opendot cl ) |
5 | * |
6 | * This file is part of FFmpeg. |
7 | * |
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. |
12 | * |
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. |
17 | * |
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 |
21 | */ |
22 | |
23 | #include "libavutil/intreadwrite.h" |
24 | #include "avformat.h" |
25 | #include "internal.h" |
26 | #include "rawdec.h" |
27 | #include "id3v1.h" |
28 | #include "apetag.h" |
29 | |
30 | static int adts_aac_probe(AVProbeData *p) |
31 | { |
32 | int max_frames = 0, first_frames = 0; |
33 | int fsize, frames; |
34 | const uint8_t *buf0 = p->buf; |
35 | const uint8_t *buf2; |
36 | const uint8_t *buf; |
37 | const uint8_t *end = buf0 + p->buf_size - 7; |
38 | |
39 | buf = buf0; |
40 | |
41 | for (; buf < end; buf = buf2 + 1) { |
42 | buf2 = buf; |
43 | |
44 | for (frames = 0; buf2 < end; frames++) { |
45 | uint32_t header = AV_RB16(buf2); |
46 | if ((header & 0xFFF6) != 0xFFF0) { |
47 | if (buf != buf0) { |
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. |
52 | frames = 0; |
53 | } |
54 | break; |
55 | } |
56 | fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF; |
57 | if (fsize < 7) |
58 | break; |
59 | fsize = FFMIN(fsize, end - buf2); |
60 | buf2 += fsize; |
61 | } |
62 | max_frames = FFMAX(max_frames, frames); |
63 | if (buf == buf0) |
64 | first_frames = frames; |
65 | } |
66 | |
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 (first_frames >= 1) |
74 | return 1; |
75 | else |
76 | return 0; |
77 | } |
78 | |
79 | static int adts_aac_read_header(AVFormatContext *s) |
80 | { |
81 | AVStream *st; |
82 | |
83 | st = avformat_new_stream(s, NULL); |
84 | if (!st) |
85 | return AVERROR(ENOMEM); |
86 | |
87 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
88 | st->codecpar->codec_id = s->iformat->raw_codec_id; |
89 | st->need_parsing = AVSTREAM_PARSE_FULL_RAW; |
90 | |
91 | ff_id3v1_read(s); |
92 | if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && |
93 | !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) { |
94 | int64_t cur = avio_tell(s->pb); |
95 | ff_ape_parse_tag(s); |
96 | avio_seek(s->pb, cur, SEEK_SET); |
97 | } |
98 | |
99 | // LCM of all possible ADTS sample rates |
100 | avpriv_set_pts_info(st, 64, 1, 28224000); |
101 | |
102 | return 0; |
103 | } |
104 | |
105 | AVInputFormat ff_aac_demuxer = { |
106 | .name = "aac", |
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, |
112 | .extensions = "aac", |
113 | .mime_type = "audio/aac,audio/aacp,audio/x-aac", |
114 | .raw_codec_id = AV_CODEC_ID_AAC, |
115 | }; |
116 |