blob: 4ba08c21807d3c4049400b5c22b9dba634e0d489
1 | /* |
2 | * AST demuxer |
3 | * Copyright (c) 2012 Paul B Mahol |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | #include "libavutil/channel_layout.h" |
23 | #include "libavutil/intreadwrite.h" |
24 | #include "avformat.h" |
25 | #include "internal.h" |
26 | #include "ast.h" |
27 | |
28 | static int ast_probe(AVProbeData *p) |
29 | { |
30 | if (AV_RL32(p->buf) != MKTAG('S','T','R','M')) |
31 | return 0; |
32 | |
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; |
37 | |
38 | return AVPROBE_SCORE_MAX / 3 * 2; |
39 | } |
40 | |
41 | static int ast_read_header(AVFormatContext *s) |
42 | { |
43 | int depth; |
44 | AVStream *st; |
45 | |
46 | st = avformat_new_stream(s, NULL); |
47 | if (!st) |
48 | return AVERROR(ENOMEM); |
49 | |
50 | avio_skip(s->pb, 8); |
51 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
52 | st->codecpar->codec_id = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb)); |
53 | |
54 | depth = avio_rb16(s->pb); |
55 | if (depth != 16) { |
56 | avpriv_request_sample(s, "depth %d", depth); |
57 | return AVERROR_INVALIDDATA; |
58 | } |
59 | |
60 | st->codecpar->channels = avio_rb16(s->pb); |
61 | if (!st->codecpar->channels) |
62 | return AVERROR_INVALIDDATA; |
63 | |
64 | if (st->codecpar->channels == 2) |
65 | st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO; |
66 | else if (st->codecpar->channels == 4) |
67 | st->codecpar->channel_layout = AV_CH_LAYOUT_4POINT0; |
68 | |
69 | avio_skip(s->pb, 2); |
70 | st->codecpar->sample_rate = avio_rb32(s->pb); |
71 | if (st->codecpar->sample_rate <= 0) |
72 | return AVERROR_INVALIDDATA; |
73 | st->start_time = 0; |
74 | st->duration = avio_rb32(s->pb); |
75 | avio_skip(s->pb, 40); |
76 | avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate); |
77 | |
78 | return 0; |
79 | } |
80 | |
81 | static int ast_read_packet(AVFormatContext *s, AVPacket *pkt) |
82 | { |
83 | uint32_t type, size; |
84 | int64_t pos; |
85 | int ret; |
86 | |
87 | if (avio_feof(s->pb)) |
88 | return AVERROR_EOF; |
89 | |
90 | pos = avio_tell(s->pb); |
91 | type = avio_rl32(s->pb); |
92 | size = avio_rb32(s->pb); |
93 | if (!s->streams[0]->codecpar->channels || size > INT_MAX / s->streams[0]->codecpar->channels) |
94 | return AVERROR_INVALIDDATA; |
95 | |
96 | size *= s->streams[0]->codecpar->channels; |
97 | if ((ret = avio_skip(s->pb, 24)) < 0) // padding |
98 | return ret; |
99 | |
100 | if (type == MKTAG('B','L','C','K')) { |
101 | ret = av_get_packet(s->pb, pkt, size); |
102 | pkt->stream_index = 0; |
103 | pkt->pos = pos; |
104 | } else { |
105 | av_log(s, AV_LOG_ERROR, "unknown chunk %"PRIx32"\n", type); |
106 | avio_skip(s->pb, size); |
107 | ret = AVERROR_INVALIDDATA; |
108 | } |
109 | |
110 | return ret; |
111 | } |
112 | |
113 | AVInputFormat ff_ast_demuxer = { |
114 | .name = "ast", |
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, |
119 | .extensions = "ast", |
120 | .flags = AVFMT_GENERIC_INDEX, |
121 | .codec_tag = (const AVCodecTag* const []){ff_codec_ast_tags, 0}, |
122 | }; |
123 |