1 /*
2 * ACE demuxer
3 * Copyright (c) 2020 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/intreadwrite.h"
23 #include "avformat.h"
24 #include "internal.h"
25
ace_probe(const AVProbeData * p)26 static int ace_probe(const AVProbeData *p)
27 {
28 uint32_t asc;
29
30 if (AV_RB32(p->buf) != MKBETAG('A','A','C',' '))
31 return 0;
32 if (p->buf_size < 0x44)
33 return 0;
34 asc = AV_RB32(p->buf + 0x40);
35 if (asc < 0x44 || asc > p->buf_size - 4)
36 return 0;
37 if (AV_RB32(p->buf + asc) != MKBETAG('A','S','C',' '))
38 return 0;
39
40 return AVPROBE_SCORE_MAX / 2 + 1;
41 }
42
ace_read_header(AVFormatContext * s)43 static int ace_read_header(AVFormatContext *s)
44 {
45 AVIOContext *pb = s->pb;
46 AVCodecParameters *par;
47 int ret, codec, rate, nb_channels;
48 uint32_t asc_pos, size;
49 AVStream *st;
50
51 avio_skip(pb, 0x40);
52 asc_pos = avio_rb32(pb);
53 if (asc_pos < 0x44)
54 return AVERROR_INVALIDDATA;
55 avio_skip(pb, asc_pos - 0x44);
56 if (avio_rb32(pb) != MKBETAG('A','S','C',' '))
57 return AVERROR_INVALIDDATA;
58 avio_skip(pb, 0xec);
59 codec = avio_rb32(pb);
60 nb_channels = avio_rb32(pb);
61 if (nb_channels <= 0 || nb_channels > 8)
62 return AVERROR_INVALIDDATA;
63 size = avio_rb32(pb);
64 if (size == 0)
65 return AVERROR_INVALIDDATA;
66 rate = avio_rb32(pb);
67 if (rate <= 0)
68 return AVERROR_INVALIDDATA;
69 avio_skip(pb, 16);
70
71 st = avformat_new_stream(s, NULL);
72 if (!st)
73 return AVERROR(ENOMEM);
74 st->start_time = 0;
75 par = st->codecpar;
76 par->codec_type = AVMEDIA_TYPE_AUDIO;
77 par->channels = nb_channels;
78 par->sample_rate = rate;
79 par->block_align = (codec == 4 ? 0x60 : codec == 5 ? 0x98 : 0xC0) * nb_channels;
80 st->duration = (size / par->block_align) * 1024LL;
81 par->codec_id = AV_CODEC_ID_ATRAC3;
82
83 ret = ff_alloc_extradata(par, 14);
84 if (ret < 0)
85 return ret;
86
87 AV_WL16(st->codecpar->extradata, 1);
88 AV_WL16(st->codecpar->extradata+2, 2048 * par->channels);
89 AV_WL16(st->codecpar->extradata+4, 0);
90 AV_WL16(st->codecpar->extradata+6, codec == 4 ? 1 : 0);
91 AV_WL16(st->codecpar->extradata+8, codec == 4 ? 1 : 0);
92 AV_WL16(st->codecpar->extradata+10, 1);
93 AV_WL16(st->codecpar->extradata+12, 0);
94
95 avpriv_set_pts_info(st, 64, 1, par->sample_rate);
96
97 return 0;
98 }
99
ace_read_packet(AVFormatContext * s,AVPacket * pkt)100 static int ace_read_packet(AVFormatContext *s, AVPacket *pkt)
101 {
102 AVCodecParameters *par = s->streams[0]->codecpar;
103
104 return av_get_packet(s->pb, pkt, par->block_align);
105 }
106
107 AVInputFormat ff_ace_demuxer = {
108 .name = "ace",
109 .long_name = NULL_IF_CONFIG_SMALL("tri-Ace Audio Container"),
110 .read_probe = ace_probe,
111 .read_header = ace_read_header,
112 .read_packet = ace_read_packet,
113 .flags = AVFMT_GENERIC_INDEX,
114 };
115