1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/*
* LEGO Racers ALP (.tun & .pcm) demuxer
*
* Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "internal.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/internal.h"
#define ALP_TAG MKTAG('A', 'L', 'P', ' ')
#define ALP_MAX_READ_SIZE 4096
typedef struct ALPHeader {
uint32_t magic; /*< Magic Number, {'A', 'L', 'P', ' '} */
uint32_t header_size; /*< Header size (after this). */
char adpcm[6]; /*< "ADPCM" */
uint8_t unk1; /*< Unknown */
uint8_t num_channels; /*< Channel Count. */
uint32_t sample_rate; /*< Sample rate, only if header_size >= 12. */
} ALPHeader;
static int alp_probe(const AVProbeData *p)
{
uint32_t i;
if (AV_RL32(p->buf) != ALP_TAG)
return 0;
/* Only allowed header sizes are 8 and 12. */
i = AV_RL32(p->buf + 4);
if (i != 8 && i != 12)
return 0;
if (strncmp("ADPCM", p->buf + 8, 6) != 0)
return 0;
return AVPROBE_SCORE_MAX - 1;
}
static int alp_read_header(AVFormatContext *s)
{
int ret;
AVStream *st;
ALPHeader hdr;
AVCodecParameters *par;
if ((hdr.magic = avio_rl32(s->pb)) != ALP_TAG)
return AVERROR_INVALIDDATA;
hdr.header_size = avio_rl32(s->pb);
if (hdr.header_size != 8 && hdr.header_size != 12) {
return AVERROR_INVALIDDATA;
}
if ((ret = avio_read(s->pb, hdr.adpcm, sizeof(hdr.adpcm))) < 0)
return ret;
else if (ret != sizeof(hdr.adpcm))
return AVERROR(EIO);
if (strncmp("ADPCM", hdr.adpcm, sizeof(hdr.adpcm)) != 0)
return AVERROR_INVALIDDATA;
hdr.unk1 = avio_r8(s->pb);
hdr.num_channels = avio_r8(s->pb);
if (hdr.header_size == 8) {
/* .TUN music file */
hdr.sample_rate = 22050;
} else {
/* .PCM sound file */
hdr.sample_rate = avio_rl32(s->pb);
}
if (hdr.sample_rate > 44100) {
avpriv_request_sample(s, "Sample Rate > 44100");
return AVERROR_PATCHWELCOME;
}
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
par = st->codecpar;
par->codec_type = AVMEDIA_TYPE_AUDIO;
par->codec_id = AV_CODEC_ID_ADPCM_IMA_ALP;
par->format = AV_SAMPLE_FMT_S16;
par->sample_rate = hdr.sample_rate;
par->channels = hdr.num_channels;
if (hdr.num_channels == 1)
par->channel_layout = AV_CH_LAYOUT_MONO;
else if (hdr.num_channels == 2)
par->channel_layout = AV_CH_LAYOUT_STEREO;
else
return AVERROR_INVALIDDATA;
par->bits_per_coded_sample = 4;
par->bits_per_raw_sample = 16;
par->block_align = 1;
par->bit_rate = par->channels *
par->sample_rate *
par->bits_per_coded_sample;
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
return 0;
}
static int alp_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
AVCodecParameters *par = s->streams[0]->codecpar;
if ((ret = av_get_packet(s->pb, pkt, ALP_MAX_READ_SIZE)) < 0)
return ret;
pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
pkt->stream_index = 0;
pkt->duration = ret * 2 / par->channels;
return 0;
}
AVInputFormat ff_alp_demuxer = {
.name = "alp",
.long_name = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"),
.read_probe = alp_probe,
.read_header = alp_read_header,
.read_packet = alp_read_packet
};
|
