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
|
/*
* ISS (.iss) file demuxer
* Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
*
* 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
*/
/**
* @file
* Funcom ISS file demuxer
* @author Jaikrishnan Menon
* @see http://wiki.multimedia.cx/index.php?title=FunCom_ISS
*/
#include "avformat.h"
#include "internal.h"
#include "libavutil/avstring.h"
#define ISS_SIG "IMA_ADPCM_Sound"
#define ISS_SIG_LEN 15
#define MAX_TOKEN_SIZE 20
typedef struct {
int packet_size;
int sample_start_pos;
} IssDemuxContext;
static void get_token(AVIOContext *s, char *buf, int maxlen)
{
int i = 0;
char c;
while ((c = avio_r8(s))) {
if(c == ' ')
break;
if (i < maxlen-1)
buf[i++] = c;
}
if(!c)
avio_r8(s);
buf[i] = 0; /* Ensure null terminated, but may be truncated */
}
static int iss_probe(AVProbeData *p)
{
if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN))
return 0;
return AVPROBE_SCORE_MAX;
}
static av_cold int iss_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
IssDemuxContext *iss = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *st;
char token[MAX_TOKEN_SIZE];
int stereo, rate_divisor;
get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound"
get_token(pb, token, sizeof(token)); //packet size
sscanf(token, "%d", &iss->packet_size);
get_token(pb, token, sizeof(token)); //File ID
get_token(pb, token, sizeof(token)); //out size
get_token(pb, token, sizeof(token)); //stereo
sscanf(token, "%d", &stereo);
get_token(pb, token, sizeof(token)); //Unknown1
get_token(pb, token, sizeof(token)); //RateDivisor
sscanf(token, "%d", &rate_divisor);
get_token(pb, token, sizeof(token)); //Unknown2
get_token(pb, token, sizeof(token)); //Version ID
get_token(pb, token, sizeof(token)); //Size
iss->sample_start_pos = avio_tell(pb);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_ADPCM_IMA_ISS;
st->codec->channels = stereo ? 2 : 1;
st->codec->sample_rate = 44100;
if(rate_divisor > 0)
st->codec->sample_rate /= rate_divisor;
st->codec->bits_per_coded_sample = 4;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate
* st->codec->bits_per_coded_sample;
st->codec->block_align = iss->packet_size;
avpriv_set_pts_info(st, 32, 1, st->codec->sample_rate);
return 0;
}
static int iss_read_packet(AVFormatContext *s, AVPacket *pkt)
{
IssDemuxContext *iss = s->priv_data;
int ret = av_get_packet(s->pb, pkt, iss->packet_size);
if(ret != iss->packet_size)
return AVERROR(EIO);
pkt->stream_index = 0;
pkt->pts = avio_tell(s->pb) - iss->sample_start_pos;
if(s->streams[0]->codec->channels > 0)
pkt->pts /= s->streams[0]->codec->channels*2;
return 0;
}
AVInputFormat ff_iss_demuxer = {
.name = "ISS",
.long_name = NULL_IF_CONFIG_SMALL("Funcom ISS format"),
.priv_data_size = sizeof(IssDemuxContext),
.read_probe = iss_probe,
.read_header = iss_read_header,
.read_packet = iss_read_packet,
};
|
