chiark / gitweb /
Unify sound API configuration.
[disorder] / lib / mixer-oss.c
CommitLineData
bd8895a8 1/*
2 * This file is part of DisOrder
3 * Copyright (C) 2004, 2007 Richard Kettlewell
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
18 * USA
19 */
20
21#include <config.h>
22#include "types.h"
23
24#include <stdio.h>
25#include <string.h>
26#include <fcntl.h>
27#include <unistd.h>
28#include <stdlib.h>
29#include <errno.h>
30#include <stddef.h>
31#include <sys/ioctl.h>
32
33#include "configuration.h"
34#include "mixer.h"
35#include "log.h"
36#include "syscalls.h"
37
38#if HAVE_SYS_SOUNDCARD_H
39#include <sys/soundcard.h>
40
41/* documentation does not match implementation! */
42#ifndef SOUND_MIXER_READ
43# define SOUND_MIXER_READ(x) MIXER_READ(x)
44#endif
45#ifndef SOUND_MIXER_WRITE
46# define SOUND_MIXER_WRITE(x) MIXER_WRITE(x)
47#endif
48
49static const char *channels[] = SOUND_DEVICE_NAMES;
50
51static int mixer_channel(const char *c) {
52 unsigned n;
53
54 if(!c[strspn(c, "0123456789")])
55 return atoi(c);
56 else {
57 for(n = 0; n < sizeof channels / sizeof *channels; ++n)
58 if(!strcmp(channels[n], c))
59 return n;
60 return -1;
61 }
62}
63
64static int oss_validate_channel(const char *c) {
65 if(mixer_channel(c) != -1)
66 return 1;
67 else
68 return 0;
69}
70
71static int oss_validate_device(const char *d) {
72 struct stat sb;
73
74 if(stat(d, &sb) < 0) {
75 error(errno, "%s", d);
76 return 0;
77 }
78 if(!S_ISCHR(sb.st_mode)) {
79 error(0, "%s: not a character device", d);
80 return 0;
81 }
82 return 1;
83}
84
85static int oss_do_open(void) {
86 int fd;
87
88 if((fd = open(config->mixer, O_RDWR, 0)) < 0)
89 error(errno, "error opening %s", config->mixer);
90 return fd;
91}
92
93static int oss_do_get(int *left, int *right, int fd, int ch) {
94 int r;
95
96 if(ioctl(fd, SOUND_MIXER_READ(ch), &r) == -1) {
97 error(errno, "error reading %s channel %s",
98 config->mixer, config->channel);
99 return -1;
100 }
101 *left = r & 0xff;
102 *right = (r >> 8) & 0xff;
103 return 0;
104}
105
106static int oss_get(int *left, int *right) {
107 int ch, fd;
108
109 if(config->mixer
110 && config->channel
111 && (ch = mixer_channel(config->channel)) != -1) {
112 if((fd = oss_do_open()) < 0)
113 return -1;
114 if(oss_do_get(left, right, fd, ch) < 0) {
115 xclose(fd);
116 return -1;
117 }
118 xclose(fd);
119 return 0;
120 } else
121 return -1;
122}
123
124static int oss_set(int *left, int *right) {
125 int ch, fd, r;
126
127 if(config->mixer
128 && config->channel
129 && (ch = mixer_channel(config->channel)) != -1) {
130 if((fd = oss_do_open()) < 0)
131 return -1;
132 r = (*left & 0xff) + (*right & 0xff) * 256;
133 if(ioctl(fd, SOUND_MIXER_WRITE(ch), &r) == -1) {
134 error(errno, "error changing %s channel %s",
135 config->mixer, config->channel);
136 xclose(fd);
137 return -1;
138 }
139 if(oss_do_get(left, right, fd, ch) < 0) {
140 xclose(fd);
141 return -1;
142 }
143 xclose(fd);
144 return 0;
145 } else
146 return -1;
147}
148
149const struct mixer mixer_oss = {
150 BACKEND_OSS,
151 oss_validate_device,
152 oss_validate_channel,
153 oss_get,
154 oss_set,
155 "/dev/mixer",
156 "pcm"
157};
158#endif
159
160/*
161Local Variables:
162c-basic-offset:2
163comment-column:40
164End:
165*/