2 * This file is part of DisOrder
3 * Copyright (C) 2007 Richard Kettlewell
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.
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.
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
21 * @brief Mixer support
27 #include "configuration.h"
32 /** @brief Whether lack of volume support has been reported yet */
33 static int none_reported;
35 /** @brief Get/set volume stub if volume control is not supported */
36 static int none_get_set(int attribute((unused)) *left,
37 int attribute((unused)) *right) {
39 error(0, "don't know how to get/set volume with this api");
45 /** @brief Stub mixer control */
46 static const struct mixer mixer_none = {
54 /** @brief Table of mixer definitions */
55 static const struct mixer *mixers[] = {
56 #if HAVE_SYS_SOUNDCARD_H
59 #if HAVE_ALSA_ASOUNDLIB_H
62 &mixer_none /* make sure array is never empty */
65 /** @brief Number of mixer definitions */
66 #define NMIXERS (sizeof mixers / sizeof *mixers)
68 /** @brief Find the mixer definition */
69 static const struct mixer *find_mixer(int api) {
74 for(n = 0; n < NMIXERS; ++n)
75 if(mixers[n]->api == api)
80 /** @brief Return true if we know how to drive the mixer
81 * @param api Sound api or -1 for default
82 * @return true if suppored, false otherwise
84 int mixer_supported(int api) {
85 const struct mixer *const m = find_mixer(api);
86 return m != &mixer_none;
89 /** @brief Get/set volume
90 * @param api Sound api or -1 for default
91 * @param left Left channel level, 0-100
92 * @param right Right channel level, 0-100
93 * @param set Set volume if non-0
94 * @return 0 on success, non-0 on error
96 * If getting the volume then @p left and @p right are filled in.
98 * If setting the volume then the target levels are read from @p left and
99 * @p right, and the actual level set is stored in them.
101 int mixer_control(int api, int *left, int *right, int set) {
102 const struct mixer *const m = find_mixer(api);
104 /* We impose defaults bizarrely late, but this has the advantage of
105 * not making everything depend on sound libraries */
107 config->mixer = xstrdup(m->device);
109 config->channel = xstrdup(m->channel);
111 return m->set(left, right);
113 return m->get(left, right);