aboutsummaryrefslogtreecommitdiffstats
path: root/src/mixer/alsa_mixer.c
blob: ea113b86175b0339445a81f25f09f9fca4253559 (plain) (blame)
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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/*
 * Copyright (C) 2003-2009 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "../output_api.h"
#include "../mixer_api.h"

#include <glib.h>
#include <alsa/asoundlib.h>

#define VOLUME_MIXER_ALSA_DEFAULT		"default"
#define VOLUME_MIXER_ALSA_CONTROL_DEFAULT	"PCM"

struct alsa_mixer {
	/** the base mixer class */
	struct mixer base;

	char *device;
	char *control;
	snd_mixer_t *handle;
	snd_mixer_elem_t *elem;
	long volume_min;
	long volume_max;
	int volume_set;
};

static struct mixer *
alsa_mixer_init(const struct config_param *param)
{
	struct alsa_mixer *am = g_new(struct alsa_mixer, 1);

	mixer_init(&am->base, &alsa_mixer);

	am->device = config_dup_block_string(param, "mixer_device", NULL);
	am->control = config_dup_block_string(param, "mixer_control", NULL);

	am->handle = NULL;
	am->elem = NULL;
	am->volume_min = 0;
	am->volume_max = 0;
	am->volume_set = -1;

	return &am->base;
}

static void
alsa_mixer_finish(struct mixer *data)
{
	struct alsa_mixer *am = (struct alsa_mixer *)data;

	g_free(am->device);
	g_free(am->control);
	g_free(am);
}

static void
alsa_mixer_close(struct mixer *data)
{
	struct alsa_mixer *am = (struct alsa_mixer *)data;
	if (am->handle) snd_mixer_close(am->handle);
	am->handle = NULL;
}

static bool
alsa_mixer_open(struct mixer *data)
{
	struct alsa_mixer *am = (struct alsa_mixer *)data;
	int err;
	snd_mixer_elem_t *elem;
	const char *control_name = VOLUME_MIXER_ALSA_CONTROL_DEFAULT;
	const char *device = VOLUME_MIXER_ALSA_DEFAULT;

	if (am->device) {
		device = am->device;
	}
	err = snd_mixer_open(&am->handle, 0);
	snd_config_update_free_global();
	if (err < 0) {
		g_warning("problems opening alsa mixer: %s\n", snd_strerror(err));
		return false;
	}

	if ((err = snd_mixer_attach(am->handle, device)) < 0) {
		g_warning("problems attaching alsa mixer: %s\n",
			snd_strerror(err));
		alsa_mixer_close(data);
		return false;
	}

	if ((err = snd_mixer_selem_register(am->handle, NULL,
		    NULL)) < 0) {
		g_warning("problems snd_mixer_selem_register'ing: %s\n",
			snd_strerror(err));
		alsa_mixer_close(data);
		return false;
	}

	if ((err = snd_mixer_load(am->handle)) < 0) {
		g_warning("problems snd_mixer_selem_register'ing: %s\n",
			snd_strerror(err));
		alsa_mixer_close(data);
		return false;
	}

	elem = snd_mixer_first_elem(am->handle);

	if (am->control) {
		control_name = am->control;
	}

	while (elem) {
		if (snd_mixer_elem_get_type(elem) == SND_MIXER_ELEM_SIMPLE) {
			if (strcasecmp(control_name,
				       snd_mixer_selem_get_name(elem)) == 0) {
				break;
			}
		}
		elem = snd_mixer_elem_next(elem);
	}

	if (elem) {
		am->elem = elem;
		snd_mixer_selem_get_playback_volume_range(am->elem,
							  &am->volume_min,
							  &am->volume_max);
		return true;
	}

	g_warning("can't find alsa mixer control \"%s\"\n", control_name);

	alsa_mixer_close(data);
	return false;
}

static int
alsa_mixer_get_volume(struct mixer *mixer)
{
	struct alsa_mixer *am = (struct alsa_mixer *)mixer;
	int err;
	int ret;
	long level;

	if (am->handle == NULL && !alsa_mixer_open(mixer))
		return -1;

	err = snd_mixer_handle_events(am->handle);
	if (err < 0) {
		g_warning("problems getting alsa volume: %s (snd_mixer_%s)\n",
			  snd_strerror(err), "handle_events");
		alsa_mixer_close(mixer);
		return false;
	}

	err = snd_mixer_selem_get_playback_volume(am->elem,
						  SND_MIXER_SCHN_FRONT_LEFT,
						  &level);
	if (err < 0) {
		g_warning("problems getting alsa volume: %s (snd_mixer_%s)\n",
			  snd_strerror(err), "selem_get_playback_volume");
		alsa_mixer_close(mixer);
		return false;
	}

	ret = ((am->volume_set / 100.0) * (am->volume_max - am->volume_min)
	       + am->volume_min) + 0.5;
	if (am->volume_set > 0 && ret == level) {
		ret = am->volume_set;
	} else {
		ret = (int)(100 * (((float)(level - am->volume_min)) /
				   (am->volume_max - am->volume_min)) + 0.5);
	}

	return ret;
}

static bool
alsa_mixer_set_volume(struct mixer *mixer, unsigned volume)
{
	struct alsa_mixer *am = (struct alsa_mixer *)mixer;
	float vol;
	long level;
	int err;

	if (am->handle == NULL && !alsa_mixer_open(mixer))
		return false;

	vol = volume;

	am->volume_set = vol + 0.5;
	am->volume_set = am->volume_set > 100
		? 100 :
		(am->volume_set < 0
		 ? 0 : am->volume_set);

	level = (long)(((vol / 100.0) * (am->volume_max - am->volume_min) +
			am->volume_min) + 0.5);
	level = level > am->volume_max ? am->volume_max : level;
	level = level < am->volume_min ? am->volume_min : level;

	err = snd_mixer_selem_set_playback_volume_all(am->elem, level);
	if (err < 0) {
		g_warning("problems setting alsa volume: %s\n",
			  snd_strerror(err));
		alsa_mixer_close(mixer);
		return false;
	}

	return true;
}

const struct mixer_plugin alsa_mixer = {
	.init = alsa_mixer_init,
	.finish = alsa_mixer_finish,
	.open = alsa_mixer_open,
	.close = alsa_mixer_close,
	.get_volume = alsa_mixer_get_volume,
	.set_volume = alsa_mixer_set_volume,
};