diff options
Diffstat (limited to 'src/mixer/alsa_mixer_plugin.c')
| -rw-r--r-- | src/mixer/alsa_mixer_plugin.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/src/mixer/alsa_mixer_plugin.c b/src/mixer/alsa_mixer_plugin.c new file mode 100644 index 000000000..6726f785a --- /dev/null +++ b/src/mixer/alsa_mixer_plugin.c @@ -0,0 +1,240 @@ +/* + * 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 "config.h" +#include "mixer_api.h" +#include "output_api.h" + +#include <glib.h> +#include <alsa/asoundlib.h> + +#define VOLUME_MIXER_ALSA_DEFAULT "default" +#define VOLUME_MIXER_ALSA_CONTROL_DEFAULT "PCM" +#define VOLUME_MIXER_ALSA_INDEX_DEFAULT 0 + +struct alsa_mixer { + /** the base mixer class */ + struct mixer base; + + const char *device; + const char *control; + unsigned int index; + + snd_mixer_t *handle; + snd_mixer_elem_t *elem; + long volume_min; + long volume_max; + int volume_set; +}; + +/** + * The quark used for GError.domain. + */ +static inline GQuark +alsa_mixer_quark(void) +{ + return g_quark_from_static_string("alsa_mixer"); +} + +static struct mixer * +alsa_mixer_init(G_GNUC_UNUSED void *ao, const struct config_param *param, + G_GNUC_UNUSED GError **error_r) +{ + struct alsa_mixer *am = g_new(struct alsa_mixer, 1); + + mixer_init(&am->base, &alsa_mixer_plugin); + + am->device = config_get_block_string(param, "mixer_device", + VOLUME_MIXER_ALSA_DEFAULT); + am->control = config_get_block_string(param, "mixer_control", + VOLUME_MIXER_ALSA_CONTROL_DEFAULT); + am->index = config_get_block_unsigned(param, "mixer_index", + VOLUME_MIXER_ALSA_INDEX_DEFAULT); + + return &am->base; +} + +static void +alsa_mixer_finish(struct mixer *data) +{ + struct alsa_mixer *am = (struct alsa_mixer *)data; + + g_free(am); + + /* free libasound's config cache */ + snd_config_update_free_global(); +} + +static void +alsa_mixer_close(struct mixer *data) +{ + struct alsa_mixer *am = (struct alsa_mixer *)data; + + assert(am->handle != NULL); + + snd_mixer_close(am->handle); +} + +static bool +alsa_mixer_open(struct mixer *data, GError **error_r) +{ + struct alsa_mixer *am = (struct alsa_mixer *)data; + int err; + snd_mixer_elem_t *elem; + + am->volume_set = -1; + + err = snd_mixer_open(&am->handle, 0); + if (err < 0) { + g_set_error(error_r, alsa_mixer_quark(), err, + "snd_mixer_open() failed: %s", snd_strerror(err)); + return false; + } + + if ((err = snd_mixer_attach(am->handle, am->device)) < 0) { + alsa_mixer_close(data); + g_set_error(error_r, alsa_mixer_quark(), err, + "failed to attach to %s: %s", + am->device, snd_strerror(err)); + return false; + } + + if ((err = snd_mixer_selem_register(am->handle, NULL, + NULL)) < 0) { + alsa_mixer_close(data); + g_set_error(error_r, alsa_mixer_quark(), err, + "snd_mixer_selem_register() failed: %s", + snd_strerror(err)); + return false; + } + + if ((err = snd_mixer_load(am->handle)) < 0) { + alsa_mixer_close(data); + g_set_error(error_r, alsa_mixer_quark(), err, + "snd_mixer_load() failed: %s\n", + snd_strerror(err)); + return false; + } + + elem = snd_mixer_first_elem(am->handle); + + while (elem) { + if (snd_mixer_elem_get_type(elem) == SND_MIXER_ELEM_SIMPLE) { + if ((g_ascii_strcasecmp(am->control, + snd_mixer_selem_get_name(elem)) == 0) && + (am->index == snd_mixer_selem_get_index(elem))) { + 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; + } + + alsa_mixer_close(data); + g_set_error(error_r, alsa_mixer_quark(), 0, + "no such mixer control: %s", am->control); + return false; +} + +static int +alsa_mixer_get_volume(struct mixer *mixer, GError **error_r) +{ + struct alsa_mixer *am = (struct alsa_mixer *)mixer; + int err; + int ret; + long level; + + assert(am->handle != NULL); + + err = snd_mixer_handle_events(am->handle); + if (err < 0) { + g_set_error(error_r, alsa_mixer_quark(), err, + "snd_mixer_handle_events() failed: %s", + snd_strerror(err)); + return false; + } + + err = snd_mixer_selem_get_playback_volume(am->elem, + SND_MIXER_SCHN_FRONT_LEFT, + &level); + if (err < 0) { + g_set_error(error_r, alsa_mixer_quark(), err, + "failed to read ALSA volume: %s", + snd_strerror(err)); + 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, GError **error_r) +{ + struct alsa_mixer *am = (struct alsa_mixer *)mixer; + float vol; + long level; + int err; + + assert(am->handle != NULL); + + vol = volume; + + am->volume_set = vol + 0.5; + + 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_set_error(error_r, alsa_mixer_quark(), err, + "failed to set ALSA volume: %s", + snd_strerror(err)); + return false; + } + + return true; +} + +const struct mixer_plugin alsa_mixer_plugin = { + .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, + .global = true, +}; |