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Diffstat (limited to '')
| -rw-r--r-- | src/mixer/AlsaMixerPlugin.cxx | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/src/mixer/AlsaMixerPlugin.cxx b/src/mixer/AlsaMixerPlugin.cxx new file mode 100644 index 000000000..31e9997e3 --- /dev/null +++ b/src/mixer/AlsaMixerPlugin.cxx @@ -0,0 +1,370 @@ +/* + * Copyright (C) 2003-2013 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 "MixerInternal.hxx" +#include "OutputAPI.hxx" +#include "GlobalEvents.hxx" +#include "Main.hxx" +#include "event/MultiSocketMonitor.hxx" + +#include <algorithm> + +#include <glib.h> +#include <alsa/asoundlib.h> + +#define VOLUME_MIXER_ALSA_DEFAULT "default" +#define VOLUME_MIXER_ALSA_CONTROL_DEFAULT "PCM" +static constexpr unsigned VOLUME_MIXER_ALSA_INDEX_DEFAULT = 0; + +class AlsaMixerMonitor final : private MultiSocketMonitor { + snd_mixer_t *const mixer; + +public: + AlsaMixerMonitor(EventLoop &_loop, snd_mixer_t *_mixer) + :MultiSocketMonitor(_loop), mixer(_mixer) {} + +private: + virtual void PrepareSockets(gcc_unused gint *timeout_r) override; + virtual void DispatchSockets() override; +}; + +class AlsaMixer final : public Mixer { + 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; + + AlsaMixerMonitor *monitor; + +public: + AlsaMixer():Mixer(alsa_mixer_plugin) {} + + void Configure(const config_param ¶m); + bool Setup(GError **error_r); + bool Open(GError **error_r); + void Close(); + + int GetVolume(GError **error_r); + bool SetVolume(unsigned volume, GError **error_r); +}; + +/** + * The quark used for GError.domain. + */ +static inline GQuark +alsa_mixer_quark(void) +{ + return g_quark_from_static_string("alsa_mixer"); +} + +void +AlsaMixerMonitor::PrepareSockets(gcc_unused gint *timeout_r) +{ + int count = snd_mixer_poll_descriptors_count(mixer); + if (count < 0) + count = 0; + + struct pollfd *pfds = g_new(struct pollfd, count); + count = snd_mixer_poll_descriptors(mixer, pfds, count); + if (count < 0) + count = 0; + + struct pollfd *end = pfds + count; + + UpdateSocketList([pfds, end](int fd) -> unsigned { + auto i = std::find_if(pfds, end, [fd](const struct pollfd &pfd){ + return pfd.fd == fd; + }); + if (i == end) + return 0; + + auto events = i->events; + i->events = 0; + return events; + }); + + for (auto i = pfds; i != end; ++i) + if (i->events != 0) + AddSocket(i->fd, i->events); + + g_free(pfds); +} + +void +AlsaMixerMonitor::DispatchSockets() +{ + snd_mixer_handle_events(mixer); +} + +/* + * libasound callbacks + * + */ + +static int +alsa_mixer_elem_callback(G_GNUC_UNUSED snd_mixer_elem_t *elem, unsigned mask) +{ + if (mask & SND_CTL_EVENT_MASK_VALUE) + GlobalEvents::Emit(GlobalEvents::MIXER); + + return 0; +} + +/* + * mixer_plugin methods + * + */ + +inline void +AlsaMixer::Configure(const config_param ¶m) +{ + device = param.GetBlockValue("mixer_device", + VOLUME_MIXER_ALSA_DEFAULT); + control = param.GetBlockValue("mixer_control", + VOLUME_MIXER_ALSA_CONTROL_DEFAULT); + index = param.GetBlockValue("mixer_index", + VOLUME_MIXER_ALSA_INDEX_DEFAULT); +} + +static Mixer * +alsa_mixer_init(G_GNUC_UNUSED void *ao, const config_param ¶m, + G_GNUC_UNUSED GError **error_r) +{ + AlsaMixer *am = new AlsaMixer(); + am->Configure(param); + + return am; +} + +static void +alsa_mixer_finish(Mixer *data) +{ + AlsaMixer *am = (AlsaMixer *)data; + + delete am; + + /* free libasound's config cache */ + snd_config_update_free_global(); +} + +G_GNUC_PURE +static snd_mixer_elem_t * +alsa_mixer_lookup_elem(snd_mixer_t *handle, const char *name, unsigned idx) +{ + for (snd_mixer_elem_t *elem = snd_mixer_first_elem(handle); + elem != NULL; elem = snd_mixer_elem_next(elem)) { + if (snd_mixer_elem_get_type(elem) == SND_MIXER_ELEM_SIMPLE && + g_ascii_strcasecmp(snd_mixer_selem_get_name(elem), + name) == 0 && + snd_mixer_selem_get_index(elem) == idx) + return elem; + } + + return NULL; +} + +inline bool +AlsaMixer::Setup(GError **error_r) +{ + int err; + + if ((err = snd_mixer_attach(handle, device)) < 0) { + g_set_error(error_r, alsa_mixer_quark(), err, + "failed to attach to %s: %s", + device, snd_strerror(err)); + return false; + } + + if ((err = snd_mixer_selem_register(handle, NULL, + NULL)) < 0) { + 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(handle)) < 0) { + g_set_error(error_r, alsa_mixer_quark(), err, + "snd_mixer_load() failed: %s\n", + snd_strerror(err)); + return false; + } + + elem = alsa_mixer_lookup_elem(handle, control, index); + if (elem == NULL) { + g_set_error(error_r, alsa_mixer_quark(), 0, + "no such mixer control: %s", control); + return false; + } + + snd_mixer_selem_get_playback_volume_range(elem, &volume_min, + &volume_max); + + snd_mixer_elem_set_callback(elem, alsa_mixer_elem_callback); + + monitor = new AlsaMixerMonitor(*main_loop, handle); + + return true; +} + +inline bool +AlsaMixer::Open(GError **error_r) +{ + int err; + + volume_set = -1; + + err = snd_mixer_open(&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 (!Setup(error_r)) { + snd_mixer_close(handle); + return false; + } + + return true; +} + +static bool +alsa_mixer_open(Mixer *data, GError **error_r) +{ + AlsaMixer *am = (AlsaMixer *)data; + + return am->Open(error_r); +} + +inline void +AlsaMixer::Close() +{ + assert(handle != NULL); + + delete monitor; + + snd_mixer_elem_set_callback(elem, NULL); + snd_mixer_close(handle); +} + +static void +alsa_mixer_close(Mixer *data) +{ + AlsaMixer *am = (AlsaMixer *)data; + am->Close(); +} + +inline int +AlsaMixer::GetVolume(GError **error_r) +{ + int err; + int ret; + long level; + + assert(handle != NULL); + + err = snd_mixer_handle_events(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(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 = ((volume_set / 100.0) * (volume_max - volume_min) + + volume_min) + 0.5; + if (volume_set > 0 && ret == level) { + ret = volume_set; + } else { + ret = (int)(100 * (((float)(level - volume_min)) / + (volume_max - volume_min)) + 0.5); + } + + return ret; +} + +static int +alsa_mixer_get_volume(Mixer *mixer, GError **error_r) +{ + AlsaMixer *am = (AlsaMixer *)mixer; + return am->GetVolume(error_r); +} + +inline bool +AlsaMixer::SetVolume(unsigned volume, GError **error_r) +{ + float vol; + long level; + int err; + + assert(handle != NULL); + + vol = volume; + + volume_set = vol + 0.5; + + level = (long)(((vol / 100.0) * (volume_max - volume_min) + + volume_min) + 0.5); + level = level > volume_max ? volume_max : level; + level = level < volume_min ? volume_min : level; + + err = snd_mixer_selem_set_playback_volume_all(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; +} + +static bool +alsa_mixer_set_volume(Mixer *mixer, unsigned volume, GError **error_r) +{ + AlsaMixer *am = (AlsaMixer *)mixer; + return am->SetVolume(volume, error_r); +} + +const struct mixer_plugin alsa_mixer_plugin = { + alsa_mixer_init, + alsa_mixer_finish, + alsa_mixer_open, + alsa_mixer_close, + alsa_mixer_get_volume, + alsa_mixer_set_volume, + true, +}; |