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Diffstat (limited to '')
-rw-r--r-- | src/mixer/plugins/SoftwareMixerPlugin.cxx | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/src/mixer/plugins/SoftwareMixerPlugin.cxx b/src/mixer/plugins/SoftwareMixerPlugin.cxx new file mode 100644 index 000000000..f14766002 --- /dev/null +++ b/src/mixer/plugins/SoftwareMixerPlugin.cxx @@ -0,0 +1,144 @@ +/* + * Copyright (C) 2003-2014 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 "SoftwareMixerPlugin.hxx" +#include "mixer/MixerInternal.hxx" +#include "filter/FilterPlugin.hxx" +#include "filter/FilterRegistry.hxx" +#include "filter/FilterInternal.hxx" +#include "filter/plugins/VolumeFilterPlugin.hxx" +#include "pcm/Volume.hxx" +#include "config/ConfigData.hxx" +#include "util/Error.hxx" + +#include <assert.h> +#include <math.h> + +static Filter * +CreateVolumeFilter() +{ + return filter_new(&volume_filter_plugin, config_param(), + IgnoreError()); +} + +class SoftwareMixer final : public Mixer { + Filter *filter; + + /** + * If this is true, then this object "owns" the #Filter + * instance (see above). It will be set to false by + * software_mixer_get_filter(); after that, the caller will be + * responsible for the #Filter. + */ + bool owns_filter; + + /** + * The current volume in percent (0..100). + */ + unsigned volume; + +public: + SoftwareMixer(MixerListener &_listener) + :Mixer(software_mixer_plugin, _listener), + filter(CreateVolumeFilter()), + owns_filter(true), + volume(100) + { + assert(filter != nullptr); + } + + virtual ~SoftwareMixer() { + if (owns_filter) + delete filter; + } + + Filter *GetFilter(); + + /* virtual methods from class Mixer */ + virtual bool Open(gcc_unused Error &error) override { + return true; + } + + virtual void Close() override { + } + + virtual int GetVolume(gcc_unused Error &error) override { + return volume; + } + + virtual bool SetVolume(unsigned volume, Error &error) override; +}; + +static Mixer * +software_mixer_init(gcc_unused EventLoop &event_loop, + gcc_unused AudioOutput &ao, + MixerListener &listener, + gcc_unused const config_param ¶m, + gcc_unused Error &error) +{ + return new SoftwareMixer(listener); +} + +gcc_const +static unsigned +PercentVolumeToSoftwareVolume(unsigned volume) +{ + assert(volume <= 100); + + if (volume >= 100) + return PCM_VOLUME_1; + else if (volume > 0) + return pcm_float_to_volume((exp(volume / 25.0) - 1) / + (54.5981500331F - 1)); + else + return 0; +} + +bool +SoftwareMixer::SetVolume(unsigned new_volume, gcc_unused Error &error) +{ + assert(new_volume <= 100); + + volume = new_volume; + volume_filter_set(filter, PercentVolumeToSoftwareVolume(new_volume)); + return true; +} + +const MixerPlugin software_mixer_plugin = { + software_mixer_init, + true, +}; + +inline Filter * +SoftwareMixer::GetFilter() +{ + assert(owns_filter); + + owns_filter = false; + return filter; +} + +Filter * +software_mixer_get_filter(Mixer *mixer) +{ + SoftwareMixer *sm = (SoftwareMixer *)mixer; + assert(sm->IsPlugin(software_mixer_plugin)); + return sm->GetFilter(); +} |