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/*
* Copyright (C) 2003-2015 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();
}
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