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// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/chromeos/audio_handler.h"
#include <math.h>
#include "base/logging.h"
#include "chrome/browser/chromeos/pulse_audio_mixer.h"
namespace chromeos {
namespace {
const double kSilenceDb = -200.0;
const double kMinVolumeDb = -90.0;
const double kMaxVolumeDb = 6.0;
// A value of less than one adjusts quieter volumes in larger steps (giving
// finer resolution in the higher volumes).
const double kVolumeBias = 0.7;
} // namespace
// This class will set volume using PulseAudio to adjust volume and mute, and
// handles the volume level logic.
// TODO(davej): Serialize volume/mute for next startup?
// TODO(davej): Should we try to regain a connection if for some reason all was
// initialized fine, but later IsValid() returned false? Maybe N retries?
double AudioHandler::GetVolumeDb() const {
if (!SanityCheck())
return kSilenceDb;
double volume_db = mixer_->GetVolumeDb();
if (volume_db <= kSilenceDb)
return kSilenceDb;
return volume_db;
}
void AudioHandler::SetVolumeDb(double volume_db) {
if (!SanityCheck())
return;
mixer_->SetVolumeDb(volume_db);
}
double AudioHandler::GetVolumePercent() const {
if (!SanityCheck())
return 0;
return VolumeDbToPercent(mixer_->GetVolumeDb());
}
// Set volume using our internal 0-100% range. Notice 0% is a special case of
// silence, so we set the mixer volume to kSilenceDb instead of kMinVolumeDb.
void AudioHandler::SetVolumePercent(double volume_percent) {
if (!SanityCheck())
return;
DCHECK(volume_percent >= 0.0);
double vol_db;
if (volume_percent <= 0)
vol_db = kSilenceDb;
else
vol_db = PercentToVolumeDb(volume_percent);
mixer_->SetVolumeDb(vol_db);
}
// Volume range is from kMinVolumeDb at just above 0% to kMaxVolumeDb at 100%
// with a special case at 0% which maps to kSilenceDb.
void AudioHandler::AdjustVolumeByPercent(double adjust_by_percent) {
if (!SanityCheck())
return;
DLOG(INFO) << "Adjusting Volume by " << adjust_by_percent << " percent";
double vol = mixer_->GetVolumeDb();
double pct = VolumeDbToPercent(vol);
if (pct < 0)
pct = 0;
pct = pct + adjust_by_percent;
if (pct > 100.0)
pct = 100.0;
double new_volume;
if (pct <= 0.1)
new_volume = kSilenceDb;
else
new_volume = PercentToVolumeDb(pct);
if (new_volume != vol)
mixer_->SetVolumeDb(new_volume);
}
bool AudioHandler::IsMute() const {
if (!SanityCheck())
return false;
return mixer_->IsMute();
}
void AudioHandler::SetMute(bool do_mute) {
if (!SanityCheck())
return;
DLOG(INFO) << "Setting Mute to " << do_mute;
mixer_->SetMute(do_mute ? 1 : 0);
}
void AudioHandler::ToggleMute() {
if (!SanityCheck())
return;
mixer_->ToggleMute();
}
AudioHandler::AudioHandler()
: connected_(false) {
mixer_.reset(new PulseAudioMixer());
if (mixer_->Init()) {
connected_ = true;
} else {
LOG(ERROR) << "Unable to connect to PulseAudio";
}
}
AudioHandler::~AudioHandler() {
};
inline bool AudioHandler::SanityCheck() const {
if (!mixer_->IsValid()) {
if (connected_) {
LOG(ERROR) << "Lost connection to PulseAudio";
}
return false;
}
return true;
}
// VolumeDbToPercent() and PercentToVolumeDb() conversion functions allow us
// complete control over how the 0 to 100% range is mapped to actual loudness.
//
// The mapping is confined to these two functions to make it easy to adjust and
// have everything else just work. The range is biased to give finer resolution
// in the higher volumes if kVolumeBias is less than 1.0.
// static
double AudioHandler::VolumeDbToPercent(double volume_db) {
if (volume_db < kMinVolumeDb)
return 0;
return 100.0 * pow((volume_db - kMinVolumeDb) /
(kMaxVolumeDb - kMinVolumeDb), 1/kVolumeBias);
}
// static
double AudioHandler::PercentToVolumeDb(double volume_percent) {
return pow(volume_percent / 100.0, kVolumeBias) *
(kMaxVolumeDb - kMinVolumeDb) + kMinVolumeDb;
}
} // namespace chromeos
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