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// Copyright (c) 2012 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 "media/base/audio_renderer_mixer.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/logging.h"
namespace media {
enum { kPauseDelaySeconds = 10 };
AudioRendererMixer::AudioRendererMixer(
const AudioParameters& input_params, const AudioParameters& output_params,
const scoped_refptr<AudioRendererSink>& sink)
: audio_sink_(sink),
audio_converter_(input_params, output_params, true),
pause_delay_(base::TimeDelta::FromSeconds(kPauseDelaySeconds)),
last_play_time_(base::Time::Now()),
// Initialize |playing_| to true since Start() results in an auto-play.
playing_(true) {
audio_sink_->Initialize(output_params, this);
audio_sink_->Start();
}
AudioRendererMixer::~AudioRendererMixer() {
// AudioRendererSinks must be stopped before being destructed.
audio_sink_->Stop();
// Ensures that all mixer inputs have stopped themselves prior to destruction
// and have called RemoveMixerInput().
DCHECK_EQ(mixer_inputs_.size(), 0U);
}
void AudioRendererMixer::AddMixerInput(
const scoped_refptr<AudioRendererMixerInput>& input) {
base::AutoLock auto_lock(mixer_inputs_lock_);
if (!playing_) {
playing_ = true;
last_play_time_ = base::Time::Now();
audio_sink_->Play();
}
mixer_inputs_.push_back(input);
audio_converter_.AddInput(input);
}
void AudioRendererMixer::RemoveMixerInput(
const scoped_refptr<AudioRendererMixerInput>& input) {
base::AutoLock auto_lock(mixer_inputs_lock_);
audio_converter_.RemoveInput(input);
mixer_inputs_.remove(input);
}
int AudioRendererMixer::Render(AudioBus* audio_bus,
int audio_delay_milliseconds) {
base::AutoLock auto_lock(mixer_inputs_lock_);
// If there are no mixer inputs and we haven't seen one for a while, pause the
// sink to avoid wasting resources when media elements are present but remain
// in the pause state.
base::Time now = base::Time::Now();
if (!mixer_inputs_.empty()) {
last_play_time_ = now;
} else if (now - last_play_time_ >= pause_delay_ && playing_) {
audio_sink_->Pause(false);
playing_ = false;
}
// Set the delay information for each mixer input.
for (AudioRendererMixerInputSet::iterator it = mixer_inputs_.begin();
it != mixer_inputs_.end(); ++it) {
(*it)->set_audio_delay_milliseconds(audio_delay_milliseconds);
}
audio_converter_.Convert(audio_bus);
return audio_bus->frames();
}
void AudioRendererMixer::OnRenderError() {
base::AutoLock auto_lock(mixer_inputs_lock_);
// Call each mixer input and signal an error.
for (AudioRendererMixerInputSet::iterator it = mixer_inputs_.begin();
it != mixer_inputs_.end(); ++it) {
(*it)->OnRenderError();
}
}
} // namespace media
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