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// Copyright 2013 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/audio/sounds/audio_stream_handler.h"
#include <string>
#include "base/cancelable_callback.h"
#include "base/logging.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/lock.h"
#include "base/time/time.h"
#include "media/audio/audio_manager.h"
#include "media/audio/audio_manager_base.h"
#include "media/base/channel_layout.h"
namespace media {
namespace {
// Volume percent.
const double kOutputVolumePercent = 0.8;
// The number of frames each OnMoreData() call will request.
const int kDefaultFrameCount = 1024;
// Keep alive timeout for audio stream.
const int kKeepAliveMs = 1500;
AudioStreamHandler::TestObserver* g_observer_for_testing = NULL;
AudioOutputStream::AudioSourceCallback* g_audio_source_for_testing = NULL;
} // namespace
class AudioStreamHandler::AudioStreamContainer
: public AudioOutputStream::AudioSourceCallback {
public:
explicit AudioStreamContainer(const WavAudioHandler& wav_audio)
: started_(false),
stream_(NULL),
cursor_(0),
delayed_stop_posted_(false),
wav_audio_(wav_audio) {}
~AudioStreamContainer() override {
DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
}
void Play() {
DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
if (!stream_) {
const AudioParameters params(
AudioParameters::AUDIO_PCM_LOW_LATENCY,
GuessChannelLayout(wav_audio_.num_channels()),
wav_audio_.sample_rate(), wav_audio_.bits_per_sample(),
kDefaultFrameCount);
stream_ = AudioManager::Get()->MakeAudioOutputStreamProxy(params,
std::string());
if (!stream_ || !stream_->Open()) {
LOG(ERROR) << "Failed to open an output stream.";
return;
}
stream_->SetVolume(kOutputVolumePercent);
}
{
base::AutoLock al(state_lock_);
delayed_stop_posted_ = false;
stop_closure_.Reset(base::Bind(&AudioStreamContainer::StopStream,
base::Unretained(this)));
if (started_) {
if (wav_audio_.AtEnd(cursor_))
cursor_ = 0;
return;
}
cursor_ = 0;
}
started_ = true;
if (g_audio_source_for_testing)
stream_->Start(g_audio_source_for_testing);
else
stream_->Start(this);
if (g_observer_for_testing)
g_observer_for_testing->OnPlay();
}
void Stop() {
DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
StopStream();
if (stream_)
stream_->Close();
stream_ = NULL;
stop_closure_.Cancel();
}
private:
// AudioOutputStream::AudioSourceCallback overrides:
// Following methods could be called from *ANY* thread.
int OnMoreData(AudioBus* dest, uint32 /* total_bytes_delay */) override {
base::AutoLock al(state_lock_);
size_t bytes_written = 0;
if (wav_audio_.AtEnd(cursor_) ||
!wav_audio_.CopyTo(dest, cursor_, &bytes_written)) {
if (delayed_stop_posted_)
return 0;
delayed_stop_posted_ = true;
AudioManager::Get()->GetTaskRunner()->PostDelayedTask(
FROM_HERE,
stop_closure_.callback(),
base::TimeDelta::FromMilliseconds(kKeepAliveMs));
return 0;
}
cursor_ += bytes_written;
return dest->frames();
}
void OnError(AudioOutputStream* /* stream */) override {
LOG(ERROR) << "Error during system sound reproduction.";
}
void StopStream() {
DCHECK(AudioManager::Get()->GetTaskRunner()->BelongsToCurrentThread());
if (stream_ && started_) {
// Do not hold the |state_lock_| while stopping the output stream.
stream_->Stop();
if (g_observer_for_testing)
g_observer_for_testing->OnStop(cursor_);
}
started_ = false;
}
// Must only be accessed on the AudioManager::GetTaskRunner() thread.
bool started_;
AudioOutputStream* stream_;
// All variables below must be accessed under |state_lock_| when |started_|.
base::Lock state_lock_;
size_t cursor_;
bool delayed_stop_posted_;
const WavAudioHandler wav_audio_;
base::CancelableClosure stop_closure_;
DISALLOW_COPY_AND_ASSIGN(AudioStreamContainer);
};
AudioStreamHandler::AudioStreamHandler(const base::StringPiece& wav_data)
: wav_audio_(wav_data),
initialized_(false) {
AudioManager* manager = AudioManager::Get();
if (!manager) {
LOG(ERROR) << "Can't get access to audio manager.";
return;
}
const AudioParameters params(
AudioParameters::AUDIO_PCM_LOW_LATENCY,
GuessChannelLayout(wav_audio_.num_channels()), wav_audio_.sample_rate(),
wav_audio_.bits_per_sample(), kDefaultFrameCount);
if (!params.IsValid()) {
LOG(ERROR) << "Audio params are invalid.";
return;
}
stream_.reset(new AudioStreamContainer(wav_audio_));
initialized_ = true;
}
AudioStreamHandler::~AudioStreamHandler() {
DCHECK(CalledOnValidThread());
AudioManager::Get()->GetTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&AudioStreamContainer::Stop, base::Unretained(stream_.get())));
AudioManager::Get()->GetTaskRunner()->DeleteSoon(FROM_HERE,
stream_.release());
}
bool AudioStreamHandler::IsInitialized() const {
DCHECK(CalledOnValidThread());
return initialized_;
}
bool AudioStreamHandler::Play() {
DCHECK(CalledOnValidThread());
if (!IsInitialized())
return false;
AudioManager::Get()->GetTaskRunner()->PostTask(
FROM_HERE,
base::Bind(base::IgnoreResult(&AudioStreamContainer::Play),
base::Unretained(stream_.get())));
return true;
}
void AudioStreamHandler::Stop() {
DCHECK(CalledOnValidThread());
AudioManager::Get()->GetTaskRunner()->PostTask(
FROM_HERE,
base::Bind(&AudioStreamContainer::Stop, base::Unretained(stream_.get())));
}
// static
void AudioStreamHandler::SetObserverForTesting(TestObserver* observer) {
g_observer_for_testing = observer;
}
// static
void AudioStreamHandler::SetAudioSourceForTesting(
AudioOutputStream::AudioSourceCallback* source) {
g_audio_source_for_testing = source;
}
} // namespace media
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