// 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.
#ifndef MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
#define MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_
#include <string>
#include <utility>
#include "base/compiler_specific.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/scoped_vector.h"
#include "base/observer_list.h"
#include "base/threading/thread.h"
#include "media/audio/audio_manager.h"
#include "media/audio/audio_output_dispatcher.h"
#if defined(OS_WIN)
#include "base/win/scoped_com_initializer.h"
#endif
namespace media {
class AudioOutputDispatcher;
// AudioManagerBase provides AudioManager functions common for all platforms.
class MEDIA_EXPORT AudioManagerBase : public AudioManager {
public:
// TODO(sergeyu): The constants below belong to AudioManager interface, not
// to the base implementation.
// Name of the generic "default" device.
static const char kDefaultDeviceName[];
// Unique Id of the generic "default" device.
static const char kDefaultDeviceId[];
// Input device ID used to capture the default system playback stream. When
// this device ID is passed to MakeAudioInputStream() the returned
// AudioInputStream will be capturing audio currently being played on the
// default playback device. At the moment this feature is supported only on
// some platforms. AudioInputStream::Intialize() will return an error on
// platforms that don't support it. GetInputStreamParameters() must be used
// to get the parameters of the loopback device before creating a loopback
// stream, otherwise stream initialization may fail.
static const char kLoopbackInputDeviceId[];
virtual ~AudioManagerBase();
virtual scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner() OVERRIDE;
virtual scoped_refptr<base::SingleThreadTaskRunner> GetWorkerTaskRunner()
OVERRIDE;
virtual base::string16 GetAudioInputDeviceModel() OVERRIDE;
virtual void ShowAudioInputSettings() OVERRIDE;
virtual void GetAudioInputDeviceNames(
AudioDeviceNames* device_names) OVERRIDE;
virtual void GetAudioOutputDeviceNames(
AudioDeviceNames* device_names) OVERRIDE;
virtual AudioOutputStream* MakeAudioOutputStream(
const AudioParameters& params,
const std::string& device_id) OVERRIDE;
virtual AudioInputStream* MakeAudioInputStream(
const AudioParameters& params, const std::string& device_id) OVERRIDE;
virtual AudioOutputStream* MakeAudioOutputStreamProxy(
const AudioParameters& params,
const std::string& device_id) OVERRIDE;
// Called internally by the audio stream when it has been closed.
virtual void ReleaseOutputStream(AudioOutputStream* stream);
virtual void ReleaseInputStream(AudioInputStream* stream);
// Creates the output stream for the |AUDIO_PCM_LINEAR| format. The legacy
// name is also from |AUDIO_PCM_LINEAR|.
virtual AudioOutputStream* MakeLinearOutputStream(
const AudioParameters& params) = 0;
// Creates the output stream for the |AUDIO_PCM_LOW_LATENCY| format.
virtual AudioOutputStream* MakeLowLatencyOutputStream(
const AudioParameters& params,
const std::string& device_id) = 0;
// Creates the input stream for the |AUDIO_PCM_LINEAR| format. The legacy
// name is also from |AUDIO_PCM_LINEAR|.
virtual AudioInputStream* MakeLinearInputStream(
const AudioParameters& params, const std::string& device_id) = 0;
// Creates the input stream for the |AUDIO_PCM_LOW_LATENCY| format.
virtual AudioInputStream* MakeLowLatencyInputStream(
const AudioParameters& params, const std::string& device_id) = 0;
// Listeners will be notified on the GetTaskRunner() task runner.
virtual void AddOutputDeviceChangeListener(
AudioDeviceListener* listener) OVERRIDE;
virtual void RemoveOutputDeviceChangeListener(
AudioDeviceListener* listener) OVERRIDE;
virtual AudioParameters GetDefaultOutputStreamParameters() OVERRIDE;
virtual AudioParameters GetOutputStreamParameters(
const std::string& device_id) OVERRIDE;
virtual AudioParameters GetInputStreamParameters(
const std::string& device_id) OVERRIDE;
virtual std::string GetAssociatedOutputDeviceID(
const std::string& input_device_id) OVERRIDE;
virtual scoped_ptr<AudioLog> CreateAudioLog(
AudioLogFactory::AudioComponent component) OVERRIDE;
virtual void FixWedgedAudio() OVERRIDE;
protected:
AudioManagerBase(AudioLogFactory* audio_log_factory);
// Shuts down the audio thread and releases all the audio output dispatchers
// on the audio thread. All audio streams should be freed before Shutdown()
// is called. This must be called in the destructor of every AudioManagerBase
// implementation.
void Shutdown();
void SetMaxOutputStreamsAllowed(int max) { max_num_output_streams_ = max; }
// Called by each platform specific AudioManager to notify output state change
// listeners that a state change has occurred. Must be called from the audio
// thread.
void NotifyAllOutputDeviceChangeListeners();
// Returns user buffer size as specified on the command line or 0 if no buffer
// size has been specified.
int GetUserBufferSize();
// Returns the preferred hardware audio output parameters for opening output
// streams. If the users inject a valid |input_params|, each AudioManager
// will decide if they should return the values from |input_params| or the
// default hardware values. If the |input_params| is invalid, it will return
// the default hardware audio parameters.
// If |output_device_id| is empty, the implementation must treat that as
// a request for the default output device.
virtual AudioParameters GetPreferredOutputStreamParameters(
const std::string& output_device_id,
const AudioParameters& input_params) = 0;
// Returns the ID of the default audio output device.
// Implementations that don't yet support this should return an empty string.
virtual std::string GetDefaultOutputDeviceID();
// Get number of input or output streams.
int input_stream_count() { return num_input_streams_; }
int output_stream_count() { return num_output_streams_; }
private:
struct DispatcherParams;
typedef ScopedVector<DispatcherParams> AudioOutputDispatchers;
class CompareByParams;
// Called by Shutdown().
void ShutdownOnAudioThread();
// Max number of open output streams, modified by
// SetMaxOutputStreamsAllowed().
int max_num_output_streams_;
// Max number of open input streams.
int max_num_input_streams_;
// Number of currently open output streams.
int num_output_streams_;
// Number of currently open input streams.
int num_input_streams_;
// Track output state change listeners.
ObserverList<AudioDeviceListener> output_listeners_;
// Thread used to interact with audio streams created by this audio manager.
base::Thread audio_thread_;
// The task runner of the audio thread this object runs on. Used for internal
// tasks which run on the audio thread even after Shutdown() has been started
// and GetTaskRunner() starts returning NULL.
scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
// Map of cached AudioOutputDispatcher instances. Must only be touched
// from the audio thread (no locking).
AudioOutputDispatchers output_dispatchers_;
// Proxy for creating AudioLog objects.
AudioLogFactory* const audio_log_factory_;
DISALLOW_COPY_AND_ASSIGN(AudioManagerBase);
};
} // namespace media
#endif // MEDIA_AUDIO_AUDIO_MANAGER_BASE_H_