media/audio/android/audio_manager_android.h

// 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_ANDROID_AUDIO_MANAGER_ANDROID_H_
#define MEDIA_AUDIO_ANDROID_AUDIO_MANAGER_ANDROID_H_

#include <set>

#include "base/android/jni_android.h"
#include "base/macros.h"
#include "base/synchronization/lock.h"
#include "base/synchronization/waitable_event.h"
#include "media/audio/audio_manager_base.h"

namespace media {

class MuteableAudioOutputStream;

// Android implemention of AudioManager.
class MEDIA_EXPORT AudioManagerAndroid : public AudioManagerBase {
 public:
  AudioManagerAndroid(std::unique_ptr<AudioThread> audio_thread,
                      AudioLogFactory* audio_log_factory);
  ~AudioManagerAndroid() override;

  void InitializeIfNeeded();

  // Implementation of AudioManager.
  bool HasAudioOutputDevices() override;
  bool HasAudioInputDevices() override;
  void GetAudioInputDeviceNames(AudioDeviceNames* device_names) override;
  void GetAudioOutputDeviceNames(AudioDeviceNames* device_names) override;
  AudioParameters GetInputStreamParameters(
      const std::string& device_id) override;

  AudioOutputStream* MakeAudioOutputStream(
      const AudioParameters& params,
      const std::string& device_id,
      const LogCallback& log_callback) override;
  AudioInputStream* MakeAudioInputStream(
      const AudioParameters& params,
      const std::string& device_id,
      const LogCallback& log_callback) override;
  void ReleaseOutputStream(AudioOutputStream* stream) override;
  void ReleaseInputStream(AudioInputStream* stream) override;
  const char* GetName() override;

  // Implementation of AudioManagerBase.
  AudioOutputStream* MakeLinearOutputStream(
      const AudioParameters& params,
      const LogCallback& log_callback) override;
  AudioOutputStream* MakeLowLatencyOutputStream(
      const AudioParameters& params,
      const std::string& device_id,
      const LogCallback& log_callback) override;
  AudioOutputStream* MakeBitstreamOutputStream(
      const AudioParameters& params,
      const std::string& device_id,
      const LogCallback& log_callback) override;
  AudioInputStream* MakeLinearInputStream(
      const AudioParameters& params,
      const std::string& device_id,
      const LogCallback& log_callback) override;
  AudioInputStream* MakeLowLatencyInputStream(
      const AudioParameters& params,
      const std::string& device_id,
      const LogCallback& log_callback) override;

  // Indicates if there's support for the OpenSLES performance mode keys. See
  // OpenSLESOutputStream for specific details. Essentially this allows for low
  // power audio when large buffer sizes can be used.
  static bool SupportsPerformanceModeForOutput();

  void SetMute(JNIEnv* env,
               const base::android::JavaParamRef<jobject>& obj,
               jboolean muted);

  // Sets a volume that applies to all this manager's output audio streams.
  // This overrides other SetVolume calls (e.g. through AudioHostMsg_SetVolume).
  void SetOutputVolumeOverride(double volume);
  bool HasOutputVolumeOverride(double* out_volume) const;

  // Get the latency introduced by the hardware.  It relies on
  // AudioManager.getOutputLatency, which is both (a) hidden and (b) not
  // guaranteed to be meaningful.  Do not use this, except in the context of
  // b/80326798 to adjust (hackily) for hardware latency that OpenSLES isn't
  // otherwise accounting for.
  base::TimeDelta GetOutputLatency();

 protected:
  void ShutdownOnAudioThread() override;
  AudioParameters GetPreferredOutputStreamParameters(
      const std::string& output_device_id,
      const AudioParameters& input_params) override;

 private:
  const base::android::JavaRef<jobject>& GetJavaAudioManager();
  bool HasNoAudioInputStreams();
  void SetCommunicationAudioModeOn(bool on);
  bool SetAudioDevice(const std::string& device_id);
  int GetNativeOutputSampleRate();
  bool IsAudioLowLatencySupported();
  int GetAudioLowLatencyOutputFrameSize();
  int GetOptimalOutputFrameSize(int sample_rate, int channels);

  void DoSetMuteOnAudioThread(bool muted);
  void DoSetVolumeOnAudioThread(double volume);

  // Returns whether or not we can and should use AAudio.
  bool UseAAudio();

  // Java AudioManager instance.
  base::android::ScopedJavaGlobalRef<jobject> j_audio_manager_;

  typedef std::set<MuteableAudioOutputStream*> OutputStreams;
  OutputStreams streams_;

  // Enabled when first input stream is created and set to false when last
  // input stream is destroyed. Also affects the stream type of output streams.
  bool communication_mode_is_on_;

  base::Optional<bool> is_aaudio_available_;

  // If set, overrides volume level on output streams
  bool output_volume_override_set_;
  double output_volume_override_;

  DISALLOW_COPY_AND_ASSIGN(AudioManagerAndroid);
};

}  // namespace media

#endif  // MEDIA_AUDIO_ANDROID_AUDIO_MANAGER_ANDROID_H_