media/audio/clockless_audio_sink.h

// 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.

#ifndef MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_
#define MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_

#include <string>

#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "base/time/time.h"
#include "media/base/audio_renderer_sink.h"

namespace base {
class SingleThreadTaskRunner;
}

namespace media {
class AudioBus;
class ClocklessAudioSinkThread;
class OutputDevice;

// Implementation of an AudioRendererSink that consumes the audio as fast as
// possible. This class does not support multiple Play()/Pause() events.
class MEDIA_EXPORT ClocklessAudioSink
    : NON_EXPORTED_BASE(public AudioRendererSink) {
 public:
  ClocklessAudioSink();

  // AudioRendererSink implementation.
  void Initialize(const AudioParameters& params,
                  RenderCallback* callback) override;
  void Start() override;
  void Stop() override;
  void Pause() override;
  void Play() override;
  bool SetVolume(double volume) override;
  OutputDevice* GetOutputDevice() override;

  // Returns the time taken to consume all the audio.
  base::TimeDelta render_time() { return playback_time_; }

  // Enables audio frame hashing.  Must be called prior to Initialize().
  void StartAudioHashForTesting();

  // Returns the hash of all audio frames seen since construction.
  std::string GetAudioHashForTesting();

 protected:
  ~ClocklessAudioSink() override;

 private:
  scoped_ptr<ClocklessAudioSinkThread> thread_;
  bool initialized_;
  bool playing_;
  bool hashing_;

  // Time taken in last set of Render() calls.
  base::TimeDelta playback_time_;

  DISALLOW_COPY_AND_ASSIGN(ClocklessAudioSink);
};

}  // namespace media

#endif  // MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_