[Chromecast] Plumbs raw audio through CMA backend.

chromecast/media/audio/cast_audio_output_stream.h

+// Copyright 2015 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 CHROMECAST_MEDIA_AUDIO_CAST_AUDIO_OUTPUT_STREAM_H_
+#define CHROMECAST_MEDIA_AUDIO_CAST_AUDIO_OUTPUT_STREAM_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "chromecast/public/media/media_component_device.h"
+#include "media/audio/audio_io.h"
+#include "media/audio/audio_parameters.h"
+
+namespace media {
+class FakeAudioWorker;
+}  // namespace media
+
+namespace chromecast {
+namespace media {
+
+class CastAudioManager;
+class MediaPipelineBackend;
+
+class CastAudioOutputStream : public ::media::AudioOutputStream {
+ public:
+  CastAudioOutputStream(const ::media::AudioParameters& audio_params,
+                        CastAudioManager* audio_manager);
+  ~CastAudioOutputStream() override;
+
+  // ::media::AudioOutputStream implementation.
+  bool Open() override;
+  void Close() override;
+  void Start(AudioSourceCallback* source_callback) override;
+  void Stop() override;
+  void SetVolume(double volume) override;
+  void GetVolume(double* volume) override;
+
+ private:
+  // Task to push frame into audio pipeline device.
+  void PushFrame(AudioSourceCallback* source_callback);
+  void OnPushFrameStatus(AudioSourceCallback* source_callback,
+                         MediaComponentDevice::FrameStatus status);
+  void OnPushFrameError(AudioSourceCallback* source_callback);
+
+  ::media::AudioParameters audio_params_;
+  CastAudioManager* audio_manager_;
+
+  double volume_;
+  bool audio_device_busy_;
+  scoped_ptr<::media::FakeAudioWorker> audio_worker_;
+  scoped_ptr<::media::AudioBus> audio_bus_;
+  scoped_ptr<MediaPipelineBackend> media_pipeline_backend_;
+
+  base::WeakPtrFactory<CastAudioOutputStream> weak_factory_;
+  DISALLOW_COPY_AND_ASSIGN(CastAudioOutputStream);
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_AUDIO_CAST_AUDIO_OUTPUT_STREAM_H_