Exposes a shlib interface for media/audio path.

chromecast/media/audio/cast_audio_manager.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_MANAGER_H_
+#define CHROMECAST_MEDIA_AUDIO_CAST_AUDIO_MANAGER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/linked_ptr.h"
+#include "media/audio/audio_manager_base.h"
+
+namespace media {
+class AudioLogFactory;
+}
+
+namespace chromecast {
+
+class CastAudioOutputDevice;
+class ChromecastDeviceAudioOutputStream;
+
+class CastAudioManager : public media::AudioManagerBase {

[gunsch, 2015/04/27 16:09:11]

+1 to Eric's comment about namespacing, prefer ::media::AudioManagerBase (and
other references throughout this file). This will break if you add an include
from "chromecast/media/base/", for an example.

[slan, 2015/04/28 00:11:38]

Done for entire chromecast/media/audio directory.

+ public:
+  // This class acts as a proxy for chromecast::CastAudioOutputDevice,

[gunsch, 2015/04/27 16:09:11]

Documentation nit: separate the "class" docs from the "ctor" docs, put those
just above the class name

[slan, 2015/04/28 00:11:38]

Done.

+  // converting external-facing chromecast interfaces and data structures to
+  // those expected by media::AudioManager. It does not take ownership of
+  // |audio_output_device|, which must be non-null and which must outlive this
+  // class. All calls to CreateAudioLog() will be forwarded to
+  // |audio_log_factory|, which also must outlive this class.
+  CastAudioManager(media::AudioLogFactory* audio_log_factory,
+                   CastAudioOutputDevice* audio_output_device);

[byungchul, 2015/04/27 17:38:06]

who instantiate CastAudioOutputDevice?

[slan, 2015/04/28 00:11:38]

|audio_output_device| should be a global instance instatiated by the thirdparty
platform code. We will likely need to expose a public method with the following
signature:

static void CastAudioOutputDevice::SetDevice(CastAudioOutputDevice* device); 

This will come in a following CL: b/20551606

+  ~CastAudioManager() override;
+
+  // media::AudioManager implementation:
+  bool HasAudioOutputDevices() override;
+  bool HasAudioInputDevices() override;
+  void ShowAudioInputSettings() override;
+  void GetAudioInputDeviceNames(media::AudioDeviceNames* device_names) override;
+  media::AudioParameters GetInputStreamParameters(
+      const std::string& device_id) override;
+
+  // media::AudioManagerBase implementation:
+  media::AudioParameters GetPreferredOutputStreamParameters(
+      const std::string& output_device_id,
+      const media::AudioParameters& input_params) override;
+  media::AudioOutputStream* MakeLinearOutputStream(
+      const media::AudioParameters& params) override;
+  media::AudioOutputStream* MakeLowLatencyOutputStream(
+      const media::AudioParameters& params,
+      const std::string& device_id) override;
+  media::AudioInputStream* MakeLinearInputStream(
+      const media::AudioParameters& params,
+      const std::string& device_id) override;
+  media::AudioInputStream* MakeLowLatencyInputStream(
+      const media::AudioParameters& params,
+      const std::string& device_id) override;
+
+ private:
+  // Host a media::AudioOutputStream interface which wraps a
+  // chromecast::AudioOutputStream.
+  media::AudioOutputStream* MakeCastOutputStream(
+      const media::AudioParameters& params);
+
+  // Bindings between media and chromecast audio streams.
+  std::vector<linked_ptr<ChromecastDeviceAudioOutputStream>> streams_;
+
+  // The underlying audio output device.
+  chromecast::CastAudioOutputDevice* audio_output_device_;

[byungchul, 2015/04/27 17:38:06]

* const

[slan, 2015/04/28 00:11:38]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(CastAudioManager);
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_MEDIA_AUDIO_CAST_AUDIO_MANAGER_H_