Exposes a shlib interface for media/audio path.

chromecast/public/media/cast_audio_output_device.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_PUBLIC_CAST_AUDIO_OUTPUT_DEVICE_H_
+#define CHROMECAST_PUBLIC_CAST_AUDIO_OUTPUT_DEVICE_H_
+
+#include "cast_audio_output_stream.h"
+
+namespace chromecast {
+
+class TaskRunner;
+
+namespace media {
+
+// This is an interface used to provide platform-specific audio streams.
+// Implementations of this interface should survive for the duration of the
+// process.
+
+// Note: This interface should be implemented by third parties seeking to
+// provide an audio manager platform for Cast. CastAudioManager will call
+// this interface.
+
+class CastAudioOutputDevice {
+ public:
+  virtual ~CastAudioOutputDevice() {}
+
+  // Returns the maximum number of output streams allowed.
+  virtual int GetMaximumOutputStreamsAllowed() const = 0;

[halliwell, 2015/07/29 22:10:14]

In general, don't we stay away from const on objects that vendors must
implement?

[slan, 2015/07/30 21:00:42]

Done.

+
+  // Returns the preferred output stream parameters. The caller may inject
+  // |suggested| parameters, but it is left to the implementation to decide
+  // which of these to return.
+  virtual AudioParameters GetPreferredOutputStreamParameters(
+      const AudioParameters& suggested) const = 0;
+
+  // Creates the output stream with parameters described by |params|. The stream
+  // should be created on the thread on which this is called. Caller does not
+  // take ownership of the returned stream. All callbacks to
+  // CastAudioOutputStream::AudioSourceCallback objects should be made on the
+  // thread to which |task_runner| belongs.
+  virtual CastAudioOutputStream* MakeOutputStream(const AudioParameters& params,
+                                                  TaskRunner* task_runner) = 0;
+};
+
+}  // namespace media
+}  // namespace chromecast
+
+#endif  // CHROMECAST_PUBLIC_CAST_AUDIO_OUTPUT_DEVICE_H_