Exposes a shlib interface for media/audio path.

chromecast/public/cast_audio_stream_provider.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_STREAM_PROVIDER_H_
+#define CHROMECAST_PUBLIC_CAST_AUDIO_STREAM_PROVIDER_H_
+
+#include <string>
+#include "cast_audio_stream.h"
+#include "chromecast_export.h"
+
+namespace chromecast {
+
+// 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 CHROMECAST_EXPORT CastAudioStreamProvider {

[lcwu1, 2015/04/24 02:18:24]

This name is actually a bit misleading as it seems to suggest this is a class
that 'provides' the audio stream, while it is actually a class that we can query
the output device's capability, parameters, etc. I would probably rename it to
something like 'CastAudioOutputProvider' or 'CastAudioOutputDevice'.

[slan, 2015/04/24 05:34:26]

I like the second one. Done.

+ public:
+  virtual ~CastAudioStreamProvider() {}
+
+  // Returns the maximum number of output streams allowed.
+  virtual int GetMaximumOutputStreamsAllowed() const = 0;
+
+  // 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|. Caller
+  // does not take ownership of the returned stream.
+  virtual AudioOutputStream* MakeOutputStream(
+      const AudioParameters& params) = 0;
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_PUBLIC_CAST_AUDIO_STREAM_PROVIDER_H_