Moving device description utils from AudioManager[Base] into AudioDeviceDescription; to be shared b…

media/audio/audio_device_description.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 MEDIA_AUDIO_AUDIO_DEVICE_DESCRIPTION_H_
+#define MEDIA_AUDIO_AUDIO_DEVICE_DESCRIPTION_H_
+
+#include <string>
+#include "media/base/media_export.h"
+
+namespace media {
+
+// Provides common information on audio device names and ids.
+class MEDIA_EXPORT AudioDeviceDescription {
+ public:
+  // Unique Id of the generic "default" device. Associated with the localized
+  // name returned from GetDefaultDeviceName().
+  static const char kDefaultDeviceId[];
+
+  // Unique Id of the generic default communications device. Associated with
+  // the localized name returned from GetCommunicationsDeviceName().
+  static const char kCommunicationsDeviceId[];
+
+  // Input device ID used to capture the default system playback stream. When
+  // this device ID is passed to MakeAudioInputStream() the returned
+  // AudioInputStream will be capturing audio currently being played on the
+  // default playback device. At the moment this feature is supported only on
+  // some platforms. AudioInputStream::Intialize() will return an error on
+  // platforms that don't support it. GetInputStreamParameters() must be used
+  // to get the parameters of the loopback device before creating a loopback
+  // stream, otherwise stream initialization may fail.
+  static const char kLoopbackInputDeviceId[];
+
+  // Returns true if |device_id| represents the default device.
+  static bool IsDefaultDevice(const std::string& device_id);
+
+  // If |device_id| is not empty, |session_id| should be ignored and the output
+  // device should be selected basing on |device_id|.
+  // If |device_id| is empty and |session_id| is nonzero, output device
+  // associated with the opened input device designated by |session_id| should
+  // be used.
+  static bool UseSessionIdToSelectDevice(int session_id,
+                                         const std::string& device_id);
+
+  // Returns the localized name of the generic "default" device.
+  static std::string GetDefaultDeviceName();
+
+  // Returns the localized name of the generic default communications device.
+  // This device is not supported on all platforms.
+  static std::string GetCommunicationsDeviceName();
+
+ private:
+  AudioDeviceDescription() {}
+  ~AudioDeviceDescription() {}
+};
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_AUDIO_DEVICE_DESCRIPTION_H_