Allow AudioOutputDevice objects to be initialized with a specific hardware output device and store …

media/base/output_device.h

 // Copyright (c) 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_BASE_OUTPUT_DEVICE_H_
 #define MEDIA_BASE_OUTPUT_DEVICE_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/media_export.h"
 #include "url/gurl.h"
 
 namespace media {
 
 // Result of an audio output device switch operation
 enum SwitchOutputDeviceResult {
   SWITCH_OUTPUT_DEVICE_RESULT_SUCCESS = 0,
   SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_FOUND,
   SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_AUTHORIZED,
-  SWITCH_OUTPUT_DEVICE_RESULT_ERROR_OBSOLETE,
-  SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED,
-  SWITCH_OUTPUT_DEVICE_RESULT_LAST =
-      SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED,
+  SWITCH_OUTPUT_DEVICE_RESULT_ERROR_INTERNAL,
+  SWITCH_OUTPUT_DEVICE_RESULT_LAST = SWITCH_OUTPUT_DEVICE_RESULT_ERROR_INTERNAL,
 };
 
 typedef base::Callback<void(SwitchOutputDeviceResult)> SwitchOutputDeviceCB;
 
 // OutputDevice is an interface that allows performing operations related
 // audio output devices.
 
 class OutputDevice {
  public:
   // Attempts to switch the audio output device.
   // Once the attempt is finished, |callback| is invoked with the
   // result of the operation passed as a parameter. The result is a value from
   // the  media::SwitchOutputDeviceResult enum.
   // There is no guarantee about the thread where |callback| will
   // be invoked, so users are advised to use media::BindToCurrentLoop() to
   // ensure that |callback| runs on the correct thread.
   // Note also that copy constructors and destructors for arguments bound to
   // |callback| may run on arbitrary threads as |callback| is moved across
   // threads. It is advisable to bind arguments such that they are released by
   // |callback| when it runs in order to avoid surprises.
   virtual void SwitchOutputDevice(const std::string& device_id,
                                   const GURL& security_origin,
                                   const SwitchOutputDeviceCB& callback) = 0;
 
+  // Returns the device's audio output parameters.
+  // If the parameters are not available, this method blocks until they
+  // become available.

[DaleCurtis, 2015/09/12 01:17:19]

Add a clause saying it must never be called on the IO thread?

[Guido Urdaneta, 2015/09/14 11:35:48]

Done.

+  virtual AudioParameters GetOutputParameters() = 0;
+
  protected:
   virtual ~OutputDevice() {}
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_OUTPUT_DEVICE_H_