Adding microphone volume support to chrome.

media/audio/audio_io.h

 // Copyright (c) 2011 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_IO_H_
 #define MEDIA_AUDIO_AUDIO_IO_H_
 
 #include "base/basictypes.h"
 #include "media/audio/audio_buffers_state.h"
 
@@ skipping 136 matching lines @@
   virtual void Start(AudioInputCallback* callback) = 0;
 
   // Stops recording audio. Effect might not be instantaneous as there could be
   // pending audio callbacks in the queue which will be issued first before
   // recording stops.
   virtual void Stop() = 0;
 
   // Close the stream. This also generates AudioInputCallback::OnClose(). This
   // should be the last call made on this object.
   virtual void Close() = 0;
+
+  // Gets the maximum microphone analog volume.
+  virtual void GetMaxMicVolume(double* max_volume) = 0;

[scherkus (not reviewing), 2012/02/21 19:20:01]

do we really want to introduce "Mic" into our naming scheme?

the class in question is already an AudioInputStream -- would dropping "Mic"
from these method names be sufficient?

[no longer working on chromium, 2012/02/22 17:02:23]

Done, removed the "Mic".

+
+  // Sets the microphone analog volume, with range [0.0, max_volume] inclusive.
+  virtual void SetMicVolume(double volume) = 0;
+
+  // Gets the microphone analog volume, with range [0.0, max_volume] inclusive.
+  virtual void GetMicVolume(double* volume) = 0;

[scherkus (not reviewing), 2012/02/21 19:20:01]

any reason why these getters need to use out-params? I wouldn't copy
AudioOutputStream -- it should also return a double instead of using an
out-param

it looks like this was changed a long time ago when Get/SetVolume used to have
separate left/right volumes:
http://src.chromium.org/viewvc/chrome?view=rev&revision=31018

[no longer working on chromium, 2012/02/22 17:27:24]

Thanks for pointing out, I was assuming the code in AudioOutputStream should be
all right.

 };
 
 #endif  // MEDIA_AUDIO_AUDIO_IO_H_