Improved AGC update scheme for the audio backend in Chrome

media/audio/audio_io.h

 // Copyright (c) 2012 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"
 #include "media/base/audio_bus.h"
@@ skipping 89 matching lines @@
 
   // Sets the relative volume, with range [0.0, 1.0] inclusive.
   virtual void SetVolume(double volume) = 0;
 
   // Gets the relative volume, with range [0.0, 1.0] inclusive.
   virtual void GetVolume(double* volume) = 0;
 
   // Close the stream. This also generates AudioSourceCallback::OnClose().
   // After calling this method, the object should not be used anymore.
   virtual void Close() = 0;
+
+  // Sets the Automatic Gain Control (AGC) state.
+  // Utilized in live-audio (unified) IO mode.
+  virtual void SetAutomaticGainControl(bool enabled) {}

[tommi (sloooow) - chröme, 2013/05/24 18:21:11]

pure virtual?

[henrika (OOO until Aug 14), 2013/05/27 12:17:43]

Actually the idea was to add these in a follow-up CL when refactoring was done
in the input part. Hence, I remove these for now. Hope that is OK.

+
+  // Returns the Automatic Gain Control (AGC) state.
+  // Utilized in live-audio (unified) IO mode.
+  virtual bool GetAutomaticGainControl() { return false; }

[tommi (sloooow) - chröme, 2013/05/24 18:21:11]

same here

[henrika (OOO until Aug 14), 2013/05/27 12:17:43]

see above

 };
 
 // Models an audio sink receiving recorded audio from the audio driver.
 class MEDIA_EXPORT AudioInputStream {
  public:
   class MEDIA_EXPORT AudioInputCallback {
    public:
     // Called by the audio recorder when a full packet of audio data is
     // available. This is called from a special audio thread and the
     // implementation should return as soon as possible.
@@ skipping 47 matching lines @@
   // Sets the Automatic Gain Control (AGC) state.
   virtual void SetAutomaticGainControl(bool enabled) = 0;
 
   // Returns the Automatic Gain Control (AGC) state.
   virtual bool GetAutomaticGainControl() = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_IO_H_