Pass more detailed audio hardware configuration information to the renderer

media/base/audio_hardware_config.h

 // Copyright (c) 2013 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_AUDIO_HARDWARE_CONFIG_H_
 #define MEDIA_BASE_AUDIO_HARDWARE_CONFIG_H_
 
 #include "base/compiler_specific.h"
 #include "base/synchronization/lock.h"
+#include "media/audio/audio_parameters.h"
 #include "media/base/channel_layout.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 // Provides thread safe access to the audio hardware configuration.
 class MEDIA_EXPORT AudioHardwareConfig {
  public:
-  AudioHardwareConfig(int output_buffer_size, int output_sample_rate,
-                      int input_sample_rate,
-                      ChannelLayout input_channel_layout);
+  AudioHardwareConfig(const media::AudioParameters& input_params,
+                      const media::AudioParameters& output_params);
   virtual ~AudioHardwareConfig();
 
   // Accessors for the currently cached hardware configuration.  Safe to call
   // from any thread.
   int GetOutputBufferSize();
   int GetOutputSampleRate();
+  ChannelLayout GetOutputChannelLayout();
+  int GetOutputChannels();
+
   int GetInputSampleRate();
   ChannelLayout GetInputChannelLayout();
+  int GetInputChannels();
 
   // Allows callers to update the cached values for either input or output.  The
   // values are paired under the assumption that these values will only be set
   // after an input or output device change respectively.  Safe to call from
   // any thread.
+  // TODO(crogers): These methods should be updated to take AudioParameters!

[DaleCurtis, 2013/03/06 19:19:30]

Seems like that should be done in this CL? You're already tinkering with the
complete path here.

1. UpdateInputConfig has no current users, so that's easy :)
2. UpdateOutputConfig could be easily changed to take the full AudioParameters
object from browser side. Just change the IPC type to AudioParameters.

   void UpdateInputConfig(int sample_rate, media::ChannelLayout channel_layout);
   void UpdateOutputConfig(int buffer_size, int sample_rate);
 
  private:
   // Cached values; access is protected by |config_lock_|.
   base::Lock config_lock_;
-  int output_buffer_size_;
-  int output_sample_rate_;
-  int input_sample_rate_;
-  ChannelLayout input_channel_layout_;
+  media::AudioParameters input_params_;
+  media::AudioParameters output_params_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioHardwareConfig);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_AUDIO_HARDWARE_CONFIG_H_