The first step to add device selection to linux.

media/audio/linux/audio_manager_linux.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_LINUX_AUDIO_MANAGER_LINUX_H_
 #define MEDIA_AUDIO_LINUX_AUDIO_MANAGER_LINUX_H_
 
 #include <set>
 
 #include "base/memory/ref_counted.h"
@@ skipping 21 matching lines @@
 
   virtual void MuteAll();
   virtual void UnMuteAll();
 
   virtual void ReleaseOutputStream(AudioOutputStream* stream);
 
  protected:
   virtual ~AudioManagerLinux();
 
  private:
-  // Helper method to query if there is any valid input device
-  bool HasAnyValidAudioInputDevice(void** hint);
+  enum StreamType {
+    kStreamPlayback = 0,
+    kStreamCapture,
+  };
+
+  // Get a list of available ALSA input devices.
+  void GetAlsaAudioInputDevices(media::AudioDeviceNames* device_names);
+
+  // Get the ALSA devices' information like names and ids.

[henrika (OOO until Aug 14), 2011/10/13 09:41:17]

Nit. We only get name and ID here. Not clear.

[no longer working on chromium, 2011/10/19 16:06:03]

Done.

+  void GetAlsaDevicesInfo(void** hint, media::AudioDeviceNames* device_names);
+
+  // Check if the specific ALSA device is available.
+  bool IsAlsaDeviceAvailable(const char* device_name);
+
+  // Query if there is any valid ALSA input device?

[henrika (OOO until Aug 14), 2011/10/13 09:41:17]

??

[scherkus (not reviewing), 2011/10/18 23:22:51]

this comment would be clearer if stated as "Returns true if a device is present
for the given stream type."

[no longer working on chromium, 2011/10/19 16:06:03]

Done.

[no longer working on chromium, 2011/10/19 16:06:03]

Done.

+  bool HasAnyAlsaAudioDevice(StreamType stream);
 
   scoped_ptr<AlsaWrapper> wrapper_;
 
   std::set<AudioOutputStream*> active_streams_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioManagerLinux);
 };
 
 #endif  // MEDIA_AUDIO_LINUX_AUDIO_MANAGER_LINUX_H_