Upstream version 9.38.198.0

[platform/framework/web/crosswalk.git] / src / media / audio / win / core_audio_util_win.h

diff --git a/src/media/audio/win/core_audio_util_win.h b/src/media/audio/win/core_audio_util_win.h
index a210af9..4e93531 100644 (file)
--- a/src/media/audio/win/core_audio_util_win.h
+++ b/src/media/audio/win/core_audio_util_win.h
@@ -4,7 +4,7 @@
 
 // Utility methods for the Core Audio API on Windows.
 // Always ensure that Core Audio is supported before using these methods.
-// Use media::CoreAudioIsSupported() for this purpose.
+// Use media::CoreAudioUtil::IsSupported() for this purpose.
 // Also, all methods must be called on a valid COM thread. This can be done
 // by using the base::win::ScopedCOMInitializer helper class.
 
@@ -37,6 +37,8 @@ class MEDIA_EXPORT CoreAudioUtil {
   // Returns true if Windows Core Audio is supported.
   // Always verify that this method returns true before using any of the
   // methods in this class.
+  // WARNING: This function must be called once from the main thread before
+  // it is safe to call from other threads.
   static bool IsSupported();
 
   // Converts between reference time to base::TimeDelta.
@@ -198,10 +200,15 @@ class MEDIA_EXPORT CoreAudioUtil {
   // If a valid event is provided in |event_handle|, the client will be
   // initialized for event-driven buffer handling. If |event_handle| is set to
   // NULL, event-driven buffer handling is not utilized.
+  // This function will initialize the audio client as part of the default
+  // audio session if NULL is passed for |session_guid|, otherwise the client
+  // will be associated with the specified session.
   static HRESULT SharedModeInitialize(IAudioClient* client,
                                       const WAVEFORMATPCMEX* format,
                                       HANDLE event_handle,
-                                      uint32* endpoint_buffer_size);
+                                      uint32* endpoint_buffer_size,
+                                      const GUID* session_guid);
+
   // TODO(henrika): add ExclusiveModeInitialize(...)
 
   // Create an IAudioRenderClient client for an existing IAudioClient given by
@@ -228,6 +235,13 @@ class MEDIA_EXPORT CoreAudioUtil {
   DISALLOW_COPY_AND_ASSIGN(CoreAudioUtil);
 };
 
+// The special audio session identifier we use when opening up the default
+// communication device.  This has the effect that a separate volume control
+// will be shown in the system's volume mixer and control over ducking and
+// visually observing the behavior of ducking, is easier.
+// Use with |SharedModeInitialize|.
+extern const GUID kCommunicationsSessionId;
+
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_WIN_CORE_AUDIO_UTIL_WIN_H_