diff -r 000000000000 -r b8ed18f6c07b devsound/a3facf/inc/maudioprocessingunit.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/devsound/a3facf/inc/maudioprocessingunit.h	Thu Oct 07 22:34:12 2010 +0100
@@ -0,0 +1,96 @@
+// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+//
+
+
+
+/**
+ @file
+ @publishedPartner
+ @released
+*/
+
+
+#ifndef MAUDIOPROCESSINGUNIT_H
+#define MAUDIOPROCESSINGUNIT_H
+
+#include <e32base.h>
+#include <f32file.h>
+#include <mmf/common/mmfcontroller.h>
+#include <a3f/a3fbase.h>
+
+class MAudioProcessingUnitObserver;
+
+/**
+ * A generic interface for audio processing units.
+ */
+class MAudioProcessingUnit
+	{
+public:
+
+	/**
+	 * Fetches the identifier of the context in which this processing unit exists.
+	 *
+	 * @return TUid context instance id.
+	 */
+	virtual TAudioContextId ContextId() const = 0;
+
+
+	/**
+	 * Fetches the specified interface to this processing unit.
+	 * The interface must not be deleted by the client.
+	 * The processing unit must be removed once from the context using
+	 * any of the retrieved processing unit interfaces.
+	 * @param aTypeId the type of the interface
+	 */
+	virtual TAny* Interface(TUid aType)=0;
+
+	/**
+	 * Registers a processing unit observer.
+	 *
+	 * The observer must be unregistered before the processing unit is removed from the context.
+	 * 
+	 * @see MAudioProcessingUnitObserver for further inforamtion about the observer usage.
+	 * @param aObserver a reference to the observer to register
+	 * @return an error code. KErrNone if successful.
+	 *         KErrNotSupported the processing unit does not provide support for this type of observation.
+	 *         Other system wide error codes are also possible.
+	 */
+	virtual TInt RegisterProcessingUnitObserver(MAudioProcessingUnitObserver& aObserver)=0;
+
+	/**
+	 * Unregisters audio processing unit observer.
+	 *
+	 * @see RegisterProcessingUnitObserver for further information.
+	 * @param aObserver a reference to the processing unit observer to unregister.
+	 * @return an error code. KErrNone if successful.
+	 */
+	virtual void UnregisterProcessingUnitObserver(MAudioProcessingUnitObserver& aObserver)=0; 
+
+	/**
+	 * Returns the component instance id.
+	 *
+	 * @return TUid component instance id.
+	 */
+	virtual TAudioComponentId InstanceId() const = 0;
+
+	/** 
+	 * Returns if the component is the same type of the given feature Uid. 
+ 	 * @param aTypeId a feature Uid to compare with.
+	 */
+	virtual TBool IsTypeOf(TUid aTypeId) const =  0;
+
+	};
+
+#endif // MAUDIOPROCESSINGUNIT_H