--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mmserv/voipaudioservices/JitterBufferUtility/inc/CngGenerator.h	Tue Feb 02 01:08:46 2010 +0200
@@ -0,0 +1,141 @@
+/*
+* Copyright (c) 2008 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:  Declares class for comfort noise generating utility (CNG)
+*
+*/
+
+
+#ifndef CNGGENERATOR_H
+#define CNGGENERATOR_H
+
+#include <mmfutilities.h>
+
+// FORWARD DECLARATIONS
+class MJitterBufferObserver;
+
+/**
+ * Comfort noise generating utility
+ *
+ * @lib MMccJitterBuffer.lib
+ * @since Series 60 5.0
+ */
+NONSHARABLE_CLASS (CVoIPCNGenerator) : public CBase
+    {
+public:  // Constructor and destructor
+
+    /**
+     * Two phased constructor
+     */
+    static CVoIPCNGenerator* NewL(MJitterBufferObserver* iObserver,
+                                  const TFourCC& aCodec);
+
+    /**
+     * Destructor
+     */
+    virtual ~CVoIPCNGenerator();
+
+public: // New functions
+
+    /**
+     * Generates an SID packet to given buffer
+     * @since Series 60 5.0
+     * @param aPayload Buffer to be filled with SID data
+     * @param aRequestSize Amount of data to be generated to buffer.
+     * @return void
+     */
+    void GenerateSidPacket(TDes8& aPayload, TInt aRequestSize);
+
+    /**
+     * Requests error concealment for the next frame.
+     * @since Series 60 5.0
+     * @param None
+     * @return void
+     */
+    void ConcealErrorForNextFrame() const;
+
+    /**
+     * Returns current DTX status
+     * @since Series 60 5.0
+     * @param None
+     * @return TBool ETrue if DTX period ongoing
+     */
+    TBool DtxPeriodStatus() const;
+
+    /**
+     * Decide whether we are in DTX period or in normal speech period
+     * @since Series 60 5.0
+     * @param const TDes8& - Buffer containing data
+     * @return TInt
+     */
+    void DoDtxDecision(const TDes8& aPayload);
+
+    /**
+     * Checks whether buffer contains SID frame.
+     * @since Series 60 5.0
+     * @param const TDes8& - Buffer containing data
+     * @return TBool - ETrue if buffer contains SID frame
+     */
+    TBool IsSidBuffer(const TDes8& aData);
+        
+private: // New functions
+
+    /**
+     * Generates an AMR CN packet into aPayload
+     * @since Series 60 5.0
+     * @param aPayload
+     * @return void
+     */
+    void GenerateAmrNoDataPacket(TDes8& aPayload) const;
+
+    /**
+     * Generates an VoIP NO_DATA frame into aPayload
+     * @since Series 60 5.0
+     * @param aPayload Buffer to be filled with VoIP NO_DATA information
+     * @param aRequestSize Amount of data to be generated to buffer.
+     * @return void
+     */
+    void GenerateVoIPNoDataPacket(TDes8& aPayload, TInt aRequestSize) const;
+
+private: //Constructors
+
+    /**
+     * C++ default constructor.
+     */
+    CVoIPCNGenerator(MJitterBufferObserver* iObserver, const TFourCC& aCodec);
+
+    /**
+     * Symbian 2nd phase constructor.
+     */
+    void ConstructL();
+
+private:    // Data
+
+    // Codec type
+    TFourCC iCodec;
+
+    // For Error Concealment IF creation
+    MJitterBufferObserver* iObserver;
+
+    // Generated CN frames
+    TInt iGeneratedCNFrames;
+
+    // DTX period started
+    TBool iDtxPeriodStarted;
+
+    };
+
+#endif  // CNGGENERATOR_H
+
+
+// End of file