--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mmlibs/mmfw/inc/mmf/common/mmfhelper.h	Tue Feb 02 01:56:55 2010 +0200
@@ -0,0 +1,176 @@
+// Copyright (c) 2002-2009 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:
+// include\mmf\common\mmfutilities.h
+// 
+//
+
+#ifndef __MMF_COMMON_HELPER_H__
+#define __MMF_COMMON_HELPER_H__
+
+#include <e32base.h>
+#include <mmf/server/mmfdatabuffer.h>
+#include <mmf/common/mmffourcc.h>
+
+
+/**
+@internalAll
+
+Base utility class to change the sample rate of audio data in a buffer
+*/
+class CMMFChannelAndSampleRateConverter : public CBase
+	{
+public:
+	/**
+	Reads the audio data from the source buffer,
+	converts the number of channels and the sample rate
+	and copies the result to the destination buffer
+
+	@param  aSrcBuffer
+	        A pointer to a source buffer containing the audio data to convert.
+	@param  aDstBuffer
+	        A pointer to a destination buffer.
+
+	@return The length of the destination buffer.
+	*/
+	virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer) =0;
+	virtual void Reset() {};
+
+	/*
+	Indicates what buffer size is required to hold the converted data.
+	*/
+	virtual TUint MaxConvertBufferSize(TUint aSrcBufferSize) {return aSrcBufferSize;}
+
+	void SetRates(TInt aSrcRate,TInt aSrcChannels,TInt aDstRate,TInt aDstChannels);
+public:
+	/*
+	The sample rate of the data in the source buffer
+	*/
+	TInt iFromRate;
+	/*
+	The sample rate of the data in the destination buffer
+	*/
+	TInt iToRate;
+	/*
+	The number of channels of data in the source buffer
+	*/
+	TInt iFromChannels;
+	/*
+	The number of channels of data in the destination buffer
+	*/
+	TInt iToChannels;
+protected:
+	TReal iRatio;
+	TInt iFraction;
+	TInt iIndex;
+	};
+
+/**
+@internalAll
+*/
+class CMMFStereoToMonoRateConverter : public CMMFChannelAndSampleRateConverter
+	{
+	public:
+		virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer);
+		virtual TUint MaxConvertBufferSize(TUint aSrcBufferSize);
+
+	};
+
+/**
+@internalAll
+*/
+class CMMFStereoToMonoConverter : public CMMFChannelAndSampleRateConverter
+	{
+	public:
+		virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer);
+		virtual TUint MaxConvertBufferSize(TUint aSrcBufferSize);
+	};
+
+/**
+@internalAll
+*/
+class CMMFStereoToStereoRateConverter : public CMMFChannelAndSampleRateConverter
+	{
+	public:
+		virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer);
+	};
+
+/**
+@internalAll
+*/
+class CMMFMonoToMonoRateConverter : public CMMFChannelAndSampleRateConverter
+	{
+	public:
+		virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer);
+	};
+
+/**
+@internalAll
+*/
+class CMMFMonoToStereoConverter : public CMMFChannelAndSampleRateConverter
+	{
+	public:
+		virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer);
+		virtual TUint MaxConvertBufferSize(TUint aSrcBufferSize);
+	};
+
+/**
+@internalAll
+*/
+class CMMFMonoToStereoRateConverter : public CMMFChannelAndSampleRateConverter
+	{
+	public:
+		virtual TInt Convert(const CMMFDataBuffer& aSrcBuffer, CMMFDataBuffer& aDstBuffer);
+		virtual TUint MaxConvertBufferSize(TUint aSrcBufferSize);
+	};
+
+/**
+@internalAll
+
+Factory class to create the appropriate CMMFChannelAndSampleRateConverter-derived
+class depending on the supplied number of channels and bit rate
+*/
+class CMMFChannelAndSampleRateConverterFactory : public CBase
+	{
+
+public:
+	IMPORT_C CMMFChannelAndSampleRateConverter* CreateConverterL(TInt aFromRate,TInt aFromChannels,
+												 TInt aToRate,TInt aToChannels);
+	IMPORT_C CMMFChannelAndSampleRateConverter* CreateConverterL();
+	CMMFChannelAndSampleRateConverter* Converter() {return iConverter;}
+	IMPORT_C ~CMMFChannelAndSampleRateConverterFactory();
+	TInt Rate() {return iToRate;}
+	TInt Channels() {return iToChannels;}
+public:
+	/**
+	The sample rate of the data in the source buffer
+	*/
+	TInt iFromRate;
+	/**
+	The sample rate of the data in the destination buffer
+	*/
+	TInt iToRate;
+	/**
+	The number of channels of data in the source buffer
+	*/
+	TInt iFromChannels;
+	/**
+	The number of channels of data in the destination buffer
+	*/
+	TInt iToChannels;
+private:
+	CMMFChannelAndSampleRateConverter* iConverter;
+	};
+
+#endif //__MMF_COMMON_HELPER_H__
+