// 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__