// 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:

//

#ifndef RATECONVERTIMPL_H

#define RATECONVERTIMPL_H

#include "rateconvert.h"

/**

Abstract class that all specific converters derive from.

*/

NONSHARABLE_CLASS( CChannelAndSampleRateConverterCommon ) : public CChannelAndSampleRateConverter

	{

public:

	virtual void SetRates(TInt aSrcRate,TInt aDstRate);

	// from CChannelAndSampleRateConverter

	void Reset();

	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);

protected:

	CChannelAndSampleRateConverterCommon();

	static TInt NextPowerUp(TInt aValue);

	inline static TInt StereoToMono(TInt aSample);

	inline static TInt MonoToStereo(TInt aSample);

	inline static TInt LengthBytesTo16Bit(TInt aLength);

	inline static TInt LengthBytesTo32Bit(TInt aLength);

	inline static TInt Length16BitToBytes(TInt aLength);

	inline static TInt Length32BitToBytes(TInt aLength);

	};

/* functions for copying from mono to stereo and from stereo to mono */

inline TInt CChannelAndSampleRateConverterCommon::StereoToMono(TInt aSample)

	{

	TInt topChannel = aSample>>16; // will naturally keep sign

	TInt bottomChannel = TInt16(aSample&0xffff); // need to sign extend

	TInt monoSample = (topChannel + bottomChannel)/2; // add two channels and divide

	return monoSample;

	}

inline TInt CChannelAndSampleRateConverterCommon::MonoToStereo(TInt aSample)

	{

	TInt32 stereoSample = (aSample<<16) | (aSample&0xffff);

#ifdef _DEBUG

	TInt monoSample = StereoToMono(stereoSample);

	ASSERT(monoSample==aSample);

#endif

	return TInt(stereoSample);

	}

// Convert various lengths by multipling or dividing by 2 or 4

inline TInt CChannelAndSampleRateConverterCommon::LengthBytesTo16Bit(TInt aLength)

	{

	return aLength/sizeof(TInt16);

	}

inline TInt CChannelAndSampleRateConverterCommon::LengthBytesTo32Bit(TInt aLength)

	{

	return aLength/sizeof(TInt32);

	}

inline TInt CChannelAndSampleRateConverterCommon::Length16BitToBytes(TInt aLength)

	{

	return aLength*sizeof(TInt16);

	}

inline TInt CChannelAndSampleRateConverterCommon::Length32BitToBytes(TInt aLength)

	{

	return aLength*sizeof(TInt32);

	}

/**

Abstract class that all specific rate converters derive from - as opposed to channel converters

*/

NONSHARABLE_CLASS( CChannelAndSampleRateConvert ) : public CChannelAndSampleRateConverterCommon

	{

public:

	// from CChannelAndSampleRateConverterCommon

	void Reset();

	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);

	void SetRates(TInt aSrcRate,TInt aDstRate);

protected:

	CChannelAndSampleRateConvert();

	TInt SizeOfUpsampleBuffer(TInt aBufferLength);

protected:

	/*

	The sample rate of the data in the source buffer

	*/

	TInt iFromRate;

	/*

	The sample rate of the data in the destination buffer

	*/

	TInt iToRate;

	TInt iFraction;

	TInt iIndex;

	};

NONSHARABLE_CLASS( CStereoToMonoRateConverter ) : public CChannelAndSampleRateConvert

	{

public:

	CStereoToMonoRateConverter();

protected:

	// from CChannelAndSampleRateConvert

	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);

	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);

	};

NONSHARABLE_CLASS( CStereoToMonoConverter ) : public CChannelAndSampleRateConverterCommon

	{

public:

	CStereoToMonoConverter();

protected:

	// from CChannelAndSampleRateConverterCommon

	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);

	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);

	};

NONSHARABLE_CLASS( CStereoToStereoRateConverter ) : public CChannelAndSampleRateConvert

	{

public:

	CStereoToStereoRateConverter();

protected:

	// from CChannelAndSampleRateConvert

	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);

	};

NONSHARABLE_CLASS( CMonoToMonoRateConverter ) : public CChannelAndSampleRateConvert

	{

public:

	CMonoToMonoRateConverter();

protected:

	// from CChannelAndSampleRateConvert

	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);

	};

NONSHARABLE_CLASS( CMonoToStereoConverter ) : public CChannelAndSampleRateConverterCommon

	{

public:

	CMonoToStereoConverter();

protected:

	// from CChannelAndSampleRateConverterCommon

	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);

	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);

	};

NONSHARABLE_CLASS( CMonoToStereoRateConverter ) : public CChannelAndSampleRateConvert

	{

public:

	CMonoToStereoRateConverter();

protected:

	// from CChannelAndSampleRateConvert

	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);

	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);

	};

#endif