sl@0: // Copyright (c) 2002-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: //
sl@0: 
sl@0: #ifndef RATECONVERTIMPL_H
sl@0: #define RATECONVERTIMPL_H
sl@0: 
sl@0: #include "mmf/utils/rateconvert.h"
sl@0: 
sl@0: /**
sl@0: Abstract class that all specific converters derive from.
sl@0: */
sl@0: NONSHARABLE_CLASS( CChannelAndSampleRateConverterCommon ) : public CChannelAndSampleRateConverter
sl@0: 	{
sl@0: public:
sl@0: 	virtual void SetRates(TInt aSrcRate,TInt aDstRate);
sl@0: 	
sl@0: 	// from CChannelAndSampleRateConverter
sl@0: 	void Reset();
sl@0: 	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);
sl@0: 	
sl@0: protected:
sl@0: 	CChannelAndSampleRateConverterCommon();
sl@0: 	
sl@0: 	static TInt NextPowerUp(TInt aValue);
sl@0: 	inline static TInt StereoToMono(TInt aSample);
sl@0: 	inline static TInt MonoToStereo(TInt aSample);
sl@0: 	
sl@0: 	inline static TInt LengthBytesTo16Bit(TInt aLength);
sl@0: 	inline static TInt LengthBytesTo32Bit(TInt aLength);
sl@0: 	inline static TInt Length16BitToBytes(TInt aLength);
sl@0: 	inline static TInt Length32BitToBytes(TInt aLength);
sl@0: 	};
sl@0: 	
sl@0: /* functions for copying from mono to stereo and from stereo to mono */
sl@0: 
sl@0: inline TInt CChannelAndSampleRateConverterCommon::StereoToMono(TInt aSample)
sl@0: 	{
sl@0: 	TInt topChannel = aSample>>16; // will naturally keep sign
sl@0: 	TInt bottomChannel = TInt16(aSample&0xffff); // need to sign extend
sl@0: 	TInt monoSample = (topChannel + bottomChannel)/2; // add two channels and divide
sl@0: 	return monoSample;
sl@0: 	}
sl@0: 	
sl@0: inline TInt CChannelAndSampleRateConverterCommon::MonoToStereo(TInt aSample)
sl@0: 	{
sl@0: 	TInt32 stereoSample = (aSample<<16) | (aSample&0xffff);
sl@0: #ifdef _DEBUG
sl@0: 	TInt monoSample = StereoToMono(stereoSample);
sl@0: 	ASSERT(monoSample==aSample);
sl@0: #endif
sl@0: 	return TInt(stereoSample);
sl@0: 	}
sl@0: 	
sl@0: // Convert various lengths by multipling or dividing by 2 or 4
sl@0: 
sl@0: inline TInt CChannelAndSampleRateConverterCommon::LengthBytesTo16Bit(TInt aLength)
sl@0: 	{
sl@0: 	return aLength/sizeof(TInt16);
sl@0: 	}
sl@0: 	
sl@0: inline TInt CChannelAndSampleRateConverterCommon::LengthBytesTo32Bit(TInt aLength)
sl@0: 	{
sl@0: 	return aLength/sizeof(TInt32);
sl@0: 	}
sl@0: 	
sl@0: inline TInt CChannelAndSampleRateConverterCommon::Length16BitToBytes(TInt aLength)
sl@0: 	{
sl@0: 	return aLength*sizeof(TInt16);
sl@0: 	}
sl@0: 	
sl@0: inline TInt CChannelAndSampleRateConverterCommon::Length32BitToBytes(TInt aLength)
sl@0: 	{
sl@0: 	return aLength*sizeof(TInt32);
sl@0: 	}
sl@0: 
sl@0: /**
sl@0: Abstract class that all specific rate converters derive from - as opposed to channel converters
sl@0: */
sl@0: NONSHARABLE_CLASS( CChannelAndSampleRateConvert ) : public CChannelAndSampleRateConverterCommon
sl@0: 	{
sl@0: public:
sl@0: 	
sl@0: 	// from CChannelAndSampleRateConverterCommon
sl@0: 	void Reset();
sl@0: 	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);
sl@0: 	void SetRates(TInt aSrcRate,TInt aDstRate);
sl@0: 	
sl@0: protected:
sl@0: 	CChannelAndSampleRateConvert();
sl@0: 	
sl@0: 	TInt SizeOfUpsampleBuffer(TInt aBufferLength);
sl@0: protected:
sl@0: 	/*
sl@0: 	The sample rate of the data in the source buffer
sl@0: 	*/
sl@0: 	TInt iFromRate;
sl@0: 	/*
sl@0: 	The sample rate of the data in the destination buffer
sl@0: 	*/
sl@0: 	TInt iToRate;
sl@0: 
sl@0: 	TInt iFraction;
sl@0: 	TInt iIndex;
sl@0: 	};
sl@0: 
sl@0: NONSHARABLE_CLASS( CStereoToMonoRateConverter ) : public CChannelAndSampleRateConvert
sl@0: 	{
sl@0: public:
sl@0: 	CStereoToMonoRateConverter();
sl@0: 	
sl@0: protected:
sl@0: 	// from CChannelAndSampleRateConvert
sl@0: 	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);
sl@0: 	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);
sl@0: 	};
sl@0: 
sl@0: NONSHARABLE_CLASS( CStereoToMonoConverter ) : public CChannelAndSampleRateConverterCommon
sl@0: 	{
sl@0: public:
sl@0: 	CStereoToMonoConverter();
sl@0: 	
sl@0: protected:
sl@0: 	// from CChannelAndSampleRateConverterCommon
sl@0: 	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);
sl@0: 	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);
sl@0: 	};
sl@0: 
sl@0: NONSHARABLE_CLASS( CStereoToStereoRateConverter ) : public CChannelAndSampleRateConvert
sl@0: 	{
sl@0: public:
sl@0: 	CStereoToStereoRateConverter();
sl@0: 	
sl@0: protected:
sl@0: 	// from CChannelAndSampleRateConvert
sl@0: 	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);
sl@0: 	};
sl@0: 
sl@0: NONSHARABLE_CLASS( CMonoToMonoRateConverter ) : public CChannelAndSampleRateConvert
sl@0: 	{
sl@0: public:
sl@0: 	CMonoToMonoRateConverter();
sl@0: 	
sl@0: protected:
sl@0: 	// from CChannelAndSampleRateConvert
sl@0: 	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);
sl@0: 	};
sl@0: 
sl@0: NONSHARABLE_CLASS( CMonoToStereoConverter ) : public CChannelAndSampleRateConverterCommon
sl@0: 	{
sl@0: public:
sl@0: 	CMonoToStereoConverter();
sl@0: 	
sl@0: protected:
sl@0: 	// from CChannelAndSampleRateConverterCommon
sl@0: 	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);
sl@0: 	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);
sl@0: 	};
sl@0: 
sl@0: NONSHARABLE_CLASS( CMonoToStereoRateConverter ) : public CChannelAndSampleRateConvert
sl@0: 	{
sl@0: public:
sl@0: 	CMonoToStereoRateConverter();
sl@0: 	
sl@0: protected:
sl@0: 	// from CChannelAndSampleRateConvert
sl@0: 	TInt Convert(const TDesC8& aSrcBuffer, TDes8& aDstBuffer);
sl@0: 	TInt MaxConvertBufferSize(TInt aSrcBufferSize, TBool aRoundUpToPower);
sl@0: 	};
sl@0: 
sl@0: #endif
sl@0: