// Copyright (c) 2003-2009 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 "MMFAudioSPcm16ToMuLawCodec.h"

/***

*

* Convert

*

*/

EXPORT_C void TMMFAudioSPcm16ToMuLawCodec::Convert(TUint8* aSrc, TUint8* aDst, TInt aSamples)

	{

	TInt pcm;

	while (aSamples--)

		{

		pcm = (aSrc[0]+(aSrc[1]<<8));

		*aDst++ = PcmSampleToMuLaw(STATIC_CAST(TInt16 , pcm));

		aSrc+=2;

		}

	}

//[ conversion look up table pcm16 to Mulaw ]

const TInt8 TMMFAudioSPcm16ToMuLawCodec::KExpLut[] = 

	{

	0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,

	4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,

	5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,

	5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,

	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,

	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,

	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,

	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,

	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7

	};

/***

*

* PcmSampleToMulaw

* @param Mulaw

* @return TUint8

*

*/

TUint8 TMMFAudioSPcm16ToMuLawCodec::PcmSampleToMuLaw(TInt aPcm)

	{

    TInt sign, exponent, mantissa;

    TUint8 ulawbyte;

    sign = (aPcm >> 8) & KMaskSign8bit;		

    if ( sign != 0 )

		aPcm = STATIC_CAST( TUint16,-aPcm);

	if ( STATIC_CAST(TUint , aPcm) > STATIC_CAST(TUint , KMda16PcmToMulawClip ))

		aPcm = KMda16PcmToMulawClip;	

    aPcm = STATIC_CAST(TInt16 , aPcm + KMda16PcmToMulawBias);

    exponent = KExpLut[( aPcm >> 7 ) & KAndMask8bit];

    mantissa = ( aPcm >> ( exponent + 3 ) ) & 0x0F;

    ulawbyte = STATIC_CAST( TUint8, ~ ( sign | ( exponent << 4 ) | mantissa ));

    return ulawbyte;

	}