// 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 "MMFAudioALawToS16PcmCodec.h"

/***

*

* Convert

*

*/

EXPORT_C void TMMFAudioALawToS16PcmCodec::Convert(TUint8* aSrc, TUint8* aDst, TInt aSamples)

	{

	ASSERT(aSrc);

	ASSERT(aDst);

	TInt pcm;

	while (aSamples--)

		{

		pcm = AlawSampleToPcm(*aSrc++);

		*aDst++ = STATIC_CAST( TUint8, pcm&KAndMask8bit);

		*aDst++ = STATIC_CAST( TUint8, pcm>>8);

		}

	}

/***

*

* AlawSampleToPcm

* @param aLaw

* @return TInt

*

*/

TInt TMMFAudioALawToS16PcmCodec::AlawSampleToPcm(TUint8 aAlaw)

	{

    TInt sign, exponent, mantissa, sample;

    aAlaw ^= 0x55;	//will leave this as is, more readable

    sign = ( aAlaw & KMaskSign8bit );

    aAlaw &= 0x7f;			/* get magnitude */

    if (aAlaw >= 16)

		{

		exponent = (aAlaw >> 4 ) & 0x07;

		mantissa = aAlaw & 0x0F;

		sample = KExpLut[exponent] + ( mantissa << ( exponent + 3 ) );

		}

    else

		sample = (aAlaw << 4) + 8;

    if ( sign == 0 )

		sample = -sample;

    return sample;

	}

const TInt TMMFAudioALawToS16PcmCodec::KExpLut[] = 

	{

	0, 264, 528, 1056, 2112, 4224, 8448, 16896

	};