sl@0: // Copyright (c) 2003-2009 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: #include "MMFAudioSPcm16ToMuLawCodec.h"
sl@0: 
sl@0: /***
sl@0: *
sl@0: * Convert
sl@0: *
sl@0: */
sl@0: EXPORT_C void TMMFAudioSPcm16ToMuLawCodec::Convert(TUint8* aSrc, TUint8* aDst, TInt aSamples)
sl@0: 	{
sl@0: 	TInt pcm;
sl@0: 	while (aSamples--)
sl@0: 		{
sl@0: 		pcm = (aSrc[0]+(aSrc[1]<<8));
sl@0: 		*aDst++ = PcmSampleToMuLaw(STATIC_CAST(TInt16 , pcm));
sl@0: 		aSrc+=2;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: //[ conversion look up table pcm16 to Mulaw ]
sl@0: const TInt8 TMMFAudioSPcm16ToMuLawCodec::KExpLut[] = 
sl@0: 	{
sl@0: 	0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,
sl@0: 	4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
sl@0: 	5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
sl@0: 	5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
sl@0: 	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
sl@0: 	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
sl@0: 	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
sl@0: 	6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
sl@0: 	7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
sl@0: 	};
sl@0: 
sl@0: /***
sl@0: *
sl@0: * PcmSampleToMulaw
sl@0: * @param Mulaw
sl@0: * @return TUint8
sl@0: *
sl@0: */
sl@0: TUint8 TMMFAudioSPcm16ToMuLawCodec::PcmSampleToMuLaw(TInt aPcm)
sl@0: 	{
sl@0:     TInt sign, exponent, mantissa;
sl@0:     TUint8 ulawbyte;
sl@0: 
sl@0:     sign = (aPcm >> 8) & KMaskSign8bit;		
sl@0:     if ( sign != 0 )
sl@0: 		aPcm = STATIC_CAST( TUint16,-aPcm);
sl@0: 	if ( STATIC_CAST(TUint , aPcm) > STATIC_CAST(TUint , KMda16PcmToMulawClip ))
sl@0: 		aPcm = KMda16PcmToMulawClip;	
sl@0: 
sl@0:     aPcm = STATIC_CAST(TInt16 , aPcm + KMda16PcmToMulawBias);
sl@0:     exponent = KExpLut[( aPcm >> 7 ) & KAndMask8bit];
sl@0:     mantissa = ( aPcm >> ( exponent + 3 ) ) & 0x0F;
sl@0:     ulawbyte = STATIC_CAST( TUint8, ~ ( sign | ( exponent << 4 ) | mantissa ));
sl@0: 
sl@0:     return ulawbyte;
sl@0: 	}