1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/mm/mmlibs/mmfw/Codecs/Src/MMFCodecCommon/MMFAudioSPcm16ToALawCodec.cpp	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,89 @@
     1.4 +// Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.5 +// All rights reserved.
     1.6 +// This component and the accompanying materials are made available
     1.7 +// under the terms of "Eclipse Public License v1.0"
     1.8 +// which accompanies this distribution, and is available
     1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
    1.10 +//
    1.11 +// Initial Contributors:
    1.12 +// Nokia Corporation - initial contribution.
    1.13 +//
    1.14 +// Contributors:
    1.15 +//
    1.16 +// Description:
    1.17 +//
    1.18 +
    1.19 +#include "MMFAudioSPcm16ToALawCodec.h"
    1.20 +
    1.21 +/***
    1.22 +*
    1.23 +* Convert
    1.24 +*
    1.25 +*/
    1.26 +EXPORT_C void TMMFAudioSPcm16ToAlawCodec::Convert(TUint8* aSrc, TUint8* aDst, TInt aSamples)
    1.27 +	{
    1.28 +	TInt16* pcm = (TInt16*)aSrc;
    1.29 +	TInt16* pcmLimit = pcm + aSamples; 
    1.30 +
    1.31 +	while (pcm < pcmLimit)
    1.32 +		{
    1.33 +		*aDst++ = PcmSampleToAlaw(*pcm++);
    1.34 +		}
    1.35 +
    1.36 +	}
    1.37 +
    1.38 +//[ conversion look up table pcm16 to alaw ]
    1.39 +const TInt8 TMMFAudioSPcm16ToAlawCodec::KExpLut[] = 
    1.40 +	{
    1.41 +	1,1,2,2,3,3,3,3,
    1.42 +	4,4,4,4,4,4,4,4,
    1.43 +	5,5,5,5,5,5,5,5,
    1.44 +	5,5,5,5,5,5,5,5,
    1.45 +	6,6,6,6,6,6,6,6,
    1.46 +	6,6,6,6,6,6,6,6,
    1.47 +	6,6,6,6,6,6,6,6,
    1.48 +	6,6,6,6,6,6,6,6,
    1.49 +	7,7,7,7,7,7,7,7,
    1.50 +	7,7,7,7,7,7,7,7,
    1.51 +	7,7,7,7,7,7,7,7,
    1.52 +	7,7,7,7,7,7,7,7,
    1.53 +	7,7,7,7,7,7,7,7,
    1.54 +	7,7,7,7,7,7,7,7,
    1.55 +	7,7,7,7,7,7,7,7,
    1.56 +	7,7,7,7,7,7,7,7
    1.57 +	};
    1.58 +
    1.59 +/***
    1.60 +*
    1.61 +* PcmSampleToAlaw
    1.62 +* @param aLaw
    1.63 +* @return TUint8
    1.64 +*
    1.65 +*/
    1.66 +TUint8 TMMFAudioSPcm16ToAlawCodec::PcmSampleToAlaw(TInt aPcm)
    1.67 +	{
    1.68 +    TInt sign;
    1.69 +	TInt exponent;
    1.70 +	TInt mantissa;
    1.71 +	TUint8 alawbyte;
    1.72 +
    1.73 +    sign = ((~aPcm) >> 8) & KMaskSign8bit;		
    1.74 +    if (sign == 0)
    1.75 +		aPcm = -aPcm;	
    1.76 +    if (aPcm > KMda16PcmToAlawClip) 
    1.77 +		aPcm = KMda16PcmToAlawClip;
    1.78 +
    1.79 +    if (aPcm >= 256)
    1.80 +		{
    1.81 +		exponent = KExpLut[( aPcm >> 8 ) & 0x7F];
    1.82 +		mantissa = ( aPcm >> ( exponent + 3 ) ) & 0x0F;
    1.83 +		alawbyte = STATIC_CAST( TUint8, (( exponent << 4 ) | mantissa));
    1.84 +		}
    1.85 +    else
    1.86 +		alawbyte = STATIC_CAST( TUint8, aPcm >> 4);
    1.87 +
    1.88 +    alawbyte ^= (sign ^ 0x55);
    1.89 +
    1.90 +    return alawbyte;
    1.91 +	}
    1.92 +