diff -r 000000000000 -r bde4ae8d615e os/mm/mmlibs/mmfw/Codecs/Src/MMFCodecCommon/MMFAudioALawToPcm16Codec.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/mm/mmlibs/mmfw/Codecs/Src/MMFCodecCommon/MMFAudioALawToPcm16Codec.cpp Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,70 @@ +// 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 + };