Symaptic: os/mm/mmlibs/mmfw/Codecs/Src/MMFCodecCommon/MMFAudioMuLawToS16PcmCodec.cpp@260cb5ec6c19

     1 // Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 //

    16 #include "MMFAudioMuLawToS16PcmCodec.h"

    18 /***

    19 *

    20 * Convert

    21 *

    22 */

    23 EXPORT_C void TMMFAudioMuLawToS16PcmCodec::Convert(TUint8* aSrc, TUint8* aDst, TInt aSamples)

    24 	{

    25 	ASSERT(aSrc);

    26 	ASSERT(aDst);

    28 	TInt pcm;

    29 	while (aSamples--)

    30 		{

    31 		pcm = MulawSampleToPcm(*aSrc++);

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

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

    34 		}

    36 	}

    38 /***

    39 *

    40 * MulawSampleToPcm

    41 * @param aMuLaw

    42 * @return TInt

    43 *

    44 */

    45 TInt TMMFAudioMuLawToS16PcmCodec::MulawSampleToPcm(TUint8 aMulaw)

    46 	{

    47 	TInt sign, exponent, mantissa, sample;

    49     aMulaw = STATIC_CAST( TUint8, ~aMulaw);

    50     sign = ( aMulaw & KMaskSign8bit );

    51     exponent = ( aMulaw >> 4 ) & 0x07;

    52     mantissa = aMulaw & 0x0F;

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

    54     if ( sign != 0 )

    55 		sample = -sample;

    57     return sample;

    58 	}

    60 const TInt TMMFAudioMuLawToS16PcmCodec::KExpLut[KMdaMulawTo16PcmExpLutSize] =

    61 	{

    62 	0, 132, 396, 924, 1980, 4092, 8316, 16764

    63 	};

author	sl
	Tue, 10 Jun 2014 14:32:02 +0200
changeset 1	260cb5ec6c19
permissions	-rw-r--r--