1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/os/mm/mmlibs/mmfw/Codecs/Src/MMFCodecCommon/MMFAudioImaAdpcmToS16Codec.cpp	Fri Jun 15 03:10:57 2012 +0200
     1.3 @@ -0,0 +1,121 @@
     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 +// MMFAudioImaAdpcmToS16PcmCodec.cpp
    1.18 +// 
    1.19 +//
    1.20 +
    1.21 +#include "MMFAudioImaAdpcmToS16PcmCodec.h"
    1.22 +
    1.23 +/**
    1.24 +*
    1.25 +* Convert
    1.26 +* @param aSrc
    1.27 +* @param aDst
    1.28 +* @param aSamples
    1.29 +*
    1.30 +*/
    1.31 +EXPORT_C void TMMFAudioImaAdpcmToS16PcmCodec::Convert(TUint8* aSrc, TUint8* aDst, TInt aSamples)
    1.32 +	{
    1.33 +	TInt delta;			// Current adpcm output value 
    1.34 +    TInt step;			// Stepsize
    1.35 +    TInt valpred;		// Predicted value 
    1.36 +    TInt vpdiff;		// Current change to valpred 
    1.37 +    TInt index;			// Current step change index 
    1.38 +
    1.39 +	//[Read first sample and index from block header
    1.40 +	// we do not need to store the information across calls 
    1.41 +	//since we process the entire block here]
    1.42 +	valpred = (*aSrc++) & KAndMask8bit;
    1.43 +	valpred |= STATIC_CAST(TInt16, ((*aSrc++) << 8));
    1.44 +	index = *aSrc++;
    1.45 +	TUint8* dst=aDst;
    1.46 +
    1.47 +	aSrc++; //skip reserved header byte
    1.48 +
    1.49 +	//Write first sample to dest
    1.50 +	*aDst++ = STATIC_CAST( TUint8, valpred);
    1.51 +	*aDst++ = STATIC_CAST( TUint8, valpred >> 8);
    1.52 +	dst += 2;
    1.53 +	aSamples --;
    1.54 +
    1.55 +	TBool theBufferStep = ETrue;
    1.56 +    TInt  bufferValue = 0;
    1.57 +	for ( ; aSamples > 0 ; aSamples-- ) 
    1.58 +		{ 
    1.59 +		// Step 1 - get the delta value
    1.60 +		if ( theBufferStep) 
    1.61 +			{
    1.62 +			bufferValue = *aSrc++;
    1.63 +			delta = bufferValue & 0xf;
    1.64 +			} 
    1.65 +		else 
    1.66 +			{
    1.67 +			delta = (bufferValue >> 4) & 0xf;
    1.68 +			}
    1.69 +
    1.70 +		theBufferStep = !theBufferStep;
    1.71 +
    1.72 +		ASSERT(index >= 0);
    1.73 +		step = KStepSizeTable[index];
    1.74 +
    1.75 +		vpdiff = step>>3;
    1.76 +		if ( delta & 4 ) 
    1.77 +			vpdiff += step;
    1.78 +		if ( delta & 2 ) 
    1.79 +			vpdiff += step>>1;
    1.80 +		if ( delta & 1 ) 
    1.81 +			vpdiff += step>>2;
    1.82 +
    1.83 +		if ( delta & 8 )
    1.84 +			valpred -= vpdiff;
    1.85 +		else
    1.86 +			valpred += vpdiff;
    1.87 +
    1.88 +		if ( valpred > (KClamp - 1) )
    1.89 +			valpred = (KClamp - 1);
    1.90 +		else if ( valpred < -KClamp )
    1.91 +			valpred = -KClamp;
    1.92 +
    1.93 +		index += KIndexTable[delta];
    1.94 +		if ( index < 0 ) 
    1.95 +			index = 0;
    1.96 +		if ( index > KMaxImaAdpcmTableEntries ) 
    1.97 +			index = KMaxImaAdpcmTableEntries;
    1.98 +
    1.99 +		*dst++ = STATIC_CAST( TUint8, valpred&KAndMask8bit);
   1.100 +		*dst++ = STATIC_CAST( TUint8, (valpred>>8) );
   1.101 +		}
   1.102 +	}
   1.103 +
   1.104 +
   1.105 +
   1.106 +// IMA-ADPCM step variation table 
   1.107 +const TInt TMMFAudioImaAdpcmToS16PcmCodec::KIndexTable[] =
   1.108 + 	{
   1.109 +    -1, -1, -1, -1, 2, 4, 6, 8,
   1.110 +    -1, -1, -1, -1, 2, 4, 6, 8
   1.111 +	};
   1.112 +
   1.113 +const TInt TMMFAudioImaAdpcmToS16PcmCodec::KStepSizeTable[89] = 
   1.114 +	{
   1.115 +   7, 8, 9, 10, 11, 12, 13, 14, 16, 17,
   1.116 +   19, 21, 23, 25, 28, 31, 34, 37, 41, 45,
   1.117 +   50, 55, 60, 66, 73, 80, 88, 97, 107, 118,
   1.118 +   130, 143, 157, 173, 190, 209, 230, 253, 279, 307,
   1.119 +   337, 371, 408, 449, 494, 544, 598, 658, 724, 796,
   1.120 +   876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066,
   1.121 +   2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358,
   1.122 +   5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
   1.123 +   15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767
   1.124 +	};