// 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 "MmfPcm16toAlawhwDevice.h"

/**
*
* NewL
*
*/
CMMFPcm16ToAlawHwDevice* CMMFPcm16ToAlawHwDevice::NewL()
	{
	CMMFPcm16ToAlawHwDevice* self=new(ELeave) CMMFPcm16ToAlawHwDevice();
	CleanupStack::PushL(self);
	self->ConstructL();
	CleanupStack::Pop(self);
	return self;
	}

/**
*
* ~CMMFPcm16ToAlawHwDevice
*
*/
CMMFPcm16ToAlawHwDevice::~CMMFPcm16ToAlawHwDevice()
	{
	}

/**
*
* ConstructL
*
*/
void CMMFPcm16ToAlawHwDevice::ConstructL()
	{
	iCodec = new (ELeave) CMMFPcm16ToALawCodec();
	}


/**
*
* Codec
*
*/
CMMFSwCodec &CMMFPcm16ToAlawHwDevice::Codec()
	{
	return *iCodec;
	}

/**
*
* ProcessL
* @param aSrc
* @param aDst
* @pre position of buffer aSrc is 0
* @pre position of buffer aDst is 0
* @pre sufficient bytes in output to consume input
* @return TCodecProcessResult
*
*/
CMMFSwCodec::TCodecProcessResult CMMFPcm16ToALawCodec::ProcessL(const CMMFBuffer& aSrc, CMMFBuffer& aDst)
	{
	CMMFSwCodec::TCodecProcessResult result;
	result.iCodecProcessStatus = TCodecProcessResult::EProcessComplete;
	
	//convert from generic CMMFBuffer to CMMFDataBuffer
	const CMMFDataBuffer* src = STATIC_CAST(const CMMFDataBuffer*, &aSrc);
	CMMFDataBuffer* dst = STATIC_CAST(CMMFDataBuffer*, &aDst);
	
    if( !CheckPreconditions( src, dst ))
		{
		//[ precondition violation ]
		User::Leave( KErrArgument );
		}
	
	//we need to cast away CONST even on the source, as the TClass needs a TUint8*
	TUint8* pSrc = CONST_CAST(TUint8*,src->Data().Ptr());
	pSrc += src->Position();
	TUint8* pDst = CONST_CAST(TUint8*,dst->Data().Ptr());
	pDst += dst->Position();
	
	TUint destUse = src->Data().Length()/2;
	
	//compress TWO bytes (16-bit PCM word) into a to 1 byte sample
	iPcm16ToALaw.Convert(pSrc, pDst, destUse );
	
	result.iCodecProcessStatus = TCodecProcessResult::EProcessComplete;
	result.iSrcBytesProcessed  = src->Data().Length();
	result.iDstBytesAdded      = destUse;
	
	dst->Data().SetLength(result.iDstBytesAdded);
	
	//[ post condition evaluation here ]
	__ASSERT_DEBUG( (src->Position() == 0), TMmfAudioCodecPanicsNameSpace::Panic( 	TMmfAudioCodecPanicsNameSpace::EPostConditionViolation ));
	__ASSERT_DEBUG( (dst->Position() == 0), TMmfAudioCodecPanicsNameSpace::Panic( 	TMmfAudioCodecPanicsNameSpace::EPostConditionViolation ));
	__ASSERT_DEBUG( src->Data().Length()/2 == dst->Data().Length(), TMmfAudioCodecPanicsNameSpace::Panic( 	TMmfAudioCodecPanicsNameSpace::EPostConditionViolation ));
		
	return result;
	}

/**
*
* Preconditions
* This methos tests the preconditions of the ProcessL method
* @return TBool ETrue for sucess and EFalse for failure of the preconditions
*
**/
TBool CMMFPcm16ToALawCodec::CheckPreconditions( const CMMFDataBuffer* aSrcBuffer, CMMFDataBuffer* aDestBuffer )
	{
	TBool result = EFalse;
	
	if(! aSrcBuffer )
		{
		return result;
		}
	
	if( ! aDestBuffer )
		{
		return result;
		}
	
	// Check position of src and dest are 0
	if( aSrcBuffer->Position() )
		{
		return result;
		}
	
	// Check position of src and dest are 0
	if( aDestBuffer->Position() )
		{
		return result;
		}
	
	// check there are sufficient bytes in the output to consume the input
	if( ( aSrcBuffer->Data().Length()/2 > aDestBuffer->Data().MaxLength()) ||
		( aSrcBuffer->Data().Length() % 2 != 0 ))
		{
		return result;
		}
	
	result = ETrue;  // preconditions have been satisfied
	
	return result;
	}