/*

* Copyright (c) 1997-2002 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 "MMFAudioS16ToPcmS8Codec.h"

// __________________________________________________________________________

// Implementation

CMMFCodec* CMMFAudioS16PcmS8Codec::NewL(TAny* aInitParams)

	{

	CMMFAudioS16PcmS8Codec* self=new(ELeave) CMMFAudioS16PcmS8Codec();

	CleanupStack::PushL(self);

	self->ConstructL(aInitParams);

	CleanupStack::Pop(self);

	return STATIC_CAST( CMMFCodec*, self );

	}

CMMFAudioS16PcmS8Codec::~CMMFAudioS16PcmS8Codec()

	{

	}

CMMFAudioS16PcmS8Codec::CMMFAudioS16PcmS8Codec()

	{

	}

void CMMFAudioS16PcmS8Codec::ConstructL(TAny* /*aInitParams*/)

	{

	}

//this codec converts 2 bytes into 1

TCodecProcessResult CMMFAudioS16PcmS8Codec::ProcessL(const CMMFBuffer& aSrc, CMMFBuffer& aDst)

	{

	TCodecProcessResult result;

	result.iStatus = TCodecProcessResult::EProcessIncomplete;

	//convert from generic CMMFBuffer to CMMFDataBuffer

	iSrc = STATIC_CAST(const CMMFDataBuffer*, &aSrc);

	iDst = STATIC_CAST(CMMFDataBuffer*, &aDst);

	const TUint dstMaxLen = iDst->Data().MaxLength();

	if (!dstMaxLen)

		User::Leave(KErrArgument);

	//don't scribble Destination (pDst) by only consuming enough source to fill pDst

	TUint srcUse = (dstMaxLen - iDst->Position()) * 2;

	const TUint srcLen = iSrc->Data().Length();

	const TUint sourceRemain = srcLen - iSrc->Position();

	//make sure we don't blow source by checking against remaining

	//and clipping to minimum remaining if necessary

	srcUse = (srcUse<sourceRemain ? srcUse : sourceRemain);

	//we need to cast away CONST even on the source, as the TClass needs a TUint8*

	TUint8* pSrc = CONST_CAST(TUint8*,iSrc->Data().Ptr());

	pSrc += iSrc->Position();

	TUint8* pDst = CONST_CAST(TUint8*,iDst->Data().Ptr());

	pDst += iDst->Position();

	//compress TWO bytes (16-bit PCM word) into a to 1 byte sample

	iAudioS16ToS8Pcm.Convert(pSrc, pDst, srcUse / 2);

	TUint dstBytesAdded = srcUse / 2;

	if (dstBytesAdded + iDst->Position() < dstMaxLen)

		result.iStatus = TCodecProcessResult::EDstNotFilled;

	else if (srcUse + iSrc->Position() >= srcLen)

		result.iStatus = TCodecProcessResult::EProcessComplete;

	result.iSrcBytesProcessed = srcUse;

	result.iDstBytesAdded = dstBytesAdded;

	iDst->Data().SetLength(iDst->Position() + result.iDstBytesAdded);

	return result;

	}