devsound/devsoundrefplugin/src/plugin/audio/mmfpcmS16PcmS8HwDevice.cpp
changeset 0 40261b775718
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/devsound/devsoundrefplugin/src/plugin/audio/mmfpcmS16PcmS8HwDevice.cpp	Tue Feb 02 01:56:55 2010 +0200
@@ -0,0 +1,159 @@
+// 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 "mmfpcmS16PcmS8HwDevice.h"
+
+/**
+ *
+ *	Returns the created hw device for passing audio through audio.
+ *  for the wins implementation this would always be pcm16 although
+ *  this is effectively a null hw device that will pass any datatype through
+ *	@return	"CMMFPcm16ToPcmU16BEHwDevice"
+ *
+ */
+CMMFPcmS16ToPcmS8HwDevice* CMMFPcmS16ToPcmS8HwDevice::NewL()
+	{
+    CMMFPcmS16ToPcmS8HwDevice* self = new (ELeave) CMMFPcmS16ToPcmS8HwDevice();
+	CleanupStack::PushL(self);
+	self->ConstructL();
+	CleanupStack::Pop(self);
+	return self;
+	}
+
+/**
+*
+* ~CMMFPcmS16ToPcmS8HwDevice
+*/
+CMMFPcmS16ToPcmS8HwDevice::~CMMFPcmS16ToPcmS8HwDevice()
+	{
+	}
+
+/**
+*
+* ConstructL
+*
+*/
+void CMMFPcmS16ToPcmS8HwDevice::ConstructL()
+	{
+	iCodec = new (ELeave) CMMFPcmS16ToPcmS8Codec();
+	}
+
+/**
+*
+* Codec
+* @return 'CMMFSwCodec&'
+*
+*/
+CMMFSwCodec& CMMFPcmS16ToPcmS8HwDevice::Codec()
+	{
+	return *iCodec;
+	}
+
+/**
+*
+* ProcessL
+* @param aSrc
+* @param aDst
+* @param aSamples
+*
+*/
+CMMFSwCodec::TCodecProcessResult CMMFPcmS16ToPcmS8Codec::ProcessL(const CMMFBuffer& aSrc, CMMFBuffer& aDst)
+	{
+	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);
+	
+	//[Check Preconditions]
+	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());
+	TUint8* pDst = CONST_CAST(TUint8*,dst->Data().Ptr());
+    
+	TInt srcUse = src->Data().Length();
+	TInt noSamples = srcUse/2;
+	
+	//compress TWO bytes (16-bit PCM word) into a to 1 byte sample
+	iAudioPcmS16ToPcmS8.Convert(pSrc, pDst, noSamples );
+	
+	result.iCodecProcessStatus = TCodecProcessResult::EProcessComplete;
+	result.iSrcBytesProcessed  = srcUse;
+	result.iDstBytesAdded      = srcUse/2;
+	
+	dst->Data().SetLength(result.iDstBytesAdded);
+	
+	//[ post conditions
+    // srcbytes/2 == destbytes added
+	// pos src == 0
+	// pos dest == 0 ]
+	__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 CMMFPcmS16ToPcmS8Codec::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 ) ) // must have pcm16 samples on input
+		{
+		return result;
+		}
+	
+	result = ETrue;  // preconditions have been satisfied
+	
+	return result;
+	}
+