/*

* Copyright (c) 2005 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:    AVC De-Payloadization class

*

*/

// ============================ INCLUDES =======================================

#include"rfc3984decode.h"

// ============================ MEMBER FUNCTIONS ===============================

_LIT8(AVCPSC1, "\x0\x0\x0\x1");

// -----------------------------------------------------------------------------

// CRFC3984Decode::CRFC3984Decode()

// Default Constructor

// (other items were commented in a header).

// -----------------------------------------------------------------------------

//

CRFC3984Decode::CRFC3984Decode()

{

		iNalCount = 0;

		iVirtualDON = 0;

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::~CRFC3984Decode()

// Default Destructor

// (other items were commented in a header).

// -----------------------------------------------------------------------------

//

CRFC3984Decode::~CRFC3984Decode()

{

	// TODO :: cleanup iBuffer in this destructor

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::NewL()

// First stage constructor

// (other items were commented in a header).

// -----------------------------------------------------------------------------

//

CRFC3984Decode * CRFC3984Decode::NewL()

{

	CRFC3984Decode * self = new(ELeave) CRFC3984Decode;

	CleanupStack::PushL( self );

    self->ConstructL( );

    CleanupStack::Pop();

    return self;		

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::ConstructL()

// Initializing common members

// -----------------------------------------------------------------------------

//

void CRFC3984Decode::ConstructL()

{

	iNalCount = 0;

	iVirtualDON = 0;

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::DePayloadizeFrame()

// Purpose     : This function receives the encoded frame and payloadizes it based on the packetization_mode value

// Parameters  : aBuffer - Buffer containing the received NAL unit

//				 aTimeStamp - Timestamp to go into RTP

// 				 aMarkerBit - Marker Bit indication (this function sets it for key frames)

//				 aNalCount - Returns the NAL count through this reference

// Return Value: ETrue if correct parsing done, EFalse if an error occured

// -----------------------------------------------------------------------------

//

TBool CRFC3984Decode::DePayloadizeFrameL(TDes8 & aBuffer, TUint aTimeStamp, TUint aArrivalTime, TUint16 aSeqNo, TUint8 & aMarkerBit, TInt & aNalCount)

{

	TInt index = 0;

	CAvcRtpStruct * pRtpStruct = NULL;

	HBufC8 * pBuffer = NULL;

	TInt16	lowerSeqNo = aSeqNo;

	TUint8 header = aBuffer[index];

	TUint8 type = header & 0x1f;

	if(type <= PACKET_NAL_UNIT){		// SNALU packet -- add as they are

		// storing reference as it is

		pRtpStruct = new (ELeave) CAvcRtpStruct;			// allocating memory to store RTP header information and data pointer

		pRtpStruct->iMarkerBit = aMarkerBit;

		pRtpStruct->iArrivalTime = aArrivalTime;

		pRtpStruct->iTimeStamp = aTimeStamp;

		pRtpStruct->iSeqNo = aSeqNo;

		pRtpStruct->iPacketType = type;

		pRtpStruct->iDon = (iVirtualDON++)%65535; 		// Since 1 NAL/slice, no need for virtual DON and keeping it constant.

		CleanupStack::PushL( pRtpStruct );					// pushing to stack for leave operation	

		//pDes = new (ELeave) TBuf8<aBuffer.Size());    		// allocating memory for data

    	pBuffer = HBufC8::New(aBuffer.Size());

    	if(!pBuffer)

    	{

    		User::Leave(KErrNoMemory);

    	}

    	CleanupStack::Pop();

    	TPtr8 pDes = pBuffer->Des( );					

    	pDes.Copy(aBuffer);									// copying data

    	pRtpStruct->iDes = pBuffer;			

    	pBuffer = NULL;

    	iBuffers.Insert(pRtpStruct, iNalCount);				// storing pointer into the pointer array for retreival later on

    	iNalCount += 1;										// incrementing total NAL count by 1

	}   

	else if(type == PACKET_STAP_A){		// STAP-A packet -- seperate and add using a virtual don number

		TUint accumSize = 0;

		TUint16 nalSize = 0;	

		accumSize += 1; 		// incrementing to point ahead of header

		while(accumSize != aBuffer.Size()){

			nalSize = Read16(aBuffer, accumSize);

			accumSize += 2;

			if(nalSize > 0 && nalSize <= aBuffer.Size()){			// valid size, copy data

				// storing reference as it is

				pRtpStruct = new (ELeave) CAvcRtpStruct;			// allocating memory to store RTP header information and data pointer

				pRtpStruct->iMarkerBit = aMarkerBit;

				pRtpStruct->iArrivalTime = aArrivalTime;

				pRtpStruct->iTimeStamp = aTimeStamp;

				pRtpStruct->iSeqNo = aSeqNo;

				pRtpStruct->iPacketType = type;	

				pRtpStruct->iDon = (iVirtualDON++)%65535;  			// virtual DON, wrapping around at 65K (it spans over many NAL units)

				CleanupStack::PushL( pRtpStruct );					// pushing to stack for leave operation	

			//	pDes = new (ELeave) TBuf8<aBuffer.Size());    		// allocating memory for data

    			//pBuffer = HBufC8::New(aBuffer.Size());

    			pBuffer = HBufC8::New(nalSize);

    			if(!pBuffer)

    			{

    				User::Leave(KErrNoMemory);

    			}

    			CleanupStack::Pop();

    			TPtr8 pDes1 = pBuffer->Des( );

    			TPtr8 pStart = aBuffer.MidTPtr(accumSize); 

    			pDes1.Copy(pStart.Ptr(), nalSize);					// copying data

    			pRtpStruct->iDes = pBuffer;			

    			pBuffer = NULL;

    			iBuffers.Insert(pRtpStruct, iNalCount);				// storing pointer into the pointer array for retreival later on

    			iNalCount += 1;										// incrementing total NAL count by 1

				accumSize += nalSize;

			}

		}

	}

	else if(type == PACKET_FU_A){		// FU-A packet -- add as they are, the jitter buffer removal side will assemble them

		// storing reference as it is, since FU-A and FU-B will be depacketized at removal time from the jitter buffer

		// however, for FU-B extract the DON number

		// reading from FU-header byte the start bit

		index++;	// going to FU-Header Byte start bit, end bit and R bit

		TUint8 startBit = 0;

		const TUint8 * FUHeader = NULL;

		TUint8 FUHeader1 = 0;

		TInt   bufSize = aBuffer.Size();

		startBit = aBuffer[index];

		startBit &= 0x80;   // keeping just the start bit

		startBit = startBit >> 7;

		if(startBit == 1)

		{

			pBuffer = HBufC8::New(aBuffer.Size( )+3);	// excluding FU NAL Header byte and adding size of AVCPSC1

			if(!pBuffer)

    		{

				User::Leave(KErrNoMemory);

    		}

			TPtr8 pDesBuf = pBuffer->Des();

			TPtr8 headerPtr = aBuffer.MidTPtr(index);

			FUHeader = headerPtr.Ptr();

			FUHeader1 = *FUHeader;

			header &= 0xE0;		// making lower bits 0 i.e. type field 

			header |= (*FUHeader & 0x1F);		// now header has the actual NAL unit header values.

			pDesBuf.Append(AVCPSC1);				// appending start code

			pDesBuf.Append(&header, 1);				// appending reconstructed header

			TPtr8 startPtr = aBuffer.MidTPtr(index+1);	// getting pointer to start of NAL unit

			pDesBuf.Append(startPtr.Ptr(), bufSize-2);	// copying NAL data

		}

		else

		{

			pBuffer = HBufC8::New(aBuffer.Size( )-1);	// excluding FU NAL Header byte

			if(!pBuffer)

    		{

				User::Leave(KErrNoMemory);

    		}

    		TPtr8 pDesBuf = pBuffer->Des();

    		TPtr8 startPtr = aBuffer.MidTPtr(index);	// pointing to FUHeader byte

    		FUHeader = startPtr.Ptr();

    		FUHeader1 = *FUHeader;

    		startPtr = aBuffer.MidTPtr(index+1);  // pointing to start of actual data

    		pDesBuf.Append(startPtr.Ptr( ), bufSize-2); // copying FU-Header and data

		}

		pRtpStruct = new (ELeave) CAvcRtpStruct;			// allocating memory to store RTP header information and data pointer

		pRtpStruct->iMarkerBit = aMarkerBit;

		pRtpStruct->iArrivalTime = aArrivalTime;

		pRtpStruct->iTimeStamp = aTimeStamp;

		pRtpStruct->iSeqNo = aSeqNo;

		pRtpStruct->iPacketType = type;

		pRtpStruct->iDon = (iVirtualDON++)%65535;			// keeping virtual DON for FU-A as zero too

		pRtpStruct->iDes = pBuffer;			

    	pRtpStruct->iFUHeader = FUHeader1;				// index currently pointing to FU-Header Byte

    	pBuffer = NULL;

    	iBuffers.Insert(pRtpStruct, iNalCount);				// storing pointer into the pointer array for retreival later on

    	iNalCount += 1;						

	}

	aNalCount = iNalCount;

	return ETrue;

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::Write16()

// Purpose     : This function writes the 16 bit value in network byte order in buffer aDes (appends it to the next location)

// Parameters  : aDes - Buffer to which value has to be written

//				 aValue - Value to be written

// Return Value: 

// -----------------------------------------------------------------------------

//

void CRFC3984Decode::Write16(TDes8 & aDes, TUint16 aValue)

{

	TUint8 firstByte = (aValue & 0xFF00) >> 8;

	TUint8 secondByte = (aValue & 0xFF);

	aDes.Append(&firstByte, 1);

	aDes.Append(&secondByte, 1);	

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::Read16()

// Purpose     : This function reads the 16 bit value in network byte order in buffer aDes (appends it to the next location)

// Parameters  : aDes - Buffer to read from

//				 aIndex - Buffer index where to read from

// Return Value: Returns the 16-bit value

// -----------------------------------------------------------------------------

//

TUint16 CRFC3984Decode::Read16(TDes8 & aDes, TInt aIndex)

{

	TUint16 value;

	value = (aDes[aIndex+1]) + (aDes[aIndex] << 8);

	return value;	

}

// -----------------------------------------------------------------------------

// CRFC3984Decode::GetNalUnit(TInt aIndex)

// Purpose     : This function returns the depayloadized NAL unit with RTP header information

// Parameters  : aIndex - Index of the entry

//				 

// Return Value: Returns a pointer to the CAvcRtpStruct structure.

// -----------------------------------------------------------------------------

//

CAvcRtpStruct * CRFC3984Decode::GetNalUnit(TInt aIndex)

{

	CAvcRtpStruct * ptr;

	if(aIndex >= iNalCount)

		return 0;

	ptr = iBuffers[aIndex];

	return ptr;

}

void CRFC3984Decode::ClearBuffer()

{

	if(iNalCount == 0)

		return;

	TInt count = 0;

	CAvcRtpStruct * ptr = NULL;

	for(count = 0; count < iNalCount; count++){

		ptr = iBuffers[count];

		if(ptr->iDes)	delete ptr->iDes;

		if(ptr)			delete ptr;

		ptr = NULL;

	}

	iBuffers.Reset( );

	iNalCount = 0;

}

// EOF