e32tools/elf2e32/source/huffman.cpp
author Alex Gilkes <alex.gilkes@nokia.com>
Tue, 27 Oct 2009 16:36:35 +0000
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// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
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// All rights reserved.
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// This component and the accompanying materials are made available
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// under the terms of "Eclipse Public License v1.0"
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// which accompanies this distribution, and is available
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// at the URL "http://www.eclipse.org/legal/epl-v10.html".
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//
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// Initial Contributors:
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// Nokia Corporation - initial contribution.
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//
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// Contributors:
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//
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// Description:
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// Implementation of the Huffman technique for the elf2e32 tool
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// @internalComponent
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// @released
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// 
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//
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#ifdef _MSC_VER
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	#pragma warning(disable: 4710) // function not inlined
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#endif
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#include <cassert>
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#include "huffman.h"
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#include "errorhandler.h"
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#include "farray.h"
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/**
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Function for overflow
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@internalComponent
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@released
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*/
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void TBitOutput::OverflowL()
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{
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}
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/**
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Construct a bit stream output object
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Following construction the bit stream is ready for writing bits, but will first call
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OverflowL() as the output buffer is 'full'. A derived class can detect this state as
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Ptr() will return null.
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*/
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TBitOutput::TBitOutput():iCode(0),iBits(-8),iPtr(0),iEnd(0)
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{
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}
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/**
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Construct a bit stream output object over a buffer
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Data will be written to the buffer until it is full, at which point OverflowL() will
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be called. This should handle the data and then can Set() again to reset the buffer
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for further output.
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@param "TUint8* aBuf" The buffer for output
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@param "TInt aSize" The size of the buffer in bytes
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*/
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TBitOutput::TBitOutput(TUint8* aBuf,TInt aSize):iCode(0),iBits(-8),iPtr(aBuf),iEnd(aBuf+aSize)
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{
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}
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/**
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Write a huffman code
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This expects a huffman code value as generated by Huffman::Encoding()
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@param "TUint aHuffCode" The huffman code write to the stream
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@leave "OverflowL()" If the output buffer is full, OverflowL() is called
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*/
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void TBitOutput::HuffmanL(TUint aHuffCode)
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{
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	DoWriteL(aHuffCode<<(32-Huffman::KMaxCodeLength),aHuffCode>>Huffman::KMaxCodeLength);
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}
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/**
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Write an arbitrary integer value
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Write an unsigned integer using the number of bits specified. Only the low order bits of the
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value are written to the output, most significant bit first.
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@param "TUint aValue" The value to write to the stream
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@param "TUint aLength" The number of bits to output
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@leave "OverflowL()" If the output buffer is full, OverflowL() is called
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*/
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void TBitOutput::WriteL(TUint aValue,TInt aLength)
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{
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	if (aLength)
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		DoWriteL(aValue<<=32-aLength,aLength);
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}
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/**
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Pad the bitstream to the next byte boundary
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Terminate the bitstream by padding the last byte with the requested value.
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Following this operation the bitstream can continue to be used, the data will start at the
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next byte.
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@param "TUint aPadding" The bit value to pad the final byte with
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@leave "OverflowL()" If the output buffer is full, OverflowL() is called
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*/
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void TBitOutput::PadL(TUint aPadding)
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{
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	if (iBits>-8)
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		WriteL(aPadding?0xffffffffu:0,-iBits);
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}
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/**
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Write the higher order bits to the stream
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@internalComponent
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@released
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*/
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void TBitOutput::DoWriteL(TUint aBits,TInt aSize)
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{
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	if (aSize>25)
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	{
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		// cannot process >25 bits in a single pass so do the top 8 bits first
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		assert(aSize<=32);
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		DoWriteL(aBits&0xff000000u,8);
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		aBits<<=8;
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		aSize-=8;
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	}
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	TInt bits=iBits;
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	TUint code=iCode|(aBits>>(bits+8));
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	bits+=aSize;
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	if (bits>=0)
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	{
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		TUint8* p=iPtr;
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		do
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		{
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			if (p==iEnd)
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			{
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				// run out of buffer space so invoke the overflow handler
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				iPtr=p;
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				OverflowL();
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				p=iPtr;
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				assert(p!=iEnd);
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			}
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			*p++=TUint8(code>>24);
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			code<<=8;
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			bits-=8;
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		} while (bits>=0);
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		iPtr=p;
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	}
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	iCode=code;
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	iBits=bits;
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}
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/**
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Constructor for class TFileOutput
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@internalComponent
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@released
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*/
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TFileOutput::TFileOutput(std::ofstream & os):iOutStream(os)
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{
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	Set(iBuf,KBufSize);
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}
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/**
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Function to empty the buffer and reset the pointers
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@internalComponent
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@released
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*/
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void TFileOutput::OverflowL()
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{
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	FlushL();
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	Set(iBuf,KBufSize);
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}
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/**
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Function to write out the contents of the buffer
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@internalComponent
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@released
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*/
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void TFileOutput::FlushL()
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{
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	TInt len=Ptr()-iBuf;
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	if (len)
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	{
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		iOutStream.write(reinterpret_cast<char *>(iBuf), len); // write extended header
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		iDataCount += len;
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	}
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}
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/**
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Recursive function to calculate the code lengths from the node tree
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@internalComponent
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@released
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*/
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void HuffmanLengthsL(TUint32* aLengths,const TNode* aNodes,TInt aNode,TInt aLen)
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{
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	if (++aLen>Huffman::KMaxCodeLength)
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		throw E32ImageCompressionError(HUFFMANBUFFEROVERFLOWERROR);
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	const TNode& node=aNodes[aNode];
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	TUint x=node.iLeft;
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	if (x&KLeaf)
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		aLengths[x&~KLeaf]=aLen;
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	else
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		HuffmanLengthsL(aLengths,aNodes,x,aLen);
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	x=node.iRight;
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	if (x&KLeaf)
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		aLengths[x&~KLeaf]=aLen;
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	else
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		HuffmanLengthsL(aLengths,aNodes,x,aLen);
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}
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/**
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Function to Insert the {aCount,aValue} pair into the already sorted array of nodes
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@internalComponent
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@released
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*/
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void InsertInOrder(TNode* aNodes, TInt aSize, TUint aCount, TInt aVal)
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{
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	// Uses Insertion sort following a binary search...
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	TInt l=0, r=aSize;
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	while (l < r)
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	{
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		TInt m = (l+r) >> 1;
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		if (aNodes[m].iCount<aCount)
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			r=m;
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		else
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			l=m+1;
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	}
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	memmove(aNodes+l+1,aNodes+l,sizeof(TNode)*(aSize-l));
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	aNodes[l].iCount=aCount;
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	aNodes[l].iRight=TUint16(aVal);
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}
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/**
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Generate a Huffman code.
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This generates a Huffman code for a given set of code frequencies. The output is a table of
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code lengths which can be used to build canonincal encoding tables or decoding trees for use
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with the TBitInput and TBitOutput classes.
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Entries in the table with a frequency of zero will have a zero code length and thus no
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associated huffman encoding. If each such symbol should have a maximum length encoding, they
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must be given at least a frequency of 1.
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For an alphabet of n symbols, this algorithm has a transient memory overhead of 8n, and a
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time complexity of O(n*log(n)).
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@param "const TUint32 aFrequency[]" The table of code frequencies
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@param "TInt aNumCodes" The number of codes in the table
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@param "TUint32 aHuffman[]" The table for the output code-length table. This must be the same
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size as the frequency table, and can safely be the same table
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@leave "KErrNoMemory" If memory used for code generation cannot be allocated
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@panic "USER ???" If the number of codes exceeds Huffman::KMaxCodes
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*/
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void Huffman::HuffmanL(const TUint32 aFrequency[],TInt aNumCodes,TUint32 aHuffman[])
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{
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	if(TUint(aNumCodes)>TUint(KMaxCodes))
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		throw E32ImageCompressionError(HUFFMANTOOMANYCODESERROR);
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	// Sort the values into decreasing order of frequency
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	TNode* nodes = new TNode[aNumCodes];
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	TInt lCount=0;
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	for (TInt ii=0;ii<aNumCodes;++ii)
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	{
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		TInt c=aFrequency[ii];
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		if (c!=0)
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			InsertInOrder(nodes,lCount++,c,ii|KLeaf);
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	}
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	// default code length is zero
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	memset(aHuffman,0,aNumCodes*sizeof(TUint32));
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	if (lCount==0)
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	{
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		// no codes with frequency>0. No code has a length
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	}
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	else if (lCount==1)
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	{
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		// special case for a single value (always encode as "0")
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		aHuffman[nodes[0].iRight&~KLeaf]=1;
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	}
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	else
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	{
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		// Huffman algorithm: pair off least frequent nodes and reorder
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		do
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		{
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			--lCount;
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			TUint c=nodes[lCount].iCount + nodes[lCount-1].iCount;
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			nodes[lCount].iLeft=nodes[lCount-1].iRight;
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			// re-order the leaves now to reflect new combined frequency 'c'
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			InsertInOrder(nodes,lCount-1,c,lCount);
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		} while (lCount>1);
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		// generate code lengths in aHuffman[]
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		HuffmanLengthsL(aHuffman,nodes,1,0);
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	}
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	delete [] nodes;
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	if(!IsValid(aHuffman,aNumCodes))
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		throw E32ImageCompressionError(HUFFMANINVALIDCODINGERROR);
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}
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/**
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Validate a Huffman encoding
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This verifies that a Huffman coding described by the code lengths is valid. In particular,
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it ensures that no code exceeds the maximum length and that it is possible to generate a
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canonical coding for the specified lengths.
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@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
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@param "TInt aNumCodes" The number of codes in the table
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@return True if the code is valid, otherwise false
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*/
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TBool Huffman::IsValid(const TUint32 aHuffman[],TInt aNumCodes)
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{
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	// The code is valid if one of the following holds:
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	// (a) the code exactly fills the 'code space'
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	// (b) there is only a single symbol with code length 1
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	// (c) there are no encoded symbols
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	//
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	TUint remain=1<<KMaxCodeLength;
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	TInt totlen=0;
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	for (const TUint32* p=aHuffman+aNumCodes; p>aHuffman;)
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	{
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		TInt len=*--p;
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		if (len>0)
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		{
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			totlen+=len;
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			if (len>KMaxCodeLength)
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				return 0;
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			TUint c=1<<(KMaxCodeLength-len);
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			if (c>remain)
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				return 0;
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			remain-=c;
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   338
		}
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	}
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   340
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	return remain==0 || totlen<=1;
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}
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/**
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Create a canonical Huffman encoding table
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   346
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This generates the huffman codes used by TBitOutput::HuffmanL() to write huffman encoded data.
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   348
The input is table of code lengths, as generated by Huffman::HuffmanL() and must represent a
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   349
valid huffman code.
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   350
	
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   351
@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
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@param "TInt aNumCodes" The number of codes in the table
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@param "TUint32 aEncodeTable[]" The table for the output huffman codes. This must be the same
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   354
size as the code-length table, and can safely be the same table.
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   355
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   356
@panic "USER ???" If the provided code is not a valid Huffman coding
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   357
	
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   358
@see IsValid()
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   359
@see HuffmanL()
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   360
*/
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   361
void Huffman::Encoding(const TUint32 aHuffman[],TInt aNumCodes,TUint32 aEncodeTable[])
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   362
{
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	if (!IsValid(aHuffman,aNumCodes)) 
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   364
		throw E32ImageCompressionError(HUFFMANINVALIDCODINGERROR);
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   365
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	TFixedArray<TInt,KMaxCodeLength> lenCount;
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   367
	lenCount.Reset();
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   368
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   369
	TInt ii;
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   370
	for (ii=0;ii<aNumCodes;++ii)
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   371
	{
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   372
		TInt len=aHuffman[ii]-1;
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   373
		if (len>=0)
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   374
			++lenCount[len];
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   375
	}
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   376
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   377
	TFixedArray<TUint,KMaxCodeLength> nextCode;
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   378
	TUint code=0;
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   379
	for (ii=0;ii<KMaxCodeLength;++ii)
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diff changeset
   380
	{
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   381
		code<<=1;
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   382
		nextCode[ii]=code;
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diff changeset
   383
		code+=lenCount[ii];
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diff changeset
   384
	}
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   385
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diff changeset
   386
	for (ii=0;ii<aNumCodes;++ii)
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diff changeset
   387
	{
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   388
		TInt len=aHuffman[ii];
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diff changeset
   389
		if (len==0)
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diff changeset
   390
			aEncodeTable[ii]=0;
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diff changeset
   391
		else
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diff changeset
   392
		{
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   393
			aEncodeTable[ii] = (nextCode[len-1]<<(KMaxCodeLength-len))|(len<<KMaxCodeLength);
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diff changeset
   394
			++nextCode[len-1];
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diff changeset
   395
		}
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diff changeset
   396
	}
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diff changeset
   397
}
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diff changeset
   398
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diff changeset
   399
/**
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diff changeset
   400
The encoding table for the externalised code
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diff changeset
   401
@internalComponent
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diff changeset
   402
@released
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diff changeset
   403
*/
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diff changeset
   404
const TUint32 HuffmanEncoding[]=
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diff changeset
   405
{
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diff changeset
   406
	0x10000000,
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parents:
diff changeset
   407
	0x1c000000,
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parents:
diff changeset
   408
	0x12000000,
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parents:
diff changeset
   409
	0x1d000000,
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parents:
diff changeset
   410
	0x26000000,
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parents:
diff changeset
   411
	0x26800000,
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parents:
diff changeset
   412
	0x2f000000,
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parents:
diff changeset
   413
	0x37400000,
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parents:
diff changeset
   414
	0x37600000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   415
	0x37800000,
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parents:
diff changeset
   416
	0x3fa00000,
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parents:
diff changeset
   417
	0x3fb00000,
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parents:
diff changeset
   418
	0x3fc00000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   419
	0x3fd00000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   420
	0x47e00000,
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parents:
diff changeset
   421
	0x47e80000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   422
	0x47f00000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   423
	0x4ff80000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   424
	0x57fc0000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   425
	0x5ffe0000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   426
	0x67ff0000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   427
	0x77ff8000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   428
	0x7fffa000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   429
	0x7fffb000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   430
	0x7fffc000,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   431
	0x7fffd000,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   432
	0x7fffe000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   433
	0x87fff000,
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   434
	0x87fff800
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   435
};
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   436
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   437
/**
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   438
Function to encode 0a as '0' and 0b as '1', return number of symbols created
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   439
@internalComponent
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   440
@released
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   441
*/
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   442
void EncodeRunLengthL(TBitOutput& aOutput, TInt aLength)
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   443
{
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   444
	if (aLength>0)
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   445
	{
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   446
		EncodeRunLengthL(aOutput,(aLength-1)>>1);
044383f39525 Convert Build package from SFL to EPL
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parents:
diff changeset
   447
		aOutput.HuffmanL(HuffmanEncoding[1-(aLength&1)]);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   448
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   449
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   450
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   451
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   452
Store a canonical huffman encoding in compact form
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   453
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   454
As the encoding is canonical, only the code lengths of each code needs to be saved.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   455
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   456
Due to the nature of code length tables, these can usually be stored very compactly by
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   457
encoding the encoding itself, hence the use of the bit output stream.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   458
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   459
@param "TBitOutput& aOutput" The output stream for the encoding
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   460
@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   461
@param "TInt aNumCodes" The number of huffman codes in the table
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   462
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   463
@leave "TBitOutput::HuffmanL()"
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   464
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   465
void Huffman::ExternalizeL(TBitOutput& aOutput,const TUint32 aHuffman[],TInt aNumCodes)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   466
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   467
	// We assume that the code length table is generated by the huffman generator,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   468
	// in which case the maxmimum code length is 27 bits.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   469
	//
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   470
	// We apply three transformations to the data:
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   471
	// 1. the data goes through a move-to-front coder
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   472
	// 2. apply a rle-0 coder which replace runs of '0' with streams of '0a' and '0b'
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   473
	// 3. encode the result using a predefined (average) huffman coding
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   474
	//
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   475
	// This can be done in a single pass over the data, avoiding the need for additional
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   476
	// memory.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   477
	//
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   478
	// initialise the list for the MTF coder
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   479
	TFixedArray<TUint8,Huffman::KMetaCodes> list;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   480
	TInt i;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   481
	for (i=0;i<list.Count();++i)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   482
		list[i]=TUint8(i);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   483
	TInt last=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   484
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   485
	TInt rl=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   486
	const TUint32* p32=aHuffman;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   487
	const TUint32* e32=p32+aNumCodes;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   488
	while (p32<e32)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   489
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   490
		TInt c=*p32++;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   491
		if (c==last)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   492
			++rl;	// repeat of last symbol
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   493
		else
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   494
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   495
			// encode run-length
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   496
			EncodeRunLengthL(aOutput,rl);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   497
			rl=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   498
			// find code in MTF list
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   499
			TInt j;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   500
			for (j=1;list[j]!=c;++j)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   501
				;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   502
			// store this code
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   503
			aOutput.HuffmanL(HuffmanEncoding[j+1]);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   504
			// adjust list for MTF algorithm
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   505
			while (--j>0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   506
				list[j+1]=list[j];
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   507
			list[1]=TUint8(last);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   508
			last=c;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   509
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   510
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   511
	// encod any remaining run-length
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   512
	EncodeRunLengthL(aOutput,rl);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   513
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   514
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   515
const TInt KHuffTerminate=0x0001;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   516
const TUint32 KBranch1=sizeof(TUint32)<<16;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   517
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   518
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   519
Function to write the subtree below aPtr and return the head
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   520
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   521
TUint32* HuffmanSubTree(TUint32* aPtr,const TUint32* aValue,TUint32** aLevel)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   522
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   523
	TUint32* l=*aLevel++;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   524
	if (l>aValue)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   525
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   526
		TUint32* sub0=HuffmanSubTree(aPtr,aValue,aLevel);		// 0-tree first
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   527
		aPtr=HuffmanSubTree(sub0,aValue-(aPtr-sub0)-1,aLevel);	// 1-tree
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   528
		TInt branch0=(TUint8*)sub0-(TUint8*)(aPtr-1);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   529
		*--aPtr=KBranch1|branch0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   530
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   531
	else if (l==aValue)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   532
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   533
		TUint term0=*aValue--;						// 0-term
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   534
		aPtr=HuffmanSubTree(aPtr,aValue,aLevel);	// 1-tree
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   535
		*--aPtr=KBranch1|(term0>>16);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   536
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   537
	else	// l<iNext
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   538
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   539
		TUint term0=*aValue--;						// 0-term
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   540
		TUint term1=*aValue--;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   541
		*--aPtr=(term1>>16<<16)|(term0>>16);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   542
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   543
	return aPtr;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   544
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   545
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   546
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   547
Create a canonical Huffman decoding tree
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   548
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   549
This generates the huffman decoding tree used by TBitInput::HuffmanL() to read huffman
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   550
encoded data. The input is table of code lengths, as generated by Huffman::HuffmanL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   551
and must represent a valid huffman code.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   552
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   553
@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   554
@param "TInt aNumCodes" The number of codes in the table
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   555
@param "TUint32 aDecodeTree[]" The space for the decoding tree. This must be the same
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   556
size as the code-length table, and can safely be the same memory
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   557
@param "TInt aSymbolBase" the base value for the output 'symbols' from the decoding tree, by default
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   558
this is zero.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   559
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   560
@panic "USER ???" If the provided code is not a valid Huffman coding
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   561
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   562
@see IsValid()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   563
@see HuffmanL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   564
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   565
void Huffman::Decoding(const TUint32 aHuffman[],TInt aNumCodes,TUint32 aDecodeTree[],TInt aSymbolBase)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   566
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   567
	if(!IsValid(aHuffman,aNumCodes))
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   568
		throw E32ImageCompressionError(HUFFMANINVALIDCODINGERROR);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   569
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   570
	TFixedArray<TInt,KMaxCodeLength> counts;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   571
	counts.Reset();
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   572
	TInt codes=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   573
	TInt ii;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   574
	for (ii=0;ii<aNumCodes;++ii)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   575
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   576
		TInt len=aHuffman[ii];
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   577
		aDecodeTree[ii]=len;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   578
		if (--len>=0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   579
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   580
			++counts[len];
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   581
			++codes;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   582
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   583
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   584
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   585
	TFixedArray<TUint32*,KMaxCodeLength> level;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   586
	TUint32* lit=aDecodeTree+codes;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   587
	for (ii=0;ii<KMaxCodeLength;++ii)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   588
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   589
		level[ii]=lit;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   590
		lit-=counts[ii];
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   591
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   592
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   593
	aSymbolBase=(aSymbolBase<<17)+(KHuffTerminate<<16);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   594
	for (ii=0;ii<aNumCodes;++ii)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   595
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   596
		TUint len=TUint8(aDecodeTree[ii]);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   597
		if (len)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   598
			*--level[len-1]|=(ii<<17)+aSymbolBase;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   599
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   600
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   601
	if (codes==1)	// codes==1 special case: tree isn't complete
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   602
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   603
		TUint term=aDecodeTree[0]>>16;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   604
		aDecodeTree[0]=term|(term<<16); // 0- and 1-terminate at root
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   605
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   606
	else if (codes>1)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   607
		HuffmanSubTree(aDecodeTree+codes-1,aDecodeTree+codes-1,&level[0]);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   608
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   609
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   610
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   611
The decoding tree for the externalised code
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   612
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   613
const TUint32 HuffmanDecoding[]=
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   614
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   615
	0x0004006c,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   616
	0x00040064,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   617
	0x0004005c,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   618
	0x00040050,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   619
	0x00040044,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   620
	0x0004003c,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   621
	0x00040034,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   622
	0x00040021,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   623
	0x00040023,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   624
	0x00040025,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   625
	0x00040027,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   626
	0x00040029,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   627
	0x00040014,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   628
	0x0004000c,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   629
	0x00040035,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   630
	0x00390037,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   631
	0x00330031,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   632
	0x0004002b,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   633
	0x002f002d,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   634
	0x001f001d,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   635
	0x001b0019,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   636
	0x00040013,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   637
	0x00170015,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   638
	0x0004000d,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   639
	0x0011000f,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   640
	0x000b0009,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   641
	0x00070003,
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   642
	0x00050001
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   643
};
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   644
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   645
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   646
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   647
Restore a canonical huffman encoding from a bit stream
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   648
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   649
The encoding must have been stored using Huffman::ExternalizeL(). The resulting
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   650
code-length table can be used to create an encoding table using Huffman::Encoding()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   651
or a decoding tree using Huffman::Decoding().
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   652
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   653
@param "TBitInput& aInput" The input stream with the encoding
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   654
@param "TUint32 aHuffman[]" The internalized code-length table is placed here
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   655
@param "TInt aNumCodes" The number of huffman codes in the table
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   656
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   657
@leave "TBitInput::HuffmanL()"
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   658
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   659
@see ExternalizeL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   660
See ExternalizeL for a description of the format
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   661
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   662
void Huffman::InternalizeL(TBitInput& aInput,TUint32 aHuffman[],TInt aNumCodes)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   663
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   664
	// initialise move-to-front list
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   665
	TFixedArray<TUint8,Huffman::KMetaCodes> list;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   666
	for (TInt i=0;i<list.Count();++i)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   667
		list[i]=TUint8(i);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   668
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   669
	TInt last=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   670
	// extract codes, reverse rle-0 and mtf encoding in one pass
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   671
	TUint32* p=aHuffman;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   672
	const TUint32* end=aHuffman+aNumCodes;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   673
	TInt rl=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   674
	while (p+rl<end)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   675
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   676
		TInt c=aInput.HuffmanL(HuffmanDecoding);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   677
		if (c<2)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   678
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   679
			// one of the zero codes used by RLE-0
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   680
			// update he run-length
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   681
			rl+=rl+c+1;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   682
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   683
		else
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   684
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   685
			while (rl>0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   686
			{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   687
				if (p>end)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   688
				{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   689
					throw E32ImageCompressionError(HUFFMANINVALIDCODINGERROR);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   690
				}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   691
				*p++=last;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   692
				--rl;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   693
			}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   694
			--c;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   695
			list[0]=TUint8(last);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   696
			last=list[c];
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   697
			
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   698
			memmove((void * const)&list[1],(const void * const)&list[0],(size_t)c);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   699
			if (p>end)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   700
			{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   701
				throw E32ImageCompressionError(HUFFMANINVALIDCODINGERROR);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   702
			}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   703
			*p++=last;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   704
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   705
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   706
	while (rl>0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   707
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   708
		if (p>end)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   709
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   710
			throw E32ImageCompressionError(HUFFMANINVALIDCODINGERROR);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   711
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   712
		*p++=last;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   713
		--rl;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   714
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   715
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   716
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   717
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   718
bit-stream input class
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   719
Reverse the byte-order of a 32 bit value
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   720
This generates optimal ARM code (4 instructions)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   721
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   722
inline TUint reverse(TUint aVal)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   723
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   724
	TUint v=(aVal<<16)|(aVal>>16);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   725
	v^=aVal;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   726
	v&=0xff00ffff;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   727
	aVal=(aVal>>8)|(aVal<<24);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   728
	return aVal^(v>>8);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   729
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   730
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   731
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   732
Construct a bit stream input object
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   733
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   734
Following construction the bit stream is ready for reading bits, but will
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   735
immediately call UnderflowL() as the input buffer is empty.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   736
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   737
TBitInput::TBitInput():iCount(0),iRemain(0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   738
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   739
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   740
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   741
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   742
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   743
Construct a bit stream input object over a buffer
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   744
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   745
Following construction the bit stream is ready for reading bits from the specified buffer.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   746
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   747
@param "const TUint8* aPtr" The address of the buffer containing the bit stream
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   748
@param "TInt aLength" The length of the bitstream in bits
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   749
@param "TInt aOffset" The bit offset from the start of the buffer to the bit stream (defaults to zero)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   750
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   751
TBitInput::TBitInput(const TUint8* aPtr, TInt aLength, TInt aOffset)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   752
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   753
	Set(aPtr,aLength,aOffset);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   754
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   755
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   756
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   757
Set the memory buffer to use for input.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   758
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   759
Bits will be read from this buffer until it is empty, at which point UnderflowL() will be called.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   760
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   761
@param "const TUint8* aPtr" The address of the buffer containing the bit stream
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   762
@param "TInt aLength" The length of the bitstream in bits
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   763
@param "TInt aOffset" The bit offset from the start of the buffer to the bit stream (defaults to zero)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   764
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   765
void TBitInput::Set(const TUint8* aPtr, TInt aLength, TInt aOffset)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   766
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   767
	TUint p=(TUint)aPtr;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   768
	p+=aOffset>>3;			// nearest byte to the specified bit offset
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   769
	aOffset&=7;				// bit offset within the byte
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   770
	const TUint32* ptr=(const TUint32*)(p&~3);	// word containing this byte
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   771
	aOffset+=(p&3)<<3;		// bit offset within the word
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   772
	if (aLength==0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   773
		iCount=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   774
	else
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   775
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   776
		// read the first few bits of the stream
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   777
		iBits=reverse(*ptr++)<<aOffset;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   778
		aOffset=32-aOffset;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   779
		aLength-=aOffset;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   780
		if (aLength<0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   781
			aOffset+=aLength;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   782
		iCount=aOffset;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   783
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   784
	iRemain=aLength;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   785
	iPtr=ptr;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   786
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   787
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   788
#ifndef __HUFFMAN_MACHINE_CODED__
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   789
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   790
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   791
Read a single bit from the input
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   792
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   793
Return the next bit in the input stream. This will call UnderflowL() if there are no more
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   794
bits available.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   795
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   796
@return The next bit in the stream
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   797
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   798
@leave "UnderflowL()" It the bit stream is exhausted more UnderflowL is called to get more
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   799
data
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   800
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   801
TUint TBitInput::ReadL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   802
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   803
	TInt c=iCount;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   804
	TUint bits=iBits;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   805
	if (--c<0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   806
		return ReadL(1);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   807
	iCount=c;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   808
	iBits=bits<<1;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   809
	return bits>>31;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   810
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   811
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   812
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   813
Read a multi-bit value from the input
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   814
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   815
Return the next few bits as an unsigned integer. The last bit read is the least significant
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   816
bit of the returned value, and the value is zero extended to return a 32-bit result.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   817
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   818
A read of zero bits will always reaturn zero.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   819
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   820
This will call UnderflowL() if there are not enough bits available.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   821
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   822
@param "TInt aSize" The number of bits to read
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   823
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   824
@return The bits read from the stream
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   825
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   826
@leave "UnderflowL()" It the bit stream is exhausted more UnderflowL is called to get more
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   827
data
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   828
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   829
TUint TBitInput::ReadL(TInt aSize)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   830
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   831
	if (!aSize)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   832
		return 0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   833
	TUint val=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   834
	TUint bits=iBits;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   835
	iCount-=aSize;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   836
	while (iCount<0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   837
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   838
		// need more bits
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   839
#ifdef __CPU_X86
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   840
		// X86 does not allow shift-by-32
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   841
		if (iCount+aSize!=0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   842
			val|=bits>>(32-(iCount+aSize))<<(-iCount);	// scrub low order bits
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   843
#else
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   844
		val|=bits>>(32-(iCount+aSize))<<(-iCount);	// scrub low order bits
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   845
#endif
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   846
		aSize=-iCount;	// bits still required
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   847
		if (iRemain>0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   848
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   849
			bits=reverse(*iPtr++);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   850
			iCount+=32;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   851
			iRemain-=32;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   852
			if (iRemain<0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   853
				iCount+=iRemain;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   854
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   855
		else
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   856
		{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   857
			UnderflowL();
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   858
			bits=iBits;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   859
			iCount-=aSize;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   860
		}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   861
	}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   862
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   863
#ifdef __CPU_X86
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   864
	// X86 does not allow shift-by-32
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   865
	iBits=aSize==32?0:bits<<aSize;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   866
#else
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   867
	iBits=bits<<aSize;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   868
#endif
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   869
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   870
	return val|(bits>>(32-aSize));
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   871
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   872
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   873
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   874
Read and decode a Huffman Code
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   875
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   876
Interpret the next bits in the input as a Huffman code in the specified decoding.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   877
The decoding tree should be the output from Huffman::Decoding().
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   878
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   879
@param "const TUint32* aTree" The huffman decoding tree
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   880
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   881
@return The symbol that was decoded
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   882
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   883
@leave "UnderflowL()" It the bit stream is exhausted more UnderflowL is called to get more
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   884
data
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   885
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   886
TUint TBitInput::HuffmanL(const TUint32* aTree)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   887
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   888
	TUint huff=0;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   889
	do
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   890
	{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   891
		aTree=(const TUint32*)(((TUint8*)aTree)+(huff>>16));
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   892
		huff=*aTree;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   893
		if (ReadL()==0)
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   894
			huff<<=16;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   895
	} while ((huff&0x10000u)==0);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   896
	
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   897
	return huff>>17;
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   898
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   899
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   900
#endif
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   901
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   902
/**
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   903
Handle an empty input buffer
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   904
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   905
This virtual function is called when the input buffer is empty and more bits are required.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   906
It should reset the input buffer with more data using Set().
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   907
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   908
A derived class can replace this to read the data from a file (for example) before reseting
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   909
the input buffer.
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   910
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   911
@leave "KErrUnderflow" The default implementation leaves
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   912
*/
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   913
void TBitInput::UnderflowL()
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   914
{
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   915
	throw E32ImageCompressionError(HUFFMANBUFFEROVERFLOWERROR);
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   916
}
044383f39525 Convert Build package from SFL to EPL
Alex Gilkes <alex.gilkes@nokia.com>
parents:
diff changeset
   917