--- a/e32tools/e32lib/e32image/deflate/encode.cpp	Thu Nov 04 09:25:46 2010 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,491 +0,0 @@
-// Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
-// All rights reserved.
-// This component and the accompanying materials are made available
-// under the terms of "Eclipse Public License v1.0"
-// which accompanies this distribution, and is available
-// at the URL "http://www.eclipse.org/legal/epl-v10.html".
-//
-// Initial Contributors:
-// Nokia Corporation - initial contribution.
-//
-// Contributors:
-//
-// Description:
-// e32tools\petran\Szip\encode.cpp
-// 
-//
-
-#include "huffman.h"
-#include "panic.h"
-#include <e32base.h>
-#include "h_utl.h"
-#include <assert.h>
-#include "farray.h"
-#include <stdlib.h>
-
-void User::Invariant()
-	{
-	fprintf(stderr, "User::Invariant() called\n");
-	exit(1);
-	}
-
-// local definitions used for Huffman code generation
-typedef TUint16 THuff;		/** @internal */
-const THuff KLeaf=0x8000;	/** @internal */
-struct TNode
-/** @internal */
-	{
-	TUint iCount;
-	THuff iLeft;
-	THuff iRight;
-	};
-
-void HuffmanLengthsL(TUint32* aLengths,const TNode* aNodes,TInt aNode,TInt aLen)
-/** recursive function to calculate the code lengths from the node tree
-
-	@internal
-*/
-	{
-	if (++aLen>Huffman::KMaxCodeLength)
-		Panic(EHuffmanBufferOverflow);
-
-	const TNode& node=aNodes[aNode];
-	TUint x=node.iLeft;
-	if (x&KLeaf)
-		aLengths[x&~KLeaf]=aLen;
-	else
-		HuffmanLengthsL(aLengths,aNodes,x,aLen);
-	x=node.iRight;
-	if (x&KLeaf)
-		aLengths[x&~KLeaf]=aLen;
-	else
-		HuffmanLengthsL(aLengths,aNodes,x,aLen);
-	}
-
-void InsertInOrder(TNode* aNodes, TInt aSize, TUint aCount, TInt aVal)
-/**	Insert the {aCount,aValue} pair into the already sorted array of nodes
-
-	@internal
-*/
-	{
-	// Uses Insertion sort following a binary search...
-	TInt l=0, r=aSize;
-	while (l < r)
-		{
-		TInt m = (l+r) >> 1;
-		if (aNodes[m].iCount<aCount)
-			r=m;
-		else
-			l=m+1;
-		}
-	HMem::Copy(aNodes+l+1,aNodes+l,sizeof(TNode)*(aSize-l));
-	aNodes[l].iCount=aCount;
-	aNodes[l].iRight=TUint16(aVal);
-	}
-
-void Huffman::HuffmanL(const TUint32 aFrequency[],TInt aNumCodes,TUint32 aHuffman[])
-/** Generate a Huffman code
-
-	This generates a Huffman code for a given set of code frequencies. The output
-	is a table of code lengths which can be used to build canonincal encoding tables
-	or decoding trees for use with the TBitInput and TBitOutput classes.
-
-	Entries in the table with a frequency of zero will have a zero code length
-	and thus no associated huffman encoding. If each such symbol should have a
-	maximum length encoding, they must be given at least a frequency of 1.
-
-	For an alphabet of n symbols, this algorithm has a transient memory overhead
-	of 8n, and a time complexity of O(n*log(n)).
-
-	@param "const TUint32 aFrequency[]" The table of code frequencies
-	@param "TInt aNumCodes" The number of codes in the table
-	@param "TUint32 aHuffman[]" The table for the output code-length table. This must be
-		the same size as the frequency table, and can safely be the same table
-
-	@leave "KErrNoMemory" If memory used for code generation cannot be allocated
-
-  	@panic "USER ???" If the number of codes exceeds Huffman::KMaxCodes
-*/
-	{
-	if(TUint(aNumCodes)>TUint(KMaxCodes))
-		Panic(EHuffmanTooManyCodes);
-
-	// Sort the values into decreasing order of frequency
-	//
-	TNode* nodes = new TNode[aNumCodes];
-	if(nodes==NULL)
-		Panic(EHuffmanOutOfMemory);
-
-	TInt lCount=0;
-
-	for (TInt ii=0;ii<aNumCodes;++ii)
-		{
-		TInt c=aFrequency[ii];
-		if (c!=0)
-			InsertInOrder(nodes,lCount++,c,ii|KLeaf);
-		}
-
-	// default code length is zero
-	HMem::FillZ(aHuffman,aNumCodes*sizeof(TUint32));
-
-	if (lCount==0)
-		{
-		// no codes with frequency>0. No code has a length
-		}
-	else if (lCount==1)
-		{
-		// special case for a single value (always encode as "0")
-		aHuffman[nodes[0].iRight&~KLeaf]=1;
-		}
-	else
-		{
-		// Huffman algorithm: pair off least frequent nodes and reorder
-		//
-		do
-			{
-			--lCount;
-			TUint c=nodes[lCount].iCount + nodes[lCount-1].iCount;
-			nodes[lCount].iLeft=nodes[lCount-1].iRight;
-			// re-order the leaves now to reflect new combined frequency 'c'
-			InsertInOrder(nodes,lCount-1,c,lCount);
-			} while (lCount>1);
-		// generate code lengths in aHuffman[]
-		HuffmanLengthsL(aHuffman,nodes,1,0);
-		}
-
-	delete [] nodes;
-
-	if(!IsValid(aHuffman,aNumCodes))
-		Panic(EHuffmanInvalidCoding);
-	}
-
-TBool Huffman::IsValid(const TUint32 aHuffman[],TInt aNumCodes)
-/** Validate a Huffman encoding
-
-	This verifies that a Huffman coding described by the code lengths is valid.
-	In particular, it ensures that no code exceeds the maximum length and
-	that it is possible to generate a canonical coding for the specified lengths.
-	
-	@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
-	@param "TInt aNumCodes" The number of codes in the table
-
-	@return True if the code is valid, otherwise false
-*/
-	{
-	// The code is valid if one of the following holds:
-	// (a) the code exactly fills the 'code space'
-	// (b) there is only a single symbol with code length 1
-	// (c) there are no encoded symbols
-	//
-	TUint remain=1<<KMaxCodeLength;
-	TInt totlen=0;
-	for (const TUint32* p=aHuffman+aNumCodes; p>aHuffman;)
-		{
-		TInt len=*--p;
-		if (len>0)
-			{
-			totlen+=len;
-			if (len>KMaxCodeLength)
-				return EFalse;
-			TUint c=1<<(KMaxCodeLength-len);
-			if (c>remain)
-				return EFalse;
-			remain-=c;
-			}
-		}
-
-	return remain==0 || totlen<=1;
-	}
-
-void Huffman::Encoding(const TUint32 aHuffman[],TInt aNumCodes,TUint32 aEncodeTable[])
-/** Create a canonical Huffman encoding table
-
-	This generates the huffman codes used by TBitOutput::HuffmanL() to write huffman
-	encoded data. The input is table of code lengths, as generated by Huffman::HuffmanL()
-	and must represent a valid huffman code.
-	
-	@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
-	@param "TInt aNumCodes" The number of codes in the table
-	@param "TUint32 aEncodeTable[]" The table for the output huffman codes. This must be
-		the same size as the code-length table, and can safely be the same table
-
-	@panic "USER ???" If the provided code is not a valid Huffman coding
-	
-	@see IsValid()
-	@see HuffmanL()
-*/
-	{
-	__ASSERT_ALWAYS(IsValid(aHuffman,aNumCodes),Panic(EHuffmanInvalidCoding));
-
-	TFixedArray<TInt,KMaxCodeLength> lenCount;
-	lenCount.Reset();
-
-	TInt ii;
-	for (ii=0;ii<aNumCodes;++ii)
-		{
-		TInt len=aHuffman[ii]-1;
-		if (len>=0)
-			++lenCount[len];
-		}
-
-	TFixedArray<TUint,KMaxCodeLength> nextCode;
-	TUint code=0;
-	for (ii=0;ii<KMaxCodeLength;++ii)
-		{
-		code<<=1;
-		nextCode[ii]=code;
-		code+=lenCount[ii];
-		}
-
-	for (ii=0;ii<aNumCodes;++ii)
-		{
-		TInt len=aHuffman[ii];
-		if (len==0)
-			aEncodeTable[ii]=0;
-		else
-			{
-			aEncodeTable[ii] = (nextCode[len-1]<<(KMaxCodeLength-len))|(len<<KMaxCodeLength);
-			++nextCode[len-1];
-			}
-		}
-	}
-
-/** the encoding table for the externalised code
-	@internal
-*/
-const TUint32 HuffmanEncoding[]=
-	{
-	0x10000000,
-	0x1c000000,
-	0x12000000,
-	0x1d000000,
-	0x26000000,
-	0x26800000,
-	0x2f000000,
-	0x37400000,
-	0x37600000,
-	0x37800000,
-	0x3fa00000,
-	0x3fb00000,
-	0x3fc00000,
-	0x3fd00000,
-	0x47e00000,
-	0x47e80000,
-	0x47f00000,
-	0x4ff80000,
-	0x57fc0000,
-	0x5ffe0000,
-	0x67ff0000,
-	0x77ff8000,
-	0x7fffa000,
-	0x7fffb000,
-	0x7fffc000,
-	0x7fffd000,
-	0x7fffe000,
-	0x87fff000,
-	0x87fff800
-	};
-
-void EncodeRunLengthL(TBitOutput& aOutput, TInt aLength)
-/** encode 0a as '0' and 0b as '1', return number of symbols created
-
-	@internal
-*/
-	{
-	if (aLength>0)
-		{
-		EncodeRunLengthL(aOutput,(aLength-1)>>1);
-		aOutput.HuffmanL(HuffmanEncoding[1-(aLength&1)]);
-		}
-	}
-
-void Huffman::ExternalizeL(TBitOutput& aOutput,const TUint32 aHuffman[],TInt aNumCodes)
-/** Store a canonical huffman encoding in compact form
-
-	As the encoding is canonical, only the code lengths of each code needs to be saved.
-
-	Due to the nature of code length tables, these can usually be stored very compactly
-	by encoding the encoding itself, hence the use of the bit output stream.
-	
-	@param "TBitOutput& aOutput" The output stream for the encoding
-	@param "const TUint32 aHuffman[]" The table of code lengths as generated by Huffman::HuffmanL()
-	@param "TInt aNumCodes" The number of huffman codes in the table
-
-	@leave "TBitOutput::HuffmanL()"
-*/
-	{
-	// We assume that the code length table is generated by the huffman generator,
-	// in which case the maxmimum code length is 27 bits.
-	//
-	// We apply three transformations to the data:
-	// 1. the data goes through a move-to-front coder
-	// 2. apply a rle-0 coder which replace runs of '0' with streams of '0a' and '0b'
-	// 3. encode the result using a predefined (average) huffman coding
-	//
-	// This can be done in a single pass over the data, avoiding the need for additional
-	// memory.
-	//
-	// initialise the list for the MTF coder
-	TFixedArray<TUint8,Huffman::KMetaCodes> list;
-	TInt i;
-	for (i=0;i<list.Count();++i)
-		list[i]=TUint8(i);
-	TInt last=0;
-
-	TInt rl=0;
-	const TUint32* p32=aHuffman;
-	const TUint32* e32=p32+aNumCodes;
-	while (p32<e32)
-		{
-		TInt c=*p32++;
-		if (c==last)
-			++rl;	// repeat of last symbol
-		else
-			{
-			// encode run-length
-			EncodeRunLengthL(aOutput,rl);
-			rl=0;
-			// find code in MTF list
-			TInt j;
-			for (j=1;list[j]!=c;++j)
-				;
-			// store this code
-			aOutput.HuffmanL(HuffmanEncoding[j+1]);
-			// adjust list for MTF algorithm
-			while (--j>0)
-				list[j+1]=list[j];
-			list[1]=TUint8(last);
-			last=c;
-			}
-		}
-	// encod any remaining run-length
-	EncodeRunLengthL(aOutput,rl);
-	}
-
-
-TBitOutput::TBitOutput()
-/** Construct a bit stream output object
-
-	Following construction the bit stream is ready for writing bits, but will first call
-	OverflowL() as the output buffer is 'full'. A derived class can detect this state as
-	Ptr() will return null.
-*/
-	:iCode(0),iBits(-8),iPtr(0),iEnd(0)
-	{}
-
-TBitOutput::TBitOutput(TUint8* aBuf,TInt aSize)
-/** Construct a bit stream output object over a buffer
-
-	Data will be written to the buffer until it is full, at which point OverflowL() will
-	be called. This should handle the data and then can Set() again to reset the buffer
-	for further output.
-	
-	@param "TUint8* aBuf" The buffer for output
-	@param "TInt aSize" The size of the buffer in bytes
-*/
-	:iCode(0),iBits(-8),iPtr(aBuf),iEnd(aBuf+aSize)
-	{}
-
-void TBitOutput::HuffmanL(TUint aHuffCode)
-/** Write a huffman code
-
-	This expects a huffman code value as generated by Huffman::Encoding()
-
-	@param "TUint aHuffCode" The huffman code write to the stream
-
-	@leave "OverflowL()" If the output buffer is full, OverflowL() is called
-*/
-	{
-	DoWriteL(aHuffCode<<(32-Huffman::KMaxCodeLength),aHuffCode>>Huffman::KMaxCodeLength);
-	}
-
-void TBitOutput::WriteL(TUint aValue,TInt aLength)
-/** Write an arbitrary integer value
-
-	Write an unsigned integer using the number of bits specified. Only
-	the low order bits of the value are written to the output, most
-	significant bit first.
-
-	@param "TUint aValue" The value to write to the stream
-	@param "TUint aLength" The number of bits to output
-
-	@leave "OverflowL()" If the output buffer is full, OverflowL() is called
-*/
-	{
-	if (aLength)
-		DoWriteL(aValue<<=32-aLength,aLength);
-	}
-
-void TBitOutput::PadL(TUint aPadding)
-/** Pad the bitstream to the next byte boundary
-
-	Terminate the bitstream by padding the last byte with the requested value.
-	Following this operation the bitstream can continue to be used, the data will
-	start at the next byte.
-
-	@param "TUint aPadding" The bit value to pad the final byte with
-
-	@leave "OverflowL()" If the output buffer is full, OverflowL() is called
-*/
-	{
-	if (iBits>-8)
-		WriteL(aPadding?0xffffffffu:0,-iBits);
-	}
-
-void TBitOutput::DoWriteL(TUint aBits,TInt aSize)
-/** Write the higher order bits to the stream
-	
-	@internal
-*/
-	{
-	if (aSize>25)
-		{
-		// cannot process >25 bits in a single pass
-		// so do the top 8 bits first
-		ASSERT(aSize<=32);
-		DoWriteL(aBits&0xff000000u,8);
-		aBits<<=8;
-		aSize-=8;
-		}
-
-	TInt bits=iBits;
-	TUint code=iCode|(aBits>>(bits+8));
-	bits+=aSize;
-	if (bits>=0)
-		{
-		TUint8* p=iPtr;
-		do
-			{
-			if (p==iEnd)
-				{
-				// run out of buffer space so invoke the overflow handler
-				iPtr=p;
-				OverflowL();
-				p=iPtr;
-				ASSERT(p!=iEnd);
-				}
-			*p++=TUint8(code>>24);
-			code<<=8;
-			bits-=8;
-			} while (bits>=0);
-		iPtr=p;
-		}
-	iCode=code;
-	iBits=bits;
-	}
-
-void TBitOutput::OverflowL()
-/** Handle a full output buffer
-
-	This virtual function is called when the output buffer is full. It should deal
-	with the data in the buffer before reseting the buffer using Set(), allowing
-	further data to be written.
-
-	A derived class can replace this to write the data to a file (for example)
-	before marking the buffer as empty.
-
-	@leave "KErrOverflow" The default implementation leaves
-*/
-	{
-	Panic(EHuffmanBufferOverflow);
-	}