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/**********************************************************

** Copyright 1998 Earth Resource Mapping Ltd.

** This document contains proprietary source code of

** Earth Resource Mapping Ltd, and can only be used under

** one of the three licenses as described in the

** license.txt file supplied with this distribution.

** See separate license.txt file for license details

** and conditions.

**

** This software is covered by US patent #6,442,298,

** #6,102,897 and #6,633,688.  Rights to use these patents

** is included in the license agreements.

**

** FILE:           NCSHuffmanCoder.h

** CREATED:        30 Jun 2004

** AUTHOR:         Simon Cope

** PURPOSE:        CNCSHuffmanCoder class header

** EDITS:

*******************************************************/

#ifndef NCSHUFFMANCODER_H

#define NCSHUFFMANCODER_H

#ifdef _MSC_VER

#pragma warning( disable : 4786 )

#endif

#include "NCSTypes.h"

#ifdef __cplusplus

#include <map>

extern "C" {

#endif // __cplusplus

typedef struct _NCSHuffmanSymbol {

        UINT16 nValue;

        BOOLEAN bZeroRun;

} NCSHuffmanSymbol;

#ifdef __cplusplus

#include "NCSError.h"

/**

 * CNCSHuffmanCoder class - ECW Huffman Coder/Decoder.

 *

 * @author       Simon Cope

 * @version      $Revision$ $Author$ $Date$

 */

class CNCSHuffmanCoder {

public:

        const static UINT32 NUM_SYMBOL_VALUES;

        const static UINT16 SIGN_MASK;

        const static UINT16 RUN_MASK;

        const static INT16 MAX_BIN_VALUE;

        const static INT16 MIN_BIN_VALUE;

        const static UINT16 VALUE_MASK;

        const static UINT16 MAX_RUN_LENGTH;

        const static UINT8 SMALL_SYMBOL;

        const static UINT8 SMALL_SHIFT;

        /*

        **        Huffman structures and definitions

        */

        class CTree;

        class CCodeNode {

        public:

                typedef struct {

                        class CCodeNode *m_p0Child;

                        class CCodeNode *m_p1Child;

                } A;

                typedef union {

                        A                                m_P;

                        class CCodeNode *m_Children[2];

                } U;

                U m_Children;

                NCSHuffmanSymbol m_Symbol;

                UINT32        m_nFrequency;

                class CCodeNode        *m_pNext;

                UINT32         m_nCode;

                UINT8        m_nCodeBits;

                bool        m_bInHistogram;

                CCodeNode();

                CCodeNode(UINT8 **ppPacked, UINT32 &nNodes);

                virtual ~CCodeNode();

                void Pack(UINT8 **ppPacked, UINT32 &nNodes);

                CCodeNode *Unpack(UINT8 **ppPacked, UINT32 &nNodes);

                void SetCode(UINT32 nCode, UINT8 nCodeBits);

        };

        class CTree: public CCodeNode {

        public:

                CCodeNode *m_pRoot;

                std::map<INT16, CCodeNode*> m_Histogram;

                CTree();

                CTree(UINT8 **ppPacked);

                virtual ~CTree();

                CNCSError Pack(UINT8 **ppPacked, INT16 *pUnPacked, UINT32 nSymbols);

                CNCSError Unpack(UINT8 **ppPacked);

        protected:

                CCodeNode *UnpackNode(UINT8 **ppPacked, UINT32 &nNodes);

        };

                /** Default constructor. */

        CNCSHuffmanCoder();

                /** virtual default destructor. */

        virtual ~CNCSHuffmanCoder();

        CNCSError Pack(UINT8 *pPacked, UINT32 *pPackedLength, INT16 *pUnPacked, UINT32 nRawLength);

        CNCSError UnPack(UINT8 *pPacked, INT16 *pUnPacked, UINT32 nRawLength);

private:

        CTree *m_pTree;

};

};

#endif

#ifdef __cplusplus

extern "C" {

#endif

#define NCS_HUFFMAN_MAX_RUN_LENGTH 0x7fff

#define NCS_HUFFMAN_SIGN_MASK        0x4000

#define NCS_HUFFMAN_VALUE_MASK        0x3fff

#define NCS_HUFFMAN_RUN_MASK        0x8000

typedef struct {

        void        *pTree;

        UINT32        nBitsUsed;

} NCSHuffmanState;

NCSError unpack_huffman(UINT8 *pPacked, INT16 *pUnPacked, UINT32 nRawLength);

void unpack_huffman_init_state(NCSHuffmanState *pState, UINT8 **ppPacked);

void unpack_huffman_fini_state(NCSHuffmanState *pState);

NCSHuffmanSymbol *unpack_huffman_symbol(UINT8 **ppPacked, NCSHuffmanState *pState);

static NCS_INLINE BOOLEAN unpack_huffman_symbol_zero_run(NCSHuffmanSymbol *pSymbol) {

                                return(pSymbol->bZeroRun);

                        }

static NCS_INLINE UINT16 unpack_huffman_symbol_zero_length(NCSHuffmanSymbol *pSymbol) {

                                return(pSymbol->nValue);

                        };

static NCS_INLINE INT16 unpack_huffman_symbol_value(NCSHuffmanSymbol *pSymbol) {

                                return(pSymbol->nValue);

                        };

UINT32        pack_huffman(UINT8 *pPacked, INT16 *pUnPacked, UINT32 symbol_stream_length);

#ifdef __cplusplus

};

#endif

#endif /* NCSHUFFMANCODER_H */