Decoder.h

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/*
 * The Progressive Graphics File; http://www.libpgf.org
 * 
 * $Date: 2006-06-04 22:05:59 +0200 (So, 04 Jun 2006) $
 * $Revision: 229 $
 * 
 * This file Copyright (C) 2006 xeraina GmbH, Switzerland
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU LESSER GENERAL PUBLIC LICENSE
 * as published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */


#ifndef PGF_DECODER_H
#define PGF_DECODER_H

#include "PGFstream.h"
#include "BitStream.h"
#include "Subband.h"
#include "WaveletTransform.h"

// Constants
#define BufferLen           (BufferSize/WordWidth)  
#define CodeBufferLen       BufferSize              

class CDecoder {
    class CMacroBlock {
    public:
        CMacroBlock()
        : m_header(0)                               // makes sure that IsCompletelyRead() returns true for an empty macro block
#if defined(WIN32) || defined(WINCE) || defined(WIN64)
#pragma warning( suppress : 4351 )
#endif
        , m_value()
        , m_codeBuffer()
        , m_valuePos(0)
        , m_sigFlagVector()
        {
        }

        bool IsCompletelyRead() const   { return m_valuePos >= m_header.rbh.bufferSize; }

        void BitplaneDecode();

        ROIBlockHeader m_header;                    
        DataT  m_value[BufferSize];                 
        UINT32 m_codeBuffer[CodeBufferLen];         
        UINT32 m_valuePos;                          

    private:
        UINT32 ComposeBitplane(UINT32 bufferSize, DataT planeMask, UINT32* sigBits, UINT32* refBits, UINT32* signBits);
        UINT32 ComposeBitplaneRLD(UINT32 bufferSize, DataT planeMask, UINT32 sigPos, UINT32* refBits);
        UINT32 ComposeBitplaneRLD(UINT32 bufferSize, DataT planeMask, UINT32* sigBits, UINT32* refBits, UINT32 signPos);
        void  SetBitAtPos(UINT32 pos, DataT planeMask)          { (m_value[pos] >= 0) ? m_value[pos] |= planeMask : m_value[pos] -= planeMask; }
        void  SetSign(UINT32 pos, bool sign)                    { m_value[pos] = -m_value[pos]*sign + m_value[pos]*(!sign); }

        bool m_sigFlagVector[BufferSize+1];         // see paper from Malvar, Fast Progressive Wavelet Coder
    };

public:
    CDecoder(CPGFStream* stream, PGFPreHeader& preHeader, PGFHeader& header, 
             PGFPostHeader& postHeader, UINT32*& levelLength, UINT64& userDataPos, 
             bool useOMP, bool skipUserData) THROW_; // throws IOException

    ~CDecoder();

    void Partition(CSubband* band, int quantParam, int width, int height, int startPos, int pitch) THROW_;

    void DecodeInterleaved(CWaveletTransform* wtChannel, int level, int quantParam) THROW_;

    UINT32 GetEncodedHeaderLength() const           { return m_encodedHeaderLength; }

    void SetStreamPosToStart() THROW_               { ASSERT(m_stream); m_stream->SetPos(FSFromStart, m_startPos); }

    void SetStreamPosToData() THROW_                { ASSERT(m_stream); m_stream->SetPos(FSFromStart, m_startPos + m_encodedHeaderLength); }

    void Skip(UINT64 offset) THROW_;

    void DequantizeValue(CSubband* band, UINT32 bandPos, int quantParam) THROW_;

    UINT32 ReadEncodedData(UINT8* target, UINT32 len) const THROW_;

    void DecodeBuffer() THROW_;

    CPGFStream* GetStream()                         { return m_stream; }

    bool MacroBlocksAvailable() const               { return m_macroBlocksAvailable > 1; }

#ifdef __PGFROISUPPORT__
    void DecodeTileBuffer() THROW_;

    void SkipTileBuffer() THROW_;

    void SetROI()                   { m_roi = true; }
#endif

#ifdef TRACE
    void DumpBuffer();
#endif

private:
    void ReadMacroBlock(CMacroBlock* block) THROW_; 

    CPGFStream *m_stream;                       
    UINT64 m_startPos;                          
    UINT64 m_streamSizeEstimation;              
    UINT32 m_encodedHeaderLength;               

    CMacroBlock **m_macroBlocks;                
    int m_currentBlockIndex;                    
    int m_macroBlockLen;                        
    int m_macroBlocksAvailable;                 
    CMacroBlock *m_currentBlock;                

#ifdef __PGFROISUPPORT__
    bool   m_roi;                               
#endif
};

#endif //PGF_DECODER_H