File indexing completed on 2025-01-05 03:56:36

 /*
  * 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.
  */
 
 //////////////////////////////////////////////////////////////////////
 /// @file Decoder.h
 /// @brief PGF decoder class
 /// @author C. Stamm, R. Spuler
 
 #ifndef PGF_DECODER_H
 #define PGF_DECODER_H
 
 #include "PGFstream.h"
 #include "BitStream.h"
 #include "Subband.h"
 #include "WaveletTransform.h"
 
 #include "digikam_export.h"
 
 /////////////////////////////////////////////////////////////////////
 // Constants
 #define BufferLen           (BufferSize/WordWidth)  ///< number of words per buffer
 #define CodeBufferLen       BufferSize              ///< number of words in code buffer (CodeBufferLen > BufferLen)
 
 /////////////////////////////////////////////////////////////////////
 /// PGF decoder class.
 /// @author C. Stamm, R. Spuler
 /// @brief PGF decoder
 class DIGIKAM_EXPORT CDecoder {
     //////////////////////////////////////////////////////////////////////
     /// PGF decoder macro block class.
     /// @author C. Stamm, I. Bauersachs
     /// @brief A macro block is a decoding unit of fixed size (uncoded)
     class CMacroBlock {
     public:
         //////////////////////////////////////////////////////////////////////
         /// Constructor: Initializes new macro block.
         CMacroBlock()
         : m_header(0)                               // makes sure that IsCompletelyRead() returns true for an empty macro block
 #ifdef _MSC_VER
 #pragma warning( suppress : 4351 )
 #endif
         , m_value()
         , m_codeBuffer()
         , m_valuePos(0)
         , m_sigFlagVector()
         {
         }
 
         //////////////////////////////////////////////////////////////////////
         /// Returns true if this macro block has been completely read.
         /// @return true if current value position is at block end
         bool IsCompletelyRead() const   { return m_valuePos >= m_header.rbh.bufferSize; }
 
         //////////////////////////////////////////////////////////////////////
         /// Decodes already read input data into this macro block.
         /// Several macro blocks can be decoded in parallel.
         /// Call CDecoder::ReadMacroBlock before this method.
         void BitplaneDecode();
 
         ROIBlockHeader m_header;                    ///< block header
         DataT  m_value[BufferSize];                 ///< output buffer of values with index m_valuePos
         UINT32 m_codeBuffer[CodeBufferLen];         ///< input buffer for encoded bitstream
         UINT32 m_valuePos;                          ///< current position in m_value
 
     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:
     /////////////////////////////////////////////////////////////////////
     /// Constructor: Read pre-header, header, and levelLength at current stream position.
     /// It might throw an IOException.
     /// @param stream A PGF stream
     /// @param preHeader [out] A PGF pre-header
     /// @param header [out] A PGF header
     /// @param postHeader [out] A PGF post-header
     /// @param levelLength The location of the levelLength array. The array is allocated in this method. The caller has to delete this array.
     /// @param userDataPos The stream position of the user data (metadata)
     /// @param useOMP If true, then the decoder will use multi-threading based on openMP
     /// @param userDataPolicy Policy of user data (meta-data) handling while reading PGF headers.
     CDecoder(CPGFStream* stream, PGFPreHeader& preHeader, PGFHeader& header,
              PGFPostHeader& postHeader, UINT32*& levelLength, UINT64& userDataPos,
              bool useOMP, UINT32 userDataPolicy); // throws IOException
 
     /////////////////////////////////////////////////////////////////////
     /// Destructor
     ~CDecoder();
 
     /////////////////////////////////////////////////////////////////////
     /// Unpartitions a rectangular region of a given subband.
     /// Partitioning scheme: The plane is partitioned in squares of side length LinBlockSize.
     /// Read wavelet coefficients from the output buffer of a macro block.
     /// It might throw an IOException.
     /// @param band A subband
     /// @param quantParam Dequantization value
     /// @param width The width of the rectangle
     /// @param height The height of the rectangle
     /// @param startPos The relative subband position of the top left corner of the rectangular region
     /// @param pitch The number of bytes in row of the subband
     void Partition(CSubband* band, int quantParam, int width, int height, int startPos, int pitch);
 
     /////////////////////////////////////////////////////////////////////
     /// Deccoding and dequantization of HL and LH subband (interleaved) using partitioning scheme.
     /// Partitioning scheme: The plane is partitioned in squares of side length InterBlockSize.
     /// It might throw an IOException.
     /// @param wtChannel A wavelet transform channel containing the HL and HL band
     /// @param level Wavelet transform level
     /// @param quantParam Dequantization value
     void DecodeInterleaved(CWaveletTransform* wtChannel, int level, int quantParam);
 
     //////////////////////////////////////////////////////////////////////
     /// Returns the length of all encoded headers in bytes.
     /// @return The length of all encoded headers in bytes
     UINT32 GetEncodedHeaderLength() const           { return m_encodedHeaderLength; }
 
     ////////////////////////////////////////////////////////////////////
     /// Resets stream position to beginning of PGF pre-header
     void SetStreamPosToStart()              { ASSERT(m_stream); m_stream->SetPos(FSFromStart, m_startPos); }
 
     ////////////////////////////////////////////////////////////////////
     /// Resets stream position to beginning of data block
     void SetStreamPosToData()               { ASSERT(m_stream); m_stream->SetPos(FSFromStart, m_startPos + m_encodedHeaderLength); }
 
     ////////////////////////////////////////////////////////////////////
     /// Skips a given number of bytes in the open stream.
     /// It might throw an IOException.
     void Skip(UINT64 offset);
 
     /////////////////////////////////////////////////////////////////////
     /// Dequantization of a single value at given position in subband.
     /// It might throw an IOException.
     /// @param band A subband
     /// @param bandPos A valid position in subband band
     /// @param quantParam The quantization parameter
     void DequantizeValue(CSubband* band, UINT32 bandPos, int quantParam);
 
     //////////////////////////////////////////////////////////////////////
     /// Copies data from the open stream to a target buffer.
     /// It might throw an IOException.
     /// @param target The target buffer
     /// @param len The number of bytes to read
     /// @return The number of bytes copied to the target buffer
     UINT32 ReadEncodedData(UINT8* target, UINT32 len) const;
 
     /////////////////////////////////////////////////////////////////////
     /// Reads next block(s) from stream and decodes them
     /// It might throw an IOException.
     void DecodeBuffer();
 
     /////////////////////////////////////////////////////////////////////
     /// @return Stream
     CPGFStream* GetStream()                         { return m_stream; }
 
     /////////////////////////////////////////////////////////////////////
     /// Gets next macro block
     /// It might throw an IOException.
     void GetNextMacroBlock();
 
 #ifdef __PGFROISUPPORT__
     /////////////////////////////////////////////////////////////////////
     /// Resets stream position to next tile.
     /// Used with ROI encoding scheme only.
     /// It might throw an IOException.
     void SkipTileBuffer();
 
     /////////////////////////////////////////////////////////////////////
     /// Enables region of interest (ROI) status.
     void SetROI()                   { m_roi = true; }
 #endif
 
 #ifdef TRACE
     void DumpBuffer();
 #endif
 
 private:
     void ReadMacroBlock(CMacroBlock* block); ///< throws IOException
 
     CPGFStream *m_stream;                       ///< input PGF stream
     UINT64 m_startPos;                          ///< stream position at the beginning of the PGF pre-header
     UINT64 m_streamSizeEstimation;              ///< estimation of stream size
     UINT32 m_encodedHeaderLength;               ///< stream offset from startPos to the beginning of the data part (highest level)
 
     CMacroBlock **m_macroBlocks;                ///< array of macroblocks
     int m_currentBlockIndex;                    ///< index of current macro block
     int m_macroBlockLen;                        ///< array length
     int m_macroBlocksAvailable;                 ///< number of decoded macro blocks (including currently used macro block)
     CMacroBlock *m_currentBlock;                ///< current macro block (used by main thread)
 
 #ifdef __PGFROISUPPORT__
     bool   m_roi;                               ///< true: ensures region of interest (ROI) decoding
 #endif
 };
 
 #endif //PGF_DECODER_H