btreecd.h

SFC游戏模拟器 snes9x 1.43 的原代码

/*
Copyright (C) 2002 Andrea Mazzoleni ( http://advancemame.sf.net )
Copyright (C) 2001-4 Igor Pavlov ( http://www.7-zip.org )

This library 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 library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef __BITTREECODER_H
#define __BITTREECODER_H

#include "aribitcd.h"
#include "rcdefs.h"


//////////////////////////
// CBitTreeDecoder

template <int aNumMoveBits, UINT32 m_NumBitLevels>
class CBitTreeDecoder
{
  CMyBitDecoder<aNumMoveBits> m_Models[1 << m_NumBitLevels];
public:
  void Init()
  {
    for(UINT32 i = 1; i < (1 << m_NumBitLevels); i++)
      m_Models[i].Init();
  }
  UINT32 Decode(CMyRangeDecoder *aRangeDecoder)
  {
    UINT32 aModelIndex = 1;
    RC_INIT_VAR
    for(UINT32 aBitIndex = m_NumBitLevels; aBitIndex > 0; aBitIndex--)
    {
      // aModelIndex = (aModelIndex << 1) + m_Models[aModelIndex].Decode(aRangeDecoder);
      RC_GETBIT(aNumMoveBits, m_Models[aModelIndex].m_Probability, aModelIndex)
    }
    RC_FLUSH_VAR
    return aModelIndex - (1 << m_NumBitLevels);
  };
};

////////////////////////////////
// CReverseBitTreeDecoder

template <int aNumMoveBits>
class CReverseBitTreeDecoder2
{
  CMyBitDecoder<aNumMoveBits> *m_Models;
  UINT32 m_NumBitLevels;
public:
  CReverseBitTreeDecoder2(): m_Models(0) { }
  ~CReverseBitTreeDecoder2() { delete []m_Models; }
  bool Create(UINT32 aNumBitLevels)
  {
    m_NumBitLevels = aNumBitLevels;
    m_Models = new CMyBitDecoder<aNumMoveBits>[1 << aNumBitLevels];
    return (m_Models != 0);
  }
  void Init()
  {
    UINT32 aNumModels = 1 << m_NumBitLevels;
    for(UINT32 i = 1; i < aNumModels; i++)
      m_Models[i].Init();
  }
  UINT32 Decode(CMyRangeDecoder *aRangeDecoder)
  {
    UINT32 aModelIndex = 1;
    UINT32 aSymbol = 0;
    RC_INIT_VAR
    for(UINT32 aBitIndex = 0; aBitIndex < m_NumBitLevels; aBitIndex++)
    {
      // UINT32 aBit = m_Models[aModelIndex].Decode(aRangeDecoder);
      // aModelIndex <<= 1;
      // aModelIndex += aBit;
      // aSymbol |= (aBit << aBitIndex);
      RC_GETBIT2(aNumMoveBits, m_Models[aModelIndex].m_Probability, aModelIndex, ; , aSymbol |= (1 << aBitIndex))
    }
    RC_FLUSH_VAR
    return aSymbol;
  };
};
////////////////////////////
// CReverseBitTreeDecoder2

template <int aNumMoveBits, UINT32 m_NumBitLevels>
class CReverseBitTreeDecoder
{
  CMyBitDecoder<aNumMoveBits> m_Models[1 << m_NumBitLevels];
public:
  void Init()
  {
    for(UINT32 i = 1; i < (1 << m_NumBitLevels); i++)
      m_Models[i].Init();
  }
  UINT32 Decode(CMyRangeDecoder *aRangeDecoder)
  {
    UINT32 aModelIndex = 1;
    UINT32 aSymbol = 0;
    RC_INIT_VAR
    for(UINT32 aBitIndex = 0; aBitIndex < m_NumBitLevels; aBitIndex++)
    {
      // UINT32 aBit = m_Models[aModelIndex].Decode(aRangeDecoder);
      // aModelIndex <<= 1;
      // aModelIndex += aBit;
      // aSymbol |= (aBit << aBitIndex);
      RC_GETBIT2(aNumMoveBits, m_Models[aModelIndex].m_Probability, aModelIndex, ; , aSymbol |= (1 << aBitIndex))
    }
    RC_FLUSH_VAR
    return aSymbol;
  }
};



#endif