3.13

7zip/Compress/LZMA/LZMALen.h

@@ -0,0 +1,114 @@
+// LenCoder.h
+
+// #pragma once
+
+#ifndef __LENCODER_H
+#define __LENCODER_H
+
+#include "../RangeCoder/RangeCoderBitTree.h"
+
+namespace NCompress {
+namespace NLZMA {
+namespace NLength {
+
+const int kNumMoveBits = 5;
+
+const int kNumPosStatesBitsMax = 4;
+const UINT32 kNumPosStatesMax = (1 << kNumPosStatesBitsMax);
+
+const int kNumPosStatesBitsEncodingMax = 4;
+const UINT32 kNumPosStatesEncodingMax = (1 << kNumPosStatesBitsEncodingMax);
+
+const int kNumLenBits = 3;
+const UINT32 kNumLowSymbols = 1 << kNumLenBits;
+const int kNumMidBits = 3;
+const UINT32 kNumMidSymbols = 1 << kNumMidBits;
+
+const int kNumHighBits = 8;
+
+const UINT32 kNumSymbolsTotal = kNumLowSymbols + kNumMidSymbols + (1 << kNumHighBits);
+
+class CEncoder
+{
+  NRangeCoder::CBitEncoder<kNumMoveBits> _choice;
+  NRangeCoder::CBitTreeEncoder<kNumMoveBits, kNumLenBits>  _lowCoder[kNumPosStatesEncodingMax];
+  NRangeCoder::CBitEncoder<kNumMoveBits>  _choice2;
+  NRangeCoder::CBitTreeEncoder<kNumMoveBits, kNumMidBits>  _midCoder[kNumPosStatesEncodingMax];
+  NRangeCoder::CBitTreeEncoder<kNumMoveBits, kNumHighBits>  _highCoder;
+protected:
+  UINT32 _numPosStates;
+public:
+  void Create(UINT32 numPosStates)
+    { _numPosStates = numPosStates; }
+  void Init();
+  void Encode(NRangeCoder::CEncoder *rangeEncoder, UINT32 symbol, UINT32 posState);
+  UINT32 GetPrice(UINT32 symbol, UINT32 posState) const;
+};
+
+const UINT32 kNumSpecSymbols = kNumLowSymbols + kNumMidSymbols;
+
+class CPriceTableEncoder: public CEncoder
+{
+  UINT32 _prices[kNumSymbolsTotal][kNumPosStatesEncodingMax];
+  UINT32 _tableSize;
+  UINT32 _counters[kNumPosStatesEncodingMax];
+public:
+  void SetTableSize(UINT32 tableSize)
+    { _tableSize = tableSize;  }
+  UINT32 GetPrice(UINT32 symbol, UINT32 posState) const
+    { return _prices[symbol][posState]; }
+  void UpdateTable(UINT32 posState)
+  {
+    for (UINT32 len = 0; len < _tableSize; len++)
+      _prices[len][posState] = CEncoder::GetPrice(len , posState);
+    _counters[posState] = _tableSize;
+  }
+  void UpdateTables()
+  {
+    for (UINT32 posState = 0; posState < _numPosStates; posState++)
+      UpdateTable(posState);
+  }
+  void Encode(NRangeCoder::CEncoder *rangeEncoder, UINT32 symbol, UINT32 posState)
+  {
+    CEncoder::Encode(rangeEncoder, symbol, posState);
+    if (--_counters[posState] == 0)
+      UpdateTable(posState);
+  }
+};
+
+
+class CDecoder
+{
+  NRangeCoder::CBitDecoder<kNumMoveBits> _choice;
+  NRangeCoder::CBitTreeDecoder<kNumMoveBits, kNumLenBits>  _lowCoder[kNumPosStatesMax];
+  NRangeCoder::CBitDecoder<kNumMoveBits> _choice2;
+  NRangeCoder::CBitTreeDecoder<kNumMoveBits, kNumMidBits>  _midCoder[kNumPosStatesMax];
+  NRangeCoder::CBitTreeDecoder<kNumMoveBits, kNumHighBits> _highCoder; 
+  UINT32 _numPosStates;
+public:
+  void Create(UINT32 numPosStates)
+    { _numPosStates = numPosStates; }
+  void Init()
+  {
+    _choice.Init();
+    for (UINT32 posState = 0; posState < _numPosStates; posState++)
+    {
+      _lowCoder[posState].Init();
+      _midCoder[posState].Init();
+    }
+    _choice2.Init();
+    _highCoder.Init();
+  }
+  UINT32 Decode(NRangeCoder::CDecoder *rangeDecoder, UINT32 posState)
+  {
+    if(_choice.Decode(rangeDecoder) == 0)
+      return _lowCoder[posState].Decode(rangeDecoder);
+    if(_choice2.Decode(rangeDecoder) == 0)
+      return kNumLowSymbols + _midCoder[posState].Decode(rangeDecoder);
+    return kNumLowSymbols + kNumMidSymbols + _highCoder.Decode(rangeDecoder);
+  }
+};
+
+}}}
+
+#endif