3.13

7zip/Compress/LZMA/LZMALiteral.cpp

@@ -0,0 +1,69 @@
+// LZMALiteral.cpp
+
+#include "StdAfx.h"
+
+#include "LZMALiteral.h"
+
+namespace NCompress {
+namespace NLZMA {
+namespace NLiteral {
+
+void CEncoder2::Init()
+{
+  for (int i = 0; i < 3; i++)
+    for (int j = 1; j < (1 << 8); j++)
+      _encoders[i][j].Init();
+}
+
+void CEncoder2::Encode(NRangeCoder::CEncoder *rangeEncoder, 
+    bool matchMode, BYTE matchByte, BYTE symbol)
+{
+  UINT32 context = 1;
+  bool same = true;
+  for (int i = 7; i >= 0; i--)
+  {
+    UINT32 bit = (symbol >> i) & 1;
+    UINT state;
+    if (matchMode && same)
+    {
+      UINT32 matchBit = (matchByte >> i) & 1;
+      state = 1 + matchBit;
+      same = (matchBit == bit);
+    }
+    else
+      state = 0;
+    _encoders[state][context].Encode(rangeEncoder, bit);
+    context = (context << 1) | bit;
+  }
+}
+
+UINT32 CEncoder2::GetPrice(bool matchMode, BYTE matchByte, BYTE symbol) const
+{
+  UINT32 price = 0;
+  UINT32 context = 1;
+  int i = 7;
+  if (matchMode)
+  {
+    for (; i >= 0; i--)
+    {
+      UINT32 matchBit = (matchByte >> i) & 1;
+      UINT32 bit = (symbol >> i) & 1;
+      price += _encoders[1 + matchBit][context].GetPrice(bit);
+      context = (context << 1) | bit;
+      if (matchBit != bit)
+      {
+        i--;
+        break;
+      }
+    }
+  }
+  for (; i >= 0; i--)
+  {
+    UINT32 bit = (symbol >> i) & 1;
+    price += _encoders[0][context].GetPrice(bit);
+    context = (context << 1) | bit;
+  }
+  return price;
+};
+
+}}}