3.13

7zip/Compress/PPMD/PPMDEncode.h

@@ -0,0 +1,144 @@
+// PPMDEncode.h
+// This code is based on Dmitry Shkarin's PPMdH code
+
+#pragma once
+
+#ifndef __COMPRESS_PPM_PPMD_ENCODE_H
+#define __COMPRESS_PPM_PPMD_ENCODE_H
+
+#include "PPMDContext.h"
+
+namespace NCompress {
+namespace NPPMD {
+
+struct CEncodeInfo: public CInfo
+{
+
+  void EncodeBinSymbol(int symbol, NRangeCoder::CEncoder *rangeEncoder)
+  {
+    PPM_CONTEXT::STATE& rs = MinContext->oneState();                   
+    WORD &bs = GetBinSumm(rs, MinContext->Suffix->NumStats);
+    if (rs.Symbol == symbol) 
+    {
+      FoundState = &rs;
+      rs.Freq += (rs.Freq < 128);
+      rangeEncoder->EncodeBit(bs, TOT_BITS, 0);
+      bs += UINT16(INTERVAL-GET_MEAN(bs,PERIOD_BITS, 2));
+      PrevSuccess = 1;
+      RunLength++;
+    } 
+    else 
+    {
+      rangeEncoder->EncodeBit(bs, TOT_BITS, 1);
+      bs -= UINT16(GET_MEAN(bs,PERIOD_BITS, 2));
+      InitEsc = ExpEscape[bs >> 10];
+      NumMasked = 1;                        
+      CharMask[rs.Symbol] = EscCount;
+      PrevSuccess = 0;                      
+      FoundState = NULL;
+    }
+  }
+
+  void EncodeSymbol1(int symbol, NRangeCoder::CEncoder *rangeEncoder)
+  {
+    PPM_CONTEXT::STATE* p = MinContext->Stats;
+    if (p->Symbol == symbol) 
+    {
+      PrevSuccess = (2 * (p->Freq) > MinContext->SummFreq);
+      RunLength += PrevSuccess;
+      rangeEncoder->Encode(0, MinContext->Stats->Freq, MinContext->SummFreq);
+      (FoundState = p)->Freq += 4;          
+      MinContext->SummFreq += 4;
+      if (p->Freq > MAX_FREQ)             
+        rescale();
+      return;
+    }
+    PrevSuccess = 0;
+    int LoCnt = p->Freq, i = MinContext->NumStats - 1;
+    while ((++p)->Symbol != symbol) 
+    {
+      LoCnt += p->Freq;
+      if (--i == 0) 
+      {
+        HiBitsFlag = HB2Flag[FoundState->Symbol];
+        CharMask[p->Symbol] = EscCount;
+        i=(NumMasked = MinContext->NumStats)-1;       
+        FoundState = NULL;
+        do { CharMask[(--p)->Symbol] = EscCount; } while ( --i );
+        rangeEncoder->Encode(LoCnt, MinContext->SummFreq - LoCnt, MinContext->SummFreq);
+        return;
+      }
+    }
+    rangeEncoder->Encode(LoCnt, p->Freq, MinContext->SummFreq);
+    update1(p);
+  }
+
+  void EncodeSymbol2(int symbol, NRangeCoder::CEncoder *rangeEncoder)
+  {
+    int hiCnt, i = MinContext->NumStats - NumMasked;
+    UINT32 scale;
+    SEE2_CONTEXT* psee2c = makeEscFreq2(i, scale);
+    PPM_CONTEXT::STATE* p = MinContext->Stats - 1;                       
+    hiCnt = 0;
+    do 
+    {
+      do { p++; } while (CharMask[p->Symbol] == EscCount);
+      hiCnt += p->Freq;
+      if (p->Symbol == symbol)            
+        goto SYMBOL_FOUND;
+      CharMask[p->Symbol] = EscCount;
+    } 
+    while ( --i );
+    
+    rangeEncoder->Encode(hiCnt, scale, hiCnt + scale);
+    scale += hiCnt;
+    
+    psee2c->Summ += scale;         
+    NumMasked = MinContext->NumStats;
+    return;
+SYMBOL_FOUND:
+    
+    UINT32 highCount = hiCnt;
+    UINT32 lowCount = highCount - p->Freq;
+    if ( --i ) 
+    {
+      PPM_CONTEXT::STATE* p1 = p;
+      do 
+      {
+        do { p1++; } while (CharMask[p1->Symbol] == EscCount);
+        hiCnt += p1->Freq;
+      } 
+      while ( --i );
+    }
+    // SubRange.scale += hiCnt;
+    scale += hiCnt;
+    rangeEncoder->Encode(lowCount, highCount - lowCount, scale);
+    psee2c->update();                       
+    update2(p);
+  }
+
+  void EncodeSymbol(int c, NRangeCoder::CEncoder *rangeEncoder)
+  {
+    if (MinContext->NumStats != 1) 
+      EncodeSymbol1(c, rangeEncoder);   
+    else 
+      EncodeBinSymbol(c, rangeEncoder); 
+    while ( !FoundState ) 
+    {
+      do 
+      {
+        OrderFall++;                
+        MinContext = MinContext->Suffix;
+        if ( !MinContext ) 
+          return; //  S_OK;
+      } 
+      while (MinContext->NumStats == NumMasked);
+      EncodeSymbol2(c, rangeEncoder);   
+    }
+    NextContext();
+  }
+
+};
+}}
+
+#endif