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// PpmdEncode.h
// 2009-05-30 : Igor Pavlov : Public domain
// This code is based on Dmitry Shkarin's PPMdH code (public domain)
#ifndef __COMPRESS_PPMD_ENCODE_H
#define __COMPRESS_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();
UInt16 &bs = GetBinSumm(rs, GetContextNoCheck(MinContext->Suffix)->NumStats);
if (rs.Symbol == symbol)
{
FoundState = &rs;
rs.Freq = (Byte)(rs.Freq + (rs.Freq < 128 ? 1: 0));
rangeEncoder->EncodeBit(bs, TOT_BITS, 0);
bs = (UInt16)(bs + INTERVAL - GET_MEAN(bs, PERIOD_BITS, 2));
PrevSuccess = 1;
RunLength++;
}
else
{
rangeEncoder->EncodeBit(bs, TOT_BITS, 1);
bs = (UInt16)(bs - 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 = GetStateNoCheck(MinContext->Stats);
if (p->Symbol == symbol)
{
PrevSuccess = (2 * (p->Freq) > MinContext->SummFreq);
RunLength += PrevSuccess;
rangeEncoder->Encode(0, p->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 = GetStateNoCheck(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 = (UInt16)(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 = GetContext(MinContext->Suffix);
if (MinContext == 0)
return; // S_OK;
}
while (MinContext->NumStats == NumMasked);
EncodeSymbol2(c, rangeEncoder);
}
NextContext();
}
};
}}
#endif
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