diff options
Diffstat (limited to '7zip/Compress/PPMD/PPMDDecode.h')
-rwxr-xr-x | 7zip/Compress/PPMD/PPMDDecode.h | 137 |
1 files changed, 0 insertions, 137 deletions
diff --git a/7zip/Compress/PPMD/PPMDDecode.h b/7zip/Compress/PPMD/PPMDDecode.h deleted file mode 100755 index 5eddcdf4..00000000 --- a/7zip/Compress/PPMD/PPMDDecode.h +++ /dev/null @@ -1,137 +0,0 @@ -// PPMDDecode.h -// This code is based on Dmitry Shkarin's PPMdH code - -#ifndef __COMPRESS_PPMD_DECODE_H -#define __COMPRESS_PPMD_DECODE_H - -#include "PPMDContext.h" - -namespace NCompress { -namespace NPPMD { - -struct CDecodeInfo: public CInfo -{ - void DecodeBinSymbol(NRangeCoder::CDecoder *rangeDecoder) - { - PPM_CONTEXT::STATE& rs = MinContext->oneState(); - UInt16& bs = GetBinSumm(rs, GetContextNoCheck(MinContext->Suffix)->NumStats); - if (rangeDecoder->DecodeBit(bs, TOT_BITS) == 0) - { - FoundState = &rs; - rs.Freq = (Byte)(rs.Freq + (rs.Freq < 128 ? 1: 0)); - bs = (UInt16)(bs + INTERVAL - GET_MEAN(bs, PERIOD_BITS, 2)); - PrevSuccess = 1; - RunLength++; - } - else - { - bs = (UInt16)(bs - GET_MEAN(bs, PERIOD_BITS, 2)); - InitEsc = ExpEscape[bs >> 10]; - NumMasked = 1; - CharMask[rs.Symbol] = EscCount; - PrevSuccess = 0; - FoundState = NULL; - } - } - - void DecodeSymbol1(NRangeCoder::CDecoder *rangeDecoder) - { - PPM_CONTEXT::STATE* p = GetStateNoCheck(MinContext->Stats); - int i, count, hiCnt; - if ((count = rangeDecoder->GetThreshold(MinContext->SummFreq)) < (hiCnt = p->Freq)) - { - PrevSuccess = (2 * hiCnt > MinContext->SummFreq); - RunLength += PrevSuccess; - rangeDecoder->Decode(0, p->Freq); // MinContext->SummFreq); - (FoundState = p)->Freq = (Byte)(hiCnt += 4); - MinContext->SummFreq += 4; - if (hiCnt > MAX_FREQ) - rescale(); - return; - } - PrevSuccess = 0; - i = MinContext->NumStats - 1; - while ((hiCnt += (++p)->Freq) <= count) - if (--i == 0) - { - HiBitsFlag = HB2Flag[FoundState->Symbol]; - rangeDecoder->Decode(hiCnt, MinContext->SummFreq - hiCnt); // , MinContext->SummFreq); - CharMask[p->Symbol] = EscCount; - i = (NumMasked = MinContext->NumStats)-1; - FoundState = NULL; - do { CharMask[(--p)->Symbol] = EscCount; } while ( --i ); - return; - } - rangeDecoder->Decode(hiCnt - p->Freq, p->Freq); // , MinContext->SummFreq); - update1(p); - } - - - void DecodeSymbol2(NRangeCoder::CDecoder *rangeDecoder) - { - int count, hiCnt, i = MinContext->NumStats - NumMasked; - UInt32 freqSum; - SEE2_CONTEXT* psee2c = makeEscFreq2(i, freqSum); - PPM_CONTEXT::STATE* ps[256], ** pps = ps, * p = GetStateNoCheck(MinContext->Stats)-1; - hiCnt = 0; - do - { - do { p++; } while (CharMask[p->Symbol] == EscCount); - hiCnt += p->Freq; - *pps++ = p; - } - while ( --i ); - - freqSum += hiCnt; - count = rangeDecoder->GetThreshold(freqSum); - - p = *(pps = ps); - if (count < hiCnt) - { - hiCnt = 0; - while ((hiCnt += p->Freq) <= count) - p=*++pps; - rangeDecoder->Decode(hiCnt - p->Freq, p->Freq); // , freqSum); - - psee2c->update(); - update2(p); - } - else - { - rangeDecoder->Decode(hiCnt, freqSum - hiCnt); // , freqSum); - - i = MinContext->NumStats - NumMasked; - pps--; - do { CharMask[(*++pps)->Symbol] = EscCount; } while ( --i ); - psee2c->Summ = (UInt16)(psee2c->Summ + freqSum); - NumMasked = MinContext->NumStats; - } - } - - int DecodeSymbol(NRangeCoder::CDecoder *rangeDecoder) - { - if (MinContext->NumStats != 1) - DecodeSymbol1(rangeDecoder); - else - DecodeBinSymbol(rangeDecoder); - while ( !FoundState ) - { - do - { - OrderFall++; - MinContext = GetContext(MinContext->Suffix); - if (MinContext == 0) - return -1; - } - while (MinContext->NumStats == NumMasked); - DecodeSymbol2(rangeDecoder); - } - Byte symbol = FoundState->Symbol; - NextContext(); - return symbol; - } -}; - -}} - -#endif |