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authorIgor Pavlov <ipavlov@users.sourceforge.net>2007-01-20 03:00:00 +0300
committerKornel LesiƄski <kornel@geekhood.net>2016-05-28 02:15:49 +0300
commitd9666cf046a8453b33b3e2fbf4d82295a9f87df3 (patch)
treec722ed19b844b53042aec0c1d7d2f8381140a5ed /CPP/7zip/Compress/PPMD/PPMDEncode.h
parent804edc5756fede54dbb1aefda6d39d306111938d (diff)
4.44 beta
Diffstat (limited to 'CPP/7zip/Compress/PPMD/PPMDEncode.h')
-rwxr-xr-xCPP/7zip/Compress/PPMD/PPMDEncode.h142
1 files changed, 142 insertions, 0 deletions
diff --git a/CPP/7zip/Compress/PPMD/PPMDEncode.h b/CPP/7zip/Compress/PPMD/PPMDEncode.h
new file mode 100755
index 00000000..6a720cac
--- /dev/null
+++ b/CPP/7zip/Compress/PPMD/PPMDEncode.h
@@ -0,0 +1,142 @@
+// PPMDEncode.h
+// This code is based on Dmitry Shkarin's PPMdH code
+
+#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