From d75dbab0de7da33196f08f0cf7992d906ffbb832 Mon Sep 17 00:00:00 2001 From: "R. Belmont" Date: Sun, 12 Feb 2012 17:55:51 +0000 Subject: Add LZMA codec and .7z container support [David Haywood, R. Belmont] --- src/lib/lib7z/Ppmd7Enc.c | 185 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 src/lib/lib7z/Ppmd7Enc.c (limited to 'src/lib/lib7z/Ppmd7Enc.c') diff --git a/src/lib/lib7z/Ppmd7Enc.c b/src/lib/lib7z/Ppmd7Enc.c new file mode 100644 index 00000000000..8247757d09d --- /dev/null +++ b/src/lib/lib7z/Ppmd7Enc.c @@ -0,0 +1,185 @@ +/* Ppmd7Enc.c -- PPMdH Encoder +2010-03-12 : Igor Pavlov : Public domain +This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */ + +#include "Ppmd7.h" + +#define kTopValue (1 << 24) + +void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p) +{ + p->Low = 0; + p->Range = 0xFFFFFFFF; + p->Cache = 0; + p->CacheSize = 1; +} + +static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p) +{ + if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0) + { + Byte temp = p->Cache; + do + { + p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32))); + temp = 0xFF; + } + while(--p->CacheSize != 0); + p->Cache = (Byte)((UInt32)p->Low >> 24); + } + p->CacheSize++; + p->Low = (UInt32)p->Low << 8; +} + +static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total) +{ + p->Low += start * (p->Range /= total); + p->Range *= size; + while (p->Range < kTopValue) + { + p->Range <<= 8; + RangeEnc_ShiftLow(p); + } +} + +static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0) +{ + p->Range = (p->Range >> 14) * size0; + while (p->Range < kTopValue) + { + p->Range <<= 8; + RangeEnc_ShiftLow(p); + } +} + +static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0) +{ + UInt32 newBound = (p->Range >> 14) * size0; + p->Low += newBound; + p->Range -= newBound; + while (p->Range < kTopValue) + { + p->Range <<= 8; + RangeEnc_ShiftLow(p); + } +} + +void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p) +{ + unsigned i; + for (i = 0; i < 5; i++) + RangeEnc_ShiftLow(p); +} + + +#define MASK(sym) ((signed char *)charMask)[sym] + +void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol) +{ + size_t charMask[256 / sizeof(size_t)]; + if (p->MinContext->NumStats != 1) + { + CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); + UInt32 sum; + unsigned i; + if (s->Symbol == symbol) + { + RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq); + p->FoundState = s; + Ppmd7_Update1_0(p); + return; + } + p->PrevSuccess = 0; + sum = s->Freq; + i = p->MinContext->NumStats - 1; + do + { + if ((++s)->Symbol == symbol) + { + RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq); + p->FoundState = s; + Ppmd7_Update1(p); + return; + } + sum += s->Freq; + } + while (--i); + + p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; + PPMD_SetAllBitsIn256Bytes(charMask); + MASK(s->Symbol) = 0; + i = p->MinContext->NumStats - 1; + do { MASK((--s)->Symbol) = 0; } while (--i); + RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq); + } + else + { + UInt16 *prob = Ppmd7_GetBinSumm(p); + CPpmd_State *s = Ppmd7Context_OneState(p->MinContext); + if (s->Symbol == symbol) + { + RangeEnc_EncodeBit_0(rc, *prob); + *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); + p->FoundState = s; + Ppmd7_UpdateBin(p); + return; + } + else + { + RangeEnc_EncodeBit_1(rc, *prob); + *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); + p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; + PPMD_SetAllBitsIn256Bytes(charMask); + MASK(s->Symbol) = 0; + p->PrevSuccess = 0; + } + } + for (;;) + { + UInt32 escFreq; + CPpmd_See *see; + CPpmd_State *s; + UInt32 sum; + unsigned i, numMasked = p->MinContext->NumStats; + do + { + p->OrderFall++; + if (!p->MinContext->Suffix) + return; /* EndMarker (symbol = -1) */ + p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); + } + while (p->MinContext->NumStats == numMasked); + + see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq); + s = Ppmd7_GetStats(p, p->MinContext); + sum = 0; + i = p->MinContext->NumStats; + do + { + int cur = s->Symbol; + if (cur == symbol) + { + UInt32 low = sum; + CPpmd_State *s1 = s; + do + { + sum += (s->Freq & (int)(MASK(s->Symbol))); + s++; + } + while (--i); + RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq); + Ppmd_See_Update(see); + p->FoundState = s1; + Ppmd7_Update2(p); + return; + } + sum += (s->Freq & (int)(MASK(cur))); + MASK(cur) = 0; + s++; + } + while (--i); + + RangeEnc_Encode(rc, sum, escFreq, sum + escFreq); + see->Summ = (UInt16)(see->Summ + sum + escFreq); + } +} -- cgit v1.2.3