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/* Ppmd7Enc.c -- PPMdH Encoder↩
2017-04-03 : Igor Pavlov : Public domain↩
This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */↩
↩
#include "Precomp.h"↩
↩
#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↩
{↩
IByteOut_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);↩
}↩
}↩