/* 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); | |
} | |
} |