| /* 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); |
| } |
| } |