1/* Ppmd7Enc.c -- PPMdH Encoder 22010-03-12 : Igor Pavlov : Public domain 3This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */ 4 5#include "Ppmd7.h" 6 7#define kTopValue (1 << 24) 8 9void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p) 10{ 11 p->Low = 0; 12 p->Range = 0xFFFFFFFF; 13 p->Cache = 0; 14 p->CacheSize = 1; 15} 16 17static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p) 18{ 19 if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0) 20 { 21 Byte temp = p->Cache; 22 do 23 { 24 p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32))); 25 temp = 0xFF; 26 } 27 while(--p->CacheSize != 0); 28 p->Cache = (Byte)((UInt32)p->Low >> 24); 29 } 30 p->CacheSize++; 31 p->Low = (UInt32)p->Low << 8; 32} 33 34static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total) 35{ 36 p->Low += start * (p->Range /= total); 37 p->Range *= size; 38 while (p->Range < kTopValue) 39 { 40 p->Range <<= 8; 41 RangeEnc_ShiftLow(p); 42 } 43} 44 45static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0) 46{ 47 p->Range = (p->Range >> 14) * size0; 48 while (p->Range < kTopValue) 49 { 50 p->Range <<= 8; 51 RangeEnc_ShiftLow(p); 52 } 53} 54 55static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0) 56{ 57 UInt32 newBound = (p->Range >> 14) * size0; 58 p->Low += newBound; 59 p->Range -= newBound; 60 while (p->Range < kTopValue) 61 { 62 p->Range <<= 8; 63 RangeEnc_ShiftLow(p); 64 } 65} 66 67void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p) 68{ 69 unsigned i; 70 for (i = 0; i < 5; i++) 71 RangeEnc_ShiftLow(p); 72} 73 74 75#define MASK(sym) ((signed char *)charMask)[sym] 76 77void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol) 78{ 79 size_t charMask[256 / sizeof(size_t)]; 80 if (p->MinContext->NumStats != 1) 81 { 82 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 83 UInt32 sum; 84 unsigned i; 85 if (s->Symbol == symbol) 86 { 87 RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq); 88 p->FoundState = s; 89 Ppmd7_Update1_0(p); 90 return; 91 } 92 p->PrevSuccess = 0; 93 sum = s->Freq; 94 i = p->MinContext->NumStats - 1; 95 do 96 { 97 if ((++s)->Symbol == symbol) 98 { 99 RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq); 100 p->FoundState = s; 101 Ppmd7_Update1(p); 102 return; 103 } 104 sum += s->Freq; 105 } 106 while (--i); 107 108 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 109 PPMD_SetAllBitsIn256Bytes(charMask); 110 MASK(s->Symbol) = 0; 111 i = p->MinContext->NumStats - 1; 112 do { MASK((--s)->Symbol) = 0; } while (--i); 113 RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq); 114 } 115 else 116 { 117 UInt16 *prob = Ppmd7_GetBinSumm(p); 118 CPpmd_State *s = Ppmd7Context_OneState(p->MinContext); 119 if (s->Symbol == symbol) 120 { 121 RangeEnc_EncodeBit_0(rc, *prob); 122 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 123 p->FoundState = s; 124 Ppmd7_UpdateBin(p); 125 return; 126 } 127 else 128 { 129 RangeEnc_EncodeBit_1(rc, *prob); 130 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 131 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 132 PPMD_SetAllBitsIn256Bytes(charMask); 133 MASK(s->Symbol) = 0; 134 p->PrevSuccess = 0; 135 } 136 } 137 for (;;) 138 { 139 UInt32 escFreq; 140 CPpmd_See *see; 141 CPpmd_State *s; 142 UInt32 sum; 143 unsigned i, numMasked = p->MinContext->NumStats; 144 do 145 { 146 p->OrderFall++; 147 if (!p->MinContext->Suffix) 148 return; /* EndMarker (symbol = -1) */ 149 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 150 } 151 while (p->MinContext->NumStats == numMasked); 152 153 see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq); 154 s = Ppmd7_GetStats(p, p->MinContext); 155 sum = 0; 156 i = p->MinContext->NumStats; 157 do 158 { 159 int cur = s->Symbol; 160 if (cur == symbol) 161 { 162 UInt32 low = sum; 163 CPpmd_State *s1 = s; 164 do 165 { 166 sum += (s->Freq & (int)(MASK(s->Symbol))); 167 s++; 168 } 169 while (--i); 170 RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq); 171 Ppmd_See_Update(see); 172 p->FoundState = s1; 173 Ppmd7_Update2(p); 174 return; 175 } 176 sum += (s->Freq & (int)(MASK(cur))); 177 MASK(cur) = 0; 178 s++; 179 } 180 while (--i); 181 182 RangeEnc_Encode(rc, sum, escFreq, sum + escFreq); 183 see->Summ = (UInt16)(see->Summ + sum + escFreq); 184 } 185} 186