1 /* Ppmd7Enc.c -- PPMdH Encoder
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2 2010-03-12 : Igor Pavlov : Public domain
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3 This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
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7 #define kTopValue (1 << 24)
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9 void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p)
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12 p->Range = 0xFFFFFFFF;
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17 static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p)
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19 if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0)
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21 Byte temp = p->Cache;
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24 p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32)));
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27 while(--p->CacheSize != 0);
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28 p->Cache = (Byte)((UInt32)p->Low >> 24);
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31 p->Low = (UInt32)p->Low << 8;
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34 static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total)
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36 p->Low += start * (p->Range /= total);
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38 while (p->Range < kTopValue)
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41 RangeEnc_ShiftLow(p);
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45 static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0)
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47 p->Range = (p->Range >> 14) * size0;
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48 while (p->Range < kTopValue)
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51 RangeEnc_ShiftLow(p);
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55 static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0)
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57 UInt32 newBound = (p->Range >> 14) * size0;
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59 p->Range -= newBound;
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60 while (p->Range < kTopValue)
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63 RangeEnc_ShiftLow(p);
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67 void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p)
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70 for (i = 0; i < 5; i++)
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71 RangeEnc_ShiftLow(p);
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75 #define MASK(sym) ((signed char *)charMask)[sym]
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77 void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol)
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79 size_t charMask[256 / sizeof(size_t)];
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80 if (p->MinContext->NumStats != 1)
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82 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext);
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85 if (s->Symbol == symbol)
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87 RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq);
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94 i = p->MinContext->NumStats - 1;
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97 if ((++s)->Symbol == symbol)
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99 RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq);
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108 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol];
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109 PPMD_SetAllBitsIn256Bytes(charMask);
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110 MASK(s->Symbol) = 0;
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111 i = p->MinContext->NumStats - 1;
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112 do { MASK((--s)->Symbol) = 0; } while (--i);
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113 RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq);
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117 UInt16 *prob = Ppmd7_GetBinSumm(p);
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118 CPpmd_State *s = Ppmd7Context_OneState(p->MinContext);
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119 if (s->Symbol == symbol)
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121 RangeEnc_EncodeBit_0(rc, *prob);
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122 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
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124 Ppmd7_UpdateBin(p);
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129 RangeEnc_EncodeBit_1(rc, *prob);
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130 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
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131 p->InitEsc = PPMD7_kExpEscape[*prob >> 10];
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132 PPMD_SetAllBitsIn256Bytes(charMask);
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133 MASK(s->Symbol) = 0;
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134 p->PrevSuccess = 0;
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143 unsigned i, numMasked = p->MinContext->NumStats;
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147 if (!p->MinContext->Suffix)
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148 return; /* EndMarker (symbol = -1) */
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149 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix);
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151 while (p->MinContext->NumStats == numMasked);
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153 see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq);
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154 s = Ppmd7_GetStats(p, p->MinContext);
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156 i = p->MinContext->NumStats;
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159 int cur = s->Symbol;
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163 CPpmd_State *s1 = s;
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166 sum += (s->Freq & (int)(MASK(s->Symbol)));
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170 RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq);
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171 Ppmd_See_Update(see);
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172 p->FoundState = s1;
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176 sum += (s->Freq & (int)(MASK(cur)));
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182 RangeEnc_Encode(rc, sum, escFreq, sum + escFreq);
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183 see->Summ = (UInt16)(see->Summ + sum + escFreq);
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