1 /* Ppmd7Enc.c -- PPMdH Encoder
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2 2015-09-28 : 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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9 #define kTopValue (1 << 24)
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11 void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p)
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14 p->Range = 0xFFFFFFFF;
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19 static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p)
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21 if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0)
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23 Byte temp = p->Cache;
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26 p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32)));
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29 while (--p->CacheSize != 0);
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30 p->Cache = (Byte)((UInt32)p->Low >> 24);
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33 p->Low = (UInt32)p->Low << 8;
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36 static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total)
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38 p->Low += start * (p->Range /= total);
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40 while (p->Range < kTopValue)
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43 RangeEnc_ShiftLow(p);
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47 static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0)
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49 p->Range = (p->Range >> 14) * size0;
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50 while (p->Range < kTopValue)
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53 RangeEnc_ShiftLow(p);
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57 static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0)
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59 UInt32 newBound = (p->Range >> 14) * size0;
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61 p->Range -= newBound;
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62 while (p->Range < kTopValue)
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65 RangeEnc_ShiftLow(p);
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69 void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p)
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72 for (i = 0; i < 5; i++)
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73 RangeEnc_ShiftLow(p);
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77 #define MASK(sym) ((signed char *)charMask)[sym]
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79 void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol)
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81 size_t charMask[256 / sizeof(size_t)];
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82 if (p->MinContext->NumStats != 1)
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84 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext);
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87 if (s->Symbol == symbol)
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89 RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq);
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96 i = p->MinContext->NumStats - 1;
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99 if ((++s)->Symbol == symbol)
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101 RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq);
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110 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol];
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111 PPMD_SetAllBitsIn256Bytes(charMask);
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112 MASK(s->Symbol) = 0;
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113 i = p->MinContext->NumStats - 1;
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114 do { MASK((--s)->Symbol) = 0; } while (--i);
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115 RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq);
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119 UInt16 *prob = Ppmd7_GetBinSumm(p);
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120 CPpmd_State *s = Ppmd7Context_OneState(p->MinContext);
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121 if (s->Symbol == symbol)
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123 RangeEnc_EncodeBit_0(rc, *prob);
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124 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
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126 Ppmd7_UpdateBin(p);
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131 RangeEnc_EncodeBit_1(rc, *prob);
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132 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
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133 p->InitEsc = PPMD7_kExpEscape[*prob >> 10];
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134 PPMD_SetAllBitsIn256Bytes(charMask);
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135 MASK(s->Symbol) = 0;
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136 p->PrevSuccess = 0;
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145 unsigned i, numMasked = p->MinContext->NumStats;
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149 if (!p->MinContext->Suffix)
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150 return; /* EndMarker (symbol = -1) */
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151 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix);
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153 while (p->MinContext->NumStats == numMasked);
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155 see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq);
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156 s = Ppmd7_GetStats(p, p->MinContext);
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158 i = p->MinContext->NumStats;
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161 int cur = s->Symbol;
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165 CPpmd_State *s1 = s;
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168 sum += (s->Freq & (int)(MASK(s->Symbol)));
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172 RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq);
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173 Ppmd_See_Update(see);
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174 p->FoundState = s1;
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178 sum += (s->Freq & (int)(MASK(cur)));
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184 RangeEnc_Encode(rc, sum, escFreq, sum + escFreq);
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185 see->Summ = (UInt16)(see->Summ + sum + escFreq);
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