#ifndef _RAR_PPMMODEL_ #define _RAR_PPMMODEL_ #include "coder.hpp" #include "suballoc.hpp" const int MAX_O=64; /* maximum allowed model order */ const int INT_BITS=7, PERIOD_BITS=7, TOT_BITS=INT_BITS+PERIOD_BITS, INTERVAL=1 << INT_BITS, BIN_SCALE=1 << TOT_BITS, MAX_FREQ=124; #pragma pack(1) struct SEE2_CONTEXT { // SEE-contexts for PPM-contexts with masked symbols ushort Summ; byte Shift, Count; void init(int InitVal) { Summ=InitVal << (Shift=PERIOD_BITS-4); Count=4; } uint getMean() { uint RetVal=SHORT16(Summ) >> Shift; Summ -= RetVal; return RetVal+(RetVal == 0); } void update() { if (Shift < PERIOD_BITS && --Count == 0) { Summ += Summ; Count=3 << Shift++; } } } _PACK_ATTR; class ModelPPM; struct PPM_CONTEXT; struct STATE { byte Symbol; byte Freq; PPM_CONTEXT* Successor; }; struct FreqData { ushort SummFreq; STATE _PACK_ATTR * Stats; }; struct PPM_CONTEXT { ushort NumStats; union { FreqData U; STATE OneState; }; PPM_CONTEXT* Suffix; inline void encodeBinSymbol(ModelPPM *Model,int symbol); // MaxOrder: inline void encodeSymbol1(ModelPPM *Model,int symbol); // ABCD context inline void encodeSymbol2(ModelPPM *Model,int symbol); // BCD suffix inline void decodeBinSymbol(ModelPPM *Model); // BCDE successor inline bool decodeSymbol1(ModelPPM *Model); // other orders: inline bool decodeSymbol2(ModelPPM *Model); // BCD context inline void update1(ModelPPM *Model,STATE* p); // CD suffix inline void update2(ModelPPM *Model,STATE* p); // BCDE successor void rescale(ModelPPM *Model); inline PPM_CONTEXT* createChild(ModelPPM *Model,STATE* pStats,STATE& FirstState); inline SEE2_CONTEXT* makeEscFreq2(ModelPPM *Model,int Diff); }; #ifdef _AIX #pragma pack(pop) #else #pragma pack() #endif const uint UNIT_SIZE=sizeof(PPM_CONTEXT); const uint FIXED_UNIT_SIZE=12; /* inline PPM_CONTEXT::PPM_CONTEXT(STATE* pStats,PPM_CONTEXT* ShorterContext): NumStats(1), Suffix(ShorterContext) { pStats->Successor=this; } inline PPM_CONTEXT::PPM_CONTEXT(): NumStats(0) {} */ template inline void _PPMD_SWAP(T& t1,T& t2) { T tmp=t1; t1=t2; t2=tmp; } class ModelPPM { private: friend struct PPM_CONTEXT; SEE2_CONTEXT SEE2Cont[25][16], DummySEE2Cont; struct PPM_CONTEXT *MinContext, *MedContext, *MaxContext; STATE* FoundState; // found next state transition int NumMasked, InitEsc, OrderFall, MaxOrder, RunLength, InitRL; byte CharMask[256], NS2Indx[256], NS2BSIndx[256], HB2Flag[256]; byte EscCount, PrevSuccess, HiBitsFlag; ushort BinSumm[128][64]; // binary SEE-contexts RangeCoder Coder; SubAllocator SubAlloc; void RestartModelRare(); void StartModelRare(int MaxOrder); inline PPM_CONTEXT* CreateSuccessors(bool Skip,STATE* p1); inline void UpdateModel(); inline void ClearMask(); public: ModelPPM(); bool DecodeInit(Unpack *UnpackRead,int &EscChar); int DecodeChar(); }; #endif