1 /* Ppmd7.h -- PPMdH compression codec
2 2017-04-03 : Igor Pavlov : Public domain
3 This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
4 
5 /* This code supports virtual RangeDecoder and includes the implementation
6 of RangeCoder from 7z, instead of RangeCoder from original PPMd var.H.
7 If you need the compatibility with original PPMd var.H, you can use external RangeDecoder */
8 
9 #ifndef __PPMD7_H
10 #define __PPMD7_H
11 
12 #include "Ppmd.h"
13 
14 EXTERN_C_BEGIN
15 
16 #define PPMD7_MIN_ORDER 2
17 #define PPMD7_MAX_ORDER 64
18 
19 #define PPMD7_MIN_MEM_SIZE (1 << 11)
20 #define PPMD7_MAX_MEM_SIZE (0xFFFFFFFF - 12 * 3)
21 
22 struct CPpmd7_Context_;
23 
24 typedef
25   #ifdef PPMD_32BIT
26     struct CPpmd7_Context_ *
27   #else
28     UInt32
29   #endif
30   CPpmd7_Context_Ref;
31 
32 typedef struct CPpmd7_Context_
33 {
34   UInt16 NumStats;
35   UInt16 SummFreq;
36   CPpmd_State_Ref Stats;
37   CPpmd7_Context_Ref Suffix;
38 } CPpmd7_Context;
39 
40 #define Ppmd7Context_OneState(p) ((CPpmd_State *)&(p)->SummFreq)
41 
42 typedef struct
43 {
44   CPpmd7_Context *MinContext, *MaxContext;
45   CPpmd_State *FoundState;
46   unsigned OrderFall, InitEsc, PrevSuccess, MaxOrder, HiBitsFlag;
47   Int32 RunLength, InitRL; /* must be 32-bit at least */
48 
49   UInt32 Size;
50   UInt32 GlueCount;
51   Byte *Base, *LoUnit, *HiUnit, *Text, *UnitsStart;
52   UInt32 AlignOffset;
53 
54   Byte Indx2Units[PPMD_NUM_INDEXES];
55   Byte Units2Indx[128];
56   CPpmd_Void_Ref FreeList[PPMD_NUM_INDEXES];
57   Byte NS2Indx[256], NS2BSIndx[256], HB2Flag[256];
58   CPpmd_See DummySee, See[25][16];
59   UInt16 BinSumm[128][64];
60 } CPpmd7;
61 
62 void Ppmd7_Construct(CPpmd7 *p);
63 Bool Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAllocPtr alloc);
64 void Ppmd7_Free(CPpmd7 *p, ISzAllocPtr alloc);
65 void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder);
66 #define Ppmd7_WasAllocated(p) ((p)->Base != NULL)
67 
68 
69 /* ---------- Internal Functions ---------- */
70 
71 extern const Byte PPMD7_kExpEscape[16];
72 
73 #ifdef PPMD_32BIT
74   #define Ppmd7_GetPtr(p, ptr) (ptr)
75   #define Ppmd7_GetContext(p, ptr) (ptr)
76   #define Ppmd7_GetStats(p, ctx) ((ctx)->Stats)
77 #else
78   #define Ppmd7_GetPtr(p, offs) ((void *)((p)->Base + (offs)))
79   #define Ppmd7_GetContext(p, offs) ((CPpmd7_Context *)Ppmd7_GetPtr((p), (offs)))
80   #define Ppmd7_GetStats(p, ctx) ((CPpmd_State *)Ppmd7_GetPtr((p), ((ctx)->Stats)))
81 #endif
82 
83 void Ppmd7_Update1(CPpmd7 *p);
84 void Ppmd7_Update1_0(CPpmd7 *p);
85 void Ppmd7_Update2(CPpmd7 *p);
86 void Ppmd7_UpdateBin(CPpmd7 *p);
87 
88 #define Ppmd7_GetBinSumm(p) \
89     &p->BinSumm[(size_t)(unsigned)Ppmd7Context_OneState(p->MinContext)->Freq - 1][p->PrevSuccess + \
90     p->NS2BSIndx[(size_t)Ppmd7_GetContext(p, p->MinContext->Suffix)->NumStats - 1] + \
91     (p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]) + \
92     2 * p->HB2Flag[(unsigned)Ppmd7Context_OneState(p->MinContext)->Symbol] + \
93     ((p->RunLength >> 26) & 0x20)]
94 
95 CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *scale);
96 
97 
98 /* ---------- Decode ---------- */
99 
100 typedef struct IPpmd7_RangeDec IPpmd7_RangeDec;
101 
102 struct IPpmd7_RangeDec
103 {
104   UInt32 (*GetThreshold)(const IPpmd7_RangeDec *p, UInt32 total);
105   void (*Decode)(const IPpmd7_RangeDec *p, UInt32 start, UInt32 size);
106   UInt32 (*DecodeBit)(const IPpmd7_RangeDec *p, UInt32 size0);
107 };
108 
109 typedef struct
110 {
111   IPpmd7_RangeDec vt;
112   UInt32 Range;
113   UInt32 Code;
114   IByteIn *Stream;
115 } CPpmd7z_RangeDec;
116 
117 void Ppmd7z_RangeDec_CreateVTable(CPpmd7z_RangeDec *p);
118 Bool Ppmd7z_RangeDec_Init(CPpmd7z_RangeDec *p);
119 #define Ppmd7z_RangeDec_IsFinishedOK(p) ((p)->Code == 0)
120 
121 int Ppmd7_DecodeSymbol(CPpmd7 *p, const IPpmd7_RangeDec *rc);
122 
123 
124 /* ---------- Encode ---------- */
125 
126 typedef struct
127 {
128   UInt64 Low;
129   UInt32 Range;
130   Byte Cache;
131   UInt64 CacheSize;
132   IByteOut *Stream;
133 } CPpmd7z_RangeEnc;
134 
135 void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p);
136 void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p);
137 
138 void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol);
139 
140 EXTERN_C_END
141 
142 #endif
143