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1 /* Ppmd7.h -- Ppmd7 (PPMdH) compression codec
2 2021-04-13 : Igor Pavlov : Public domain
3 This code is based on:
4   PPMd var.H (2001): Dmitry Shkarin : Public domain */
5 
6 
7 #ifndef __PPMD7_H
8 #define __PPMD7_H
9 
10 #include "Ppmd.h"
11 
12 EXTERN_C_BEGIN
13 
14 #define PPMD7_MIN_ORDER 2
15 #define PPMD7_MAX_ORDER 64
16 
17 #define PPMD7_MIN_MEM_SIZE (1 << 11)
18 #define PPMD7_MAX_MEM_SIZE (0xFFFFFFFF - 12 * 3)
19 
20 struct CPpmd7_Context_;
21 
22 typedef Ppmd_Ref_Type(struct CPpmd7_Context_) CPpmd7_Context_Ref;
23 
24 // MY_CPU_pragma_pack_push_1
25 
26 typedef struct CPpmd7_Context_
27 {
28   UInt16 NumStats;
29 
30 
31   union
32   {
33     UInt16 SummFreq;
34     CPpmd_State2 State2;
35   } Union2;
36 
37   union
38   {
39     CPpmd_State_Ref Stats;
40     CPpmd_State4 State4;
41   } Union4;
42 
43   CPpmd7_Context_Ref Suffix;
44 } CPpmd7_Context;
45 
46 // MY_CPU_pragma_pop
47 
48 #define Ppmd7Context_OneState(p) ((CPpmd_State *)&(p)->Union2)
49 
50 
51 
52 
53 typedef struct
54 {
55   UInt32 Range;
56   UInt32 Code;
57   UInt32 Low;
58   IByteIn *Stream;
59 } CPpmd7_RangeDec;
60 
61 
62 typedef struct
63 {
64   UInt32 Range;
65   Byte Cache;
66   // Byte _dummy_[3];
67   UInt64 Low;
68   UInt64 CacheSize;
69   IByteOut *Stream;
70 } CPpmd7z_RangeEnc;
71 
72 
73 typedef struct
74 {
75   CPpmd7_Context *MinContext, *MaxContext;
76   CPpmd_State *FoundState;
77   unsigned OrderFall, InitEsc, PrevSuccess, MaxOrder, HiBitsFlag;
78   Int32 RunLength, InitRL; /* must be 32-bit at least */
79 
80   UInt32 Size;
81   UInt32 GlueCount;
82   UInt32 AlignOffset;
83   Byte *Base, *LoUnit, *HiUnit, *Text, *UnitsStart;
84 
85 
86 
87 
88   union
89   {
90     CPpmd7_RangeDec dec;
91     CPpmd7z_RangeEnc enc;
92   } rc;
93 
94   Byte Indx2Units[PPMD_NUM_INDEXES + 2]; // +2 for alignment
95   Byte Units2Indx[128];
96   CPpmd_Void_Ref FreeList[PPMD_NUM_INDEXES];
97 
98   Byte NS2BSIndx[256], NS2Indx[256];
99   Byte ExpEscape[16];
100   CPpmd_See DummySee, See[25][16];
101   UInt16 BinSumm[128][64];
102   // int LastSymbol;
103 } CPpmd7;
104 
105 
106 void Ppmd7_Construct(CPpmd7 *p);
107 BoolInt Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAllocPtr alloc);
108 void Ppmd7_Free(CPpmd7 *p, ISzAllocPtr alloc);
109 void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder);
110 #define Ppmd7_WasAllocated(p) ((p)->Base != NULL)
111 
112 
113 /* ---------- Internal Functions ---------- */
114 
115 #define Ppmd7_GetPtr(p, ptr)     Ppmd_GetPtr(p, ptr)
116 #define Ppmd7_GetContext(p, ptr) Ppmd_GetPtr_Type(p, ptr, CPpmd7_Context)
117 #define Ppmd7_GetStats(p, ctx)   Ppmd_GetPtr_Type(p, (ctx)->Union4.Stats, CPpmd_State)
118 
119 void Ppmd7_Update1(CPpmd7 *p);
120 void Ppmd7_Update1_0(CPpmd7 *p);
121 void Ppmd7_Update2(CPpmd7 *p);
122 
123 #define PPMD7_HiBitsFlag_3(sym) ((((unsigned)sym + 0xC0) >> (8 - 3)) & (1 << 3))
124 #define PPMD7_HiBitsFlag_4(sym) ((((unsigned)sym + 0xC0) >> (8 - 4)) & (1 << 4))
125 // #define PPMD7_HiBitsFlag_3(sym) ((sym) < 0x40 ? 0 : (1 << 3))
126 // #define PPMD7_HiBitsFlag_4(sym) ((sym) < 0x40 ? 0 : (1 << 4))
127 
128 #define Ppmd7_GetBinSumm(p) \
129     &p->BinSumm[(size_t)(unsigned)Ppmd7Context_OneState(p->MinContext)->Freq - 1] \
130     [ p->PrevSuccess + ((p->RunLength >> 26) & 0x20) \
131     + p->NS2BSIndx[(size_t)Ppmd7_GetContext(p, p->MinContext->Suffix)->NumStats - 1] \
132     + PPMD7_HiBitsFlag_4(Ppmd7Context_OneState(p->MinContext)->Symbol) \
133     + (p->HiBitsFlag = PPMD7_HiBitsFlag_3(p->FoundState->Symbol)) ]
134 
135 CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *scale);
136 
137 
138 /*
139 We support two versions of Ppmd7 (PPMdH) methods that use same CPpmd7 structure:
140   1) Ppmd7a_*: original PPMdH
141   2) Ppmd7z_*: modified PPMdH with 7z Range Coder
142 Ppmd7_*: the structures and functions that are common for both versions of PPMd7 (PPMdH)
143 */
144 
145 /* ---------- Decode ---------- */
146 
147 #define PPMD7_SYM_END    (-1)
148 #define PPMD7_SYM_ERROR  (-2)
149 
150 /*
151 You must set (CPpmd7::rc.dec.Stream) before Ppmd7*_RangeDec_Init()
152 
153 Ppmd7*_DecodeSymbol()
154 out:
155   >= 0 : decoded byte
156     -1 : PPMD7_SYM_END   : End of payload marker
157     -2 : PPMD7_SYM_ERROR : Data error
158 */
159 
160 /* Ppmd7a_* : original PPMdH */
161 BoolInt Ppmd7a_RangeDec_Init(CPpmd7_RangeDec *p);
162 #define Ppmd7a_RangeDec_IsFinishedOK(p) ((p)->Code == 0)
163 int Ppmd7a_DecodeSymbol(CPpmd7 *p);
164 
165 /* Ppmd7z_* : modified PPMdH with 7z Range Coder */
166 BoolInt Ppmd7z_RangeDec_Init(CPpmd7_RangeDec *p);
167 #define Ppmd7z_RangeDec_IsFinishedOK(p) ((p)->Code == 0)
168 int Ppmd7z_DecodeSymbol(CPpmd7 *p);
169 // Byte *Ppmd7z_DecodeSymbols(CPpmd7 *p, Byte *buf, const Byte *lim);
170 
171 
172 /* ---------- Encode ---------- */
173 
174 void Ppmd7z_Init_RangeEnc(CPpmd7 *p);
175 void Ppmd7z_Flush_RangeEnc(CPpmd7 *p);
176 // void Ppmd7z_EncodeSymbol(CPpmd7 *p, int symbol);
177 void Ppmd7z_EncodeSymbols(CPpmd7 *p, const Byte *buf, const Byte *lim);
178 
179 EXTERN_C_END
180 
181 #endif
182