1 files changed, 181 insertions, 0 deletions

diff --git a/C/Ppmd8.h b/C/Ppmd8.h
new file mode 100644
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--- /dev/null
+++ b/C/Ppmd8.h
@@ -0,0 +1,181 @@
+/* Ppmd8.h -- Ppmd8 (PPMdI) compression codec
+2021-04-13 : Igor Pavlov : Public domain
+This code is based on:
+  PPMd var.I (2002): Dmitry Shkarin : Public domain
+  Carryless rangecoder (1999): Dmitry Subbotin : Public domain */
+
+#ifndef __PPMD8_H
+#define __PPMD8_H
+
+#include "Ppmd.h"
+
+EXTERN_C_BEGIN
+
+#define PPMD8_MIN_ORDER 2
+#define PPMD8_MAX_ORDER 16
+
+
+
+
+struct CPpmd8_Context_;
+
+typedef Ppmd_Ref_Type(struct CPpmd8_Context_) CPpmd8_Context_Ref;
+
+// MY_CPU_pragma_pack_push_1
+
+typedef struct CPpmd8_Context_
+{
+  Byte NumStats;
+  Byte Flags;
+  
+  union
+  {
+    UInt16 SummFreq;
+    CPpmd_State2 State2;
+  } Union2;
+  
+  union
+  {
+    CPpmd_State_Ref Stats;
+    CPpmd_State4 State4;
+  } Union4;
+
+  CPpmd8_Context_Ref Suffix;
+} CPpmd8_Context;
+
+// MY_CPU_pragma_pop
+
+#define Ppmd8Context_OneState(p) ((CPpmd_State *)&(p)->Union2)
+
+/* PPMdI code rev.2 contains the fix over PPMdI code rev.1.
+   But the code PPMdI.2 is not compatible with PPMdI.1 for some files compressed
+   in FREEZE mode. So we disable FREEZE mode support. */
+
+// #define PPMD8_FREEZE_SUPPORT
+
+enum
+{
+  PPMD8_RESTORE_METHOD_RESTART,
+  PPMD8_RESTORE_METHOD_CUT_OFF
+  #ifdef PPMD8_FREEZE_SUPPORT
+  , PPMD8_RESTORE_METHOD_FREEZE
+  #endif
+  , PPMD8_RESTORE_METHOD_UNSUPPPORTED
+};
+
+
+
+
+
+
+
+
+typedef struct
+{
+  CPpmd8_Context *MinContext, *MaxContext;
+  CPpmd_State *FoundState;
+  unsigned OrderFall, InitEsc, PrevSuccess, MaxOrder, RestoreMethod;
+  Int32 RunLength, InitRL; /* must be 32-bit at least */
+
+  UInt32 Size;
+  UInt32 GlueCount;
+  UInt32 AlignOffset;
+  Byte *Base, *LoUnit, *HiUnit, *Text, *UnitsStart;
+
+  UInt32 Range;
+  UInt32 Code;
+  UInt32 Low;
+  union
+  {
+    IByteIn *In;
+    IByteOut *Out;
+  } Stream;
+
+  Byte Indx2Units[PPMD_NUM_INDEXES + 2]; // +2 for alignment
+  Byte Units2Indx[128];
+  CPpmd_Void_Ref FreeList[PPMD_NUM_INDEXES];
+  UInt32 Stamps[PPMD_NUM_INDEXES];
+  Byte NS2BSIndx[256], NS2Indx[260];
+  Byte ExpEscape[16];
+  CPpmd_See DummySee, See[24][32];
+  UInt16 BinSumm[25][64];
+
+} CPpmd8;
+
+
+void Ppmd8_Construct(CPpmd8 *p);
+BoolInt Ppmd8_Alloc(CPpmd8 *p, UInt32 size, ISzAllocPtr alloc);
+void Ppmd8_Free(CPpmd8 *p, ISzAllocPtr alloc);
+void Ppmd8_Init(CPpmd8 *p, unsigned maxOrder, unsigned restoreMethod);
+#define Ppmd8_WasAllocated(p) ((p)->Base != NULL)
+
+
+/* ---------- Internal Functions ---------- */
+
+#define Ppmd8_GetPtr(p, ptr)     Ppmd_GetPtr(p, ptr)
+#define Ppmd8_GetContext(p, ptr) Ppmd_GetPtr_Type(p, ptr, CPpmd8_Context)
+#define Ppmd8_GetStats(p, ctx)   Ppmd_GetPtr_Type(p, (ctx)->Union4.Stats, CPpmd_State)
+
+void Ppmd8_Update1(CPpmd8 *p);
+void Ppmd8_Update1_0(CPpmd8 *p);
+void Ppmd8_Update2(CPpmd8 *p);
+
+
+
+
+
+
+#define Ppmd8_GetBinSumm(p) \
+    &p->BinSumm[p->NS2Indx[(size_t)Ppmd8Context_OneState(p->MinContext)->Freq - 1]] \
+    [ p->PrevSuccess + ((p->RunLength >> 26) & 0x20) \
+    + p->NS2BSIndx[Ppmd8_GetContext(p, p->MinContext->Suffix)->NumStats] + \
+    + p->MinContext->Flags ]
+
+
+CPpmd_See *Ppmd8_MakeEscFreq(CPpmd8 *p, unsigned numMasked, UInt32 *scale);
+
+
+/* 20.01: the original PPMdI encoder and decoder probably could work incorrectly in some rare cases,
+   where the original PPMdI code can give "Divide by Zero" operation.
+   We use the following fix to allow correct working of encoder and decoder in any cases.
+   We correct (Escape_Freq) and (_sum_), if (_sum_) is larger than p->Range) */
+#define PPMD8_CORRECT_SUM_RANGE(p, _sum_) if (_sum_ > p->Range /* /1 */) _sum_ = p->Range;
+
+
+/* ---------- Decode ---------- */
+
+#define PPMD8_SYM_END    (-1)
+#define PPMD8_SYM_ERROR  (-2)
+
+/*
+You must set (CPpmd8::Stream.In) before Ppmd8_RangeDec_Init()
+
+Ppmd8_DecodeSymbol()
+out:
+  >= 0 : decoded byte
+    -1 : PPMD8_SYM_END   : End of payload marker
+    -2 : PPMD8_SYM_ERROR : Data error
+*/
+
+
+BoolInt Ppmd8_Init_RangeDec(CPpmd8 *p);
+#define Ppmd8_RangeDec_IsFinishedOK(p) ((p)->Code == 0)
+int Ppmd8_DecodeSymbol(CPpmd8 *p);
+
+
+
+
+
+
+
+
+/* ---------- Encode ---------- */
+
+#define Ppmd8_Init_RangeEnc(p) { (p)->Low = 0; (p)->Range = 0xFFFFFFFF; }
+void Ppmd8_Flush_RangeEnc(CPpmd8 *p);
+void Ppmd8_EncodeSymbol(CPpmd8 *p, int symbol);
+
+
+EXTERN_C_END
+ 
+#endif