Merge pull request #461 from negativeExponent/libchdr

[pcsx_rearmed.git] / deps / lzma-16.04 / C / Ppmd.h

/* Ppmd.h -- PPMD codec common code\r
2016-05-16 : Igor Pavlov : Public domain\r
This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */\r
\r
#ifndef __PPMD_H\r
#define __PPMD_H\r
\r
#include "CpuArch.h"\r
\r
EXTERN_C_BEGIN\r
\r
#ifdef MY_CPU_32BIT\r
  #define PPMD_32BIT\r
#endif\r
\r
#define PPMD_INT_BITS 7\r
#define PPMD_PERIOD_BITS 7\r
#define PPMD_BIN_SCALE (1 << (PPMD_INT_BITS + PPMD_PERIOD_BITS))\r
\r
#define PPMD_GET_MEAN_SPEC(summ, shift, round) (((summ) + (1 << ((shift) - (round)))) >> (shift))\r
#define PPMD_GET_MEAN(summ) PPMD_GET_MEAN_SPEC((summ), PPMD_PERIOD_BITS, 2)\r
#define PPMD_UPDATE_PROB_0(prob) ((prob) + (1 << PPMD_INT_BITS) - PPMD_GET_MEAN(prob))\r
#define PPMD_UPDATE_PROB_1(prob) ((prob) - PPMD_GET_MEAN(prob))\r
\r
#define PPMD_N1 4\r
#define PPMD_N2 4\r
#define PPMD_N3 4\r
#define PPMD_N4 ((128 + 3 - 1 * PPMD_N1 - 2 * PPMD_N2 - 3 * PPMD_N3) / 4)\r
#define PPMD_NUM_INDEXES (PPMD_N1 + PPMD_N2 + PPMD_N3 + PPMD_N4)\r
\r
#pragma pack(push, 1)\r
/* Most compilers works OK here even without #pragma pack(push, 1), but some GCC compilers need it. */\r
\r
/* SEE-contexts for PPM-contexts with masked symbols */\r
typedef struct\r
{\r
  UInt16 Summ; /* Freq */\r
  Byte Shift;  /* Speed of Freq change; low Shift is for fast change */\r
  Byte Count;  /* Count to next change of Shift */\r
} CPpmd_See;\r
\r
#define Ppmd_See_Update(p)  if ((p)->Shift < PPMD_PERIOD_BITS && --(p)->Count == 0) \\r
    { (p)->Summ <<= 1; (p)->Count = (Byte)(3 << (p)->Shift++); }\r
\r
typedef struct\r
{\r
  Byte Symbol;\r
  Byte Freq;\r
  UInt16 SuccessorLow;\r
  UInt16 SuccessorHigh;\r
} CPpmd_State;\r
\r
#pragma pack(pop)\r
\r
typedef\r
  #ifdef PPMD_32BIT\r
    CPpmd_State *\r
  #else\r
    UInt32\r
  #endif\r
  CPpmd_State_Ref;\r
\r
typedef\r
  #ifdef PPMD_32BIT\r
    void *\r
  #else\r
    UInt32\r
  #endif\r
  CPpmd_Void_Ref;\r
\r
typedef\r
  #ifdef PPMD_32BIT\r
    Byte *\r
  #else\r
    UInt32\r
  #endif\r
  CPpmd_Byte_Ref;\r
\r
#define PPMD_SetAllBitsIn256Bytes(p) \\r
  { unsigned z; for (z = 0; z < 256 / sizeof(p[0]); z += 8) { \\r
  p[z+7] = p[z+6] = p[z+5] = p[z+4] = p[z+3] = p[z+2] = p[z+1] = p[z+0] = ~(size_t)0; }}\r
\r
EXTERN_C_END\r
 \r
#endif\r