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/* Ppmd7.c -- PPMdH codec↩
2017-04-03 : Igor Pavlov : Public domain↩
This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */↩
↩
#include "Precomp.h"↩
↩
#include <string.h>↩
↩
#include "Ppmd7.h"↩
↩
const Byte PPMD7_kExpEscape[16] = { 25, 14, 9, 7, 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 2, 2 };↩
static const UInt16 kInitBinEsc[] = { 0x3CDD, 0x1F3F, 0x59BF, 0x48F3, 0x64A1, 0x5ABC, 0x6632, 0x6051};↩
↩
#define MAX_FREQ 124↩
#define UNIT_SIZE 12↩
↩
#define U2B(nu) ((UInt32)(nu) * UNIT_SIZE)↩
#define U2I(nu) (p->Units2Indx[(size_t)(nu) - 1])↩
#define I2U(indx) (p->Indx2Units[indx])↩
↩
#ifdef PPMD_32BIT↩
#define REF(ptr) (ptr)↩
#else↩
#define REF(ptr) ((UInt32)((Byte *)(ptr) - (p)->Base))↩
#endif↩
↩
#define STATS_REF(ptr) ((CPpmd_State_Ref)REF(ptr))↩
↩
#define CTX(ref) ((CPpmd7_Context *)Ppmd7_GetContext(p, ref))↩
#define STATS(ctx) Ppmd7_GetStats(p, ctx)↩
#define ONE_STATE(ctx) Ppmd7Context_OneState(ctx)↩
#define SUFFIX(ctx) CTX((ctx)->Suffix)↩
↩
typedef CPpmd7_Context * CTX_PTR;↩
↩
struct CPpmd7_Node_;↩
↩
typedef↩
#ifdef PPMD_32BIT↩
struct CPpmd7_Node_ *↩
#else↩
UInt32↩
#endif↩
CPpmd7_Node_Ref;↩
↩
typedef struct CPpmd7_Node_↩
{↩
UInt16 Stamp; /* must be at offset 0 as CPpmd7_Context::NumStats. Stamp=0 means free */↩
UInt16 NU;↩
CPpmd7_Node_Ref Next; /* must be at offset >= 4 */↩
CPpmd7_Node_Ref Prev;↩
} CPpmd7_Node;↩
↩
#ifdef PPMD_32BIT↩
#define NODE(ptr) (ptr)↩
#else↩
#define NODE(offs) ((CPpmd7_Node *)(p->Base + (offs)))↩
#endif↩
↩
void Ppmd7_Construct(CPpmd7 *p)↩
{↩
unsigned i, k, m;↩
↩
p->Base = 0;↩
↩
for (i = 0, k = 0; i < PPMD_NUM_INDEXES; i++)↩
{↩
unsigned step = (i >= 12 ? 4 : (i >> 2) + 1);↩
do { p->Units2Indx[k++] = (Byte)i; } while (--step);↩
p->Indx2Units[i] = (Byte)k;↩
}↩
↩
p->NS2BSIndx[0] = (0 << 1);↩
p->NS2BSIndx[1] = (1 << 1);↩
memset(p->NS2BSIndx + 2, (2 << 1), 9);↩
memset(p->NS2BSIndx + 11, (3 << 1), 256 - 11);↩
↩
for (i = 0; i < 3; i++)↩
p->NS2Indx[i] = (Byte)i;↩
for (m = i, k = 1; i < 256; i++)↩
{↩
p->NS2Indx[i] = (Byte)m;↩
if (--k == 0)↩
k = (++m) - 2;↩
}↩
↩
memset(p->HB2Flag, 0, 0x40);↩
memset(p->HB2Flag + 0x40, 8, 0x100 - 0x40);↩
}↩
↩
void Ppmd7_Free(CPpmd7 *p, ISzAllocPtr alloc)↩
{↩
ISzAlloc_Free(alloc, p->Base);↩
p->Size = 0;↩
p->Base = 0;↩
}↩
↩
Bool Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAllocPtr alloc)↩
{↩
if (!p->Base || p->Size != size)↩
{↩
size_t size2;↩
Ppmd7_Free(p, alloc);↩
size2 = 0↩
#ifndef PPMD_32BIT↩
+ UNIT_SIZE↩
#endif↩
;↩
p->AlignOffset =↩
#ifdef PPMD_32BIT↩
(4 - size) & 3;↩
#else↩
4 - (size & 3);↩
#endif↩
if ((p->Base = (Byte *)ISzAlloc_Alloc(alloc, p->AlignOffset + size + size2)) == 0)↩
return False;↩
p->Size = size;↩
}↩
return True;↩
}↩
↩
static void InsertNode(CPpmd7 *p, void *node, unsigned indx)↩
{↩
*((CPpmd_Void_Ref *)node) = p->FreeList[indx];↩
p->FreeList[indx] = REF(node);↩
}↩
↩
static void *RemoveNode(CPpmd7 *p, unsigned indx)↩
{↩
CPpmd_Void_Ref *node = (CPpmd_Void_Ref *)Ppmd7_GetPtr(p, p->FreeList[indx]);↩
p->FreeList[indx] = *node;↩
return node;↩
}↩
↩
static void SplitBlock(CPpmd7 *p, void *ptr, unsigned oldIndx, unsigned newIndx)↩
{↩
unsigned i, nu = I2U(oldIndx) - I2U(newIndx);↩
ptr = (Byte *)ptr + U2B(I2U(newIndx));↩
if (I2U(i = U2I(nu)) != nu)↩
{↩
unsigned k = I2U(--i);↩
InsertNode(p, ((Byte *)ptr) + U2B(k), nu - k - 1);↩
}↩
InsertNode(p, ptr, i);↩
}↩
↩
static void GlueFreeBlocks(CPpmd7 *p)↩
{↩
#ifdef PPMD_32BIT↩
CPpmd7_Node headItem;↩
CPpmd7_Node_Ref head = &headItem;↩
#else↩
CPpmd7_Node_Ref head = p->AlignOffset + p->Size;↩
#endif↩
↩
CPpmd7_Node_Ref n = head;↩
unsigned i;↩
↩
p->GlueCount = 255;↩
↩
/* create doubly-linked list of free blocks */↩
for (i = 0; i < PPMD_NUM_INDEXES; i++)↩
{↩
UInt16 nu = I2U(i);↩
CPpmd7_Node_Ref next = (CPpmd7_Node_Ref)p->FreeList[i];↩
p->FreeList[i] = 0;↩
while (next != 0)↩
{↩
CPpmd7_Node *node = NODE(next);↩
node->Next = n;↩
n = NODE(n)->Prev = next;↩
next = *(const CPpmd7_Node_Ref *)node;↩
node->Stamp = 0;↩
node->NU = (UInt16)nu;↩
}↩
}↩
NODE(head)->Stamp = 1;↩
NODE(head)->Next = n;↩
NODE(n)->Prev = head;↩
if (p->LoUnit != p->HiUnit)↩
((CPpmd7_Node *)p->LoUnit)->Stamp = 1;↩
↩
/* Glue free blocks */↩
while (n != head)↩
{↩
CPpmd7_Node *node = NODE(n);↩
UInt32 nu = (UInt32)node->NU;↩
for (;;)↩
{↩
CPpmd7_Node *node2 = NODE(n) + nu;↩
nu += node2->NU;↩
if (node2->Stamp != 0 || nu >= 0x10000)↩
break;↩
NODE(node2->Prev)->Next = node2->Next;↩
NODE(node2->Next)->Prev = node2->Prev;↩
node->NU = (UInt16)nu;↩
}↩
n = node->Next;↩
}↩
↩
/* Fill lists of free blocks */↩
for (n = NODE(head)->Next; n != head;)↩
{↩
CPpmd7_Node *node = NODE(n);↩
unsigned nu;↩
CPpmd7_Node_Ref next = node->Next;↩
for (nu = node->NU; nu > 128; nu -= 128, node += 128)↩
InsertNode(p, node, PPMD_NUM_INDEXES - 1);↩
if (I2U(i = U2I(nu)) != nu)↩
{↩
unsigned k = I2U(--i);↩
InsertNode(p, node + k, nu - k - 1);↩
}↩
InsertNode(p, node, i);↩
n = next;↩
}↩
}↩
↩
static void *AllocUnitsRare(CPpmd7 *p, unsigned indx)↩
{↩
unsigned i;↩
void *retVal;↩
if (p->GlueCount == 0)↩
{↩
GlueFreeBlocks(p);↩
if (p->FreeList[indx] != 0)↩
return RemoveNode(p, indx);↩
}↩
i = indx;↩
do↩
{↩
if (++i == PPMD_NUM_INDEXES)↩
{↩
UInt32 numBytes = U2B(I2U(indx));↩
p->GlueCount--;↩
return ((UInt32)(p->UnitsStart - p->Text) > numBytes) ? (p->UnitsStart -= numBytes) : (NULL);↩
}↩
}↩
while (p->FreeList[i] == 0);↩
retVal = RemoveNode(p, i);↩
SplitBlock(p, retVal, i, indx);↩
return retVal;↩
}↩
↩
static void *AllocUnits(CPpmd7 *p, unsigned indx)↩
{↩
UInt32 numBytes;↩
if (p->FreeList[indx] != 0)↩
return RemoveNode(p, indx);↩
numBytes = U2B(I2U(indx));↩
if (numBytes <= (UInt32)(p->HiUnit - p->LoUnit))↩
{↩
void *retVal = p->LoUnit;↩
p->LoUnit += numBytes;↩
return retVal;↩
}↩
return AllocUnitsRare(p, indx);↩
}↩
↩
#define MyMem12Cpy(dest, src, num) \↩
{ UInt32 *d = (UInt32 *)dest; const UInt32 *s = (const UInt32 *)src; UInt32 n = num; \↩
do { d[0] = s[0]; d[1] = s[1]; d[2] = s[2]; s += 3; d += 3; } while (--n); }↩
↩
static void *ShrinkUnits(CPpmd7 *p, void *oldPtr, unsigned oldNU, unsigned newNU)↩
{↩
unsigned i0 = U2I(oldNU);↩
unsigned i1 = U2I(newNU);↩
if (i0 == i1)↩
return oldPtr;↩
if (p->FreeList[i1] != 0)↩
{↩
void *ptr = RemoveNode(p, i1);↩
MyMem12Cpy(ptr, oldPtr, newNU);↩
InsertNode(p, oldPtr, i0);↩
return ptr;↩
}↩
SplitBlock(p, oldPtr, i0, i1);↩
return oldPtr;↩
}↩
↩
#define SUCCESSOR(p) ((CPpmd_Void_Ref)((p)->SuccessorLow | ((UInt32)(p)->SuccessorHigh << 16)))↩
↩
static void SetSuccessor(CPpmd_State *p, CPpmd_Void_Ref v)↩
{↩
(p)->SuccessorLow = (UInt16)((UInt32)(v) & 0xFFFF);↩
(p)->SuccessorHigh = (UInt16)(((UInt32)(v) >> 16) & 0xFFFF);↩
}↩
↩
static void RestartModel(CPpmd7 *p)↩
{↩
unsigned i, k, m;↩
↩
memset(p->FreeList, 0, sizeof(p->FreeList));↩
p->Text = p->Base + p->AlignOffset;↩
p->HiUnit = p->Text + p->Size;↩
p->LoUnit = p->UnitsStart = p->HiUnit - p->Size / 8 / UNIT_SIZE * 7 * UNIT_SIZE;↩
p->GlueCount = 0;↩
↩
p->OrderFall = p->MaxOrder;↩
p->RunLength = p->InitRL = -(Int32)((p->MaxOrder < 12) ? p->MaxOrder : 12) - 1;↩
p->PrevSuccess = 0;↩
↩
p->MinContext = p->MaxContext = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); /* AllocContext(p); */↩
p->MinContext->Suffix = 0;↩
p->MinContext->NumStats = 256;↩
p->MinContext->SummFreq = 256 + 1;↩
p->FoundState = (CPpmd_State *)p->LoUnit; /* AllocUnits(p, PPMD_NUM_INDEXES - 1); */↩
p->LoUnit += U2B(256 / 2);↩
p->MinContext->Stats = REF(p->FoundState);↩
for (i = 0; i < 256; i++)↩
{↩
CPpmd_State *s = &p->FoundState[i];↩
s->Symbol = (Byte)i;↩
s->Freq = 1;↩
SetSuccessor(s, 0);↩
}↩
↩
for (i = 0; i < 128; i++)↩
for (k = 0; k < 8; k++)↩
{↩
UInt16 *dest = p->BinSumm[i] + k;↩
UInt16 val = (UInt16)(PPMD_BIN_SCALE - kInitBinEsc[k] / (i + 2));↩
for (m = 0; m < 64; m += 8)↩
dest[m] = val;↩
}↩
↩
for (i = 0; i < 25; i++)↩
for (k = 0; k < 16; k++)↩
{↩
CPpmd_See *s = &p->See[i][k];↩
s->Summ = (UInt16)((5 * i + 10) << (s->Shift = PPMD_PERIOD_BITS - 4));↩
s->Count = 4;↩
}↩
}↩
↩
void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder)↩
{↩
p->MaxOrder = maxOrder;↩
RestartModel(p);↩
p->DummySee.Shift = PPMD_PERIOD_BITS;↩
p->DummySee.Summ = 0; /* unused */↩
p->DummySee.Count = 64; /* unused */↩
}↩
↩
static CTX_PTR CreateSuccessors(CPpmd7 *p, Bool skip)↩
{↩
CPpmd_State upState;↩
CTX_PTR c = p->MinContext;↩
CPpmd_Byte_Ref upBranch = (CPpmd_Byte_Ref)SUCCESSOR(p->FoundState);↩
CPpmd_State *ps[PPMD7_MAX_ORDER];↩
unsigned numPs = 0;↩
↩
if (!skip)↩
ps[numPs++] = p->FoundState;↩
↩
while (c->Suffix)↩
{↩
CPpmd_Void_Ref successor;↩
CPpmd_State *s;↩
c = SUFFIX(c);↩
if (c->NumStats != 1)↩
{↩
for (s = STATS(c); s->Symbol != p->FoundState->Symbol; s++);↩
}↩
else↩
s = ONE_STATE(c);↩
successor = SUCCESSOR(s);↩
if (successor != upBranch)↩
{↩
c = CTX(successor);↩
if (numPs == 0)↩
return c;↩
break;↩
}↩
ps[numPs++] = s;↩
}↩
↩
upState.Symbol = *(const Byte *)Ppmd7_GetPtr(p, upBranch);↩
SetSuccessor(&upState, upBranch + 1);↩
↩
if (c->NumStats == 1)↩
upState.Freq = ONE_STATE(c)->Freq;↩
else↩
{↩
UInt32 cf, s0;↩
CPpmd_State *s;↩
for (s = STATS(c); s->Symbol != upState.Symbol; s++);↩
cf = s->Freq - 1;↩
s0 = c->SummFreq - c->NumStats - cf;↩
upState.Freq = (Byte)(1 + ((2 * cf <= s0) ? (5 * cf > s0) : ((2 * cf + 3 * s0 - 1) / (2 * s0))));↩
}↩
↩
do↩
{↩
/* Create Child */↩
CTX_PTR c1; /* = AllocContext(p); */↩
if (p->HiUnit != p->LoUnit)↩
c1 = (CTX_PTR)(p->HiUnit -= UNIT_SIZE);↩
else if (p->FreeList[0] != 0)↩
c1 = (CTX_PTR)RemoveNode(p, 0);↩
else↩
{↩
c1 = (CTX_PTR)AllocUnitsRare(p, 0);↩
if (!c1)↩
return NULL;↩
}↩
c1->NumStats = 1;↩
*ONE_STATE(c1) = upState;↩
c1->Suffix = REF(c);↩
SetSuccessor(ps[--numPs], REF(c1));↩
c = c1;↩
}↩
while (numPs != 0);↩
↩
return c;↩
}↩
↩
static void SwapStates(CPpmd_State *t1, CPpmd_State *t2)↩
{↩
CPpmd_State tmp = *t1;↩
*t1 = *t2;↩
*t2 = tmp;↩
}↩
↩
static void UpdateModel(CPpmd7 *p)↩
{↩
CPpmd_Void_Ref successor, fSuccessor = SUCCESSOR(p->FoundState);↩
CTX_PTR c;↩
unsigned s0, ns;↩
↩
if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0)↩
{↩
c = SUFFIX(p->MinContext);↩
↩
if (c->NumStats == 1)↩
{↩
CPpmd_State *s = ONE_STATE(c);↩
if (s->Freq < 32)↩
s->Freq++;↩
}↩
else↩
{↩
CPpmd_State *s = STATS(c);↩
if (s->Symbol != p->FoundState->Symbol)↩
{↩
do { s++; } while (s->Symbol != p->FoundState->Symbol);↩
if (s[0].Freq >= s[-1].Freq)↩
{↩
SwapStates(&s[0], &s[-1]);↩
s--;↩
}↩
}↩
if (s->Freq < MAX_FREQ - 9)↩
{↩
s->Freq += 2;↩
c->SummFreq += 2;↩
}↩
}↩
}↩
↩
if (p->OrderFall == 0)↩
{↩
p->MinContext = p->MaxContext = CreateSuccessors(p, True);↩
if (p->MinContext == 0)↩
{↩
RestartModel(p);↩
return;↩
}↩
SetSuccessor(p->FoundState, REF(p->MinContext));↩
return;↩
}↩
↩
*p->Text++ = p->FoundState->Symbol;↩
successor = REF(p->Text);↩
if (p->Text >= p->UnitsStart)↩
{↩
RestartModel(p);↩
return;↩
}↩
↩
if (fSuccessor)↩
{↩
if (fSuccessor <= successor)↩
{↩
CTX_PTR cs = CreateSuccessors(p, False);↩
if (cs == NULL)↩
{↩
RestartModel(p);↩
return;↩
}↩
fSuccessor = REF(cs);↩
}↩
if (--p->OrderFall == 0)↩
{↩
successor = fSuccessor;↩
p->Text -= (p->MaxContext != p->MinContext);↩
}↩
}↩
else↩
{↩
SetSuccessor(p->FoundState, successor);↩
fSuccessor = REF(p->MinContext);↩
}↩
↩
s0 = p->MinContext->SummFreq - (ns = p->MinContext->NumStats) - (p->FoundState->Freq - 1);↩
↩
for (c = p->MaxContext; c != p->MinContext; c = SUFFIX(c))↩
{↩
unsigned ns1;↩
UInt32 cf, sf;↩
if ((ns1 = c->NumStats) != 1)↩
{↩
if ((ns1 & 1) == 0)↩
{↩
/* Expand for one UNIT */↩
unsigned oldNU = ns1 >> 1;↩
unsigned i = U2I(oldNU);↩
if (i != U2I((size_t)oldNU + 1))↩
{↩
void *ptr = AllocUnits(p, i + 1);↩
void *oldPtr;↩
if (!ptr)↩
{↩
RestartModel(p);↩
return;↩
}↩
oldPtr = STATS(c);↩
MyMem12Cpy(ptr, oldPtr, oldNU);↩
InsertNode(p, oldPtr, i);↩
c->Stats = STATS_REF(ptr);↩
}↩
}↩
c->SummFreq = (UInt16)(c->SummFreq + (2 * ns1 < ns) + 2 * ((4 * ns1 <= ns) & (c->SummFreq <= 8 * ns1)));↩
}↩
else↩
{↩
CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0);↩
if (!s)↩
{↩
RestartModel(p);↩
return;↩
}↩
*s = *ONE_STATE(c);↩
c->Stats = REF(s);↩
if (s->Freq < MAX_FREQ / 4 - 1)↩
s->Freq <<= 1;↩
else↩
s->Freq = MAX_FREQ - 4;↩
c->SummFreq = (UInt16)(s->Freq + p->InitEsc + (ns > 3));↩
}↩
cf = 2 * (UInt32)p->FoundState->Freq * (c->SummFreq + 6);↩
sf = (UInt32)s0 + c->SummFreq;↩
if (cf < 6 * sf)↩
{↩
cf = 1 + (cf > sf) + (cf >= 4 * sf);↩
c->SummFreq += 3;↩
}↩
else↩
{↩
cf = 4 + (cf >= 9 * sf) + (cf >= 12 * sf) + (cf >= 15 * sf);↩
c->SummFreq = (UInt16)(c->SummFreq + cf);↩
}↩
{↩
CPpmd_State *s = STATS(c) + ns1;↩
SetSuccessor(s, successor);↩
s->Symbol = p->FoundState->Symbol;↩
s->Freq = (Byte)cf;↩
c->NumStats = (UInt16)(ns1 + 1);↩
}↩
}↩
p->MaxContext = p->MinContext = CTX(fSuccessor);↩
}↩
↩
static void Rescale(CPpmd7 *p)↩
{↩
unsigned i, adder, sumFreq, escFreq;↩
CPpmd_State *stats = STATS(p->MinContext);↩
CPpmd_State *s = p->FoundState;↩
{↩
CPpmd_State tmp = *s;↩
for (; s != stats; s--)↩
s[0] = s[-1];↩
*s = tmp;↩
}↩
escFreq = p->MinContext->SummFreq - s->Freq;↩
s->Freq += 4;↩
adder = (p->OrderFall != 0);↩
s->Freq = (Byte)((s->Freq + adder) >> 1);↩
sumFreq = s->Freq;↩
↩
i = p->MinContext->NumStats - 1;↩
do↩
{↩
escFreq -= (++s)->Freq;↩
s->Freq = (Byte)((s->Freq + adder) >> 1);↩
sumFreq += s->Freq;↩
if (s[0].Freq > s[-1].Freq)↩
{↩
CPpmd_State *s1 = s;↩
CPpmd_State tmp = *s1;↩
do↩
s1[0] = s1[-1];↩
while (--s1 != stats && tmp.Freq > s1[-1].Freq);↩
*s1 = tmp;↩
}↩
}↩
while (--i);↩
↩
if (s->Freq == 0)↩
{↩
unsigned numStats = p->MinContext->NumStats;↩
unsigned n0, n1;↩
do { i++; } while ((--s)->Freq == 0);↩
escFreq += i;↩
p->MinContext->NumStats = (UInt16)(p->MinContext->NumStats - i);↩
if (p->MinContext->NumStats == 1)↩
{↩
CPpmd_State tmp = *stats;↩
do↩
{↩
tmp.Freq = (Byte)(tmp.Freq - (tmp.Freq >> 1));↩
escFreq >>= 1;↩
}↩
while (escFreq > 1);↩
InsertNode(p, stats, U2I(((numStats + 1) >> 1)));↩
*(p->FoundState = ONE_STATE(p->MinContext)) = tmp;↩
return;↩
}↩
n0 = (numStats + 1) >> 1;↩
n1 = (p->MinContext->NumStats + 1) >> 1;↩
if (n0 != n1)↩
p->MinContext->Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1));↩
}↩
p->MinContext->SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1));↩
p->FoundState = STATS(p->MinContext);↩
}↩
↩
CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *escFreq)↩
{↩
CPpmd_See *see;↩
unsigned nonMasked = p->MinContext->NumStats - numMasked;↩
if (p->MinContext->NumStats != 256)↩
{↩
see = p->See[(unsigned)p->NS2Indx[(size_t)nonMasked - 1]] +↩
(nonMasked < (unsigned)SUFFIX(p->MinContext)->NumStats - p->MinContext->NumStats) +↩
2 * (unsigned)(p->MinContext->SummFreq < 11 * p->MinContext->NumStats) +↩
4 * (unsigned)(numMasked > nonMasked) +↩
p->HiBitsFlag;↩
{↩
unsigned r = (see->Summ >> see->Shift);↩
see->Summ = (UInt16)(see->Summ - r);↩
*escFreq = r + (r == 0);↩
}↩
}↩
else↩
{↩
see = &p->DummySee;↩
*escFreq = 1;↩
}↩
return see;↩
}↩
↩
static void NextContext(CPpmd7 *p)↩
{↩
CTX_PTR c = CTX(SUCCESSOR(p->FoundState));↩
if (p->OrderFall == 0 && (Byte *)c > p->Text)↩
p->MinContext = p->MaxContext = c;↩
else↩
UpdateModel(p);↩
}↩
↩
void Ppmd7_Update1(CPpmd7 *p)↩
{↩
CPpmd_State *s = p->FoundState;↩
s->Freq += 4;↩
p->MinContext->SummFreq += 4;↩
if (s[0].Freq > s[-1].Freq)↩
{↩
SwapStates(&s[0], &s[-1]);↩
p->FoundState = --s;↩
if (s->Freq > MAX_FREQ)↩
Rescale(p);↩
}↩
NextContext(p);↩
}↩
↩
void Ppmd7_Update1_0(CPpmd7 *p)↩
{↩
p->PrevSuccess = (2 * p->FoundState->Freq > p->MinContext->SummFreq);↩
p->RunLength += p->PrevSuccess;↩
p->MinContext->SummFreq += 4;↩
if ((p->FoundState->Freq += 4) > MAX_FREQ)↩
Rescale(p);↩
NextContext(p);↩
}↩
↩
void Ppmd7_UpdateBin(CPpmd7 *p)↩
{↩
p->FoundState->Freq = (Byte)(p->FoundState->Freq + (p->FoundState->Freq < 128 ? 1: 0));↩
p->PrevSuccess = 1;↩
p->RunLength++;↩
NextContext(p);↩
}↩
↩
void Ppmd7_Update2(CPpmd7 *p)↩
{↩
p->MinContext->SummFreq += 4;↩
if ((p->FoundState->Freq += 4) > MAX_FREQ)↩
Rescale(p);↩
p->RunLength = p->InitRL;↩
UpdateModel(p);↩
}↩