diff options
Diffstat (limited to '')
| -rw-r--r-- | other-licenses/7zstub/src/C/Ppmd7.c | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/other-licenses/7zstub/src/C/Ppmd7.c b/other-licenses/7zstub/src/C/Ppmd7.c new file mode 100644 index 0000000000..ef93cb2d47 --- /dev/null +++ b/other-licenses/7zstub/src/C/Ppmd7.c @@ -0,0 +1,712 @@ +/* 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);
+}
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