src/third-party/lzma/Ppmd7.c (view raw)
1/* Ppmd7.c -- PPMdH codec
22015-09-28 : Igor Pavlov : Public domain
3This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
4
5#include "Precomp.h"
6
7#include <string.h>
8
9#include "Ppmd7.h"
10
11const Byte PPMD7_kExpEscape[16] = { 25, 14, 9, 7, 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 2, 2 };
12static const UInt16 kInitBinEsc[] = { 0x3CDD, 0x1F3F, 0x59BF, 0x48F3, 0x64A1, 0x5ABC, 0x6632, 0x6051};
13
14#define MAX_FREQ 124
15#define UNIT_SIZE 12
16
17#define U2B(nu) ((UInt32)(nu) * UNIT_SIZE)
18#define U2I(nu) (p->Units2Indx[(nu) - 1])
19#define I2U(indx) (p->Indx2Units[indx])
20
21#ifdef PPMD_32BIT
22 #define REF(ptr) (ptr)
23#else
24 #define REF(ptr) ((UInt32)((Byte *)(ptr) - (p)->Base))
25#endif
26
27#define STATS_REF(ptr) ((CPpmd_State_Ref)REF(ptr))
28
29#define CTX(ref) ((CPpmd7_Context *)Ppmd7_GetContext(p, ref))
30#define STATS(ctx) Ppmd7_GetStats(p, ctx)
31#define ONE_STATE(ctx) Ppmd7Context_OneState(ctx)
32#define SUFFIX(ctx) CTX((ctx)->Suffix)
33
34typedef CPpmd7_Context * CTX_PTR;
35
36struct CPpmd7_Node_;
37
38typedef
39 #ifdef PPMD_32BIT
40 struct CPpmd7_Node_ *
41 #else
42 UInt32
43 #endif
44 CPpmd7_Node_Ref;
45
46typedef struct CPpmd7_Node_
47{
48 UInt16 Stamp; /* must be at offset 0 as CPpmd7_Context::NumStats. Stamp=0 means free */
49 UInt16 NU;
50 CPpmd7_Node_Ref Next; /* must be at offset >= 4 */
51 CPpmd7_Node_Ref Prev;
52} CPpmd7_Node;
53
54#ifdef PPMD_32BIT
55 #define NODE(ptr) (ptr)
56#else
57 #define NODE(offs) ((CPpmd7_Node *)(p->Base + (offs)))
58#endif
59
60void Ppmd7_Construct(CPpmd7 *p)
61{
62 unsigned i, k, m;
63
64 p->Base = 0;
65
66 for (i = 0, k = 0; i < PPMD_NUM_INDEXES; i++)
67 {
68 unsigned step = (i >= 12 ? 4 : (i >> 2) + 1);
69 do { p->Units2Indx[k++] = (Byte)i; } while (--step);
70 p->Indx2Units[i] = (Byte)k;
71 }
72
73 p->NS2BSIndx[0] = (0 << 1);
74 p->NS2BSIndx[1] = (1 << 1);
75 memset(p->NS2BSIndx + 2, (2 << 1), 9);
76 memset(p->NS2BSIndx + 11, (3 << 1), 256 - 11);
77
78 for (i = 0; i < 3; i++)
79 p->NS2Indx[i] = (Byte)i;
80 for (m = i, k = 1; i < 256; i++)
81 {
82 p->NS2Indx[i] = (Byte)m;
83 if (--k == 0)
84 k = (++m) - 2;
85 }
86
87 memset(p->HB2Flag, 0, 0x40);
88 memset(p->HB2Flag + 0x40, 8, 0x100 - 0x40);
89}
90
91void Ppmd7_Free(CPpmd7 *p, ISzAlloc *alloc)
92{
93 alloc->Free(alloc, p->Base);
94 p->Size = 0;
95 p->Base = 0;
96}
97
98Bool Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAlloc *alloc)
99{
100 if (p->Base == 0 || p->Size != size)
101 {
102 Ppmd7_Free(p, alloc);
103 p->AlignOffset =
104 #ifdef PPMD_32BIT
105 (4 - size) & 3;
106 #else
107 4 - (size & 3);
108 #endif
109 if ((p->Base = (Byte *)alloc->Alloc(alloc, p->AlignOffset + size
110 #ifndef PPMD_32BIT
111 + UNIT_SIZE
112 #endif
113 )) == 0)
114 return False;
115 p->Size = size;
116 }
117 return True;
118}
119
120static void InsertNode(CPpmd7 *p, void *node, unsigned indx)
121{
122 *((CPpmd_Void_Ref *)node) = p->FreeList[indx];
123 p->FreeList[indx] = REF(node);
124}
125
126static void *RemoveNode(CPpmd7 *p, unsigned indx)
127{
128 CPpmd_Void_Ref *node = (CPpmd_Void_Ref *)Ppmd7_GetPtr(p, p->FreeList[indx]);
129 p->FreeList[indx] = *node;
130 return node;
131}
132
133static void SplitBlock(CPpmd7 *p, void *ptr, unsigned oldIndx, unsigned newIndx)
134{
135 unsigned i, nu = I2U(oldIndx) - I2U(newIndx);
136 ptr = (Byte *)ptr + U2B(I2U(newIndx));
137 if (I2U(i = U2I(nu)) != nu)
138 {
139 unsigned k = I2U(--i);
140 InsertNode(p, ((Byte *)ptr) + U2B(k), nu - k - 1);
141 }
142 InsertNode(p, ptr, i);
143}
144
145static void GlueFreeBlocks(CPpmd7 *p)
146{
147 #ifdef PPMD_32BIT
148 CPpmd7_Node headItem;
149 CPpmd7_Node_Ref head = &headItem;
150 #else
151 CPpmd7_Node_Ref head = p->AlignOffset + p->Size;
152 #endif
153
154 CPpmd7_Node_Ref n = head;
155 unsigned i;
156
157 p->GlueCount = 255;
158
159 /* create doubly-linked list of free blocks */
160 for (i = 0; i < PPMD_NUM_INDEXES; i++)
161 {
162 UInt16 nu = I2U(i);
163 CPpmd7_Node_Ref next = (CPpmd7_Node_Ref)p->FreeList[i];
164 p->FreeList[i] = 0;
165 while (next != 0)
166 {
167 CPpmd7_Node *node = NODE(next);
168 node->Next = n;
169 n = NODE(n)->Prev = next;
170 next = *(const CPpmd7_Node_Ref *)node;
171 node->Stamp = 0;
172 node->NU = (UInt16)nu;
173 }
174 }
175 NODE(head)->Stamp = 1;
176 NODE(head)->Next = n;
177 NODE(n)->Prev = head;
178 if (p->LoUnit != p->HiUnit)
179 ((CPpmd7_Node *)p->LoUnit)->Stamp = 1;
180
181 /* Glue free blocks */
182 while (n != head)
183 {
184 CPpmd7_Node *node = NODE(n);
185 UInt32 nu = (UInt32)node->NU;
186 for (;;)
187 {
188 CPpmd7_Node *node2 = NODE(n) + nu;
189 nu += node2->NU;
190 if (node2->Stamp != 0 || nu >= 0x10000)
191 break;
192 NODE(node2->Prev)->Next = node2->Next;
193 NODE(node2->Next)->Prev = node2->Prev;
194 node->NU = (UInt16)nu;
195 }
196 n = node->Next;
197 }
198
199 /* Fill lists of free blocks */
200 for (n = NODE(head)->Next; n != head;)
201 {
202 CPpmd7_Node *node = NODE(n);
203 unsigned nu;
204 CPpmd7_Node_Ref next = node->Next;
205 for (nu = node->NU; nu > 128; nu -= 128, node += 128)
206 InsertNode(p, node, PPMD_NUM_INDEXES - 1);
207 if (I2U(i = U2I(nu)) != nu)
208 {
209 unsigned k = I2U(--i);
210 InsertNode(p, node + k, nu - k - 1);
211 }
212 InsertNode(p, node, i);
213 n = next;
214 }
215}
216
217static void *AllocUnitsRare(CPpmd7 *p, unsigned indx)
218{
219 unsigned i;
220 void *retVal;
221 if (p->GlueCount == 0)
222 {
223 GlueFreeBlocks(p);
224 if (p->FreeList[indx] != 0)
225 return RemoveNode(p, indx);
226 }
227 i = indx;
228 do
229 {
230 if (++i == PPMD_NUM_INDEXES)
231 {
232 UInt32 numBytes = U2B(I2U(indx));
233 p->GlueCount--;
234 return ((UInt32)(p->UnitsStart - p->Text) > numBytes) ? (p->UnitsStart -= numBytes) : (NULL);
235 }
236 }
237 while (p->FreeList[i] == 0);
238 retVal = RemoveNode(p, i);
239 SplitBlock(p, retVal, i, indx);
240 return retVal;
241}
242
243static void *AllocUnits(CPpmd7 *p, unsigned indx)
244{
245 UInt32 numBytes;
246 if (p->FreeList[indx] != 0)
247 return RemoveNode(p, indx);
248 numBytes = U2B(I2U(indx));
249 if (numBytes <= (UInt32)(p->HiUnit - p->LoUnit))
250 {
251 void *retVal = p->LoUnit;
252 p->LoUnit += numBytes;
253 return retVal;
254 }
255 return AllocUnitsRare(p, indx);
256}
257
258#define MyMem12Cpy(dest, src, num) \
259 { UInt32 *d = (UInt32 *)dest; const UInt32 *s = (const UInt32 *)src; UInt32 n = num; \
260 do { d[0] = s[0]; d[1] = s[1]; d[2] = s[2]; s += 3; d += 3; } while (--n); }
261
262static void *ShrinkUnits(CPpmd7 *p, void *oldPtr, unsigned oldNU, unsigned newNU)
263{
264 unsigned i0 = U2I(oldNU);
265 unsigned i1 = U2I(newNU);
266 if (i0 == i1)
267 return oldPtr;
268 if (p->FreeList[i1] != 0)
269 {
270 void *ptr = RemoveNode(p, i1);
271 MyMem12Cpy(ptr, oldPtr, newNU);
272 InsertNode(p, oldPtr, i0);
273 return ptr;
274 }
275 SplitBlock(p, oldPtr, i0, i1);
276 return oldPtr;
277}
278
279#define SUCCESSOR(p) ((CPpmd_Void_Ref)((p)->SuccessorLow | ((UInt32)(p)->SuccessorHigh << 16)))
280
281static void SetSuccessor(CPpmd_State *p, CPpmd_Void_Ref v)
282{
283 (p)->SuccessorLow = (UInt16)((UInt32)(v) & 0xFFFF);
284 (p)->SuccessorHigh = (UInt16)(((UInt32)(v) >> 16) & 0xFFFF);
285}
286
287static void RestartModel(CPpmd7 *p)
288{
289 unsigned i, k, m;
290
291 memset(p->FreeList, 0, sizeof(p->FreeList));
292 p->Text = p->Base + p->AlignOffset;
293 p->HiUnit = p->Text + p->Size;
294 p->LoUnit = p->UnitsStart = p->HiUnit - p->Size / 8 / UNIT_SIZE * 7 * UNIT_SIZE;
295 p->GlueCount = 0;
296
297 p->OrderFall = p->MaxOrder;
298 p->RunLength = p->InitRL = -(Int32)((p->MaxOrder < 12) ? p->MaxOrder : 12) - 1;
299 p->PrevSuccess = 0;
300
301 p->MinContext = p->MaxContext = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); /* AllocContext(p); */
302 p->MinContext->Suffix = 0;
303 p->MinContext->NumStats = 256;
304 p->MinContext->SummFreq = 256 + 1;
305 p->FoundState = (CPpmd_State *)p->LoUnit; /* AllocUnits(p, PPMD_NUM_INDEXES - 1); */
306 p->LoUnit += U2B(256 / 2);
307 p->MinContext->Stats = REF(p->FoundState);
308 for (i = 0; i < 256; i++)
309 {
310 CPpmd_State *s = &p->FoundState[i];
311 s->Symbol = (Byte)i;
312 s->Freq = 1;
313 SetSuccessor(s, 0);
314 }
315
316 for (i = 0; i < 128; i++)
317 for (k = 0; k < 8; k++)
318 {
319 UInt16 *dest = p->BinSumm[i] + k;
320 UInt16 val = (UInt16)(PPMD_BIN_SCALE - kInitBinEsc[k] / (i + 2));
321 for (m = 0; m < 64; m += 8)
322 dest[m] = val;
323 }
324
325 for (i = 0; i < 25; i++)
326 for (k = 0; k < 16; k++)
327 {
328 CPpmd_See *s = &p->See[i][k];
329 s->Summ = (UInt16)((5 * i + 10) << (s->Shift = PPMD_PERIOD_BITS - 4));
330 s->Count = 4;
331 }
332}
333
334void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder)
335{
336 p->MaxOrder = maxOrder;
337 RestartModel(p);
338 p->DummySee.Shift = PPMD_PERIOD_BITS;
339 p->DummySee.Summ = 0; /* unused */
340 p->DummySee.Count = 64; /* unused */
341}
342
343static CTX_PTR CreateSuccessors(CPpmd7 *p, Bool skip)
344{
345 CPpmd_State upState;
346 CTX_PTR c = p->MinContext;
347 CPpmd_Byte_Ref upBranch = (CPpmd_Byte_Ref)SUCCESSOR(p->FoundState);
348 CPpmd_State *ps[PPMD7_MAX_ORDER];
349 unsigned numPs = 0;
350
351 if (!skip)
352 ps[numPs++] = p->FoundState;
353
354 while (c->Suffix)
355 {
356 CPpmd_Void_Ref successor;
357 CPpmd_State *s;
358 c = SUFFIX(c);
359 if (c->NumStats != 1)
360 {
361 for (s = STATS(c); s->Symbol != p->FoundState->Symbol; s++);
362 }
363 else
364 s = ONE_STATE(c);
365 successor = SUCCESSOR(s);
366 if (successor != upBranch)
367 {
368 c = CTX(successor);
369 if (numPs == 0)
370 return c;
371 break;
372 }
373 ps[numPs++] = s;
374 }
375
376 upState.Symbol = *(const Byte *)Ppmd7_GetPtr(p, upBranch);
377 SetSuccessor(&upState, upBranch + 1);
378
379 if (c->NumStats == 1)
380 upState.Freq = ONE_STATE(c)->Freq;
381 else
382 {
383 UInt32 cf, s0;
384 CPpmd_State *s;
385 for (s = STATS(c); s->Symbol != upState.Symbol; s++);
386 cf = s->Freq - 1;
387 s0 = c->SummFreq - c->NumStats - cf;
388 upState.Freq = (Byte)(1 + ((2 * cf <= s0) ? (5 * cf > s0) : ((2 * cf + 3 * s0 - 1) / (2 * s0))));
389 }
390
391 do
392 {
393 /* Create Child */
394 CTX_PTR c1; /* = AllocContext(p); */
395 if (p->HiUnit != p->LoUnit)
396 c1 = (CTX_PTR)(p->HiUnit -= UNIT_SIZE);
397 else if (p->FreeList[0] != 0)
398 c1 = (CTX_PTR)RemoveNode(p, 0);
399 else
400 {
401 c1 = (CTX_PTR)AllocUnitsRare(p, 0);
402 if (!c1)
403 return NULL;
404 }
405 c1->NumStats = 1;
406 *ONE_STATE(c1) = upState;
407 c1->Suffix = REF(c);
408 SetSuccessor(ps[--numPs], REF(c1));
409 c = c1;
410 }
411 while (numPs != 0);
412
413 return c;
414}
415
416static void SwapStates(CPpmd_State *t1, CPpmd_State *t2)
417{
418 CPpmd_State tmp = *t1;
419 *t1 = *t2;
420 *t2 = tmp;
421}
422
423static void UpdateModel(CPpmd7 *p)
424{
425 CPpmd_Void_Ref successor, fSuccessor = SUCCESSOR(p->FoundState);
426 CTX_PTR c;
427 unsigned s0, ns;
428
429 if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0)
430 {
431 c = SUFFIX(p->MinContext);
432
433 if (c->NumStats == 1)
434 {
435 CPpmd_State *s = ONE_STATE(c);
436 if (s->Freq < 32)
437 s->Freq++;
438 }
439 else
440 {
441 CPpmd_State *s = STATS(c);
442 if (s->Symbol != p->FoundState->Symbol)
443 {
444 do { s++; } while (s->Symbol != p->FoundState->Symbol);
445 if (s[0].Freq >= s[-1].Freq)
446 {
447 SwapStates(&s[0], &s[-1]);
448 s--;
449 }
450 }
451 if (s->Freq < MAX_FREQ - 9)
452 {
453 s->Freq += 2;
454 c->SummFreq += 2;
455 }
456 }
457 }
458
459 if (p->OrderFall == 0)
460 {
461 p->MinContext = p->MaxContext = CreateSuccessors(p, True);
462 if (p->MinContext == 0)
463 {
464 RestartModel(p);
465 return;
466 }
467 SetSuccessor(p->FoundState, REF(p->MinContext));
468 return;
469 }
470
471 *p->Text++ = p->FoundState->Symbol;
472 successor = REF(p->Text);
473 if (p->Text >= p->UnitsStart)
474 {
475 RestartModel(p);
476 return;
477 }
478
479 if (fSuccessor)
480 {
481 if (fSuccessor <= successor)
482 {
483 CTX_PTR cs = CreateSuccessors(p, False);
484 if (cs == NULL)
485 {
486 RestartModel(p);
487 return;
488 }
489 fSuccessor = REF(cs);
490 }
491 if (--p->OrderFall == 0)
492 {
493 successor = fSuccessor;
494 p->Text -= (p->MaxContext != p->MinContext);
495 }
496 }
497 else
498 {
499 SetSuccessor(p->FoundState, successor);
500 fSuccessor = REF(p->MinContext);
501 }
502
503 s0 = p->MinContext->SummFreq - (ns = p->MinContext->NumStats) - (p->FoundState->Freq - 1);
504
505 for (c = p->MaxContext; c != p->MinContext; c = SUFFIX(c))
506 {
507 unsigned ns1;
508 UInt32 cf, sf;
509 if ((ns1 = c->NumStats) != 1)
510 {
511 if ((ns1 & 1) == 0)
512 {
513 /* Expand for one UNIT */
514 unsigned oldNU = ns1 >> 1;
515 unsigned i = U2I(oldNU);
516 if (i != U2I(oldNU + 1))
517 {
518 void *ptr = AllocUnits(p, i + 1);
519 void *oldPtr;
520 if (!ptr)
521 {
522 RestartModel(p);
523 return;
524 }
525 oldPtr = STATS(c);
526 MyMem12Cpy(ptr, oldPtr, oldNU);
527 InsertNode(p, oldPtr, i);
528 c->Stats = STATS_REF(ptr);
529 }
530 }
531 c->SummFreq = (UInt16)(c->SummFreq + (2 * ns1 < ns) + 2 * ((4 * ns1 <= ns) & (c->SummFreq <= 8 * ns1)));
532 }
533 else
534 {
535 CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0);
536 if (!s)
537 {
538 RestartModel(p);
539 return;
540 }
541 *s = *ONE_STATE(c);
542 c->Stats = REF(s);
543 if (s->Freq < MAX_FREQ / 4 - 1)
544 s->Freq <<= 1;
545 else
546 s->Freq = MAX_FREQ - 4;
547 c->SummFreq = (UInt16)(s->Freq + p->InitEsc + (ns > 3));
548 }
549 cf = 2 * (UInt32)p->FoundState->Freq * (c->SummFreq + 6);
550 sf = (UInt32)s0 + c->SummFreq;
551 if (cf < 6 * sf)
552 {
553 cf = 1 + (cf > sf) + (cf >= 4 * sf);
554 c->SummFreq += 3;
555 }
556 else
557 {
558 cf = 4 + (cf >= 9 * sf) + (cf >= 12 * sf) + (cf >= 15 * sf);
559 c->SummFreq = (UInt16)(c->SummFreq + cf);
560 }
561 {
562 CPpmd_State *s = STATS(c) + ns1;
563 SetSuccessor(s, successor);
564 s->Symbol = p->FoundState->Symbol;
565 s->Freq = (Byte)cf;
566 c->NumStats = (UInt16)(ns1 + 1);
567 }
568 }
569 p->MaxContext = p->MinContext = CTX(fSuccessor);
570}
571
572static void Rescale(CPpmd7 *p)
573{
574 unsigned i, adder, sumFreq, escFreq;
575 CPpmd_State *stats = STATS(p->MinContext);
576 CPpmd_State *s = p->FoundState;
577 {
578 CPpmd_State tmp = *s;
579 for (; s != stats; s--)
580 s[0] = s[-1];
581 *s = tmp;
582 }
583 escFreq = p->MinContext->SummFreq - s->Freq;
584 s->Freq += 4;
585 adder = (p->OrderFall != 0);
586 s->Freq = (Byte)((s->Freq + adder) >> 1);
587 sumFreq = s->Freq;
588
589 i = p->MinContext->NumStats - 1;
590 do
591 {
592 escFreq -= (++s)->Freq;
593 s->Freq = (Byte)((s->Freq + adder) >> 1);
594 sumFreq += s->Freq;
595 if (s[0].Freq > s[-1].Freq)
596 {
597 CPpmd_State *s1 = s;
598 CPpmd_State tmp = *s1;
599 do
600 s1[0] = s1[-1];
601 while (--s1 != stats && tmp.Freq > s1[-1].Freq);
602 *s1 = tmp;
603 }
604 }
605 while (--i);
606
607 if (s->Freq == 0)
608 {
609 unsigned numStats = p->MinContext->NumStats;
610 unsigned n0, n1;
611 do { i++; } while ((--s)->Freq == 0);
612 escFreq += i;
613 p->MinContext->NumStats = (UInt16)(p->MinContext->NumStats - i);
614 if (p->MinContext->NumStats == 1)
615 {
616 CPpmd_State tmp = *stats;
617 do
618 {
619 tmp.Freq = (Byte)(tmp.Freq - (tmp.Freq >> 1));
620 escFreq >>= 1;
621 }
622 while (escFreq > 1);
623 InsertNode(p, stats, U2I(((numStats + 1) >> 1)));
624 *(p->FoundState = ONE_STATE(p->MinContext)) = tmp;
625 return;
626 }
627 n0 = (numStats + 1) >> 1;
628 n1 = (p->MinContext->NumStats + 1) >> 1;
629 if (n0 != n1)
630 p->MinContext->Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1));
631 }
632 p->MinContext->SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1));
633 p->FoundState = STATS(p->MinContext);
634}
635
636CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *escFreq)
637{
638 CPpmd_See *see;
639 unsigned nonMasked = p->MinContext->NumStats - numMasked;
640 if (p->MinContext->NumStats != 256)
641 {
642 see = p->See[p->NS2Indx[nonMasked - 1]] +
643 (nonMasked < (unsigned)SUFFIX(p->MinContext)->NumStats - p->MinContext->NumStats) +
644 2 * (p->MinContext->SummFreq < 11 * p->MinContext->NumStats) +
645 4 * (numMasked > nonMasked) +
646 p->HiBitsFlag;
647 {
648 unsigned r = (see->Summ >> see->Shift);
649 see->Summ = (UInt16)(see->Summ - r);
650 *escFreq = r + (r == 0);
651 }
652 }
653 else
654 {
655 see = &p->DummySee;
656 *escFreq = 1;
657 }
658 return see;
659}
660
661static void NextContext(CPpmd7 *p)
662{
663 CTX_PTR c = CTX(SUCCESSOR(p->FoundState));
664 if (p->OrderFall == 0 && (Byte *)c > p->Text)
665 p->MinContext = p->MaxContext = c;
666 else
667 UpdateModel(p);
668}
669
670void Ppmd7_Update1(CPpmd7 *p)
671{
672 CPpmd_State *s = p->FoundState;
673 s->Freq += 4;
674 p->MinContext->SummFreq += 4;
675 if (s[0].Freq > s[-1].Freq)
676 {
677 SwapStates(&s[0], &s[-1]);
678 p->FoundState = --s;
679 if (s->Freq > MAX_FREQ)
680 Rescale(p);
681 }
682 NextContext(p);
683}
684
685void Ppmd7_Update1_0(CPpmd7 *p)
686{
687 p->PrevSuccess = (2 * p->FoundState->Freq > p->MinContext->SummFreq);
688 p->RunLength += p->PrevSuccess;
689 p->MinContext->SummFreq += 4;
690 if ((p->FoundState->Freq += 4) > MAX_FREQ)
691 Rescale(p);
692 NextContext(p);
693}
694
695void Ppmd7_UpdateBin(CPpmd7 *p)
696{
697 p->FoundState->Freq = (Byte)(p->FoundState->Freq + (p->FoundState->Freq < 128 ? 1: 0));
698 p->PrevSuccess = 1;
699 p->RunLength++;
700 NextContext(p);
701}
702
703void Ppmd7_Update2(CPpmd7 *p)
704{
705 p->MinContext->SummFreq += 4;
706 if ((p->FoundState->Freq += 4) > MAX_FREQ)
707 Rescale(p);
708 p->RunLength = p->InitRL;
709 UpdateModel(p);
710}