1 /* Ppmd7.c -- PPMdH codec 2 2010-03-12 : Igor Pavlov : Public domain 3 This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */ 4 5 #include "archive_platform.h" 6 7 #include <memory.h> 8 9 #include "archive_ppmd7_private.h" 10 11 #ifdef PPMD_32BIT 12 #define Ppmd7_GetPtr(p, ptr) (ptr) 13 #define Ppmd7_GetContext(p, ptr) (ptr) 14 #define Ppmd7_GetStats(p, ctx) ((ctx)->Stats) 15 #else 16 #define Ppmd7_GetPtr(p, offs) ((void *)((p)->Base + (offs))) 17 #define Ppmd7_GetContext(p, offs) ((CPpmd7_Context *)Ppmd7_GetPtr((p), (offs))) 18 #define Ppmd7_GetStats(p, ctx) ((CPpmd_State *)Ppmd7_GetPtr((p), ((ctx)->Stats))) 19 #endif 20 21 #define Ppmd7_GetBinSumm(p) \ 22 &p->BinSumm[Ppmd7Context_OneState(p->MinContext)->Freq - 1][p->PrevSuccess + \ 23 p->NS2BSIndx[Ppmd7_GetContext(p, p->MinContext->Suffix)->NumStats - 1] + \ 24 (p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]) + \ 25 2 * p->HB2Flag[Ppmd7Context_OneState(p->MinContext)->Symbol] + \ 26 ((p->RunLength >> 26) & 0x20)] 27 28 #define kTopValue (1 << 24) 29 #define MAX_FREQ 124 30 #define UNIT_SIZE 12 31 32 #define U2B(nu) ((UInt32)(nu) * UNIT_SIZE) 33 #define U2I(nu) (p->Units2Indx[(nu) - 1]) 34 #define I2U(indx) (p->Indx2Units[indx]) 35 36 #ifdef PPMD_32BIT 37 #define REF(ptr) (ptr) 38 #else 39 #define REF(ptr) ((UInt32)((Byte *)(ptr) - (p)->Base)) 40 #endif 41 42 #define STATS_REF(ptr) ((CPpmd_State_Ref)REF(ptr)) 43 44 #define CTX(ref) ((CPpmd7_Context *)Ppmd7_GetContext(p, ref)) 45 #define STATS(ctx) Ppmd7_GetStats(p, ctx) 46 #define ONE_STATE(ctx) Ppmd7Context_OneState(ctx) 47 #define SUFFIX(ctx) CTX((ctx)->Suffix) 48 49 static const UInt16 kInitBinEsc[] = { 0x3CDD, 0x1F3F, 0x59BF, 0x48F3, 0x64A1, 0x5ABC, 0x6632, 0x6051}; 50 static const Byte PPMD7_kExpEscape[16] = { 25, 14, 9, 7, 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 2, 2 }; 51 52 typedef CPpmd7_Context * CTX_PTR; 53 54 struct CPpmd7_Node_; 55 56 typedef 57 #ifdef PPMD_32BIT 58 struct CPpmd7_Node_ * 59 #else 60 UInt32 61 #endif 62 CPpmd7_Node_Ref; 63 64 typedef struct CPpmd7_Node_ 65 { 66 UInt16 Stamp; /* must be at offset 0 as CPpmd7_Context::NumStats. Stamp=0 means free */ 67 UInt16 NU; 68 CPpmd7_Node_Ref Next; /* must be at offset >= 4 */ 69 CPpmd7_Node_Ref Prev; 70 } CPpmd7_Node; 71 72 #ifdef PPMD_32BIT 73 #define NODE(ptr) (ptr) 74 #else 75 #define NODE(offs) ((CPpmd7_Node *)(p->Base + (offs))) 76 #endif 77 78 static void Ppmd7_Update1(CPpmd7 *p); 79 static void Ppmd7_Update1_0(CPpmd7 *p); 80 static void Ppmd7_Update2(CPpmd7 *p); 81 static void Ppmd7_UpdateBin(CPpmd7 *p); 82 static CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, 83 UInt32 *scale); 84 85 /* ----------- Base ----------- */ 86 87 static void Ppmd7_Construct(CPpmd7 *p) 88 { 89 unsigned i, k, m; 90 91 p->Base = 0; 92 93 for (i = 0, k = 0; i < PPMD_NUM_INDEXES; i++) 94 { 95 unsigned step = (i >= 12 ? 4 : (i >> 2) + 1); 96 do { p->Units2Indx[k++] = (Byte)i; } while(--step); 97 p->Indx2Units[i] = (Byte)k; 98 } 99 100 p->NS2BSIndx[0] = (0 << 1); 101 p->NS2BSIndx[1] = (1 << 1); 102 memset(p->NS2BSIndx + 2, (2 << 1), 9); 103 memset(p->NS2BSIndx + 11, (3 << 1), 256 - 11); 104 105 for (i = 0; i < 3; i++) 106 p->NS2Indx[i] = (Byte)i; 107 for (m = i, k = 1; i < 256; i++) 108 { 109 p->NS2Indx[i] = (Byte)m; 110 if (--k == 0) 111 k = (++m) - 2; 112 } 113 114 memset(p->HB2Flag, 0, 0x40); 115 memset(p->HB2Flag + 0x40, 8, 0x100 - 0x40); 116 } 117 118 static void Ppmd7_Free(CPpmd7 *p, ISzAlloc *alloc) 119 { 120 alloc->Free(alloc, p->Base); 121 p->Size = 0; 122 p->Base = 0; 123 } 124 125 static Bool Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAlloc *alloc) 126 { 127 if (p->Base == 0 || p->Size != size) 128 { 129 Ppmd7_Free(p, alloc); 130 p->AlignOffset = 131 #ifdef PPMD_32BIT 132 (4 - size) & 3; 133 #else 134 4 - (size & 3); 135 #endif 136 if ((p->Base = (Byte *)alloc->Alloc(alloc, p->AlignOffset + size 137 #ifndef PPMD_32BIT 138 + UNIT_SIZE 139 #endif 140 )) == 0) 141 return False; 142 p->Size = size; 143 } 144 return True; 145 } 146 147 static void InsertNode(CPpmd7 *p, void *node, unsigned indx) 148 { 149 *((CPpmd_Void_Ref *)node) = p->FreeList[indx]; 150 p->FreeList[indx] = REF(node); 151 } 152 153 static void *RemoveNode(CPpmd7 *p, unsigned indx) 154 { 155 CPpmd_Void_Ref *node = (CPpmd_Void_Ref *)Ppmd7_GetPtr(p, p->FreeList[indx]); 156 p->FreeList[indx] = *node; 157 return node; 158 } 159 160 static void SplitBlock(CPpmd7 *p, void *ptr, unsigned oldIndx, unsigned newIndx) 161 { 162 unsigned i, nu = I2U(oldIndx) - I2U(newIndx); 163 ptr = (Byte *)ptr + U2B(I2U(newIndx)); 164 if (I2U(i = U2I(nu)) != nu) 165 { 166 unsigned k = I2U(--i); 167 InsertNode(p, ((Byte *)ptr) + U2B(k), nu - k - 1); 168 } 169 InsertNode(p, ptr, i); 170 } 171 172 static void GlueFreeBlocks(CPpmd7 *p) 173 { 174 #ifdef PPMD_32BIT 175 CPpmd7_Node headItem; 176 CPpmd7_Node_Ref head = &headItem; 177 #else 178 CPpmd7_Node_Ref head = p->AlignOffset + p->Size; 179 #endif 180 181 CPpmd7_Node_Ref n = head; 182 unsigned i; 183 184 p->GlueCount = 255; 185 186 /* create doubly-linked list of free blocks */ 187 for (i = 0; i < PPMD_NUM_INDEXES; i++) 188 { 189 UInt16 nu = I2U(i); 190 CPpmd7_Node_Ref next = (CPpmd7_Node_Ref)p->FreeList[i]; 191 p->FreeList[i] = 0; 192 while (next != 0) 193 { 194 CPpmd7_Node *node = NODE(next); 195 node->Next = n; 196 n = NODE(n)->Prev = next; 197 next = *(const CPpmd7_Node_Ref *)node; 198 node->Stamp = 0; 199 node->NU = (UInt16)nu; 200 } 201 } 202 NODE(head)->Stamp = 1; 203 NODE(head)->Next = n; 204 NODE(n)->Prev = head; 205 if (p->LoUnit != p->HiUnit) 206 ((CPpmd7_Node *)p->LoUnit)->Stamp = 1; 207 208 /* Glue free blocks */ 209 while (n != head) 210 { 211 CPpmd7_Node *node = NODE(n); 212 UInt32 nu = (UInt32)node->NU; 213 for (;;) 214 { 215 CPpmd7_Node *node2 = NODE(n) + nu; 216 nu += node2->NU; 217 if (node2->Stamp != 0 || nu >= 0x10000) 218 break; 219 NODE(node2->Prev)->Next = node2->Next; 220 NODE(node2->Next)->Prev = node2->Prev; 221 node->NU = (UInt16)nu; 222 } 223 n = node->Next; 224 } 225 226 /* Fill lists of free blocks */ 227 for (n = NODE(head)->Next; n != head;) 228 { 229 CPpmd7_Node *node = NODE(n); 230 unsigned nu; 231 CPpmd7_Node_Ref next = node->Next; 232 for (nu = node->NU; nu > 128; nu -= 128, node += 128) 233 InsertNode(p, node, PPMD_NUM_INDEXES - 1); 234 if (I2U(i = U2I(nu)) != nu) 235 { 236 unsigned k = I2U(--i); 237 InsertNode(p, node + k, nu - k - 1); 238 } 239 InsertNode(p, node, i); 240 n = next; 241 } 242 } 243 244 static void *AllocUnitsRare(CPpmd7 *p, unsigned indx) 245 { 246 unsigned i; 247 void *retVal; 248 if (p->GlueCount == 0) 249 { 250 GlueFreeBlocks(p); 251 if (p->FreeList[indx] != 0) 252 return RemoveNode(p, indx); 253 } 254 i = indx; 255 do 256 { 257 if (++i == PPMD_NUM_INDEXES) 258 { 259 UInt32 numBytes = U2B(I2U(indx)); 260 p->GlueCount--; 261 return ((UInt32)(p->UnitsStart - p->Text) > numBytes) ? (p->UnitsStart -= numBytes) : (NULL); 262 } 263 } 264 while (p->FreeList[i] == 0); 265 retVal = RemoveNode(p, i); 266 SplitBlock(p, retVal, i, indx); 267 return retVal; 268 } 269 270 static void *AllocUnits(CPpmd7 *p, unsigned indx) 271 { 272 UInt32 numBytes; 273 if (p->FreeList[indx] != 0) 274 return RemoveNode(p, indx); 275 numBytes = U2B(I2U(indx)); 276 if (numBytes <= (UInt32)(p->HiUnit - p->LoUnit)) 277 { 278 void *retVal = p->LoUnit; 279 p->LoUnit += numBytes; 280 return retVal; 281 } 282 return AllocUnitsRare(p, indx); 283 } 284 285 #define MyMem12Cpy(dest, src, num) \ 286 { UInt32 *d = (UInt32 *)dest; const UInt32 *s = (const UInt32 *)src; UInt32 n = num; \ 287 do { d[0] = s[0]; d[1] = s[1]; d[2] = s[2]; s += 3; d += 3; } while(--n); } 288 289 static void *ShrinkUnits(CPpmd7 *p, void *oldPtr, unsigned oldNU, unsigned newNU) 290 { 291 unsigned i0 = U2I(oldNU); 292 unsigned i1 = U2I(newNU); 293 if (i0 == i1) 294 return oldPtr; 295 if (p->FreeList[i1] != 0) 296 { 297 void *ptr = RemoveNode(p, i1); 298 MyMem12Cpy(ptr, oldPtr, newNU); 299 InsertNode(p, oldPtr, i0); 300 return ptr; 301 } 302 SplitBlock(p, oldPtr, i0, i1); 303 return oldPtr; 304 } 305 306 #define SUCCESSOR(p) ((CPpmd_Void_Ref)((p)->SuccessorLow | ((UInt32)(p)->SuccessorHigh << 16))) 307 308 static void SetSuccessor(CPpmd_State *p, CPpmd_Void_Ref v) 309 { 310 (p)->SuccessorLow = (UInt16)((UInt32)(v) & 0xFFFF); 311 (p)->SuccessorHigh = (UInt16)(((UInt32)(v) >> 16) & 0xFFFF); 312 } 313 314 static void RestartModel(CPpmd7 *p) 315 { 316 unsigned i, k, m; 317 318 memset(p->FreeList, 0, sizeof(p->FreeList)); 319 p->Text = p->Base + p->AlignOffset; 320 p->HiUnit = p->Text + p->Size; 321 p->LoUnit = p->UnitsStart = p->HiUnit - p->Size / 8 / UNIT_SIZE * 7 * UNIT_SIZE; 322 p->GlueCount = 0; 323 324 p->OrderFall = p->MaxOrder; 325 p->RunLength = p->InitRL = -(Int32)((p->MaxOrder < 12) ? p->MaxOrder : 12) - 1; 326 p->PrevSuccess = 0; 327 328 p->MinContext = p->MaxContext = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); /* AllocContext(p); */ 329 p->MinContext->Suffix = 0; 330 p->MinContext->NumStats = 256; 331 p->MinContext->SummFreq = 256 + 1; 332 p->FoundState = (CPpmd_State *)p->LoUnit; /* AllocUnits(p, PPMD_NUM_INDEXES - 1); */ 333 p->LoUnit += U2B(256 / 2); 334 p->MinContext->Stats = REF(p->FoundState); 335 for (i = 0; i < 256; i++) 336 { 337 CPpmd_State *s = &p->FoundState[i]; 338 s->Symbol = (Byte)i; 339 s->Freq = 1; 340 SetSuccessor(s, 0); 341 } 342 343 for (i = 0; i < 128; i++) 344 for (k = 0; k < 8; k++) 345 { 346 UInt16 *dest = p->BinSumm[i] + k; 347 UInt16 val = (UInt16)(PPMD_BIN_SCALE - kInitBinEsc[k] / (i + 2)); 348 for (m = 0; m < 64; m += 8) 349 dest[m] = val; 350 } 351 352 for (i = 0; i < 25; i++) 353 for (k = 0; k < 16; k++) 354 { 355 CPpmd_See *s = &p->See[i][k]; 356 s->Summ = (UInt16)((5 * i + 10) << (s->Shift = PPMD_PERIOD_BITS - 4)); 357 s->Count = 4; 358 } 359 } 360 361 static void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder) 362 { 363 p->MaxOrder = maxOrder; 364 RestartModel(p); 365 p->DummySee.Shift = PPMD_PERIOD_BITS; 366 p->DummySee.Summ = 0; /* unused */ 367 p->DummySee.Count = 64; /* unused */ 368 } 369 370 static CTX_PTR CreateSuccessors(CPpmd7 *p, Bool skip) 371 { 372 CPpmd_State upState; 373 CTX_PTR c = p->MinContext; 374 CPpmd_Byte_Ref upBranch = (CPpmd_Byte_Ref)SUCCESSOR(p->FoundState); 375 CPpmd_State *ps[PPMD7_MAX_ORDER]; 376 unsigned numPs = 0; 377 378 if (!skip) 379 ps[numPs++] = p->FoundState; 380 381 while (c->Suffix) 382 { 383 CPpmd_Void_Ref successor; 384 CPpmd_State *s; 385 c = SUFFIX(c); 386 if (c->NumStats != 1) 387 { 388 for (s = STATS(c); s->Symbol != p->FoundState->Symbol; s++); 389 } 390 else 391 s = ONE_STATE(c); 392 successor = SUCCESSOR(s); 393 if (successor != upBranch) 394 { 395 c = CTX(successor); 396 if (numPs == 0) 397 return c; 398 break; 399 } 400 ps[numPs++] = s; 401 } 402 403 upState.Symbol = *(const Byte *)Ppmd7_GetPtr(p, upBranch); 404 SetSuccessor(&upState, upBranch + 1); 405 406 if (c->NumStats == 1) 407 upState.Freq = ONE_STATE(c)->Freq; 408 else 409 { 410 UInt32 cf, s0; 411 CPpmd_State *s; 412 for (s = STATS(c); s->Symbol != upState.Symbol; s++); 413 cf = s->Freq - 1; 414 s0 = c->SummFreq - c->NumStats - cf; 415 upState.Freq = (Byte)(1 + ((2 * cf <= s0) ? (5 * cf > s0) : ((2 * cf + 3 * s0 - 1) / (2 * s0)))); 416 } 417 418 do 419 { 420 /* Create Child */ 421 CTX_PTR c1; /* = AllocContext(p); */ 422 if (p->HiUnit != p->LoUnit) 423 c1 = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); 424 else if (p->FreeList[0] != 0) 425 c1 = (CTX_PTR)RemoveNode(p, 0); 426 else 427 { 428 c1 = (CTX_PTR)AllocUnitsRare(p, 0); 429 if (!c1) 430 return NULL; 431 } 432 c1->NumStats = 1; 433 *ONE_STATE(c1) = upState; 434 c1->Suffix = REF(c); 435 SetSuccessor(ps[--numPs], REF(c1)); 436 c = c1; 437 } 438 while (numPs != 0); 439 440 return c; 441 } 442 443 static void SwapStates(CPpmd_State *t1, CPpmd_State *t2) 444 { 445 CPpmd_State tmp = *t1; 446 *t1 = *t2; 447 *t2 = tmp; 448 } 449 450 static void UpdateModel(CPpmd7 *p) 451 { 452 CPpmd_Void_Ref successor, fSuccessor = SUCCESSOR(p->FoundState); 453 CTX_PTR c; 454 unsigned s0, ns; 455 456 if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0) 457 { 458 c = SUFFIX(p->MinContext); 459 460 if (c->NumStats == 1) 461 { 462 CPpmd_State *s = ONE_STATE(c); 463 if (s->Freq < 32) 464 s->Freq++; 465 } 466 else 467 { 468 CPpmd_State *s = STATS(c); 469 if (s->Symbol != p->FoundState->Symbol) 470 { 471 do { s++; } while (s->Symbol != p->FoundState->Symbol); 472 if (s[0].Freq >= s[-1].Freq) 473 { 474 SwapStates(&s[0], &s[-1]); 475 s--; 476 } 477 } 478 if (s->Freq < MAX_FREQ - 9) 479 { 480 s->Freq += 2; 481 c->SummFreq += 2; 482 } 483 } 484 } 485 486 if (p->OrderFall == 0) 487 { 488 p->MinContext = p->MaxContext = CreateSuccessors(p, True); 489 if (p->MinContext == 0) 490 { 491 RestartModel(p); 492 return; 493 } 494 SetSuccessor(p->FoundState, REF(p->MinContext)); 495 return; 496 } 497 498 *p->Text++ = p->FoundState->Symbol; 499 successor = REF(p->Text); 500 if (p->Text >= p->UnitsStart) 501 { 502 RestartModel(p); 503 return; 504 } 505 506 if (fSuccessor) 507 { 508 if (fSuccessor <= successor) 509 { 510 CTX_PTR cs = CreateSuccessors(p, False); 511 if (cs == NULL) 512 { 513 RestartModel(p); 514 return; 515 } 516 fSuccessor = REF(cs); 517 } 518 if (--p->OrderFall == 0) 519 { 520 successor = fSuccessor; 521 p->Text -= (p->MaxContext != p->MinContext); 522 } 523 } 524 else 525 { 526 SetSuccessor(p->FoundState, successor); 527 fSuccessor = REF(p->MinContext); 528 } 529 530 s0 = p->MinContext->SummFreq - (ns = p->MinContext->NumStats) - (p->FoundState->Freq - 1); 531 532 for (c = p->MaxContext; c != p->MinContext; c = SUFFIX(c)) 533 { 534 unsigned ns1; 535 UInt32 cf, sf; 536 if ((ns1 = c->NumStats) != 1) 537 { 538 if ((ns1 & 1) == 0) 539 { 540 /* Expand for one UNIT */ 541 unsigned oldNU = ns1 >> 1; 542 unsigned i = U2I(oldNU); 543 if (i != U2I(oldNU + 1)) 544 { 545 void *ptr = AllocUnits(p, i + 1); 546 void *oldPtr; 547 if (!ptr) 548 { 549 RestartModel(p); 550 return; 551 } 552 oldPtr = STATS(c); 553 MyMem12Cpy(ptr, oldPtr, oldNU); 554 InsertNode(p, oldPtr, i); 555 c->Stats = STATS_REF(ptr); 556 } 557 } 558 c->SummFreq = (UInt16)(c->SummFreq + (2 * ns1 < ns) + 2 * ((4 * ns1 <= ns) & (c->SummFreq <= 8 * ns1))); 559 } 560 else 561 { 562 CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0); 563 if (!s) 564 { 565 RestartModel(p); 566 return; 567 } 568 *s = *ONE_STATE(c); 569 c->Stats = REF(s); 570 if (s->Freq < MAX_FREQ / 4 - 1) 571 s->Freq <<= 1; 572 else 573 s->Freq = MAX_FREQ - 4; 574 c->SummFreq = (UInt16)(s->Freq + p->InitEsc + (ns > 3)); 575 } 576 cf = 2 * (UInt32)p->FoundState->Freq * (c->SummFreq + 6); 577 sf = (UInt32)s0 + c->SummFreq; 578 if (cf < 6 * sf) 579 { 580 cf = 1 + (cf > sf) + (cf >= 4 * sf); 581 c->SummFreq += 3; 582 } 583 else 584 { 585 cf = 4 + (cf >= 9 * sf) + (cf >= 12 * sf) + (cf >= 15 * sf); 586 c->SummFreq = (UInt16)(c->SummFreq + cf); 587 } 588 { 589 CPpmd_State *s = STATS(c) + ns1; 590 SetSuccessor(s, successor); 591 s->Symbol = p->FoundState->Symbol; 592 s->Freq = (Byte)cf; 593 c->NumStats = (UInt16)(ns1 + 1); 594 } 595 } 596 p->MaxContext = p->MinContext = CTX(fSuccessor); 597 } 598 599 static void Rescale(CPpmd7 *p) 600 { 601 unsigned i, adder, sumFreq, escFreq; 602 CPpmd_State *stats = STATS(p->MinContext); 603 CPpmd_State *s = p->FoundState; 604 { 605 CPpmd_State tmp = *s; 606 for (; s != stats; s--) 607 s[0] = s[-1]; 608 *s = tmp; 609 } 610 escFreq = p->MinContext->SummFreq - s->Freq; 611 s->Freq += 4; 612 adder = (p->OrderFall != 0); 613 s->Freq = (Byte)((s->Freq + adder) >> 1); 614 sumFreq = s->Freq; 615 616 i = p->MinContext->NumStats - 1; 617 do 618 { 619 escFreq -= (++s)->Freq; 620 s->Freq = (Byte)((s->Freq + adder) >> 1); 621 sumFreq += s->Freq; 622 if (s[0].Freq > s[-1].Freq) 623 { 624 CPpmd_State *s1 = s; 625 CPpmd_State tmp = *s1; 626 do 627 s1[0] = s1[-1]; 628 while (--s1 != stats && tmp.Freq > s1[-1].Freq); 629 *s1 = tmp; 630 } 631 } 632 while (--i); 633 634 if (s->Freq == 0) 635 { 636 unsigned numStats = p->MinContext->NumStats; 637 unsigned n0, n1; 638 do { i++; } while ((--s)->Freq == 0); 639 escFreq += i; 640 p->MinContext->NumStats = (UInt16)(p->MinContext->NumStats - i); 641 if (p->MinContext->NumStats == 1) 642 { 643 CPpmd_State tmp = *stats; 644 do 645 { 646 tmp.Freq = (Byte)(tmp.Freq - (tmp.Freq >> 1)); 647 escFreq >>= 1; 648 } 649 while (escFreq > 1); 650 InsertNode(p, stats, U2I(((numStats + 1) >> 1))); 651 *(p->FoundState = ONE_STATE(p->MinContext)) = tmp; 652 return; 653 } 654 n0 = (numStats + 1) >> 1; 655 n1 = (p->MinContext->NumStats + 1) >> 1; 656 if (n0 != n1) 657 p->MinContext->Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1)); 658 } 659 p->MinContext->SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1)); 660 p->FoundState = STATS(p->MinContext); 661 } 662 663 static CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *escFreq) 664 { 665 CPpmd_See *see; 666 unsigned nonMasked = p->MinContext->NumStats - numMasked; 667 if (p->MinContext->NumStats != 256) 668 { 669 see = p->See[p->NS2Indx[nonMasked - 1]] + 670 (nonMasked < (unsigned)SUFFIX(p->MinContext)->NumStats - p->MinContext->NumStats) + 671 2 * (p->MinContext->SummFreq < 11 * p->MinContext->NumStats) + 672 4 * (numMasked > nonMasked) + 673 p->HiBitsFlag; 674 { 675 unsigned r = (see->Summ >> see->Shift); 676 see->Summ = (UInt16)(see->Summ - r); 677 *escFreq = r + (r == 0); 678 } 679 } 680 else 681 { 682 see = &p->DummySee; 683 *escFreq = 1; 684 } 685 return see; 686 } 687 688 static void NextContext(CPpmd7 *p) 689 { 690 CTX_PTR c = CTX(SUCCESSOR(p->FoundState)); 691 if (p->OrderFall == 0 && (Byte *)c > p->Text) 692 p->MinContext = p->MaxContext = c; 693 else 694 UpdateModel(p); 695 } 696 697 static void Ppmd7_Update1(CPpmd7 *p) 698 { 699 CPpmd_State *s = p->FoundState; 700 s->Freq += 4; 701 p->MinContext->SummFreq += 4; 702 if (s[0].Freq > s[-1].Freq) 703 { 704 SwapStates(&s[0], &s[-1]); 705 p->FoundState = --s; 706 if (s->Freq > MAX_FREQ) 707 Rescale(p); 708 } 709 NextContext(p); 710 } 711 712 static void Ppmd7_Update1_0(CPpmd7 *p) 713 { 714 p->PrevSuccess = (2 * p->FoundState->Freq > p->MinContext->SummFreq); 715 p->RunLength += p->PrevSuccess; 716 p->MinContext->SummFreq += 4; 717 if ((p->FoundState->Freq += 4) > MAX_FREQ) 718 Rescale(p); 719 NextContext(p); 720 } 721 722 static void Ppmd7_UpdateBin(CPpmd7 *p) 723 { 724 p->FoundState->Freq = (Byte)(p->FoundState->Freq + (p->FoundState->Freq < 128 ? 1: 0)); 725 p->PrevSuccess = 1; 726 p->RunLength++; 727 NextContext(p); 728 } 729 730 static void Ppmd7_Update2(CPpmd7 *p) 731 { 732 p->MinContext->SummFreq += 4; 733 if ((p->FoundState->Freq += 4) > MAX_FREQ) 734 Rescale(p); 735 p->RunLength = p->InitRL; 736 UpdateModel(p); 737 } 738 739 /* ---------- Decode ---------- */ 740 741 static Bool Ppmd_RangeDec_Init(CPpmd7z_RangeDec *p) 742 { 743 unsigned i; 744 p->Low = p->Bottom = 0; 745 p->Range = 0xFFFFFFFF; 746 for (i = 0; i < 4; i++) 747 p->Code = (p->Code << 8) | p->Stream->Read((void *)p->Stream); 748 return (p->Code < 0xFFFFFFFF); 749 } 750 751 static Bool Ppmd7z_RangeDec_Init(CPpmd7z_RangeDec *p) 752 { 753 if (p->Stream->Read((void *)p->Stream) != 0) 754 return False; 755 return Ppmd_RangeDec_Init(p); 756 } 757 758 static Bool PpmdRAR_RangeDec_Init(CPpmd7z_RangeDec *p) 759 { 760 if (!Ppmd_RangeDec_Init(p)) 761 return False; 762 p->Bottom = 0x8000; 763 return True; 764 } 765 766 static UInt32 Range_GetThreshold(void *pp, UInt32 total) 767 { 768 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 769 return (p->Code - p->Low) / (p->Range /= total); 770 } 771 772 static void Range_Normalize(CPpmd7z_RangeDec *p) 773 { 774 while (1) 775 { 776 if((p->Low ^ (p->Low + p->Range)) >= kTopValue) 777 { 778 if(p->Range >= p->Bottom) 779 break; 780 else 781 p->Range = -p->Low & (p->Bottom - 1); 782 } 783 p->Code = (p->Code << 8) | p->Stream->Read((void *)p->Stream); 784 p->Range <<= 8; 785 p->Low <<= 8; 786 } 787 } 788 789 static void Range_Decode_7z(void *pp, UInt32 start, UInt32 size) 790 { 791 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 792 p->Code -= start * p->Range; 793 p->Range *= size; 794 Range_Normalize(p); 795 } 796 797 static void Range_Decode_RAR(void *pp, UInt32 start, UInt32 size) 798 { 799 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 800 p->Low += start * p->Range; 801 p->Range *= size; 802 Range_Normalize(p); 803 } 804 805 static UInt32 Range_DecodeBit_7z(void *pp, UInt32 size0) 806 { 807 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 808 UInt32 newBound = (p->Range >> 14) * size0; 809 UInt32 symbol; 810 if (p->Code < newBound) 811 { 812 symbol = 0; 813 p->Range = newBound; 814 } 815 else 816 { 817 symbol = 1; 818 p->Code -= newBound; 819 p->Range -= newBound; 820 } 821 Range_Normalize(p); 822 return symbol; 823 } 824 825 static UInt32 Range_DecodeBit_RAR(void *pp, UInt32 size0) 826 { 827 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 828 UInt32 bit, value = p->p.GetThreshold(p, PPMD_BIN_SCALE); 829 if(value < size0) 830 { 831 bit = 0; 832 p->p.Decode(p, 0, size0); 833 } 834 else 835 { 836 bit = 1; 837 p->p.Decode(p, size0, PPMD_BIN_SCALE - size0); 838 } 839 return bit; 840 } 841 842 static void Ppmd7z_RangeDec_CreateVTable(CPpmd7z_RangeDec *p) 843 { 844 p->p.GetThreshold = Range_GetThreshold; 845 p->p.Decode = Range_Decode_7z; 846 p->p.DecodeBit = Range_DecodeBit_7z; 847 } 848 849 static void PpmdRAR_RangeDec_CreateVTable(CPpmd7z_RangeDec *p) 850 { 851 p->p.GetThreshold = Range_GetThreshold; 852 p->p.Decode = Range_Decode_RAR; 853 p->p.DecodeBit = Range_DecodeBit_RAR; 854 } 855 856 #define MASK(sym) ((signed char *)charMask)[sym] 857 858 static int Ppmd7_DecodeSymbol(CPpmd7 *p, IPpmd7_RangeDec *rc) 859 { 860 size_t charMask[256 / sizeof(size_t)]; 861 if (p->MinContext->NumStats != 1) 862 { 863 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 864 unsigned i; 865 UInt32 count, hiCnt; 866 if ((count = rc->GetThreshold(rc, p->MinContext->SummFreq)) < (hiCnt = s->Freq)) 867 { 868 Byte symbol; 869 rc->Decode(rc, 0, s->Freq); 870 p->FoundState = s; 871 symbol = s->Symbol; 872 Ppmd7_Update1_0(p); 873 return symbol; 874 } 875 p->PrevSuccess = 0; 876 i = p->MinContext->NumStats - 1; 877 do 878 { 879 if ((hiCnt += (++s)->Freq) > count) 880 { 881 Byte symbol; 882 rc->Decode(rc, hiCnt - s->Freq, s->Freq); 883 p->FoundState = s; 884 symbol = s->Symbol; 885 Ppmd7_Update1(p); 886 return symbol; 887 } 888 } 889 while (--i); 890 if (count >= p->MinContext->SummFreq) 891 return -2; 892 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 893 rc->Decode(rc, hiCnt, p->MinContext->SummFreq - hiCnt); 894 PPMD_SetAllBitsIn256Bytes(charMask); 895 MASK(s->Symbol) = 0; 896 i = p->MinContext->NumStats - 1; 897 do { MASK((--s)->Symbol) = 0; } while (--i); 898 } 899 else 900 { 901 UInt16 *prob = Ppmd7_GetBinSumm(p); 902 if (rc->DecodeBit(rc, *prob) == 0) 903 { 904 Byte symbol; 905 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 906 symbol = (p->FoundState = Ppmd7Context_OneState(p->MinContext))->Symbol; 907 Ppmd7_UpdateBin(p); 908 return symbol; 909 } 910 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 911 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 912 PPMD_SetAllBitsIn256Bytes(charMask); 913 MASK(Ppmd7Context_OneState(p->MinContext)->Symbol) = 0; 914 p->PrevSuccess = 0; 915 } 916 for (;;) 917 { 918 CPpmd_State *ps[256], *s; 919 UInt32 freqSum, count, hiCnt; 920 CPpmd_See *see; 921 unsigned i, num, numMasked = p->MinContext->NumStats; 922 do 923 { 924 p->OrderFall++; 925 if (!p->MinContext->Suffix) 926 return -1; 927 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 928 } 929 while (p->MinContext->NumStats == numMasked); 930 hiCnt = 0; 931 s = Ppmd7_GetStats(p, p->MinContext); 932 i = 0; 933 num = p->MinContext->NumStats - numMasked; 934 do 935 { 936 int k = (int)(MASK(s->Symbol)); 937 hiCnt += (s->Freq & k); 938 ps[i] = s++; 939 i -= k; 940 } 941 while (i != num); 942 943 see = Ppmd7_MakeEscFreq(p, numMasked, &freqSum); 944 freqSum += hiCnt; 945 count = rc->GetThreshold(rc, freqSum); 946 947 if (count < hiCnt) 948 { 949 Byte symbol; 950 CPpmd_State **pps = ps; 951 for (hiCnt = 0; (hiCnt += (*pps)->Freq) <= count; pps++); 952 s = *pps; 953 rc->Decode(rc, hiCnt - s->Freq, s->Freq); 954 Ppmd_See_Update(see); 955 p->FoundState = s; 956 symbol = s->Symbol; 957 Ppmd7_Update2(p); 958 return symbol; 959 } 960 if (count >= freqSum) 961 return -2; 962 rc->Decode(rc, hiCnt, freqSum - hiCnt); 963 see->Summ = (UInt16)(see->Summ + freqSum); 964 do { MASK(ps[--i]->Symbol) = 0; } while (i != 0); 965 } 966 } 967 968 /* ---------- Encode ---------- Ppmd7Enc.c */ 969 970 #define kTopValue (1 << 24) 971 972 static void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p) 973 { 974 p->Low = 0; 975 p->Range = 0xFFFFFFFF; 976 p->Cache = 0; 977 p->CacheSize = 1; 978 } 979 980 static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p) 981 { 982 if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0) 983 { 984 Byte temp = p->Cache; 985 do 986 { 987 p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32))); 988 temp = 0xFF; 989 } 990 while(--p->CacheSize != 0); 991 p->Cache = (Byte)((UInt32)p->Low >> 24); 992 } 993 p->CacheSize++; 994 p->Low = (UInt32)p->Low << 8; 995 } 996 997 static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total) 998 { 999 p->Low += start * (p->Range /= total); 1000 p->Range *= size; 1001 while (p->Range < kTopValue) 1002 { 1003 p->Range <<= 8; 1004 RangeEnc_ShiftLow(p); 1005 } 1006 } 1007 1008 static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0) 1009 { 1010 p->Range = (p->Range >> 14) * size0; 1011 while (p->Range < kTopValue) 1012 { 1013 p->Range <<= 8; 1014 RangeEnc_ShiftLow(p); 1015 } 1016 } 1017 1018 static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0) 1019 { 1020 UInt32 newBound = (p->Range >> 14) * size0; 1021 p->Low += newBound; 1022 p->Range -= newBound; 1023 while (p->Range < kTopValue) 1024 { 1025 p->Range <<= 8; 1026 RangeEnc_ShiftLow(p); 1027 } 1028 } 1029 1030 static void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p) 1031 { 1032 unsigned i; 1033 for (i = 0; i < 5; i++) 1034 RangeEnc_ShiftLow(p); 1035 } 1036 1037 1038 #define MASK(sym) ((signed char *)charMask)[sym] 1039 1040 static void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol) 1041 { 1042 size_t charMask[256 / sizeof(size_t)]; 1043 if (p->MinContext->NumStats != 1) 1044 { 1045 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 1046 UInt32 sum; 1047 unsigned i; 1048 if (s->Symbol == symbol) 1049 { 1050 RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq); 1051 p->FoundState = s; 1052 Ppmd7_Update1_0(p); 1053 return; 1054 } 1055 p->PrevSuccess = 0; 1056 sum = s->Freq; 1057 i = p->MinContext->NumStats - 1; 1058 do 1059 { 1060 if ((++s)->Symbol == symbol) 1061 { 1062 RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq); 1063 p->FoundState = s; 1064 Ppmd7_Update1(p); 1065 return; 1066 } 1067 sum += s->Freq; 1068 } 1069 while (--i); 1070 1071 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 1072 PPMD_SetAllBitsIn256Bytes(charMask); 1073 MASK(s->Symbol) = 0; 1074 i = p->MinContext->NumStats - 1; 1075 do { MASK((--s)->Symbol) = 0; } while (--i); 1076 RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq); 1077 } 1078 else 1079 { 1080 UInt16 *prob = Ppmd7_GetBinSumm(p); 1081 CPpmd_State *s = Ppmd7Context_OneState(p->MinContext); 1082 if (s->Symbol == symbol) 1083 { 1084 RangeEnc_EncodeBit_0(rc, *prob); 1085 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 1086 p->FoundState = s; 1087 Ppmd7_UpdateBin(p); 1088 return; 1089 } 1090 else 1091 { 1092 RangeEnc_EncodeBit_1(rc, *prob); 1093 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 1094 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 1095 PPMD_SetAllBitsIn256Bytes(charMask); 1096 MASK(s->Symbol) = 0; 1097 p->PrevSuccess = 0; 1098 } 1099 } 1100 for (;;) 1101 { 1102 UInt32 escFreq; 1103 CPpmd_See *see; 1104 CPpmd_State *s; 1105 UInt32 sum; 1106 unsigned i, numMasked = p->MinContext->NumStats; 1107 do 1108 { 1109 p->OrderFall++; 1110 if (!p->MinContext->Suffix) 1111 return; /* EndMarker (symbol = -1) */ 1112 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 1113 } 1114 while (p->MinContext->NumStats == numMasked); 1115 1116 see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq); 1117 s = Ppmd7_GetStats(p, p->MinContext); 1118 sum = 0; 1119 i = p->MinContext->NumStats; 1120 do 1121 { 1122 int cur = s->Symbol; 1123 if (cur == symbol) 1124 { 1125 UInt32 low = sum; 1126 CPpmd_State *s1 = s; 1127 do 1128 { 1129 sum += (s->Freq & (int)(MASK(s->Symbol))); 1130 s++; 1131 } 1132 while (--i); 1133 RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq); 1134 Ppmd_See_Update(see); 1135 p->FoundState = s1; 1136 Ppmd7_Update2(p); 1137 return; 1138 } 1139 sum += (s->Freq & (int)(MASK(cur))); 1140 MASK(cur) = 0; 1141 s++; 1142 } 1143 while (--i); 1144 1145 RangeEnc_Encode(rc, sum, escFreq, sum + escFreq); 1146 see->Summ = (UInt16)(see->Summ + sum + escFreq); 1147 } 1148 } 1149 1150 const IPpmd7 __archive_ppmd7_functions = 1151 { 1152 &Ppmd7_Construct, 1153 &Ppmd7_Alloc, 1154 &Ppmd7_Free, 1155 &Ppmd7_Init, 1156 &Ppmd7z_RangeDec_CreateVTable, 1157 &PpmdRAR_RangeDec_CreateVTable, 1158 &Ppmd7z_RangeDec_Init, 1159 &PpmdRAR_RangeDec_Init, 1160 &Ppmd7_DecodeSymbol, 1161 &Ppmd7z_RangeEnc_Init, 1162 &Ppmd7z_RangeEnc_FlushData, 1163 &Ppmd7_EncodeSymbol 1164 }; 1165