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 while (numPs != 0) 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 } 438 439 return c; 440 } 441 442 static void SwapStates(CPpmd_State *t1, CPpmd_State *t2) 443 { 444 CPpmd_State tmp = *t1; 445 *t1 = *t2; 446 *t2 = tmp; 447 } 448 449 static void UpdateModel(CPpmd7 *p) 450 { 451 CPpmd_Void_Ref successor, fSuccessor = SUCCESSOR(p->FoundState); 452 CTX_PTR c; 453 unsigned s0, ns; 454 455 if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0) 456 { 457 c = SUFFIX(p->MinContext); 458 459 if (c->NumStats == 1) 460 { 461 CPpmd_State *s = ONE_STATE(c); 462 if (s->Freq < 32) 463 s->Freq++; 464 } 465 else 466 { 467 CPpmd_State *s = STATS(c); 468 if (s->Symbol != p->FoundState->Symbol) 469 { 470 do { s++; } while (s->Symbol != p->FoundState->Symbol); 471 if (s[0].Freq >= s[-1].Freq) 472 { 473 SwapStates(&s[0], &s[-1]); 474 s--; 475 } 476 } 477 if (s->Freq < MAX_FREQ - 9) 478 { 479 s->Freq += 2; 480 c->SummFreq += 2; 481 } 482 } 483 } 484 485 if (p->OrderFall == 0) 486 { 487 p->MinContext = p->MaxContext = CreateSuccessors(p, True); 488 if (p->MinContext == 0) 489 { 490 RestartModel(p); 491 return; 492 } 493 SetSuccessor(p->FoundState, REF(p->MinContext)); 494 return; 495 } 496 497 *p->Text++ = p->FoundState->Symbol; 498 successor = REF(p->Text); 499 if (p->Text >= p->UnitsStart) 500 { 501 RestartModel(p); 502 return; 503 } 504 505 if (fSuccessor) 506 { 507 if (fSuccessor <= successor) 508 { 509 CTX_PTR cs = CreateSuccessors(p, False); 510 if (cs == NULL) 511 { 512 RestartModel(p); 513 return; 514 } 515 fSuccessor = REF(cs); 516 } 517 if (--p->OrderFall == 0) 518 { 519 successor = fSuccessor; 520 p->Text -= (p->MaxContext != p->MinContext); 521 } 522 } 523 else 524 { 525 SetSuccessor(p->FoundState, successor); 526 fSuccessor = REF(p->MinContext); 527 } 528 529 s0 = p->MinContext->SummFreq - (ns = p->MinContext->NumStats) - (p->FoundState->Freq - 1); 530 531 for (c = p->MaxContext; c != p->MinContext; c = SUFFIX(c)) 532 { 533 unsigned ns1; 534 UInt32 cf, sf; 535 if ((ns1 = c->NumStats) != 1) 536 { 537 if ((ns1 & 1) == 0) 538 { 539 /* Expand for one UNIT */ 540 unsigned oldNU = ns1 >> 1; 541 unsigned i = U2I(oldNU); 542 if (i != U2I(oldNU + 1)) 543 { 544 void *ptr = AllocUnits(p, i + 1); 545 void *oldPtr; 546 if (!ptr) 547 { 548 RestartModel(p); 549 return; 550 } 551 oldPtr = STATS(c); 552 MyMem12Cpy(ptr, oldPtr, oldNU); 553 InsertNode(p, oldPtr, i); 554 c->Stats = STATS_REF(ptr); 555 } 556 } 557 c->SummFreq = (UInt16)(c->SummFreq + (2 * ns1 < ns) + 2 * ((4 * ns1 <= ns) & (c->SummFreq <= 8 * ns1))); 558 } 559 else 560 { 561 CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0); 562 if (!s) 563 { 564 RestartModel(p); 565 return; 566 } 567 *s = *ONE_STATE(c); 568 c->Stats = REF(s); 569 if (s->Freq < MAX_FREQ / 4 - 1) 570 s->Freq <<= 1; 571 else 572 s->Freq = MAX_FREQ - 4; 573 c->SummFreq = (UInt16)(s->Freq + p->InitEsc + (ns > 3)); 574 } 575 cf = 2 * (UInt32)p->FoundState->Freq * (c->SummFreq + 6); 576 sf = (UInt32)s0 + c->SummFreq; 577 if (cf < 6 * sf) 578 { 579 cf = 1 + (cf > sf) + (cf >= 4 * sf); 580 c->SummFreq += 3; 581 } 582 else 583 { 584 cf = 4 + (cf >= 9 * sf) + (cf >= 12 * sf) + (cf >= 15 * sf); 585 c->SummFreq = (UInt16)(c->SummFreq + cf); 586 } 587 { 588 CPpmd_State *s = STATS(c) + ns1; 589 SetSuccessor(s, successor); 590 s->Symbol = p->FoundState->Symbol; 591 s->Freq = (Byte)cf; 592 c->NumStats = (UInt16)(ns1 + 1); 593 } 594 } 595 p->MaxContext = p->MinContext = CTX(fSuccessor); 596 } 597 598 static void Rescale(CPpmd7 *p) 599 { 600 unsigned i, adder, sumFreq, escFreq; 601 CPpmd_State *stats = STATS(p->MinContext); 602 CPpmd_State *s = p->FoundState; 603 { 604 CPpmd_State tmp = *s; 605 for (; s != stats; s--) 606 s[0] = s[-1]; 607 *s = tmp; 608 } 609 escFreq = p->MinContext->SummFreq - s->Freq; 610 s->Freq += 4; 611 adder = (p->OrderFall != 0); 612 s->Freq = (Byte)((s->Freq + adder) >> 1); 613 sumFreq = s->Freq; 614 615 i = p->MinContext->NumStats - 1; 616 do 617 { 618 escFreq -= (++s)->Freq; 619 s->Freq = (Byte)((s->Freq + adder) >> 1); 620 sumFreq += s->Freq; 621 if (s[0].Freq > s[-1].Freq) 622 { 623 CPpmd_State *s1 = s; 624 CPpmd_State tmp = *s1; 625 do 626 s1[0] = s1[-1]; 627 while (--s1 != stats && tmp.Freq > s1[-1].Freq); 628 *s1 = tmp; 629 } 630 } 631 while (--i); 632 633 if (s->Freq == 0) 634 { 635 unsigned numStats = p->MinContext->NumStats; 636 unsigned n0, n1; 637 do { i++; } while ((--s)->Freq == 0); 638 escFreq += i; 639 p->MinContext->NumStats = (UInt16)(p->MinContext->NumStats - i); 640 if (p->MinContext->NumStats == 1) 641 { 642 CPpmd_State tmp = *stats; 643 do 644 { 645 tmp.Freq = (Byte)(tmp.Freq - (tmp.Freq >> 1)); 646 escFreq >>= 1; 647 } 648 while (escFreq > 1); 649 InsertNode(p, stats, U2I(((numStats + 1) >> 1))); 650 *(p->FoundState = ONE_STATE(p->MinContext)) = tmp; 651 return; 652 } 653 n0 = (numStats + 1) >> 1; 654 n1 = (p->MinContext->NumStats + 1) >> 1; 655 if (n0 != n1) 656 p->MinContext->Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1)); 657 } 658 p->MinContext->SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1)); 659 p->FoundState = STATS(p->MinContext); 660 } 661 662 static CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *escFreq) 663 { 664 CPpmd_See *see; 665 unsigned nonMasked = p->MinContext->NumStats - numMasked; 666 if (p->MinContext->NumStats != 256) 667 { 668 see = p->See[p->NS2Indx[nonMasked - 1]] + 669 (nonMasked < (unsigned)SUFFIX(p->MinContext)->NumStats - p->MinContext->NumStats) + 670 2 * (p->MinContext->SummFreq < 11 * p->MinContext->NumStats) + 671 4 * (numMasked > nonMasked) + 672 p->HiBitsFlag; 673 { 674 unsigned r = (see->Summ >> see->Shift); 675 see->Summ = (UInt16)(see->Summ - r); 676 *escFreq = r + (r == 0); 677 } 678 } 679 else 680 { 681 see = &p->DummySee; 682 *escFreq = 1; 683 } 684 return see; 685 } 686 687 static void NextContext(CPpmd7 *p) 688 { 689 CTX_PTR c = CTX(SUCCESSOR(p->FoundState)); 690 if (p->OrderFall == 0 && (Byte *)c > p->Text) 691 p->MinContext = p->MaxContext = c; 692 else 693 UpdateModel(p); 694 } 695 696 static void Ppmd7_Update1(CPpmd7 *p) 697 { 698 CPpmd_State *s = p->FoundState; 699 s->Freq += 4; 700 p->MinContext->SummFreq += 4; 701 if (s[0].Freq > s[-1].Freq) 702 { 703 SwapStates(&s[0], &s[-1]); 704 p->FoundState = --s; 705 if (s->Freq > MAX_FREQ) 706 Rescale(p); 707 } 708 NextContext(p); 709 } 710 711 static void Ppmd7_Update1_0(CPpmd7 *p) 712 { 713 p->PrevSuccess = (2 * p->FoundState->Freq > p->MinContext->SummFreq); 714 p->RunLength += p->PrevSuccess; 715 p->MinContext->SummFreq += 4; 716 if ((p->FoundState->Freq += 4) > MAX_FREQ) 717 Rescale(p); 718 NextContext(p); 719 } 720 721 static void Ppmd7_UpdateBin(CPpmd7 *p) 722 { 723 p->FoundState->Freq = (Byte)(p->FoundState->Freq + (p->FoundState->Freq < 128 ? 1: 0)); 724 p->PrevSuccess = 1; 725 p->RunLength++; 726 NextContext(p); 727 } 728 729 static void Ppmd7_Update2(CPpmd7 *p) 730 { 731 p->MinContext->SummFreq += 4; 732 if ((p->FoundState->Freq += 4) > MAX_FREQ) 733 Rescale(p); 734 p->RunLength = p->InitRL; 735 UpdateModel(p); 736 } 737 738 /* ---------- Decode ---------- */ 739 740 static Bool Ppmd_RangeDec_Init(CPpmd7z_RangeDec *p) 741 { 742 unsigned i; 743 p->Low = p->Bottom = 0; 744 p->Range = 0xFFFFFFFF; 745 for (i = 0; i < 4; i++) 746 p->Code = (p->Code << 8) | p->Stream->Read((void *)p->Stream); 747 return (p->Code < 0xFFFFFFFF); 748 } 749 750 static Bool Ppmd7z_RangeDec_Init(CPpmd7z_RangeDec *p) 751 { 752 if (p->Stream->Read((void *)p->Stream) != 0) 753 return False; 754 return Ppmd_RangeDec_Init(p); 755 } 756 757 static Bool PpmdRAR_RangeDec_Init(CPpmd7z_RangeDec *p) 758 { 759 if (!Ppmd_RangeDec_Init(p)) 760 return False; 761 p->Bottom = 0x8000; 762 return True; 763 } 764 765 static UInt32 Range_GetThreshold(void *pp, UInt32 total) 766 { 767 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 768 return (p->Code - p->Low) / (p->Range /= total); 769 } 770 771 static void Range_Normalize(CPpmd7z_RangeDec *p) 772 { 773 while (1) 774 { 775 if((p->Low ^ (p->Low + p->Range)) >= kTopValue) 776 { 777 if(p->Range >= p->Bottom) 778 break; 779 else 780 p->Range = ((uint32_t)(-(int32_t)p->Low)) & (p->Bottom - 1); 781 } 782 p->Code = (p->Code << 8) | p->Stream->Read((void *)p->Stream); 783 p->Range <<= 8; 784 p->Low <<= 8; 785 } 786 } 787 788 static void Range_Decode_7z(void *pp, UInt32 start, UInt32 size) 789 { 790 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 791 p->Code -= start * p->Range; 792 p->Range *= size; 793 Range_Normalize(p); 794 } 795 796 static void Range_Decode_RAR(void *pp, UInt32 start, UInt32 size) 797 { 798 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 799 p->Low += start * p->Range; 800 p->Range *= size; 801 Range_Normalize(p); 802 } 803 804 static UInt32 Range_DecodeBit_7z(void *pp, UInt32 size0) 805 { 806 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 807 UInt32 newBound = (p->Range >> 14) * size0; 808 UInt32 symbol; 809 if (p->Code < newBound) 810 { 811 symbol = 0; 812 p->Range = newBound; 813 } 814 else 815 { 816 symbol = 1; 817 p->Code -= newBound; 818 p->Range -= newBound; 819 } 820 Range_Normalize(p); 821 return symbol; 822 } 823 824 static UInt32 Range_DecodeBit_RAR(void *pp, UInt32 size0) 825 { 826 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 827 UInt32 bit, value = p->p.GetThreshold(p, PPMD_BIN_SCALE); 828 if(value < size0) 829 { 830 bit = 0; 831 p->p.Decode(p, 0, size0); 832 } 833 else 834 { 835 bit = 1; 836 p->p.Decode(p, size0, PPMD_BIN_SCALE - size0); 837 } 838 return bit; 839 } 840 841 static void Ppmd7z_RangeDec_CreateVTable(CPpmd7z_RangeDec *p) 842 { 843 p->p.GetThreshold = Range_GetThreshold; 844 p->p.Decode = Range_Decode_7z; 845 p->p.DecodeBit = Range_DecodeBit_7z; 846 } 847 848 static void PpmdRAR_RangeDec_CreateVTable(CPpmd7z_RangeDec *p) 849 { 850 p->p.GetThreshold = Range_GetThreshold; 851 p->p.Decode = Range_Decode_RAR; 852 p->p.DecodeBit = Range_DecodeBit_RAR; 853 } 854 855 #define MASK(sym) ((signed char *)charMask)[sym] 856 857 static int Ppmd7_DecodeSymbol(CPpmd7 *p, IPpmd7_RangeDec *rc) 858 { 859 size_t charMask[256 / sizeof(size_t)]; 860 if (p->MinContext->NumStats != 1) 861 { 862 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 863 unsigned i; 864 UInt32 count, hiCnt; 865 if ((count = rc->GetThreshold(rc, p->MinContext->SummFreq)) < (hiCnt = s->Freq)) 866 { 867 Byte symbol; 868 rc->Decode(rc, 0, s->Freq); 869 p->FoundState = s; 870 symbol = s->Symbol; 871 Ppmd7_Update1_0(p); 872 return symbol; 873 } 874 p->PrevSuccess = 0; 875 i = p->MinContext->NumStats - 1; 876 do 877 { 878 if ((hiCnt += (++s)->Freq) > count) 879 { 880 Byte symbol; 881 rc->Decode(rc, hiCnt - s->Freq, s->Freq); 882 p->FoundState = s; 883 symbol = s->Symbol; 884 Ppmd7_Update1(p); 885 return symbol; 886 } 887 } 888 while (--i); 889 if (count >= p->MinContext->SummFreq) 890 return -2; 891 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 892 rc->Decode(rc, hiCnt, p->MinContext->SummFreq - hiCnt); 893 PPMD_SetAllBitsIn256Bytes(charMask); 894 MASK(s->Symbol) = 0; 895 i = p->MinContext->NumStats - 1; 896 do { MASK((--s)->Symbol) = 0; } while (--i); 897 } 898 else 899 { 900 UInt16 *prob = Ppmd7_GetBinSumm(p); 901 if (rc->DecodeBit(rc, *prob) == 0) 902 { 903 Byte symbol; 904 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 905 symbol = (p->FoundState = Ppmd7Context_OneState(p->MinContext))->Symbol; 906 Ppmd7_UpdateBin(p); 907 return symbol; 908 } 909 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 910 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 911 PPMD_SetAllBitsIn256Bytes(charMask); 912 MASK(Ppmd7Context_OneState(p->MinContext)->Symbol) = 0; 913 p->PrevSuccess = 0; 914 } 915 for (;;) 916 { 917 CPpmd_State *ps[256], *s; 918 UInt32 freqSum, count, hiCnt; 919 CPpmd_See *see; 920 unsigned i, num, numMasked = p->MinContext->NumStats; 921 do 922 { 923 p->OrderFall++; 924 if (!p->MinContext->Suffix) 925 return -1; 926 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 927 } 928 while (p->MinContext->NumStats == numMasked); 929 hiCnt = 0; 930 s = Ppmd7_GetStats(p, p->MinContext); 931 i = 0; 932 num = p->MinContext->NumStats - numMasked; 933 do 934 { 935 int k = (int)(MASK(s->Symbol)); 936 hiCnt += (s->Freq & k); 937 ps[i] = s++; 938 i -= k; 939 } 940 while (i != num); 941 942 see = Ppmd7_MakeEscFreq(p, numMasked, &freqSum); 943 freqSum += hiCnt; 944 count = rc->GetThreshold(rc, freqSum); 945 946 if (count < hiCnt) 947 { 948 Byte symbol; 949 CPpmd_State **pps = ps; 950 for (hiCnt = 0; (hiCnt += (*pps)->Freq) <= count; pps++); 951 s = *pps; 952 rc->Decode(rc, hiCnt - s->Freq, s->Freq); 953 Ppmd_See_Update(see); 954 p->FoundState = s; 955 symbol = s->Symbol; 956 Ppmd7_Update2(p); 957 return symbol; 958 } 959 if (count >= freqSum) 960 return -2; 961 rc->Decode(rc, hiCnt, freqSum - hiCnt); 962 see->Summ = (UInt16)(see->Summ + freqSum); 963 do { MASK(ps[--i]->Symbol) = 0; } while (i != 0); 964 } 965 } 966 967 /* ---------- Encode ---------- Ppmd7Enc.c */ 968 969 #define kTopValue (1 << 24) 970 971 static void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p) 972 { 973 p->Low = 0; 974 p->Range = 0xFFFFFFFF; 975 p->Cache = 0; 976 p->CacheSize = 1; 977 } 978 979 static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p) 980 { 981 if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0) 982 { 983 Byte temp = p->Cache; 984 do 985 { 986 p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32))); 987 temp = 0xFF; 988 } 989 while(--p->CacheSize != 0); 990 p->Cache = (Byte)((UInt32)p->Low >> 24); 991 } 992 p->CacheSize++; 993 p->Low = ((UInt32)p->Low << 8) & 0xFFFFFFFF; 994 } 995 996 static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total) 997 { 998 p->Low += start * (p->Range /= total); 999 p->Range *= size; 1000 while (p->Range < kTopValue) 1001 { 1002 p->Range <<= 8; 1003 RangeEnc_ShiftLow(p); 1004 } 1005 } 1006 1007 static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0) 1008 { 1009 p->Range = (p->Range >> 14) * size0; 1010 while (p->Range < kTopValue) 1011 { 1012 p->Range <<= 8; 1013 RangeEnc_ShiftLow(p); 1014 } 1015 } 1016 1017 static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0) 1018 { 1019 UInt32 newBound = (p->Range >> 14) * size0; 1020 p->Low += newBound; 1021 p->Range -= newBound; 1022 while (p->Range < kTopValue) 1023 { 1024 p->Range <<= 8; 1025 RangeEnc_ShiftLow(p); 1026 } 1027 } 1028 1029 static void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p) 1030 { 1031 unsigned i; 1032 for (i = 0; i < 5; i++) 1033 RangeEnc_ShiftLow(p); 1034 } 1035 1036 1037 #define MASK(sym) ((signed char *)charMask)[sym] 1038 1039 static void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol) 1040 { 1041 size_t charMask[256 / sizeof(size_t)]; 1042 if (p->MinContext->NumStats != 1) 1043 { 1044 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 1045 UInt32 sum; 1046 unsigned i; 1047 if (s->Symbol == symbol) 1048 { 1049 RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq); 1050 p->FoundState = s; 1051 Ppmd7_Update1_0(p); 1052 return; 1053 } 1054 p->PrevSuccess = 0; 1055 sum = s->Freq; 1056 i = p->MinContext->NumStats - 1; 1057 do 1058 { 1059 if ((++s)->Symbol == symbol) 1060 { 1061 RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq); 1062 p->FoundState = s; 1063 Ppmd7_Update1(p); 1064 return; 1065 } 1066 sum += s->Freq; 1067 } 1068 while (--i); 1069 1070 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 1071 PPMD_SetAllBitsIn256Bytes(charMask); 1072 MASK(s->Symbol) = 0; 1073 i = p->MinContext->NumStats - 1; 1074 do { MASK((--s)->Symbol) = 0; } while (--i); 1075 RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq); 1076 } 1077 else 1078 { 1079 UInt16 *prob = Ppmd7_GetBinSumm(p); 1080 CPpmd_State *s = Ppmd7Context_OneState(p->MinContext); 1081 if (s->Symbol == symbol) 1082 { 1083 RangeEnc_EncodeBit_0(rc, *prob); 1084 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 1085 p->FoundState = s; 1086 Ppmd7_UpdateBin(p); 1087 return; 1088 } 1089 else 1090 { 1091 RangeEnc_EncodeBit_1(rc, *prob); 1092 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 1093 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 1094 PPMD_SetAllBitsIn256Bytes(charMask); 1095 MASK(s->Symbol) = 0; 1096 p->PrevSuccess = 0; 1097 } 1098 } 1099 for (;;) 1100 { 1101 UInt32 escFreq; 1102 CPpmd_See *see; 1103 CPpmd_State *s; 1104 UInt32 sum; 1105 unsigned i, numMasked = p->MinContext->NumStats; 1106 do 1107 { 1108 p->OrderFall++; 1109 if (!p->MinContext->Suffix) 1110 return; /* EndMarker (symbol = -1) */ 1111 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 1112 } 1113 while (p->MinContext->NumStats == numMasked); 1114 1115 see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq); 1116 s = Ppmd7_GetStats(p, p->MinContext); 1117 sum = 0; 1118 i = p->MinContext->NumStats; 1119 do 1120 { 1121 int cur = s->Symbol; 1122 if (cur == symbol) 1123 { 1124 UInt32 low = sum; 1125 CPpmd_State *s1 = s; 1126 do 1127 { 1128 sum += (s->Freq & (int)(MASK(s->Symbol))); 1129 s++; 1130 } 1131 while (--i); 1132 RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq); 1133 Ppmd_See_Update(see); 1134 p->FoundState = s1; 1135 Ppmd7_Update2(p); 1136 return; 1137 } 1138 sum += (s->Freq & (int)(MASK(cur))); 1139 MASK(cur) = 0; 1140 s++; 1141 } 1142 while (--i); 1143 1144 RangeEnc_Encode(rc, sum, escFreq, sum + escFreq); 1145 see->Summ = (UInt16)(see->Summ + sum + escFreq); 1146 } 1147 } 1148 1149 const IPpmd7 __archive_ppmd7_functions = 1150 { 1151 &Ppmd7_Construct, 1152 &Ppmd7_Alloc, 1153 &Ppmd7_Free, 1154 &Ppmd7_Init, 1155 &Ppmd7z_RangeDec_CreateVTable, 1156 &PpmdRAR_RangeDec_CreateVTable, 1157 &Ppmd7z_RangeDec_Init, 1158 &PpmdRAR_RangeDec_Init, 1159 &Ppmd7_DecodeSymbol, 1160 &Ppmd7z_RangeEnc_Init, 1161 &Ppmd7z_RangeEnc_FlushData, 1162 &Ppmd7_EncodeSymbol 1163 }; 1164