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) 119 { 120 free(p->Base); 121 p->Size = 0; 122 p->Base = 0; 123 } 124 125 static Bool Ppmd7_Alloc(CPpmd7 *p, UInt32 size) 126 { 127 if (p->Base == 0 || p->Size != size) 128 { 129 /* RestartModel() below assumes that p->Size >= UNIT_SIZE 130 (see the calculation of m->MinContext). */ 131 if (size < UNIT_SIZE) { 132 return False; 133 } 134 Ppmd7_Free(p); 135 p->AlignOffset = 136 #ifdef PPMD_32BIT 137 (4 - size) & 3; 138 #else 139 4 - (size & 3); 140 #endif 141 if ((p->Base = (Byte *)malloc(p->AlignOffset + size 142 #ifndef PPMD_32BIT 143 + UNIT_SIZE 144 #endif 145 )) == 0) 146 return False; 147 p->Size = size; 148 } 149 return True; 150 } 151 152 static void InsertNode(CPpmd7 *p, void *node, unsigned indx) 153 { 154 *((CPpmd_Void_Ref *)node) = p->FreeList[indx]; 155 p->FreeList[indx] = REF(node); 156 } 157 158 static void *RemoveNode(CPpmd7 *p, unsigned indx) 159 { 160 CPpmd_Void_Ref *node = (CPpmd_Void_Ref *)Ppmd7_GetPtr(p, p->FreeList[indx]); 161 p->FreeList[indx] = *node; 162 return node; 163 } 164 165 static void SplitBlock(CPpmd7 *p, void *ptr, unsigned oldIndx, unsigned newIndx) 166 { 167 unsigned i, nu = I2U(oldIndx) - I2U(newIndx); 168 ptr = (Byte *)ptr + U2B(I2U(newIndx)); 169 if (I2U(i = U2I(nu)) != nu) 170 { 171 unsigned k = I2U(--i); 172 InsertNode(p, ((Byte *)ptr) + U2B(k), nu - k - 1); 173 } 174 InsertNode(p, ptr, i); 175 } 176 177 static void GlueFreeBlocks(CPpmd7 *p) 178 { 179 #ifdef PPMD_32BIT 180 CPpmd7_Node headItem; 181 CPpmd7_Node_Ref head = &headItem; 182 #else 183 CPpmd7_Node_Ref head = p->AlignOffset + p->Size; 184 #endif 185 186 CPpmd7_Node_Ref n = head; 187 unsigned i; 188 189 p->GlueCount = 255; 190 191 /* create doubly-linked list of free blocks */ 192 for (i = 0; i < PPMD_NUM_INDEXES; i++) 193 { 194 UInt16 nu = I2U(i); 195 CPpmd7_Node_Ref next = (CPpmd7_Node_Ref)p->FreeList[i]; 196 p->FreeList[i] = 0; 197 while (next != 0) 198 { 199 CPpmd7_Node *node = NODE(next); 200 node->Next = n; 201 n = NODE(n)->Prev = next; 202 next = *(const CPpmd7_Node_Ref *)node; 203 node->Stamp = 0; 204 node->NU = (UInt16)nu; 205 } 206 } 207 NODE(head)->Stamp = 1; 208 NODE(head)->Next = n; 209 NODE(n)->Prev = head; 210 if (p->LoUnit != p->HiUnit) 211 ((CPpmd7_Node *)p->LoUnit)->Stamp = 1; 212 213 /* Glue free blocks */ 214 while (n != head) 215 { 216 CPpmd7_Node *node = NODE(n); 217 UInt32 nu = (UInt32)node->NU; 218 for (;;) 219 { 220 CPpmd7_Node *node2 = NODE(n) + nu; 221 nu += node2->NU; 222 if (node2->Stamp != 0 || nu >= 0x10000) 223 break; 224 NODE(node2->Prev)->Next = node2->Next; 225 NODE(node2->Next)->Prev = node2->Prev; 226 node->NU = (UInt16)nu; 227 } 228 n = node->Next; 229 } 230 231 /* Fill lists of free blocks */ 232 for (n = NODE(head)->Next; n != head;) 233 { 234 CPpmd7_Node *node = NODE(n); 235 unsigned nu; 236 CPpmd7_Node_Ref next = node->Next; 237 for (nu = node->NU; nu > 128; nu -= 128, node += 128) 238 InsertNode(p, node, PPMD_NUM_INDEXES - 1); 239 if (I2U(i = U2I(nu)) != nu) 240 { 241 unsigned k = I2U(--i); 242 InsertNode(p, node + k, nu - k - 1); 243 } 244 InsertNode(p, node, i); 245 n = next; 246 } 247 } 248 249 static void *AllocUnitsRare(CPpmd7 *p, unsigned indx) 250 { 251 unsigned i; 252 void *retVal; 253 if (p->GlueCount == 0) 254 { 255 GlueFreeBlocks(p); 256 if (p->FreeList[indx] != 0) 257 return RemoveNode(p, indx); 258 } 259 i = indx; 260 do 261 { 262 if (++i == PPMD_NUM_INDEXES) 263 { 264 UInt32 numBytes = U2B(I2U(indx)); 265 p->GlueCount--; 266 return ((UInt32)(p->UnitsStart - p->Text) > numBytes) ? (p->UnitsStart -= numBytes) : (NULL); 267 } 268 } 269 while (p->FreeList[i] == 0); 270 retVal = RemoveNode(p, i); 271 SplitBlock(p, retVal, i, indx); 272 return retVal; 273 } 274 275 static void *AllocUnits(CPpmd7 *p, unsigned indx) 276 { 277 UInt32 numBytes; 278 if (p->FreeList[indx] != 0) 279 return RemoveNode(p, indx); 280 numBytes = U2B(I2U(indx)); 281 if (numBytes <= (UInt32)(p->HiUnit - p->LoUnit)) 282 { 283 void *retVal = p->LoUnit; 284 p->LoUnit += numBytes; 285 return retVal; 286 } 287 return AllocUnitsRare(p, indx); 288 } 289 290 #define MyMem12Cpy(dest, src, num) \ 291 { UInt32 *d = (UInt32 *)dest; const UInt32 *s = (const UInt32 *)src; UInt32 n = num; \ 292 do { d[0] = s[0]; d[1] = s[1]; d[2] = s[2]; s += 3; d += 3; } while(--n); } 293 294 static void *ShrinkUnits(CPpmd7 *p, void *oldPtr, unsigned oldNU, unsigned newNU) 295 { 296 unsigned i0 = U2I(oldNU); 297 unsigned i1 = U2I(newNU); 298 if (i0 == i1) 299 return oldPtr; 300 if (p->FreeList[i1] != 0) 301 { 302 void *ptr = RemoveNode(p, i1); 303 MyMem12Cpy(ptr, oldPtr, newNU); 304 InsertNode(p, oldPtr, i0); 305 return ptr; 306 } 307 SplitBlock(p, oldPtr, i0, i1); 308 return oldPtr; 309 } 310 311 #define SUCCESSOR(p) ((CPpmd_Void_Ref)((p)->SuccessorLow | ((UInt32)(p)->SuccessorHigh << 16))) 312 313 static void SetSuccessor(CPpmd_State *p, CPpmd_Void_Ref v) 314 { 315 (p)->SuccessorLow = (UInt16)((UInt32)(v) & 0xFFFF); 316 (p)->SuccessorHigh = (UInt16)(((UInt32)(v) >> 16) & 0xFFFF); 317 } 318 319 static void RestartModel(CPpmd7 *p) 320 { 321 unsigned i, k, m; 322 323 memset(p->FreeList, 0, sizeof(p->FreeList)); 324 p->Text = p->Base + p->AlignOffset; 325 p->HiUnit = p->Text + p->Size; 326 p->LoUnit = p->UnitsStart = p->HiUnit - p->Size / 8 / UNIT_SIZE * 7 * UNIT_SIZE; 327 p->GlueCount = 0; 328 329 p->OrderFall = p->MaxOrder; 330 p->RunLength = p->InitRL = -(Int32)((p->MaxOrder < 12) ? p->MaxOrder : 12) - 1; 331 p->PrevSuccess = 0; 332 333 p->MinContext = p->MaxContext = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); /* AllocContext(p); */ 334 p->MinContext->Suffix = 0; 335 p->MinContext->NumStats = 256; 336 p->MinContext->SummFreq = 256 + 1; 337 p->FoundState = (CPpmd_State *)p->LoUnit; /* AllocUnits(p, PPMD_NUM_INDEXES - 1); */ 338 p->LoUnit += U2B(256 / 2); 339 p->MinContext->Stats = REF(p->FoundState); 340 for (i = 0; i < 256; i++) 341 { 342 CPpmd_State *s = &p->FoundState[i]; 343 s->Symbol = (Byte)i; 344 s->Freq = 1; 345 SetSuccessor(s, 0); 346 } 347 348 for (i = 0; i < 128; i++) 349 for (k = 0; k < 8; k++) 350 { 351 UInt16 *dest = p->BinSumm[i] + k; 352 UInt16 val = (UInt16)(PPMD_BIN_SCALE - kInitBinEsc[k] / (i + 2)); 353 for (m = 0; m < 64; m += 8) 354 dest[m] = val; 355 } 356 357 for (i = 0; i < 25; i++) 358 for (k = 0; k < 16; k++) 359 { 360 CPpmd_See *s = &p->See[i][k]; 361 s->Summ = (UInt16)((5 * i + 10) << (s->Shift = PPMD_PERIOD_BITS - 4)); 362 s->Count = 4; 363 } 364 } 365 366 static void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder) 367 { 368 p->MaxOrder = maxOrder; 369 RestartModel(p); 370 p->DummySee.Shift = PPMD_PERIOD_BITS; 371 p->DummySee.Summ = 0; /* unused */ 372 p->DummySee.Count = 64; /* unused */ 373 } 374 375 static CTX_PTR CreateSuccessors(CPpmd7 *p, Bool skip) 376 { 377 CPpmd_State upState; 378 CTX_PTR c = p->MinContext; 379 CPpmd_Byte_Ref upBranch = (CPpmd_Byte_Ref)SUCCESSOR(p->FoundState); 380 CPpmd_State *ps[PPMD7_MAX_ORDER]; 381 unsigned numPs = 0; 382 383 if (!skip) 384 ps[numPs++] = p->FoundState; 385 386 while (c->Suffix) 387 { 388 CPpmd_Void_Ref successor; 389 CPpmd_State *s; 390 c = SUFFIX(c); 391 if (c->NumStats != 1) 392 { 393 for (s = STATS(c); s->Symbol != p->FoundState->Symbol; s++); 394 } 395 else 396 s = ONE_STATE(c); 397 successor = SUCCESSOR(s); 398 if (successor != upBranch) 399 { 400 c = CTX(successor); 401 if (numPs == 0) 402 return c; 403 break; 404 } 405 ps[numPs++] = s; 406 } 407 408 upState.Symbol = *(const Byte *)Ppmd7_GetPtr(p, upBranch); 409 SetSuccessor(&upState, upBranch + 1); 410 411 if (c->NumStats == 1) 412 upState.Freq = ONE_STATE(c)->Freq; 413 else 414 { 415 UInt32 cf, s0; 416 CPpmd_State *s; 417 for (s = STATS(c); s->Symbol != upState.Symbol; s++); 418 cf = s->Freq - 1; 419 s0 = c->SummFreq - c->NumStats - cf; 420 upState.Freq = (Byte)(1 + ((2 * cf <= s0) ? (5 * cf > s0) : ((2 * cf + 3 * s0 - 1) / (2 * s0)))); 421 } 422 423 while (numPs != 0) 424 { 425 /* Create Child */ 426 CTX_PTR c1; /* = AllocContext(p); */ 427 if (p->HiUnit != p->LoUnit) 428 c1 = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); 429 else if (p->FreeList[0] != 0) 430 c1 = (CTX_PTR)RemoveNode(p, 0); 431 else 432 { 433 c1 = (CTX_PTR)AllocUnitsRare(p, 0); 434 if (!c1) 435 return NULL; 436 } 437 c1->NumStats = 1; 438 *ONE_STATE(c1) = upState; 439 c1->Suffix = REF(c); 440 SetSuccessor(ps[--numPs], REF(c1)); 441 c = c1; 442 } 443 444 return c; 445 } 446 447 static void SwapStates(CPpmd_State *t1, CPpmd_State *t2) 448 { 449 CPpmd_State tmp = *t1; 450 *t1 = *t2; 451 *t2 = tmp; 452 } 453 454 static void UpdateModel(CPpmd7 *p) 455 { 456 CPpmd_Void_Ref successor, fSuccessor = SUCCESSOR(p->FoundState); 457 CTX_PTR c; 458 unsigned s0, ns; 459 460 if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0) 461 { 462 c = SUFFIX(p->MinContext); 463 464 if (c->NumStats == 1) 465 { 466 CPpmd_State *s = ONE_STATE(c); 467 if (s->Freq < 32) 468 s->Freq++; 469 } 470 else 471 { 472 CPpmd_State *s = STATS(c); 473 if (s->Symbol != p->FoundState->Symbol) 474 { 475 do { s++; } while (s->Symbol != p->FoundState->Symbol); 476 if (s[0].Freq >= s[-1].Freq) 477 { 478 SwapStates(&s[0], &s[-1]); 479 s--; 480 } 481 } 482 if (s->Freq < MAX_FREQ - 9) 483 { 484 s->Freq += 2; 485 c->SummFreq += 2; 486 } 487 } 488 } 489 490 if (p->OrderFall == 0) 491 { 492 p->MinContext = p->MaxContext = CreateSuccessors(p, True); 493 if (p->MinContext == 0) 494 { 495 RestartModel(p); 496 return; 497 } 498 SetSuccessor(p->FoundState, REF(p->MinContext)); 499 return; 500 } 501 502 *p->Text++ = p->FoundState->Symbol; 503 successor = REF(p->Text); 504 if (p->Text >= p->UnitsStart) 505 { 506 RestartModel(p); 507 return; 508 } 509 510 if (fSuccessor) 511 { 512 if (fSuccessor <= successor) 513 { 514 CTX_PTR cs = CreateSuccessors(p, False); 515 if (cs == NULL) 516 { 517 RestartModel(p); 518 return; 519 } 520 fSuccessor = REF(cs); 521 } 522 if (--p->OrderFall == 0) 523 { 524 successor = fSuccessor; 525 p->Text -= (p->MaxContext != p->MinContext); 526 } 527 } 528 else 529 { 530 SetSuccessor(p->FoundState, successor); 531 fSuccessor = REF(p->MinContext); 532 } 533 534 s0 = p->MinContext->SummFreq - (ns = p->MinContext->NumStats) - (p->FoundState->Freq - 1); 535 536 for (c = p->MaxContext; c != p->MinContext; c = SUFFIX(c)) 537 { 538 unsigned ns1; 539 UInt32 cf, sf; 540 if ((ns1 = c->NumStats) != 1) 541 { 542 if ((ns1 & 1) == 0) 543 { 544 /* Expand for one UNIT */ 545 unsigned oldNU = ns1 >> 1; 546 unsigned i = U2I(oldNU); 547 if (i != U2I(oldNU + 1)) 548 { 549 void *ptr = AllocUnits(p, i + 1); 550 void *oldPtr; 551 if (!ptr) 552 { 553 RestartModel(p); 554 return; 555 } 556 oldPtr = STATS(c); 557 MyMem12Cpy(ptr, oldPtr, oldNU); 558 InsertNode(p, oldPtr, i); 559 c->Stats = STATS_REF(ptr); 560 } 561 } 562 c->SummFreq = (UInt16)(c->SummFreq + (2 * ns1 < ns) + 2 * ((4 * ns1 <= ns) & (c->SummFreq <= 8 * ns1))); 563 } 564 else 565 { 566 CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0); 567 if (!s) 568 { 569 RestartModel(p); 570 return; 571 } 572 *s = *ONE_STATE(c); 573 c->Stats = REF(s); 574 if (s->Freq < MAX_FREQ / 4 - 1) 575 s->Freq <<= 1; 576 else 577 s->Freq = MAX_FREQ - 4; 578 c->SummFreq = (UInt16)(s->Freq + p->InitEsc + (ns > 3)); 579 } 580 cf = 2 * (UInt32)p->FoundState->Freq * (c->SummFreq + 6); 581 sf = (UInt32)s0 + c->SummFreq; 582 if (cf < 6 * sf) 583 { 584 cf = 1 + (cf > sf) + (cf >= 4 * sf); 585 c->SummFreq += 3; 586 } 587 else 588 { 589 cf = 4 + (cf >= 9 * sf) + (cf >= 12 * sf) + (cf >= 15 * sf); 590 c->SummFreq = (UInt16)(c->SummFreq + cf); 591 } 592 { 593 CPpmd_State *s = STATS(c) + ns1; 594 SetSuccessor(s, successor); 595 s->Symbol = p->FoundState->Symbol; 596 s->Freq = (Byte)cf; 597 c->NumStats = (UInt16)(ns1 + 1); 598 } 599 } 600 p->MaxContext = p->MinContext = CTX(fSuccessor); 601 } 602 603 static void Rescale(CPpmd7 *p) 604 { 605 unsigned i, adder, sumFreq, escFreq; 606 CPpmd_State *stats = STATS(p->MinContext); 607 CPpmd_State *s = p->FoundState; 608 { 609 CPpmd_State tmp = *s; 610 for (; s != stats; s--) 611 s[0] = s[-1]; 612 *s = tmp; 613 } 614 escFreq = p->MinContext->SummFreq - s->Freq; 615 s->Freq += 4; 616 adder = (p->OrderFall != 0); 617 s->Freq = (Byte)((s->Freq + adder) >> 1); 618 sumFreq = s->Freq; 619 620 i = p->MinContext->NumStats - 1; 621 do 622 { 623 escFreq -= (++s)->Freq; 624 s->Freq = (Byte)((s->Freq + adder) >> 1); 625 sumFreq += s->Freq; 626 if (s[0].Freq > s[-1].Freq) 627 { 628 CPpmd_State *s1 = s; 629 CPpmd_State tmp = *s1; 630 do 631 s1[0] = s1[-1]; 632 while (--s1 != stats && tmp.Freq > s1[-1].Freq); 633 *s1 = tmp; 634 } 635 } 636 while (--i); 637 638 if (s->Freq == 0) 639 { 640 unsigned numStats = p->MinContext->NumStats; 641 unsigned n0, n1; 642 do { i++; } while ((--s)->Freq == 0); 643 escFreq += i; 644 p->MinContext->NumStats = (UInt16)(p->MinContext->NumStats - i); 645 if (p->MinContext->NumStats == 1) 646 { 647 CPpmd_State tmp = *stats; 648 do 649 { 650 tmp.Freq = (Byte)(tmp.Freq - (tmp.Freq >> 1)); 651 escFreq >>= 1; 652 } 653 while (escFreq > 1); 654 InsertNode(p, stats, U2I(((numStats + 1) >> 1))); 655 *(p->FoundState = ONE_STATE(p->MinContext)) = tmp; 656 return; 657 } 658 n0 = (numStats + 1) >> 1; 659 n1 = (p->MinContext->NumStats + 1) >> 1; 660 if (n0 != n1) 661 p->MinContext->Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1)); 662 } 663 p->MinContext->SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1)); 664 p->FoundState = STATS(p->MinContext); 665 } 666 667 static CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *escFreq) 668 { 669 CPpmd_See *see; 670 unsigned nonMasked = p->MinContext->NumStats - numMasked; 671 if (p->MinContext->NumStats != 256) 672 { 673 see = p->See[p->NS2Indx[nonMasked - 1]] + 674 (nonMasked < (unsigned)SUFFIX(p->MinContext)->NumStats - p->MinContext->NumStats) + 675 2 * (p->MinContext->SummFreq < 11 * p->MinContext->NumStats) + 676 4 * (numMasked > nonMasked) + 677 p->HiBitsFlag; 678 { 679 unsigned r = (see->Summ >> see->Shift); 680 see->Summ = (UInt16)(see->Summ - r); 681 *escFreq = r + (r == 0); 682 } 683 } 684 else 685 { 686 see = &p->DummySee; 687 *escFreq = 1; 688 } 689 return see; 690 } 691 692 static void NextContext(CPpmd7 *p) 693 { 694 CTX_PTR c = CTX(SUCCESSOR(p->FoundState)); 695 if (p->OrderFall == 0 && (Byte *)c > p->Text) 696 p->MinContext = p->MaxContext = c; 697 else 698 UpdateModel(p); 699 } 700 701 static void Ppmd7_Update1(CPpmd7 *p) 702 { 703 CPpmd_State *s = p->FoundState; 704 s->Freq += 4; 705 p->MinContext->SummFreq += 4; 706 if (s[0].Freq > s[-1].Freq) 707 { 708 SwapStates(&s[0], &s[-1]); 709 p->FoundState = --s; 710 if (s->Freq > MAX_FREQ) 711 Rescale(p); 712 } 713 NextContext(p); 714 } 715 716 static void Ppmd7_Update1_0(CPpmd7 *p) 717 { 718 p->PrevSuccess = (2 * p->FoundState->Freq > p->MinContext->SummFreq); 719 p->RunLength += p->PrevSuccess; 720 p->MinContext->SummFreq += 4; 721 if ((p->FoundState->Freq += 4) > MAX_FREQ) 722 Rescale(p); 723 NextContext(p); 724 } 725 726 static void Ppmd7_UpdateBin(CPpmd7 *p) 727 { 728 p->FoundState->Freq = (Byte)(p->FoundState->Freq + (p->FoundState->Freq < 128 ? 1: 0)); 729 p->PrevSuccess = 1; 730 p->RunLength++; 731 NextContext(p); 732 } 733 734 static void Ppmd7_Update2(CPpmd7 *p) 735 { 736 p->MinContext->SummFreq += 4; 737 if ((p->FoundState->Freq += 4) > MAX_FREQ) 738 Rescale(p); 739 p->RunLength = p->InitRL; 740 UpdateModel(p); 741 } 742 743 /* ---------- Decode ---------- */ 744 745 static Bool Ppmd_RangeDec_Init(CPpmd7z_RangeDec *p) 746 { 747 unsigned i; 748 p->Low = p->Bottom = 0; 749 p->Range = 0xFFFFFFFF; 750 for (i = 0; i < 4; i++) 751 p->Code = (p->Code << 8) | p->Stream->Read((void *)p->Stream); 752 return (p->Code < 0xFFFFFFFF); 753 } 754 755 static Bool Ppmd7z_RangeDec_Init(CPpmd7z_RangeDec *p) 756 { 757 if (p->Stream->Read((void *)p->Stream) != 0) 758 return False; 759 return Ppmd_RangeDec_Init(p); 760 } 761 762 static Bool PpmdRAR_RangeDec_Init(CPpmd7z_RangeDec *p) 763 { 764 if (!Ppmd_RangeDec_Init(p)) 765 return False; 766 p->Bottom = 0x8000; 767 return True; 768 } 769 770 static UInt32 Range_GetThreshold(void *pp, UInt32 total) 771 { 772 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 773 return (p->Code - p->Low) / (p->Range /= total); 774 } 775 776 static void Range_Normalize(CPpmd7z_RangeDec *p) 777 { 778 while (1) 779 { 780 if((p->Low ^ (p->Low + p->Range)) >= kTopValue) 781 { 782 if(p->Range >= p->Bottom) 783 break; 784 else 785 p->Range = ((uint32_t)(-(int32_t)p->Low)) & (p->Bottom - 1); 786 } 787 p->Code = (p->Code << 8) | p->Stream->Read((void *)p->Stream); 788 p->Range <<= 8; 789 p->Low <<= 8; 790 } 791 } 792 793 static void Range_Decode_7z(void *pp, UInt32 start, UInt32 size) 794 { 795 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 796 p->Code -= start * p->Range; 797 p->Range *= size; 798 Range_Normalize(p); 799 } 800 801 static void Range_Decode_RAR(void *pp, UInt32 start, UInt32 size) 802 { 803 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 804 p->Low += start * p->Range; 805 p->Range *= size; 806 Range_Normalize(p); 807 } 808 809 static UInt32 Range_DecodeBit_7z(void *pp, UInt32 size0) 810 { 811 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 812 UInt32 newBound = (p->Range >> 14) * size0; 813 UInt32 symbol; 814 if (p->Code < newBound) 815 { 816 symbol = 0; 817 p->Range = newBound; 818 } 819 else 820 { 821 symbol = 1; 822 p->Code -= newBound; 823 p->Range -= newBound; 824 } 825 Range_Normalize(p); 826 return symbol; 827 } 828 829 static UInt32 Range_DecodeBit_RAR(void *pp, UInt32 size0) 830 { 831 CPpmd7z_RangeDec *p = (CPpmd7z_RangeDec *)pp; 832 UInt32 bit, value = p->p.GetThreshold(p, PPMD_BIN_SCALE); 833 if(value < size0) 834 { 835 bit = 0; 836 p->p.Decode(p, 0, size0); 837 } 838 else 839 { 840 bit = 1; 841 p->p.Decode(p, size0, PPMD_BIN_SCALE - size0); 842 } 843 return bit; 844 } 845 846 static void Ppmd7z_RangeDec_CreateVTable(CPpmd7z_RangeDec *p) 847 { 848 p->p.GetThreshold = Range_GetThreshold; 849 p->p.Decode = Range_Decode_7z; 850 p->p.DecodeBit = Range_DecodeBit_7z; 851 } 852 853 static void PpmdRAR_RangeDec_CreateVTable(CPpmd7z_RangeDec *p) 854 { 855 p->p.GetThreshold = Range_GetThreshold; 856 p->p.Decode = Range_Decode_RAR; 857 p->p.DecodeBit = Range_DecodeBit_RAR; 858 } 859 860 #define MASK(sym) ((signed char *)charMask)[sym] 861 862 static int Ppmd7_DecodeSymbol(CPpmd7 *p, IPpmd7_RangeDec *rc) 863 { 864 size_t charMask[256 / sizeof(size_t)]; 865 if (p->MinContext->NumStats != 1) 866 { 867 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 868 unsigned i; 869 UInt32 count, hiCnt; 870 if ((count = rc->GetThreshold(rc, p->MinContext->SummFreq)) < (hiCnt = s->Freq)) 871 { 872 Byte symbol; 873 rc->Decode(rc, 0, s->Freq); 874 p->FoundState = s; 875 symbol = s->Symbol; 876 Ppmd7_Update1_0(p); 877 return symbol; 878 } 879 p->PrevSuccess = 0; 880 i = p->MinContext->NumStats - 1; 881 do 882 { 883 if ((hiCnt += (++s)->Freq) > count) 884 { 885 Byte symbol; 886 rc->Decode(rc, hiCnt - s->Freq, s->Freq); 887 p->FoundState = s; 888 symbol = s->Symbol; 889 Ppmd7_Update1(p); 890 return symbol; 891 } 892 } 893 while (--i); 894 if (count >= p->MinContext->SummFreq) 895 return -2; 896 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 897 rc->Decode(rc, hiCnt, p->MinContext->SummFreq - hiCnt); 898 PPMD_SetAllBitsIn256Bytes(charMask); 899 MASK(s->Symbol) = 0; 900 i = p->MinContext->NumStats - 1; 901 do { MASK((--s)->Symbol) = 0; } while (--i); 902 } 903 else 904 { 905 UInt16 *prob = Ppmd7_GetBinSumm(p); 906 if (rc->DecodeBit(rc, *prob) == 0) 907 { 908 Byte symbol; 909 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 910 symbol = (p->FoundState = Ppmd7Context_OneState(p->MinContext))->Symbol; 911 Ppmd7_UpdateBin(p); 912 return symbol; 913 } 914 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 915 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 916 PPMD_SetAllBitsIn256Bytes(charMask); 917 MASK(Ppmd7Context_OneState(p->MinContext)->Symbol) = 0; 918 p->PrevSuccess = 0; 919 } 920 for (;;) 921 { 922 CPpmd_State *ps[256], *s; 923 UInt32 freqSum, count, hiCnt; 924 CPpmd_See *see; 925 unsigned i, num, numMasked = p->MinContext->NumStats; 926 do 927 { 928 p->OrderFall++; 929 if (!p->MinContext->Suffix) 930 return -1; 931 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 932 } 933 while (p->MinContext->NumStats == numMasked); 934 hiCnt = 0; 935 s = Ppmd7_GetStats(p, p->MinContext); 936 i = 0; 937 num = p->MinContext->NumStats - numMasked; 938 do 939 { 940 int k = (int)(MASK(s->Symbol)); 941 hiCnt += (s->Freq & k); 942 ps[i] = s++; 943 i -= k; 944 } 945 while (i != num); 946 947 see = Ppmd7_MakeEscFreq(p, numMasked, &freqSum); 948 freqSum += hiCnt; 949 count = rc->GetThreshold(rc, freqSum); 950 951 if (count < hiCnt) 952 { 953 Byte symbol; 954 CPpmd_State **pps = ps; 955 for (hiCnt = 0; (hiCnt += (*pps)->Freq) <= count; pps++); 956 s = *pps; 957 rc->Decode(rc, hiCnt - s->Freq, s->Freq); 958 Ppmd_See_Update(see); 959 p->FoundState = s; 960 symbol = s->Symbol; 961 Ppmd7_Update2(p); 962 return symbol; 963 } 964 if (count >= freqSum) 965 return -2; 966 rc->Decode(rc, hiCnt, freqSum - hiCnt); 967 see->Summ = (UInt16)(see->Summ + freqSum); 968 do { MASK(ps[--i]->Symbol) = 0; } while (i != 0); 969 } 970 } 971 972 /* ---------- Encode ---------- Ppmd7Enc.c */ 973 974 #define kTopValue (1 << 24) 975 976 static void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p) 977 { 978 p->Low = 0; 979 p->Range = 0xFFFFFFFF; 980 p->Cache = 0; 981 p->CacheSize = 1; 982 } 983 984 static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p) 985 { 986 if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0) 987 { 988 Byte temp = p->Cache; 989 do 990 { 991 p->Stream->Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32))); 992 temp = 0xFF; 993 } 994 while(--p->CacheSize != 0); 995 p->Cache = (Byte)((UInt32)p->Low >> 24); 996 } 997 p->CacheSize++; 998 p->Low = ((UInt32)p->Low << 8) & 0xFFFFFFFF; 999 } 1000 1001 static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total) 1002 { 1003 p->Low += (UInt64)start * (UInt64)(p->Range /= total); 1004 p->Range *= size; 1005 while (p->Range < kTopValue) 1006 { 1007 p->Range <<= 8; 1008 RangeEnc_ShiftLow(p); 1009 } 1010 } 1011 1012 static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0) 1013 { 1014 p->Range = (p->Range >> 14) * size0; 1015 while (p->Range < kTopValue) 1016 { 1017 p->Range <<= 8; 1018 RangeEnc_ShiftLow(p); 1019 } 1020 } 1021 1022 static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0) 1023 { 1024 UInt32 newBound = (p->Range >> 14) * size0; 1025 p->Low += newBound; 1026 p->Range -= newBound; 1027 while (p->Range < kTopValue) 1028 { 1029 p->Range <<= 8; 1030 RangeEnc_ShiftLow(p); 1031 } 1032 } 1033 1034 static void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p) 1035 { 1036 unsigned i; 1037 for (i = 0; i < 5; i++) 1038 RangeEnc_ShiftLow(p); 1039 } 1040 1041 1042 #define MASK(sym) ((signed char *)charMask)[sym] 1043 1044 static void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol) 1045 { 1046 size_t charMask[256 / sizeof(size_t)]; 1047 if (p->MinContext->NumStats != 1) 1048 { 1049 CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext); 1050 UInt32 sum; 1051 unsigned i; 1052 if (s->Symbol == symbol) 1053 { 1054 RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq); 1055 p->FoundState = s; 1056 Ppmd7_Update1_0(p); 1057 return; 1058 } 1059 p->PrevSuccess = 0; 1060 sum = s->Freq; 1061 i = p->MinContext->NumStats - 1; 1062 do 1063 { 1064 if ((++s)->Symbol == symbol) 1065 { 1066 RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq); 1067 p->FoundState = s; 1068 Ppmd7_Update1(p); 1069 return; 1070 } 1071 sum += s->Freq; 1072 } 1073 while (--i); 1074 1075 p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]; 1076 PPMD_SetAllBitsIn256Bytes(charMask); 1077 MASK(s->Symbol) = 0; 1078 i = p->MinContext->NumStats - 1; 1079 do { MASK((--s)->Symbol) = 0; } while (--i); 1080 RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq); 1081 } 1082 else 1083 { 1084 UInt16 *prob = Ppmd7_GetBinSumm(p); 1085 CPpmd_State *s = Ppmd7Context_OneState(p->MinContext); 1086 if (s->Symbol == symbol) 1087 { 1088 RangeEnc_EncodeBit_0(rc, *prob); 1089 *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); 1090 p->FoundState = s; 1091 Ppmd7_UpdateBin(p); 1092 return; 1093 } 1094 else 1095 { 1096 RangeEnc_EncodeBit_1(rc, *prob); 1097 *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); 1098 p->InitEsc = PPMD7_kExpEscape[*prob >> 10]; 1099 PPMD_SetAllBitsIn256Bytes(charMask); 1100 MASK(s->Symbol) = 0; 1101 p->PrevSuccess = 0; 1102 } 1103 } 1104 for (;;) 1105 { 1106 UInt32 escFreq; 1107 CPpmd_See *see; 1108 CPpmd_State *s; 1109 UInt32 sum; 1110 unsigned i, numMasked = p->MinContext->NumStats; 1111 do 1112 { 1113 p->OrderFall++; 1114 if (!p->MinContext->Suffix) 1115 return; /* EndMarker (symbol = -1) */ 1116 p->MinContext = Ppmd7_GetContext(p, p->MinContext->Suffix); 1117 } 1118 while (p->MinContext->NumStats == numMasked); 1119 1120 see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq); 1121 s = Ppmd7_GetStats(p, p->MinContext); 1122 sum = 0; 1123 i = p->MinContext->NumStats; 1124 do 1125 { 1126 int cur = s->Symbol; 1127 if (cur == symbol) 1128 { 1129 UInt32 low = sum; 1130 CPpmd_State *s1 = s; 1131 do 1132 { 1133 sum += (s->Freq & (int)(MASK(s->Symbol))); 1134 s++; 1135 } 1136 while (--i); 1137 RangeEnc_Encode(rc, low, s1->Freq, sum + escFreq); 1138 Ppmd_See_Update(see); 1139 p->FoundState = s1; 1140 Ppmd7_Update2(p); 1141 return; 1142 } 1143 sum += (s->Freq & (int)(MASK(cur))); 1144 MASK(cur) = 0; 1145 s++; 1146 } 1147 while (--i); 1148 1149 RangeEnc_Encode(rc, sum, escFreq, sum + escFreq); 1150 see->Summ = (UInt16)(see->Summ + sum + escFreq); 1151 } 1152 } 1153 1154 const IPpmd7 __archive_ppmd7_functions = 1155 { 1156 &Ppmd7_Construct, 1157 &Ppmd7_Alloc, 1158 &Ppmd7_Free, 1159 &Ppmd7_Init, 1160 &Ppmd7z_RangeDec_CreateVTable, 1161 &PpmdRAR_RangeDec_CreateVTable, 1162 &Ppmd7z_RangeDec_Init, 1163 &PpmdRAR_RangeDec_Init, 1164 &Ppmd7_DecodeSymbol, 1165 &Ppmd7z_RangeEnc_Init, 1166 &Ppmd7z_RangeEnc_FlushData, 1167 &Ppmd7_EncodeSymbol 1168 }; 1169