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