| /* Ppmd8Enc.c -- PPMdI Encoder |
| 2010-04-16 : Igor Pavlov : Public domain |
| This code is based on: |
| PPMd var.I (2002): Dmitry Shkarin : Public domain |
| Carryless rangecoder (1999): Dmitry Subbotin : Public domain */ |
| |
| #include "Ppmd8.h" |
| |
| #define kTop (1 << 24) |
| #define kBot (1 << 15) |
| |
| void Ppmd8_RangeEnc_FlushData(CPpmd8 *p) |
| { |
| unsigned i; |
| for (i = 0; i < 4; i++, p->Low <<= 8 ) |
| p->Stream.Out->Write(p->Stream.Out, (Byte)(p->Low >> 24)); |
| } |
| |
| static void RangeEnc_Normalize(CPpmd8 *p) |
| { |
| while ((p->Low ^ (p->Low + p->Range)) < kTop || |
| (p->Range < kBot && ((p->Range = (0 - p->Low) & (kBot - 1)), 1))) |
| { |
| p->Stream.Out->Write(p->Stream.Out, (Byte)(p->Low >> 24)); |
| p->Range <<= 8; |
| p->Low <<= 8; |
| } |
| } |
| |
| static void RangeEnc_Encode(CPpmd8 *p, UInt32 start, UInt32 size, UInt32 total) |
| { |
| p->Low += start * (p->Range /= total); |
| p->Range *= size; |
| RangeEnc_Normalize(p); |
| } |
| |
| static void RangeEnc_EncodeBit_0(CPpmd8 *p, UInt32 size0) |
| { |
| p->Range >>= 14; |
| p->Range *= size0; |
| RangeEnc_Normalize(p); |
| } |
| |
| static void RangeEnc_EncodeBit_1(CPpmd8 *p, UInt32 size0) |
| { |
| p->Low += size0 * (p->Range >>= 14); |
| p->Range *= ((1 << 14) - size0); |
| RangeEnc_Normalize(p); |
| } |
| |
| |
| #define MASK(sym) ((signed char *)charMask)[sym] |
| |
| void Ppmd8_EncodeSymbol(CPpmd8 *p, int symbol) |
| { |
| size_t charMask[256 / sizeof(size_t)]; |
| if (p->MinContext->NumStats != 0) |
| { |
| CPpmd_State *s = Ppmd8_GetStats(p, p->MinContext); |
| UInt32 sum; |
| unsigned i; |
| if (s->Symbol == symbol) |
| { |
| RangeEnc_Encode(p, 0, s->Freq, p->MinContext->SummFreq); |
| p->FoundState = s; |
| Ppmd8_Update1_0(p); |
| return; |
| } |
| p->PrevSuccess = 0; |
| sum = s->Freq; |
| i = p->MinContext->NumStats; |
| do |
| { |
| if ((++s)->Symbol == symbol) |
| { |
| RangeEnc_Encode(p, sum, s->Freq, p->MinContext->SummFreq); |
| p->FoundState = s; |
| Ppmd8_Update1(p); |
| return; |
| } |
| sum += s->Freq; |
| } |
| while (--i); |
| |
| PPMD_SetAllBitsIn256Bytes(charMask); |
| MASK(s->Symbol) = 0; |
| i = p->MinContext->NumStats; |
| do { MASK((--s)->Symbol) = 0; } while (--i); |
| RangeEnc_Encode(p, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq); |
| } |
| else |
| { |
| UInt16 *prob = Ppmd8_GetBinSumm(p); |
| CPpmd_State *s = Ppmd8Context_OneState(p->MinContext); |
| if (s->Symbol == symbol) |
| { |
| RangeEnc_EncodeBit_0(p, *prob); |
| *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob); |
| p->FoundState = s; |
| Ppmd8_UpdateBin(p); |
| return; |
| } |
| else |
| { |
| RangeEnc_EncodeBit_1(p, *prob); |
| *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob); |
| p->InitEsc = PPMD8_kExpEscape[*prob >> 10]; |
| PPMD_SetAllBitsIn256Bytes(charMask); |
| MASK(s->Symbol) = 0; |
| p->PrevSuccess = 0; |
| } |
| } |
| for (;;) |
| { |
| UInt32 escFreq; |
| CPpmd_See *see; |
| CPpmd_State *s; |
| UInt32 sum; |
| unsigned i, numMasked = p->MinContext->NumStats; |
| do |
| { |
| p->OrderFall++; |
| if (!p->MinContext->Suffix) |
| return; /* EndMarker (symbol = -1) */ |
| p->MinContext = Ppmd8_GetContext(p, p->MinContext->Suffix); |
| } |
| while (p->MinContext->NumStats == numMasked); |
| |
| see = Ppmd8_MakeEscFreq(p, numMasked, &escFreq); |
| s = Ppmd8_GetStats(p, p->MinContext); |
| sum = 0; |
| i = p->MinContext->NumStats + 1; |
| do |
| { |
| int cur = s->Symbol; |
| if (cur == symbol) |
| { |
| UInt32 low = sum; |
| CPpmd_State *s1 = s; |
| do |
| { |
| sum += (s->Freq & (int)(MASK(s->Symbol))); |
| s++; |
| } |
| while (--i); |
| RangeEnc_Encode(p, low, s1->Freq, sum + escFreq); |
| Ppmd_See_Update(see); |
| p->FoundState = s1; |
| Ppmd8_Update2(p); |
| return; |
| } |
| sum += (s->Freq & (int)(MASK(cur))); |
| MASK(cur) = 0; |
| s++; |
| } |
| while (--i); |
| |
| RangeEnc_Encode(p, sum, escFreq, sum + escFreq); |
| see->Summ = (UInt16)(see->Summ + sum + escFreq); |
| } |
| } |