diff options
Diffstat (limited to 'other-licenses/7zstub/src/C/Ppmd7Enc.c')
| -rw-r--r-- | other-licenses/7zstub/src/C/Ppmd7Enc.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/other-licenses/7zstub/src/C/Ppmd7Enc.c b/other-licenses/7zstub/src/C/Ppmd7Enc.c new file mode 100644 index 0000000000..a74d3002b6 --- /dev/null +++ b/other-licenses/7zstub/src/C/Ppmd7Enc.c @@ -0,0 +1,187 @@ +/* Ppmd7Enc.c -- PPMdH Encoder
+2017-04-03 : Igor Pavlov : Public domain
+This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
+
+#include "Precomp.h"
+
+#include "Ppmd7.h"
+
+#define kTopValue (1 << 24)
+
+void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p)
+{
+ p->Low = 0;
+ p->Range = 0xFFFFFFFF;
+ p->Cache = 0;
+ p->CacheSize = 1;
+}
+
+static void RangeEnc_ShiftLow(CPpmd7z_RangeEnc *p)
+{
+ if ((UInt32)p->Low < (UInt32)0xFF000000 || (unsigned)(p->Low >> 32) != 0)
+ {
+ Byte temp = p->Cache;
+ do
+ {
+ IByteOut_Write(p->Stream, (Byte)(temp + (Byte)(p->Low >> 32)));
+ temp = 0xFF;
+ }
+ while (--p->CacheSize != 0);
+ p->Cache = (Byte)((UInt32)p->Low >> 24);
+ }
+ p->CacheSize++;
+ p->Low = (UInt32)p->Low << 8;
+}
+
+static void RangeEnc_Encode(CPpmd7z_RangeEnc *p, UInt32 start, UInt32 size, UInt32 total)
+{
+ p->Low += start * (p->Range /= total);
+ p->Range *= size;
+ while (p->Range < kTopValue)
+ {
+ p->Range <<= 8;
+ RangeEnc_ShiftLow(p);
+ }
+}
+
+static void RangeEnc_EncodeBit_0(CPpmd7z_RangeEnc *p, UInt32 size0)
+{
+ p->Range = (p->Range >> 14) * size0;
+ while (p->Range < kTopValue)
+ {
+ p->Range <<= 8;
+ RangeEnc_ShiftLow(p);
+ }
+}
+
+static void RangeEnc_EncodeBit_1(CPpmd7z_RangeEnc *p, UInt32 size0)
+{
+ UInt32 newBound = (p->Range >> 14) * size0;
+ p->Low += newBound;
+ p->Range -= newBound;
+ while (p->Range < kTopValue)
+ {
+ p->Range <<= 8;
+ RangeEnc_ShiftLow(p);
+ }
+}
+
+void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p)
+{
+ unsigned i;
+ for (i = 0; i < 5; i++)
+ RangeEnc_ShiftLow(p);
+}
+
+
+#define MASK(sym) ((signed char *)charMask)[sym]
+
+void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol)
+{
+ size_t charMask[256 / sizeof(size_t)];
+ if (p->MinContext->NumStats != 1)
+ {
+ CPpmd_State *s = Ppmd7_GetStats(p, p->MinContext);
+ UInt32 sum;
+ unsigned i;
+ if (s->Symbol == symbol)
+ {
+ RangeEnc_Encode(rc, 0, s->Freq, p->MinContext->SummFreq);
+ p->FoundState = s;
+ Ppmd7_Update1_0(p);
+ return;
+ }
+ p->PrevSuccess = 0;
+ sum = s->Freq;
+ i = p->MinContext->NumStats - 1;
+ do
+ {
+ if ((++s)->Symbol == symbol)
+ {
+ RangeEnc_Encode(rc, sum, s->Freq, p->MinContext->SummFreq);
+ p->FoundState = s;
+ Ppmd7_Update1(p);
+ return;
+ }
+ sum += s->Freq;
+ }
+ while (--i);
+
+ p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol];
+ PPMD_SetAllBitsIn256Bytes(charMask);
+ MASK(s->Symbol) = 0;
+ i = p->MinContext->NumStats - 1;
+ do { MASK((--s)->Symbol) = 0; } while (--i);
+ RangeEnc_Encode(rc, sum, p->MinContext->SummFreq - sum, p->MinContext->SummFreq);
+ }
+ else
+ {
+ UInt16 *prob = Ppmd7_GetBinSumm(p);
+ CPpmd_State *s = Ppmd7Context_OneState(p->MinContext);
+ if (s->Symbol == symbol)
+ {
+ RangeEnc_EncodeBit_0(rc, *prob);
+ *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
+ p->FoundState = s;
+ Ppmd7_UpdateBin(p);
+ return;
+ }
+ else
+ {
+ RangeEnc_EncodeBit_1(rc, *prob);
+ *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
+ p->InitEsc = PPMD7_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 = Ppmd7_GetContext(p, p->MinContext->Suffix);
+ }
+ while (p->MinContext->NumStats == numMasked);
+
+ see = Ppmd7_MakeEscFreq(p, numMasked, &escFreq);
+ s = Ppmd7_GetStats(p, p->MinContext);
+ sum = 0;
+ i = p->MinContext->NumStats;
+ 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(rc, low, s1->Freq, sum + escFreq);
+ Ppmd_See_Update(see);
+ p->FoundState = s1;
+ Ppmd7_Update2(p);
+ return;
+ }
+ sum += (s->Freq & (int)(MASK(cur)));
+ MASK(cur) = 0;
+ s++;
+ }
+ while (--i);
+
+ RangeEnc_Encode(rc, sum, escFreq, sum + escFreq);
+ see->Summ = (UInt16)(see->Summ + sum + escFreq);
+ }
+}
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