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-rw-r--r--trunk/src/lib/lib7z/Ppmd8Enc.c161
1 files changed, 161 insertions, 0 deletions
diff --git a/trunk/src/lib/lib7z/Ppmd8Enc.c b/trunk/src/lib/lib7z/Ppmd8Enc.c
new file mode 100644
index 00000000000..f433fe9ee0a
--- /dev/null
+++ b/trunk/src/lib/lib7z/Ppmd8Enc.c
@@ -0,0 +1,161 @@
+/* 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);
+ }
+}