summaryrefslogtreecommitdiffstatshomepage
path: root/src/lib/lib7z/Ppmd8Dec.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib/lib7z/Ppmd8Dec.c')
-rw-r--r--src/lib/lib7z/Ppmd8Dec.c248
1 files changed, 124 insertions, 124 deletions
diff --git a/src/lib/lib7z/Ppmd8Dec.c b/src/lib/lib7z/Ppmd8Dec.c
index 12fd7ec0d79..7c9fcc095b0 100644
--- a/src/lib/lib7z/Ppmd8Dec.c
+++ b/src/lib/lib7z/Ppmd8Dec.c
@@ -11,145 +11,145 @@ This code is based on:
Bool Ppmd8_RangeDec_Init(CPpmd8 *p)
{
- unsigned i;
- p->Low = 0;
- p->Range = 0xFFFFFFFF;
- p->Code = 0;
- for (i = 0; i < 4; i++)
- p->Code = (p->Code << 8) | p->Stream.In->Read(p->Stream.In);
- return (p->Code < 0xFFFFFFFF);
+ unsigned i;
+ p->Low = 0;
+ p->Range = 0xFFFFFFFF;
+ p->Code = 0;
+ for (i = 0; i < 4; i++)
+ p->Code = (p->Code << 8) | p->Stream.In->Read(p->Stream.In);
+ return (p->Code < 0xFFFFFFFF);
}
static UInt32 RangeDec_GetThreshold(CPpmd8 *p, UInt32 total)
{
- return p->Code / (p->Range /= total);
+ return p->Code / (p->Range /= total);
}
static void RangeDec_Decode(CPpmd8 *p, UInt32 start, UInt32 size)
{
- start *= p->Range;
- p->Low += start;
- p->Code -= start;
- p->Range *= size;
+ start *= p->Range;
+ p->Low += start;
+ p->Code -= start;
+ p->Range *= size;
- while ((p->Low ^ (p->Low + p->Range)) < kTop ||
- (p->Range < kBot && ((p->Range = (0 - p->Low) & (kBot - 1)), 1)))
- {
- p->Code = (p->Code << 8) | p->Stream.In->Read(p->Stream.In);
- p->Range <<= 8;
- p->Low <<= 8;
- }
+ while ((p->Low ^ (p->Low + p->Range)) < kTop ||
+ (p->Range < kBot && ((p->Range = (0 - p->Low) & (kBot - 1)), 1)))
+ {
+ p->Code = (p->Code << 8) | p->Stream.In->Read(p->Stream.In);
+ p->Range <<= 8;
+ p->Low <<= 8;
+ }
}
#define MASK(sym) ((signed char *)charMask)[sym]
int Ppmd8_DecodeSymbol(CPpmd8 *p)
{
- size_t charMask[256 / sizeof(size_t)];
- if (p->MinContext->NumStats != 0)
- {
- CPpmd_State *s = Ppmd8_GetStats(p, p->MinContext);
- unsigned i;
- UInt32 count, hiCnt;
- if ((count = RangeDec_GetThreshold(p, p->MinContext->SummFreq)) < (hiCnt = s->Freq))
- {
- Byte symbol;
- RangeDec_Decode(p, 0, s->Freq);
- p->FoundState = s;
- symbol = s->Symbol;
- Ppmd8_Update1_0(p);
- return symbol;
- }
- p->PrevSuccess = 0;
- i = p->MinContext->NumStats;
- do
- {
- if ((hiCnt += (++s)->Freq) > count)
- {
- Byte symbol;
- RangeDec_Decode(p, hiCnt - s->Freq, s->Freq);
- p->FoundState = s;
- symbol = s->Symbol;
- Ppmd8_Update1(p);
- return symbol;
- }
- }
- while (--i);
- if (count >= p->MinContext->SummFreq)
- return -2;
- RangeDec_Decode(p, hiCnt, p->MinContext->SummFreq - hiCnt);
- PPMD_SetAllBitsIn256Bytes(charMask);
- MASK(s->Symbol) = 0;
- i = p->MinContext->NumStats;
- do { MASK((--s)->Symbol) = 0; } while (--i);
- }
- else
- {
- UInt16 *prob = Ppmd8_GetBinSumm(p);
- if (((p->Code / (p->Range >>= 14)) < *prob))
- {
- Byte symbol;
- RangeDec_Decode(p, 0, *prob);
- *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
- symbol = (p->FoundState = Ppmd8Context_OneState(p->MinContext))->Symbol;
- Ppmd8_UpdateBin(p);
- return symbol;
- }
- RangeDec_Decode(p, *prob, (1 << 14) - *prob);
- *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
- p->InitEsc = PPMD8_kExpEscape[*prob >> 10];
- PPMD_SetAllBitsIn256Bytes(charMask);
- MASK(Ppmd8Context_OneState(p->MinContext)->Symbol) = 0;
- p->PrevSuccess = 0;
- }
- for (;;)
- {
- CPpmd_State *ps[256], *s;
- UInt32 freqSum, count, hiCnt;
- CPpmd_See *see;
- unsigned i, num, numMasked = p->MinContext->NumStats;
- do
- {
- p->OrderFall++;
- if (!p->MinContext->Suffix)
- return -1;
- p->MinContext = Ppmd8_GetContext(p, p->MinContext->Suffix);
- }
- while (p->MinContext->NumStats == numMasked);
- hiCnt = 0;
- s = Ppmd8_GetStats(p, p->MinContext);
- i = 0;
- num = p->MinContext->NumStats - numMasked;
- do
- {
- int k = (int)(MASK(s->Symbol));
- hiCnt += (s->Freq & k);
- ps[i] = s++;
- i -= k;
- }
- while (i != num);
+ size_t charMask[256 / sizeof(size_t)];
+ if (p->MinContext->NumStats != 0)
+ {
+ CPpmd_State *s = Ppmd8_GetStats(p, p->MinContext);
+ unsigned i;
+ UInt32 count, hiCnt;
+ if ((count = RangeDec_GetThreshold(p, p->MinContext->SummFreq)) < (hiCnt = s->Freq))
+ {
+ Byte symbol;
+ RangeDec_Decode(p, 0, s->Freq);
+ p->FoundState = s;
+ symbol = s->Symbol;
+ Ppmd8_Update1_0(p);
+ return symbol;
+ }
+ p->PrevSuccess = 0;
+ i = p->MinContext->NumStats;
+ do
+ {
+ if ((hiCnt += (++s)->Freq) > count)
+ {
+ Byte symbol;
+ RangeDec_Decode(p, hiCnt - s->Freq, s->Freq);
+ p->FoundState = s;
+ symbol = s->Symbol;
+ Ppmd8_Update1(p);
+ return symbol;
+ }
+ }
+ while (--i);
+ if (count >= p->MinContext->SummFreq)
+ return -2;
+ RangeDec_Decode(p, hiCnt, p->MinContext->SummFreq - hiCnt);
+ PPMD_SetAllBitsIn256Bytes(charMask);
+ MASK(s->Symbol) = 0;
+ i = p->MinContext->NumStats;
+ do { MASK((--s)->Symbol) = 0; } while (--i);
+ }
+ else
+ {
+ UInt16 *prob = Ppmd8_GetBinSumm(p);
+ if (((p->Code / (p->Range >>= 14)) < *prob))
+ {
+ Byte symbol;
+ RangeDec_Decode(p, 0, *prob);
+ *prob = (UInt16)PPMD_UPDATE_PROB_0(*prob);
+ symbol = (p->FoundState = Ppmd8Context_OneState(p->MinContext))->Symbol;
+ Ppmd8_UpdateBin(p);
+ return symbol;
+ }
+ RangeDec_Decode(p, *prob, (1 << 14) - *prob);
+ *prob = (UInt16)PPMD_UPDATE_PROB_1(*prob);
+ p->InitEsc = PPMD8_kExpEscape[*prob >> 10];
+ PPMD_SetAllBitsIn256Bytes(charMask);
+ MASK(Ppmd8Context_OneState(p->MinContext)->Symbol) = 0;
+ p->PrevSuccess = 0;
+ }
+ for (;;)
+ {
+ CPpmd_State *ps[256], *s;
+ UInt32 freqSum, count, hiCnt;
+ CPpmd_See *see;
+ unsigned i, num, numMasked = p->MinContext->NumStats;
+ do
+ {
+ p->OrderFall++;
+ if (!p->MinContext->Suffix)
+ return -1;
+ p->MinContext = Ppmd8_GetContext(p, p->MinContext->Suffix);
+ }
+ while (p->MinContext->NumStats == numMasked);
+ hiCnt = 0;
+ s = Ppmd8_GetStats(p, p->MinContext);
+ i = 0;
+ num = p->MinContext->NumStats - numMasked;
+ do
+ {
+ int k = (int)(MASK(s->Symbol));
+ hiCnt += (s->Freq & k);
+ ps[i] = s++;
+ i -= k;
+ }
+ while (i != num);
- see = Ppmd8_MakeEscFreq(p, numMasked, &freqSum);
- freqSum += hiCnt;
- count = RangeDec_GetThreshold(p, freqSum);
+ see = Ppmd8_MakeEscFreq(p, numMasked, &freqSum);
+ freqSum += hiCnt;
+ count = RangeDec_GetThreshold(p, freqSum);
- if (count < hiCnt)
- {
- Byte symbol;
- CPpmd_State **pps = ps;
- for (hiCnt = 0; (hiCnt += (*pps)->Freq) <= count; pps++);
- s = *pps;
- RangeDec_Decode(p, hiCnt - s->Freq, s->Freq);
- Ppmd_See_Update(see);
- p->FoundState = s;
- symbol = s->Symbol;
- Ppmd8_Update2(p);
- return symbol;
- }
- if (count >= freqSum)
- return -2;
- RangeDec_Decode(p, hiCnt, freqSum - hiCnt);
- see->Summ = (UInt16)(see->Summ + freqSum);
- do { MASK(ps[--i]->Symbol) = 0; } while (i != 0);
- }
+ if (count < hiCnt)
+ {
+ Byte symbol;
+ CPpmd_State **pps = ps;
+ for (hiCnt = 0; (hiCnt += (*pps)->Freq) <= count; pps++);
+ s = *pps;
+ RangeDec_Decode(p, hiCnt - s->Freq, s->Freq);
+ Ppmd_See_Update(see);
+ p->FoundState = s;
+ symbol = s->Symbol;
+ Ppmd8_Update2(p);
+ return symbol;
+ }
+ if (count >= freqSum)
+ return -2;
+ RangeDec_Decode(p, hiCnt, freqSum - hiCnt);
+ see->Summ = (UInt16)(see->Summ + freqSum);
+ do { MASK(ps[--i]->Symbol) = 0; } while (i != 0);
+ }
}