internal void update1_0(ModelPpm model, int p)
{
model.FoundState.Address = p;
model.PrevSuccess = 2 * model.FoundState.Freq > _freqData.SummFreq ? 1 : 0;
model.IncRunLength(model.PrevSuccess);
_freqData.IncrementSummFreq(4);
model.FoundState.IncrementFreq(4);
if (model.FoundState.Freq > ModelPpm.MAX_FREQ)
{
Rescale(model);
}
}
internal void DecodeBinSymbol(ModelPpm model)
{
State rs = _tempState1.Initialize(model.Heap);
rs.Address = _oneState.Address; // State&
model.HiBitsFlag = model.GetHb2Flag()[model.FoundState.Symbol];
int off1 = rs.Freq - 1;
int off2 = GetArrayIndex(model, rs);
int bs = model.BinSumm[off1][off2];
if (model.Coder.GetCurrentShiftCount(ModelPpm.TOT_BITS) < bs)
{
model.FoundState.Address = rs.Address;
rs.IncrementFreq((rs.Freq < 128) ? 1 : 0);
model.Coder.SubRange.LowCount = 0;
model.Coder.SubRange.HighCount = bs;
bs = ((bs + ModelPpm.INTERVAL - GetMean(bs, ModelPpm.PERIOD_BITS, 2)) & 0xffff);
model.BinSumm[off1][off2] = bs;
model.PrevSuccess = 1;
model.IncRunLength(1);
}
else
{
model.Coder.SubRange.LowCount = bs;
bs = (bs - GetMean(bs, ModelPpm.PERIOD_BITS, 2)) & 0xFFFF;
model.BinSumm[off1][off2] = bs;
model.Coder.SubRange.HighCount = ModelPpm.BIN_SCALE;
model.InitEsc = EXP_ESCAPE[Utility.URShift(bs, 10)];
model.NumMasked = 1;
model.CharMask[rs.Symbol] = model.EscCount;
model.PrevSuccess = 0;
model.FoundState.Address = 0;
}
//int a = 0;//TODO just 4 debugging
}
internal bool DecodeSymbol1(ModelPpm model)
{
RangeCoder coder = model.Coder;
coder.SubRange.Scale = _freqData.SummFreq;
State p = new State(model.Heap);
p.Address = _freqData.GetStats();
int i, hiCnt;
long count = coder.CurrentCount;
if (count >= coder.SubRange.Scale)
{
return(false);
}
if (count < (hiCnt = p.Freq))
{
coder.SubRange.HighCount = hiCnt;
model.PrevSuccess = (2 * hiCnt > coder.SubRange.Scale) ? 1 : 0;
model.IncRunLength(model.PrevSuccess);
hiCnt += 4;
model.FoundState.Address = p.Address;
model.FoundState.Freq = hiCnt;
_freqData.IncrementSummFreq(4);
if (hiCnt > ModelPpm.MAX_FREQ)
{
Rescale(model);
}
coder.SubRange.LowCount = 0;
return(true);
}
if (model.FoundState.Address == 0)
{
return(false);
}
model.PrevSuccess = 0;
int numStats = NumStats;
i = numStats - 1;
while ((hiCnt += p.IncrementAddress().Freq) <= count)
{
if (--i == 0)
{
model.HiBitsFlag = model.GetHb2Flag()[model.FoundState.Symbol];
coder.SubRange.LowCount = hiCnt;
model.CharMask[p.Symbol] = model.EscCount;
model.NumMasked = numStats;
i = numStats - 1;
model.FoundState.Address = 0;
do
{
model.CharMask[p.DecrementAddress().Symbol] = model.EscCount;
}while (--i != 0);
coder.SubRange.HighCount = coder.SubRange.Scale;
return(true);
}
}
coder.SubRange.LowCount = hiCnt - p.Freq;
coder.SubRange.HighCount = hiCnt;
Update1(model, p.Address);
return(true);
}