public PpmdStream(PpmdProperties properties, Stream stream, bool compress)
{
this.properties = properties;
this.stream = stream;
this.compress = compress;
if (properties.Version == PpmdVersion.I1)
{
model = new I1.Model();
if (compress)
{
model.EncodeStart(properties);
}
else
{
model.DecodeStart(stream, properties);
}
}
if (properties.Version == PpmdVersion.H)
{
modelH = new H.ModelPPM();
if (compress)
{
throw new NotImplementedException();
}
else
{
modelH.decodeInit(stream, properties.ModelOrder, properties.AllocatorSize);
}
}
if (properties.Version == PpmdVersion.H7z)
{
modelH = new H.ModelPPM();
if (compress)
{
throw new NotImplementedException();
}
else
{
modelH.decodeInit(null, properties.ModelOrder, properties.AllocatorSize);
}
decoder = new TrrntzipDN.SupportedFiles.SevenZip.Compress.RangeCoder.Decoder();
decoder.Init(stream);
}
}
public int decodeChar(TrrntzipDN.SupportedFiles.SevenZip.Compress.RangeCoder.Decoder decoder)
{
if (minContext.NumStats != 1)
{
State s = tempState1.Initialize(Heap);
s.Address = minContext.FreqData.GetStats();
int i;
int count, hiCnt;
if ((count = (int)decoder.GetThreshold((uint)minContext.FreqData.SummFreq)) < (hiCnt = s.Freq))
{
byte symbol;
decoder.Decode(0, (uint)s.Freq);
symbol = (byte)s.Symbol;
minContext.update1_0(this, s.Address);
nextContext();
return(symbol);
}
prevSuccess = 0;
i = minContext.NumStats - 1;
do
{
s.IncrementAddress();
if ((hiCnt += s.Freq) > count)
{
byte symbol;
decoder.Decode((uint)(hiCnt - s.Freq), (uint)s.Freq);
symbol = (byte)s.Symbol;
minContext.update1(this, s.Address);
nextContext();
return(symbol);
}
}while (--i > 0);
if (count >= minContext.FreqData.SummFreq)
{
return(-2);
}
hiBitsFlag = HB2Flag[foundState.Symbol];
decoder.Decode((uint)hiCnt, (uint)(minContext.FreqData.SummFreq - hiCnt));
for (i = 0; i < 256; i++)
{
charMask[i] = -1;
}
charMask[s.Symbol] = 0;
i = minContext.NumStats - 1;
do
{
s.DecrementAddress();
charMask[s.Symbol] = 0;
}while (--i > 0);
}
else
{
State rs = tempState1.Initialize(Heap);
rs.Address = minContext.getOneState().Address;
hiBitsFlag = getHB2Flag()[foundState.Symbol];
int off1 = rs.Freq - 1;
int off2 = minContext.getArrayIndex(this, rs);
int bs = binSumm[off1][off2];
if (decoder.DecodeBit((uint)bs, 14) == 0)
{
byte symbol;
binSumm[off1][off2] = (bs + INTERVAL - minContext.getMean(bs, PERIOD_BITS, 2)) & 0xFFFF;
foundState.Address = rs.Address;
symbol = (byte)rs.Symbol;
rs.IncrementFreq((rs.Freq < 128) ? 1 : 0);
prevSuccess = 1;
incRunLength(1);
nextContext();
return(symbol);
}
bs = (bs - minContext.getMean(bs, PERIOD_BITS, 2)) & 0xFFFF;
binSumm[off1][off2] = bs;
initEsc = PPMContext.ExpEscape[Utility.URShift(bs, 10)];
int i;
for (i = 0; i < 256; i++)
{
charMask[i] = -1;
}
charMask[rs.Symbol] = 0;
prevSuccess = 0;
}
for (;;)
{
State s = tempState1.Initialize(Heap);
int i;
int freqSum, count, hiCnt;
SEE2Context see;
int num, numMasked = minContext.NumStats;
do
{
orderFall++;
minContext.Address = minContext.getSuffix();
if (minContext.Address <= subAlloc.PText || minContext.Address > subAlloc.HeapEnd)
{
return(-1);
}
}while (minContext.NumStats == numMasked);
hiCnt = 0;
s.Address = minContext.FreqData.GetStats();
i = 0;
num = minContext.NumStats - numMasked;
do
{
int k = charMask[s.Symbol];
hiCnt += s.Freq & k;
minContext.ps[i] = s.Address;
s.IncrementAddress();
i -= k;
}while (i != num);
see = minContext.makeEscFreq(this, numMasked, out freqSum);
freqSum += hiCnt;
count = (int)decoder.GetThreshold((uint)freqSum);
if (count < hiCnt)
{
byte symbol;
State ps = tempState2.Initialize(Heap);
for (hiCnt = 0, i = 0, ps.Address = minContext.ps[i]; (hiCnt += ps.Freq) <= count; i++, ps.Address = minContext.ps[i])
{
;
}
s.Address = ps.Address;
decoder.Decode((uint)(hiCnt - s.Freq), (uint)s.Freq);
see.update();
symbol = (byte)s.Symbol;
minContext.update2(this, s.Address);
updateModel();
return(symbol);
}
if (count >= freqSum)
{
return(-2);
}
decoder.Decode((uint)hiCnt, (uint)(freqSum - hiCnt));
see.Summ = see.Summ + freqSum;
do
{
s.Address = minContext.ps[--i];
charMask[s.Symbol] = 0;
}while (i != 0);
}
}
