public uint ReverseDecode(LZMARangeDecoder rangeDecoder)
{
uint m = 1;
uint symbol = 0;
for (int bitIndex = 0; bitIndex < NumBitLevels; bitIndex++)
{
uint bit = Models[m].Decode(rangeDecoder);
m <<= 1;
m += bit;
symbol |= (bit << bitIndex);
}
return symbol;
}
public static uint ReverseDecode(LZMARangeBitDecoder[] Models, UInt32 startIndex,
LZMARangeDecoder rangeDecoder, int NumBitLevels)
{
uint m = 1;
uint symbol = 0;
for (int bitIndex = 0; bitIndex < NumBitLevels; bitIndex++)
{
uint bit = Models[startIndex + m].Decode(rangeDecoder);
m <<= 1;
m += bit;
symbol |= (bit << bitIndex);
}
return symbol;
}
public uint Decode(LZMARangeDecoder rangeDecoder)
{
uint newBound = (uint)(rangeDecoder.Range >> kNumBitModelTotalBits) * (uint)Prob;
if (rangeDecoder.Code < newBound)
{
rangeDecoder.Range = newBound;
Prob += (kBitModelTotal - Prob) >> kNumMoveBits;
if (rangeDecoder.Range < LZMARangeDecoder.kTopValue)
{
rangeDecoder.Code = (rangeDecoder.Code << 8) | (byte)rangeDecoder.Stream.ReadByte();
rangeDecoder.Range <<= 8;
}
return 0;
}
else
{
rangeDecoder.Range -= newBound;
rangeDecoder.Code -= newBound;
Prob -= (Prob) >> kNumMoveBits;
if (rangeDecoder.Range < LZMARangeDecoder.kTopValue)
{
rangeDecoder.Code = (rangeDecoder.Code << 8) | (byte)rangeDecoder.Stream.ReadByte();
rangeDecoder.Range <<= 8;
}
return 1;
}
}
public uint Decode(LZMARangeDecoder rangeDecoder)
{
uint m = 1;
for (int bitIndex = NumBitLevels; bitIndex > 0; bitIndex--)
m = (m << 1) + Models[m].Decode(rangeDecoder);
return m - ((uint)1 << NumBitLevels);
}
public byte DecodeWithMatchByte(LZMARangeDecoder rangeDecoder, uint pos, byte prevByte, byte matchByte)
{ return m_Coders[GetState(pos, prevByte)].DecodeWithMatchByte(rangeDecoder, matchByte); }
public byte DecodeNormal(LZMARangeDecoder rangeDecoder, uint pos, byte prevByte)
{ return m_Coders[GetState(pos, prevByte)].DecodeNormal(rangeDecoder); }
public byte DecodeWithMatchByte(LZMARangeDecoder rangeDecoder, byte matchByte)
{
uint symbol = 1;
do
{
uint matchBit = (uint)(matchByte >> 7) & 1;
matchByte <<= 1;
uint bit = m_Decoders[((1 + matchBit) << 8) + symbol].Decode(rangeDecoder);
symbol = (symbol << 1) | bit;
if (matchBit != bit)
{
while (symbol < 0x100)
symbol = (symbol << 1) | m_Decoders[symbol].Decode(rangeDecoder);
break;
}
}
while (symbol < 0x100);
return (byte)symbol;
}
public byte DecodeNormal(LZMARangeDecoder rangeDecoder)
{
uint symbol = 1;
do
symbol = (symbol << 1) | m_Decoders[symbol].Decode(rangeDecoder);
while (symbol < 0x100);
return (byte)symbol;
}
public uint Decode(LZMARangeDecoder rangeDecoder, uint posState)
{
if (m_Choice.Decode(rangeDecoder) == 0)
return m_LowCoder[posState].Decode(rangeDecoder);
else
{
uint symbol = LZMABase.kNumLowLenSymbols;
if (m_Choice2.Decode(rangeDecoder) == 0)
symbol += m_MidCoder[posState].Decode(rangeDecoder);
else
{
symbol += LZMABase.kNumMidLenSymbols;
symbol += m_HighCoder.Decode(rangeDecoder);
}
return symbol;
}
}
