public static IntegerEncoded CreateEncoding(int MaxVal)
{
while (MaxVal > 0)
{
int Check = MaxVal + 1;
// Is maxVal a power of two?
if ((Check & (Check - 1)) == 0)
{
return(new IntegerEncoded(EIntegerEncoding.JustBits, BitArrayStream.PopCnt(MaxVal)));
}
// Is maxVal of the type 3*2^n - 1?
if ((Check % 3 == 0) && ((Check / 3) & ((Check / 3) - 1)) == 0)
{
return(new IntegerEncoded(EIntegerEncoding.Trit, BitArrayStream.PopCnt(Check / 3 - 1)));
}
// Is maxVal of the type 5*2^n - 1?
if ((Check % 5 == 0) && ((Check / 5) & ((Check / 5) - 1)) == 0)
{
return(new IntegerEncoded(EIntegerEncoding.Quint, BitArrayStream.PopCnt(Check / 5 - 1)));
}
// Apparently it can't be represented with a bounded integer sequence...
// just iterate.
MaxVal--;
}
return(new IntegerEncoded(EIntegerEncoding.JustBits, 0));
}
public static void DecodeIntegerSequence(
List <IntegerEncoded> DecodeIntegerSequence,
BitArrayStream BitStream,
int MaxRange,
int NumberValues)
{
// Determine encoding parameters
IntegerEncoded IntEncoded = CreateEncoding(MaxRange);
// Start decoding
int NumberValuesDecoded = 0;
while (NumberValuesDecoded < NumberValues)
{
switch (IntEncoded.GetEncoding())
{
case EIntegerEncoding.Quint:
{
DecodeQuintBlock(BitStream, DecodeIntegerSequence, IntEncoded.NumberBits);
NumberValuesDecoded += 3;
break;
}
case EIntegerEncoding.Trit:
{
DecodeTritBlock(BitStream, DecodeIntegerSequence, IntEncoded.NumberBits);
NumberValuesDecoded += 5;
break;
}
case EIntegerEncoding.JustBits:
{
IntEncoded.BitValue = BitStream.ReadBits(IntEncoded.NumberBits);
DecodeIntegerSequence.Add(IntEncoded);
NumberValuesDecoded++;
break;
}
}
}
}
public static void DecodeTritBlock(
BitArrayStream BitStream,
List <IntegerEncoded> ListIntegerEncoded,
int NumberBitsPerValue)
{
// Implement the algorithm in section C.2.12
int[] m = new int[5];
int[] t = new int[5];
int T;
// Read the trit encoded block according to
// table C.2.14
m[0] = BitStream.ReadBits(NumberBitsPerValue);
T = BitStream.ReadBits(2);
m[1] = BitStream.ReadBits(NumberBitsPerValue);
T |= BitStream.ReadBits(2) << 2;
m[2] = BitStream.ReadBits(NumberBitsPerValue);
T |= BitStream.ReadBits(1) << 4;
m[3] = BitStream.ReadBits(NumberBitsPerValue);
T |= BitStream.ReadBits(2) << 5;
m[4] = BitStream.ReadBits(NumberBitsPerValue);
T |= BitStream.ReadBits(1) << 7;
int C;
BitArrayStream Tb = new BitArrayStream(new BitArray(new int[] { T }));
if (Tb.ReadBits(2, 4) == 7)
{
C = (Tb.ReadBits(5, 7) << 2) | Tb.ReadBits(0, 1);
t[4] = t[3] = 2;
}
else
{
C = Tb.ReadBits(0, 4);
if (Tb.ReadBits(5, 6) == 3)
{
t[4] = 2;
t[3] = Tb.ReadBit(7);
}
else
{
t[4] = Tb.ReadBit(7);
t[3] = Tb.ReadBits(5, 6);
}
}
BitArrayStream Cb = new BitArrayStream(new BitArray(new int[] { C }));
if (Cb.ReadBits(0, 1) == 3)
{
t[2] = 2;
t[1] = Cb.ReadBit(4);
t[0] = (Cb.ReadBit(3) << 1) | (Cb.ReadBit(2) & ~Cb.ReadBit(3));
}
else if (Cb.ReadBits(2, 3) == 3)
{
t[2] = 2;
t[1] = 2;
t[0] = Cb.ReadBits(0, 1);
}
else
{
t[2] = Cb.ReadBit(4);
t[1] = Cb.ReadBits(2, 3);
t[0] = (Cb.ReadBit(1) << 1) | (Cb.ReadBit(0) & ~Cb.ReadBit(1));
}
for (int i = 0; i < 5; i++)
{
IntegerEncoded IntEncoded = new IntegerEncoded(EIntegerEncoding.Trit, NumberBitsPerValue)
{
BitValue = m[i],
TritValue = t[i]
};
ListIntegerEncoded.Add(IntEncoded);
}
}
public static void DecodeQuintBlock(
BitArrayStream BitStream,
List <IntegerEncoded> ListIntegerEncoded,
int NumberBitsPerValue)
{
// Implement the algorithm in section C.2.12
int[] m = new int[3];
int[] q = new int[3];
int Q;
// Read the trit encoded block according to
// table C.2.15
m[0] = BitStream.ReadBits(NumberBitsPerValue);
Q = BitStream.ReadBits(3);
m[1] = BitStream.ReadBits(NumberBitsPerValue);
Q |= BitStream.ReadBits(2) << 3;
m[2] = BitStream.ReadBits(NumberBitsPerValue);
Q |= BitStream.ReadBits(2) << 5;
BitArrayStream Qb = new BitArrayStream(new BitArray(new int[] { Q }));
if (Qb.ReadBits(1, 2) == 3 && Qb.ReadBits(5, 6) == 0)
{
q[0] = q[1] = 4;
q[2] = (Qb.ReadBit(0) << 2) | ((Qb.ReadBit(4) & ~Qb.ReadBit(0)) << 1) | (Qb.ReadBit(3) & ~Qb.ReadBit(0));
}
else
{
int C;
if (Qb.ReadBits(1, 2) == 3)
{
q[2] = 4;
C = (Qb.ReadBits(3, 4) << 3) | ((~Qb.ReadBits(5, 6) & 3) << 1) | Qb.ReadBit(0);
}
else
{
q[2] = Qb.ReadBits(5, 6);
C = Qb.ReadBits(0, 4);
}
BitArrayStream Cb = new BitArrayStream(new BitArray(new int[] { C }));
if (Cb.ReadBits(0, 2) == 5)
{
q[1] = 4;
q[0] = Cb.ReadBits(3, 4);
}
else
{
q[1] = Cb.ReadBits(3, 4);
q[0] = Cb.ReadBits(0, 2);
}
}
for (int i = 0; i < 3; i++)
{
IntegerEncoded IntEncoded = new IntegerEncoded(EIntegerEncoding.Quint, NumberBitsPerValue)
{
BitValue = m[i],
QuintValue = q[i]
};
ListIntegerEncoded.Add(IntEncoded);
}
}