public void ReadTwoMSB()
{
var buff = new byte[1] {
0x40
};
var mem = new MemoryStream(buff);
BitReaderMSB reader = new BitReaderMSB(mem);
reader.GetBits(1);
var val = reader.GetBits(1);
Assert.AreEqual(1, val);
}
public void ReadWriteMSB()
{
for (int n = 4; n <= 10; n++)
{
var max = (1 << n) - 1;
byte[] buff = new byte[max * n / 8 + 2];
var mem = new MemoryStream(buff);
BitWriterMSB writer = new BitWriterMSB(mem);
for (int i = 0; i <= max; i++)
{
writer.WriteBits(i, n);
}
writer.Flush();
mem.Seek(0, SeekOrigin.Begin);
BitReaderMSB reader = new BitReaderMSB(mem);
for (int i = 0; i <= max; i++)
{
var val = reader.GetBits((ushort)n);
Assert.AreEqual(i, val);
}
}
}
public void ReadNineMSB()
{
var buff = new byte[] { 0, 0x80 };
var mem = new MemoryStream(buff);
BitReaderMSB reader = new BitReaderMSB(mem);
var val = reader.GetBits(9);
Assert.AreEqual(1, val);
}
protected short Getc2()
{
int i = 0;
short next;
while (_nodes[i + 1] > 0)
{
if (reader.GetBits(1) > 0)
{
next = (short)(_nodes[i + 1] & 0x0F); // use lower 4 bits
if (next == 0)
{
return((short)(reader.GetByte() | 0x100));
}
}
else
{
next = (short)(_nodes[i + 1] >> 4); // use higher 4 bits
}
i += next << 1;
}
return((short)(_nodes[i] | (_nodes[i + 1] << 8)));
}
protected override void GoUnpack()
{
var reader = new BitReaderMSB(_stream);
BitReaderMSB.DEBUG = DEBUG;
ushort numbits = 9;
ushort curtoken = 0x102;
ushort endtoken = 0x1ff;
byte lastchar = 0;
ushort lastbits = 0;
bool firstChar = true;
ushort bitstring;
while (!IsFinished())
{
if (DEBUG)
{
Console.WriteLine();
}
if (DEBUG)
{
Console.WriteLine(_dwWrote);
}
bitstring = (ushort)reader.GetBits(numbits);
if (bitstring == 0x101) // found end-of-data signal
{
if (DEBUG)
{
Console.WriteLine("End");
}
return;
}
if (bitstring == 0x100) // start-over signal
{
if (DEBUG)
{
Console.WriteLine("Reset");
}
numbits = 9;
curtoken = 0x102;
endtoken = 0x1ff;
firstChar = true;
continue;
}
if (firstChar)
{
if (DEBUG)
{
Console.WriteLine("First");
}
lastchar = (byte)(bitstring & 0xff);
lastbits = bitstring;
firstChar = false;
PutByte(lastchar);
}
else
{
ushort token = bitstring;
if (token == curtoken) // index past current point
{
if (DEBUG)
{
Console.WriteLine($"Push lastchar {lastchar:X02}");
}
token = lastbits;
stack.Push(lastchar);
}
while ((token > 0xff) && (token < 0x1004)) // follow links back in data
{
if (DEBUG)
{
Console.WriteLine($"Push token[{token:X4}] {tokens[token]}");
}
stack.Push(tokens[token].data);
token = tokens[token].next;
}
lastchar = (byte)(token & 0xff);
stack.Push(lastchar);
WriteStack();
// put token into record
if (curtoken <= endtoken)
{
tokens[curtoken].data = lastchar;
tokens[curtoken].next = lastbits;
if (DEBUG)
{
Console.WriteLine($"tokens[{curtoken:X4}] = {tokens[curtoken]}");
}
curtoken++;
if (curtoken == endtoken && numbits < 12)
{
numbits++;
endtoken = (ushort)((endtoken << 1) + 1);
if (DEBUG)
{
Console.WriteLine($"New endtoken = {endtoken:X4} numbits = {numbits}");
}
}
}
lastbits = bitstring;
}
}
}