private static void DecodeInternal(Stream source, Stream destination)
{
UInt16BE_NE_H_InputBitStream bitStream = new UInt16BE_NE_H_InputBitStream(source);
for (;;)
{
if (!bitStream.Pop())
{
// Symbolwise match
ushort word = BigEndian.Read2(source);
BigEndian.Write2(destination, word);
}
else
{
// Dictionary match
int distance = (0x100 - NeutralEndian.Read1(source)) * 2;
int length = NeutralEndian.Read1(source);
if (length == 0)
{
// End-of-stream marker
break;
}
for (long i = 0; i <= length; i++)
{
long writePosition = destination.Position;
destination.Seek(writePosition - distance, SeekOrigin.Begin);
ushort s = BigEndian.Read2(destination);
destination.Seek(writePosition, SeekOrigin.Begin);
BigEndian.Write2(destination, s);
}
}
}
}
private void CheckBuffer()
{
if (this.remainingBits == 0)
{
this.byteBuffer = BigEndian.Read2(stream);
this.remainingBits = 16;
}
}
private static void Decode(Stream input, Stream output)
{
DecodingCodeTreeNode codeTree = new DecodingCodeTreeNode();
ushort numberOfTiles = BigEndian.Read2(input);
bool xorOutput = (numberOfTiles & 0x8000) != 0;
numberOfTiles &= 0x7fff;
DecodeHeader(input, output, codeTree);
DecodeInternal(input, output, codeTree, numberOfTiles, xorOutput);
}
public UInt16BEInputBitStream(Stream stream)
{
if (stream == null)
{
throw new ArgumentNullException("stream");
}
this.stream = stream;
this.remainingBits = 16;
this.byteBuffer = BigEndian.Read2(stream);
}
internal static void DecodeModuled(Stream source, Stream destination)
{
long decompressedBytes = 0;
long fullSize = BigEndian.Read2(source);
for (; ;)
{
DecodeInternal(source, destination, ref decompressedBytes);
if (decompressedBytes >= fullSize)
{
break;
}
}
}
public override ushort Read(int count)
{
this.CheckBuffer();
if (this.remainingBits < count)
{
int delta = count - this.remainingBits;
ushort lowBits = (ushort)(this.byteBuffer << delta);
this.byteBuffer = BigEndian.Read2(stream);
this.remainingBits = 16 - delta;
ushort highBits = (ushort)(this.byteBuffer >> this.remainingBits);
this.byteBuffer ^= (ushort)(highBits << this.remainingBits);
return((ushort)(lowBits | highBits));
}
this.remainingBits -= count;
ushort bits = (ushort)(this.byteBuffer >> this.remainingBits);
this.byteBuffer ^= (ushort)(bits << this.remainingBits);
return(bits);
}
internal static void Decode(Stream source, Stream destination, Endianness headerEndianness)
{
long decompressedBytes = 0;
long fullSize;
if (headerEndianness == Endianness.BigEndian)
{
fullSize = BigEndian.Read2(source);
}
else
{
fullSize = LittleEndian.Read2(source);
}
for (;;)
{
DecodeInternal(source, destination, ref decompressedBytes);
if (decompressedBytes >= fullSize)
{
break;
}
// Skip the padding between modules
int b;
long paddingEnd = (((source.Position - 2) + 0xF) & ~0xF) + 2;
while (source.Position < paddingEnd)
{
b = source.ReadByte();
if (b == -1)
{
throw new EndOfStreamException();
}
}
}
}
private static void Decode(Stream input, Stream output, Endianness endianness)
{
using (PaddedStream paddedInput = new PaddedStream(input, 2, PaddedStreamMode.Read))
{
byte packetLength = NeutralEndian.Read1(paddedInput);
var readBitfield = GetBitfieldReader(NeutralEndian.Read1(paddedInput));
ushort incrementingValue;
ushort commonValue;
InputBitStream <ushort> bitStream;
Action <Stream, ushort> write2;
if (endianness == Endianness.BigEndian)
{
incrementingValue = BigEndian.Read2(paddedInput);
commonValue = BigEndian.Read2(paddedInput);
bitStream = new UInt16BE_E_L_InputBitStream(paddedInput);
write2 = Write2BE;
}
else
{
incrementingValue = LittleEndian.Read2(paddedInput);
commonValue = LittleEndian.Read2(paddedInput);
bitStream = new UInt16LE_E_L_InputBitStream(paddedInput);
write2 = Write2LE;
}
// Loop until the end-of-data marker is found (if it is not found before the end of the stream, UInt8InputBitStream
// will throw an exception)
for (; ;)
{
if (bitStream.Get())
{
int mode = bitStream.Read(2);
int count = bitStream.Read(4);
switch (mode)
{
case 0:
case 1:
{
ushort flags = readBitfield(bitStream);
ushort outv = (ushort)(bitStream.Read(packetLength) | flags);
do
{
write2(output, outv);
outv += (ushort)mode;
} while (--count >= 0);
}
break;
case 2:
mode = -1;
goto case 0;
case 3:
{
// End of compressed data
if (count == 0xf)
{
return;
}
do
{
ushort flags = readBitfield(bitStream);
ushort outv = bitStream.Read(packetLength);
write2(output, (ushort)(outv | flags));
} while (--count >= 0);
}
break;
}
}
else
{
bool mode = bitStream.Get();
int count = bitStream.Read(4);
if (mode)
{
do
{
write2(output, commonValue);
} while (--count >= 0);
}
else
{
do
{
write2(output, incrementingValue++);
} while (--count >= 0);
}
}
}
}
}