public static byte[] Decompress(Stream stream)
{
using (var br = new BinaryReader(stream, Encoding.Default, true))
{
int sizeAndMethod = br.ReadInt32();
int size = sizeAndMethod / 8;
var method = (CompressionMethod)(sizeAndMethod % 8);
switch (method)
{
case CompressionMethod.NoCompression:
return(br.ReadBytes(size));
case CompressionMethod.LZ10:
return(LZ10.Decompress(br.BaseStream, size));
case CompressionMethod.Huffman4Bit:
case CompressionMethod.Huffman8Bit:
int num_bits = method == CompressionMethod.Huffman4Bit ? 4 : 8;
return(Huffman.Decompress(br.BaseStream, num_bits, size, ByteOrder.LittleEndian));
case CompressionMethod.RLE:
return(RLE.Decompress(br.BaseStream, size));
default:
throw new NotSupportedException($"Unknown compression method {method}");
}
}
}
public static byte[] Compress(Stream stream, CompressionMethod method)
{
if (stream.Length > 0x1fffffff)
{
throw new Exception("File is too big to be compressed with Level5 compressions!");
}
uint methodSize = (uint)stream.Length << 3;
switch (method)
{
case CompressionMethod.NoCompression:
using (var bw = new BinaryWriterX(new MemoryStream()))
{
bw.Write(methodSize);
stream.Position = 0;
stream.CopyTo(bw.BaseStream);
bw.BaseStream.Position = 0;
return(new BinaryReaderX(bw.BaseStream).ReadBytes((int)bw.BaseStream.Length));
}
case CompressionMethod.LZ10:
methodSize |= 0x1;
using (var bw = new BinaryWriterX(new MemoryStream()))
{
bw.Write(methodSize);
stream.Position = 0;
var comp = LZ10.Compress(stream);
bw.Write(comp);
bw.BaseStream.Position = 0;
return(new BinaryReaderX(bw.BaseStream).ReadBytes((int)bw.BaseStream.Length));
}
case CompressionMethod.Huffman4Bit:
methodSize |= 0x2;
using (var bw = new BinaryWriterX(new MemoryStream()))
{
bw.Write(methodSize);
stream.Position = 0;
var comp = Huffman.Compress(stream, 4);
bw.Write(comp);
bw.BaseStream.Position = 0;
return(new BinaryReaderX(bw.BaseStream).ReadBytes((int)bw.BaseStream.Length));
}
case CompressionMethod.Huffman8Bit:
methodSize |= 0x3;
using (var bw = new BinaryWriterX(new MemoryStream()))
{
bw.Write(methodSize);
stream.Position = 0;
var comp = Huffman.Compress(stream, 8);
bw.Write(comp);
bw.BaseStream.Position = 0;
return(new BinaryReaderX(bw.BaseStream).ReadBytes((int)bw.BaseStream.Length));
}
case CompressionMethod.RLE:
methodSize |= 0x4;
using (var bw = new BinaryWriterX(new MemoryStream()))
{
bw.Write(methodSize);
stream.Position = 0;
var comp = RLE.Compress(stream);
bw.Write(comp);
bw.BaseStream.Position = 0;
return(new BinaryReaderX(bw.BaseStream).ReadBytes((int)bw.BaseStream.Length));
}
default:
throw new Exception($"Unsupported compression method {method}!");
}
}
