//Huffman 4bit/8bit
public static byte[] Decompress(Stream input, int num_bits, long decompressedLength)
{
using (var br = new ImprovedBinaryReader(input, true))
{
var result = new List <byte>();
var tree_size = br.ReadByte();
var tree_root = br.ReadByte();
var tree_buffer = br.ReadBytes(tree_size * 2);
for (int i = 0, code = 0, next = 0, pos = tree_root;; i++)
{
if (i % 32 == 0)
{
code = br.ReadInt32();
}
next += (pos & 0x3F) * 2 + 2;
int direction = (code >> (31 - i)) % 2 == 0 ? 2 : 1;
var leaf = (pos >> 5 >> direction) % 2 != 0;
pos = tree_buffer[next - direction];
if (leaf)
{
result.Add((byte)pos);
pos = tree_root;
next = 0;
}
if (result.Count == decompressedLength * 8 / num_bits)
{
if (num_bits == 8)
{
return(result.ToArray());
}
else
{
return(Enumerable.Range(0, (int)decompressedLength)
.Select(j => (byte)(result[2 * j + 1] * 16 + result[2 * j])).ToArray());
}
}
}
}
}
public static byte[] Decompress(Stream instream, long decompressedLength)
{
using (var br = new ImprovedBinaryReader(instream, true))
{
var result = new List <byte>();
while (true)
{
var flag = br.ReadByte();
result.AddRange(flag >= 128
? Enumerable.Repeat(br.ReadByte(), flag - 128 + 3)
: br.ReadBytes(flag + 1));
if (result.Count == decompressedLength)
{
return(result.ToArray());
}
else if (result.Count > decompressedLength)
{
throw new InvalidDataException("Went past the end of the stream");
}
}
}
}