Сжатие/разжатие бинарных файлов (SharpZipLib)

public void Unzlib_bin(string initial_location, string target_location)
{
    byte[] data, new_data;
    Inflater inflater;
 
    inflater = new Inflater(false);
 
    data = File.ReadAllBytes(initial_location);
    inflater.SetInput(data, 16, BitConverter.ToInt32(data, 8));
    new_data = new byte[BitConverter.ToInt32(data, 12)];
    inflater.Inflate(new_data);
 
    File.WriteAllBytes(target_location, new_data);
}

public void Zlib_bin(byte[] data, string target_location)
{
    byte[] new_data;
    Deflater deflater;
 
    deflater = new Deflater();
 
    deflater.SetInput(data, 16, BitConverter.ToInt32(data, 8));
    deflater.Finish();
    new_data = new byte[BitConverter.ToInt32(data, 12)];
    deflater.Deflate(new_data);
 
    File.WriteAllBytes(target_location, new_data);
}

на вход 
BitConverter.ToInt32(data, 8)
на выход 
BitConverter.ToInt32(data, 12)

public void Compress(byte[] data, string path)
{
    using (var fstream = File.Create(path))
    using (var gzipStream = new GZipOutputStream(fstream))
    {
        //gzipStream.SetLevel(Deflater.BEST_COMPRESSION); // Максимальный уровень сжатия
        gzipStream.Write(data, 0, data.Length);
    }
}
 
public byte[] Decompress(string path)
{
    var mstream = new MemoryStream();
    using (var fstream = File.OpenRead(path))
    using (var gzipStream = new GZipInputStream(fstream))
    {
        gzipStream.CopyTo(mstream);
    }
    return mstream.ToArray();
}