void FreeUnmanaged()
{
SafeNativeMethods.VorbisBlockClear(_block);
Marshal.FreeHGlobal(_block);
SafeNativeMethods.VorbisDspClear(DspState);
Marshal.FreeHGlobal(DspState);
SafeNativeMethods.VorbisInfoClear(_info);
Marshal.FreeHGlobal(_info);
}