public override void Write(BinaryWriter writer, HashAlgorithm algo = null)
{
OutputOffset = (ulong)writer.BaseStream.Position;
writer.Ebml_Write_Id(Id);
writer.Ebml_Write_Num(Length);
OutputValueOffset = (ulong)writer.BaseStream.Position;
_inputReader.BaseStream.Seek((long)InputValueOffset, SeekOrigin.Begin);
_inputReader.CopyBytes(Length, writer, algo);
}