I understand about removing the scaling, but I don't want to apply any video filters (including deinterlacing or harddup) - just a straight copy. That said, I really have no idea how (if at all) those video filters impact a straight stream copy. When I posted this, though, I couldn't get DTb to run through the mencoder action (I still can't, but it also fails using RunExternal, so there's something else going on).