Most people running DirectFB with SDLMAME do so with a real arcade monitor, so you don't need fake scanlines smile Note also that on a dual-core system you can use the -mt switch to do the scaling on your second processor and avoid needing YUV that way.

And if you're upgrading to full-feature X why run WINE? At that point SDLMAME's more in it's element and you have access to a lot more frontends (MAMEPGUI is especially nice).