It letterboxes the 800x480 (5:3) screen into a 480 line or 576 line (4:3) output. This means the resolution on the display is about 640x384, or 768x460, interlaced in both cases. (Of course, speaking of horizontal resolution WRT composite signals is not very clear -- I'm assuming square "pixels", but it's really continuous and bandwidth-limited to rather less actual resolution.) That's pretty much what you want on a 4:3-only screen.


However, it's quite annoying to me that it doesn't have an option to fill an NTSC frame. The 480 lines works out exactly, and AFAIK all 16:9 TVs and some 4:3 TVs have an option to stretch to widescreen (in the case of a 4:3 set, letting the TV apply letterboxing fills the same screen area as now, but preserves vertical resolution) -- the aspect ratio won't be quite on (16:9/5:3 -- about 7% horizontal stretching), but I'd rather deal with the rectangular pixels than take the 7% resolution decrease; it's trivial to set mplayer to stretch 16:9 content to full-screen, thus ultimately getting correct 480i display. AFAIK this should be possible from a hardware perspective, just needs some digging around in the drivers...