Just as another data point, I have NetBSD on a PII-400 laptop with 512MB RAM
and NeoMagic 256ZX, and I can watch DVDs with ogle, no trouble at all, but
not with mplayer ... the sound stalls so much I want to throw the laptop
out the window.

I'm glad I tried ogle first--if I'd tried mplayer first I would probably
just have decided my laptop wasn't up to playing movies, and given up.
With ogle I did have to fix one line in my config to make sure I had the
piixide driver doing DMA, but after that it Just Worked.  I don't know what
mplayer's issue is.

-Chap