Also, pair a good video card with XV/XVMC support.
Also, for last drip of perfomance:
mplayer -lavdopts skiploopfilter=all file.mkv
mplayer -lavdopts skiploopfilter=nonrefs file.mkvThere was a lot of overlap in MPlayer and ffmpeg in the early days. Things like both projects sharing the same infrastructure, MPlayer developers automatically getting commit access to ffmpeg, ffmpeg sources having references to MPlayer, several top developers active in both, etc.
It's to the point that I think of ffmpeg as a spin-off of MPlayer, but perhaps that's not fair. Maybe it's more accurate to say that several prominent MPlayer developers (and infrastructure folks) did double-duty for years, then many drifted over to working on ffmpeg exclusively. I know that's true for several lead folks. I'd have to go through the ancient mailing list archives to sharpen my recollection of events. Perhaps somebody else who was also around at the time recalls a clearer perspective.
DVD ripping used transcode and/or mencoder.