Yes, that's exactly what happens on Karma, although we invented that after 2000, which is old_empeg's cutoff date.

By September 2000 all we had was the car-player functionality, as tfabris just described: "obviously incorrect" files (ones whose filename extensions we don't claim to play) don't reach the player at all; files which "turn out to be incorrect", either when playback is first attempted (e.g. if it's been named something.mp3 but isn't actually in MP3 format), or in mid-playback (e.g. if there's corruption in the middle of the file) are skipped. There's some extra logic so that, if you're in repeat mode, and all the files in the running-order are bad, it doesn't just sit there in an infinite loop of skipping: it would just stop playback.

IMO, this should all have badly failed obviousness if someone tried to patent it. Plus, we didn't really invent it (except maybe the no-infinite-loop bit); PC-based media players such as Sonique were already doing just the same thing.

Peter