Yet,
Playing an MPEG would be difficult again. You need more power then just a plain 68040. I dont see why you are worrying to play it all on the A2500 when you got that Pentium 4 of yours which obviously plays them without a problem.
You can try FroggerMPEG or something around the name of that. Best program I have used to even TRY to play an MPEG.
My Amiga 1200 did pretty good to play AVI files, but NOT divx ones.