[MPlayer-users] converting 25 fps to 24 fps

[whyohwhyohwhyoh]

apologies - i sent this from the wrong address before so i'm not sure if
it'll appear on the list twice.

i'm sure this must have come up before but i can't find the answer i'm
looking for.

i'm copying the streams from my UK PAL copy of Spirited Away on DVD and
it's stored at one film frame per video frame - so the 24 fps film is
stored (and played back) at 25 fps.

i'd like to get it back to 24fps - very easy to do for the video but i'm
stuck on the audio.

is there some option for mencoder that will take the 6 channel ac3 audio
stream and slow it down by 4% without altering the pitch?

at the moment i'm reduced to attempting to demux, convert to wav,
stretch with "sox .. tempo ..." and then re-convert and re-mux.  but sox
appears to corrupt the wav file just when it finishes writing to it so
even that isn't working!  :-(

tia