PS3 fast forward no sound problems

[Oliver Christmas]

Hi there.  I have found out about the FFMPEG problem with watching
get_iplayer MP4s on a PS3 (video plays fast and with no sound).  I
have got a problem in that I upgraded latest get_iplayer and forgot to
roll back the FFMPEG version.
1. Is there anyway I can tell which video files are affected (without
playing them)
2. Is there anyway I can "convert" the files to be playable?

Any help much appreciated.