You can try GPL Movie Studio from http://phlegma.figc.net
With this program you can take a huge amount of screenshots, which can be
either combined directly into a MPEG movie, or just convert them to another
format suitable for your favorite video codec. And of course you'll need
huge amount of disk space.
It's also possible (albeit very far from easy:) to get sounds to the
MPEG-files generated by Movie Studio. You just need appropriate MP2-encoded
stream and then you use the included MPEG Muxer to combine audio and video
streams into one file. Hard work, but it's free (and completely possible) :)
I've used it in my race reports in FGPLC2-league, good videos spice up
reports a lot.