Server-side swf to video converting

Hey guys,

I am trying to find a swf to video rendering engine - basically a server side engine that can make a video as it's being assembled (or if there is an api offered by ustream).

We made a Facebook application that basically takes your photos and makes a slideshow of them, but then we would like people to be able to save the slideshow as a movie and then upload it to youtube or email it to a friend.

We found http://www.swfkits.com/swf-to-video-sdk/ but are trying to find an alternative..something cheaper perhaps.

I even was looking at the technology behind Elf Yourself http://www.webkitchen.be/2009/11/13/video-tutorial-elf-yourself-yourself-personalized-video-on-the-web/ but the ones I found basically just mentioned the motion tracking technology and not how they converted/exported it at the end.

Thanks,

David