[Plugin: Postie] FFMPEG Convert to .flv

I’m not a PHP programmer so, I can’t do this on my own, at least not yet..

I have postie working perfectly, but I’d like to create a smaller video file for streaming on the post. I’d like to run this ffmpeg -i example.3gp -ar 22050 example.flv in between saving the attachment and posting it to wordpress. Any help would be greatly appreciated, even if it’s just a code snippet.. thanks.