Video Pre-Roll Worpdress Plugin

So I need to randomize the pre-roll ads in front of all my videos. I’ve checked out JWPlayer, but you can’t randomize the pre-rolls. You can only select one video as the pre-roll (and have some backups as waterfall). I have a lot of video on my site and my clients what equal representation. I’d like a plugin to look in a folder and pick a random video from my videos … that doesn’t sound hard … but … then again I’ve been looking for a long time for this magical plug-in to do this.

Anyone have any ideas?