Change bbpress Post Type to Video

I use a grid plugin to pull all bbpress content into a page to make a grid. The intention is to have users create a post with a video in a topic, tagged with 'multimedia' The grid queries all topic posts tagged with 'multimedia' and shows the videos. The problem is, the grid only knows to pull the videos if the post type is set to video. Currently, I have to change this myself for each post. I would like for the default to be set to video so that it works automatically. ----------------------------- Long story short: Change bbpress default post type from 'standard' to 'video'