Preview Image and Video Aspect ratio?

VisualRabbi

I'm totally new to Filebrowser, and I know about four html codes, so forgive my ignorance. How do I set up filebrowser to auto-generate preview clips for a video/image? Also, how do I set up fb so the video plays in it's native aspect ratio? I'm using this for client preview folders where they can preview videos that I'm producing for them. Thanks