Vimeo Master is a powerful and outstanding WordPress plugin that allows you to integrate superb Vimeo Video Sharing Network into your WordPress site. The plugin uses minimal html5 code (with no javascipt or Ajax) for fast page load times and gives a completely professional look. Great for professional video presentations for business, design, arts, etc. Looks great inside WordPress content like pages, posts and other custom post types with its shortcode framework implementation. Provides you full control over Auto-Play, Video Loop, Video Color and Video Size to match your template. Demo.
Now it has become very easy to display a video as background in your WordPress based website but make sure it uses a lot of bandwidth so you should have a good hosting.