Embedding Responsive Videos
As far as video formats go, in short, the theme supports what WordPress supports. In order to embed a video into your site and have it be responsive (i.e. scale down with your site on smaller devices), you must embed your video in the way WordPress describes in the codex. See article, WordPress Embeds.
This means that your video source selections are limited to what WordPress's oEmbed allows you to use. See article, Okay, So What Sites Can I Embed From?
The way this works is that the Theme Blvd framework applies a filter to WordPress's built-in oEmbed system. When WordPress transforms your video URL into an embedded video, the final step in the process is for our filter to get applied. This filter wraps the video in some additional HTML markup that we've styled according to Chris Coyier's method of embedding fluid videos.