To add your video on page, insert your files in video directory and set the src to it.
<video preload="auto" loop class="cover-el" poster="images/bg-video.jpg" muted autoplay> <source src="http://dev.vs-art.me/themes/cakes/video/cake.mp4" type="video/mp4"> <source src="http://dev.vs-art.me/themes/cakes/video/cake.webm" type="video/webm"> <source src="http://dev.vs-art.me/themes/cakes/video/cake.ogv" type="video/ogg"> </video>
In poster attribute set path to image that will be visible on devices that doesn't support video tag.