I want to wrap the HTML5 video with link tag:
<video width="560" height="315" autoplay muted controls loop>
<source src="http://video.webmfiles.org/big-buck-bunny_trailer.webm" type="video/webm">
May the Solution is being in updating Firefox? I dont know which version u are using, but the TAG
<video> is new in html5 (may you alread know that) and not all version of browsers accept them. Else i would say it is a bug in Firefox itselfs, not a mistake in your code.
On W3Schools there is a list wich version you need: klick me
Added VideoJS link
Otherways use VideoJS, an openSource video player