<audio>
and <video>
tags without Javascript.video/m4v
<video preload="auto" controls="controls">
<source src="https://www.jplayer.org/video/m4v/Big_Buck_Bunny_Trailer.m4v" type='video/m4v'>
</video>
HTMLMediaElement.canPlayType('video/m4v')
→ MediaSource.isTypeSupported('video/m4v')
→