<meta name="viewport" content="width=device-width,height=device-height,initial-scale=1">
<video src="test.mov" autoplay controls width="500"></video>
The code above is at http://form.kr/test/autoPlay.php
I found that autoplaying does work when it comes through the link in a page of same domain only,
If the domain is different, the autoplaying doesn’t work.
if you click the link above, a movie comes but not autoplaying because sitepoint.com is different domain from form.kr
It is interesting and very complex.