IE 9, HTML 5 and Video support

Weird, the Chrome fans seem to think that IE9 doesn’t support video.  But the following site seems to indicate that IE 9 does support video:

https://msdn.microsoft.com/en-us/ie/hh410106.aspx#_HTML5_video_audio

Ok, it’s a Microsoft site, but the site:

https://html5tutorial.net/general/html5-video-should-i-use-it.html

The referenced link in the normally excellent html5tutorial states in April 2011, a month after the release of IE 9 that IE 9 didn’t support video, here is a quote:

“Currently only one browser has a robust support for HTML5 video tags and that is chrome, firefox also has limited support and IE hasn’t even touched video in HTML5 in its current browsers yet. So what does that mean for you? It means a good percentage of people using computers to access the internet will not be able to render the video on your page.”

That seems strange, IE 9 seems to run video using HTML 5 types of tags for me, and a quick search would have turned up that the statement isn’t true at the time of the article.  However, I might have misread the article

I am not saying that Chrome and Firefox doesn’t perform as stated, but the IE 9 does support video using HTML 5 tags.  Is this something to do with the elements? 

Anyway, here are an example of a video tag:

<video width="400" height="300" src="video.mp4" poster="frame.png" autoplay controls loop>

This content appears if the video tag or the codec is not supported.

</video>

Maybe you could help me out, how is this not supporting video?