Dynamic Stretch to fit YouTube Video using API - php

Question

I want to recreate this: DEMO
HTML
<header role="banner">
<div id="wrapper-video">
<video poster="" autoplay loop>
<source src="https://s3-us-west-2.amazonaws.com/s.cdpn.io/156843/cut.mp4"
type="video/mp4; codecs=avc1.42E01E,mp4a.40.2">
</video>
</div>
</header>
CSS
section[role="banner"] {
position: relative;
width: 100%;
}
#wrapper-video {
position: fixed;
top: -50%;
left: -50%;
width: 200%;
height: 200%;
z-index: -100;
}
#wrapper-video video {
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
margin: auto;
min-width: 50%;
min-height: 50%;
}
...but replace the video with a YouTube video loaded via YouTube's API which loads the player into a DIV like this:
<div id="player"></div>
But as soon as I start to change the html the centering is off, even if I change the above to an image (as proof of concept) the centering is also off. What am I doing wrong here?
Does #wrapper-video video do something unexpected if I just change it to #wrapper-video2 and rename the DIV it was in?

Answer 1

#player will be replaced with an iframe. Here' how you would use that responsive code with the youtube API.
var tag = document.createElement('script');
tag.src = "https://www.youtube.com/player_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
function onYouTubePlayerAPIReady() {
player = new YT.Player('player', {
height: '360',
width: '640',
videoId: 'M7lc1UVf-VE'
});
}
section[role="banner"] {
position: relative;
width: 100%;
}
#wrapper-video {
position: fixed;
top: -50%;
left: -50%;
width: 200%;
height: 200%;
z-index: -100;
}
#wrapper-video video,
#wrapper-video iframe {
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
margin: auto;
min-width: 50%;
min-height: 50%;
}
<header role="banner">
<div id="wrapper-video">
<div id="player"></div>
</div>
</header>