get specific variable from html5player external source - php

Question

I'm trying to get the html5player.setVideoUrlHigh var from an external source that renders like this:
<script>
logged_user = false;
var static_id_cdn = 2;
var html5player = new HTML5Player('html5video', '38295'); //this is the video ID
if (html5player) {
html5player.setVideoTitle('video title goes here');
html5player.setVideoUrlHigh('https://random-prefix-here.site-url.com/videos/mp4/random-part-of-url');
...
}
</script>
Firstly, I do file_get_contents to get the embed code:
$videoID = 38295;
$url = file_get_contents('https://www.site-url.com/embedframe{$videoID}');
then, I look for a url match that contains specific parts like (site-url.com/videos/mp4/) to eco it, like this:
preg_match('/https:\/\/[^\"]*/\.site-url\.com\/videos\/mp4\/[^\"]*/', $url, $matches, PREG_OFFSET_CAPTURE);
$videoURL = ($matches[0][0]);
echo '=>' . $videoURL;
but this is not working... Where am I failing?
Please keep in mind that both random-prefix-here and random-part-of-url should be replaced by regex in a possible solution.
UPDATED
I already tried this also, witouth any results:
$url = 'http://www.site-url.com/embedframe38295/';
$content= file_get_contents($url);
preg_match_all('#html5player.setVideoUrlHigh\((.+?)\')', $url, $matches, PREG_OFFSET_CAPTURE);
$videoURL = ($matches[0][0]);
echo $videoURL;