Inserting Video code warning

Hello,
I have a concern by inserting a video in an article.
It is in MP4 format and displays correctly but there are warning line of code that start at the top.
Here is the location on my website: http://ecoledesvalettes.fr/morphing-cybercentre-cm1/
Here is the code of the line 576:

if(!function_exists('avia_is_200'))
{
	function avia_is_200($url)
	{
	    $options['http'] = array(
	        'method' => "HEAD",
	        'ignore_errors' => 1,
	        'max_redirects' => 0
	    );
	    $body = file_get_contents($url, NULL, stream_context_create($options), 0, 1);
	    sscanf($http_response_header[0], 'HTTP/%*d.%*d %d', $code);
	    return $code === 200;
	}
}

Thank you in advance
Laure