forces CDN subdomain for srcset file list on img element

php

// you MUST change static1 to your CDN subdomain as needed
function aafd_cdn_srcset($sources){
	foreach ( $sources as $source ) {
		$sources[ $source['value'] ][ 'url' ] = str_replace('http://www', 'https://static1', $sources[ $source['value'] ][ 'url' ]);
		// you MAY use external domains as well
		// $sources[ $source['value'] ][ 'url' ] = str_replace('http://www.example.com', 'https://static.examplecdnprovider.com', $sources[ $source['value'] ][ 'url' ]);
	}
	return $sources;
}