functions.php

function THEMENAME_wrap_gumby_intrinsic($html, $url, $args){
	$provider = '';
	if (preg_match("#https?://youtu\.be/.*#i", $url) || preg_match("#https?://(www\.)?youtube\.com/watch.*#i", $url)) {
		$provider = 'youtube';
	}elseif (preg_match("/vimeo.com\/([^&]+)/i", $url)) {
		$provider = 'vimeo';
	}
	//no oEmbed for Twich :<
	//elseif (preg_match("/https?:\/\/(.*twitch\.tv\/.*|.*twitch\.tv\/.*\/b\/.*)/i", $url)){
	  //$provider = 'twitch';
	//}
	$html = "<div class='video ".$provider."' >". $html . "</div>";
	return $html; 
}
add_filter( 'embed_oembed_html', 'THEMENAME_wrap_gumby_intrinsic', 10, 3);