Funciones Wordpress: Solución al problema z-index de youtube

<?php
function wmode_filter($html, $url, $attr) {
    if ( strpos( $html, "<embed src=" ) !== false )
       { return str_replace('</param><embed', '</param><param name="wmode" value="opaque"></param><embed wmode="opaque" ', $html); }
    elseif ( strpos ( $html, 'feature=oembed' ) !== false )
       { return str_replace( 'feature=oembed', 'feature=oembed&wmode=opaque', $html ); }
    else
       { return $html; }
 }
 add_filter( 'embed_oembed_html', 'wmode_filter', 10, 3);