oEmbed Transparency

functions.php

<?php

/**
 * oEmbed Transparency
 *
 * Used so that menus can appear on top of videos
 *
 * @author Bill Erickson
 * @link http://www.billerickson.net/code/oembed-transparency
 *
 * @param string $html
 * @param string $url
 * @param array $attr, shortcode attributes
 * @param int $post_id
 * @return string The embed HTML on success, otherwise the original URL.
 */
function be_oembed_transparency( $html, $url, $attr, $post_id ) {

	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', 'be_oembed_transparency', 10, 4 );