Embedded video notice for emailed feeds

gistfile1.php

function add_rss_video_embed_notice( $html, $url, $attr, $post_id ) {

	if (!is_feed()) { // No need to change anything
		return $html;
	}
	
	$permalink = get_permalink( $post_id );
	$notice = '<br /><small>If you cannot see a video, <a href="' . $permalink . '">view this post online</a></small>';
	return $html . $notice;
}
add_filter( 'embed_oembed_html', 'add_rss_video_embed_notice', 100, 4 ); // If doesn't work, increase priority from 100 to higher number