Adding Video Thumnails to Rss Feed?

The following code which can be added to functions.php in your theme is from this thread and is a global way to include the featured image (regardless if it is a video thumbnail) in RSS.

// THIS INCLUDES THE THUMBNAIL IN OUR RSS FEED
function insertThumbnailRSS($content) {
    global $post;
    if ( has_post_thumbnail( $post->ID ) ){
        $content = '' . get_the_post_thumbnail( $post->ID, 'thumbnail', array( 'alt' => get_the_title(), 'title' => get_the_title(), 'style' => 'float:right;' ) ) . '' . $content;
    }
    return $content;
}
add_filter('the_excerpt_rss', 'insertThumbnailRSS');
add_filter('the_content_feed', 'insertThumbnailRSS');

Thank you, but unfortunately this only adds the featured image and not the video thumbnail. The reason I need the video thumbnail to show in the rss feed is because 100% video thumbnails are generated when I create a post but only 50% of the time a featured image is generated. All my social media accounts post the content in the rss feed. So I need to figure out a way.

Same basic concept, but this code gets the video thumbnail instead of featured image:

// THIS INCLUDES THE VIDEO THUMBNAIL IN OUR RSS FEED
function insertVideoThumbnailRSS($content) {
	global $post;
	if ( get_video_thumbnail( $post->ID ) != null ) {
		$content = '<img src="' . get_video_thumbnail( $post->ID ) . '" />' . $content;
	}
	return $content;
}
add_filter('the_excerpt_rss', 'insertVideoThumbnailRSS');
add_filter('the_content_feed', 'insertVideoThumbnailRSS');

Thank you! It was causing my site to go entirely blank though (maybe theme related issue?) So I slightly modified it and its running great!

// THIS INCLUDES THE THUMBNAIL IN OUR RSS FEED
function insertVideoThumbnailRSS($content) {
global $post;
if ( get_video_thumbnail( $post->ID ) ){
$content = ‘<img src=”‘ . get_video_thumbnail( $post->ID ) . ‘” />’ . $content;
}
return $content;
}
add_filter(‘the_excerpt_rss’, ‘insertVideoThumbnailRSS’);
add_filter(‘the_content_feed’, ‘insertVideoThumbnailRSS’);