WP_oEmbed_Controller example

    return apply_filters( 'wp_embed_handler_video', $video, $attr, $url, $rawattr );
}

/** * Registers the oEmbed REST API route. * * @since 4.4.0 */
function wp_oembed_register_route() {
    $controller = new WP_oEmbed_Controller();
    $controller->register_routes();
}

/** * Adds oEmbed discovery links in the head element of the website. * * @since 4.4.0 */
function wp_oembed_add_discovery_links() {
    $output = '';