Display the video of a post_format Video

I made a function that return the iframe for the first video inside the post with id $post_id:

function get_first_video_embed($post_id) {
  $content = apply_filters('the_content', get_post_field('post_content', $post_id));
  $iframes = get_media_embedded_in_content( $content, 'iframe' );
  return $video_post_iframe = $iframes[0];
}