Updated my answer to a better one using youtube player API for more option and dynamic output. It has many option to select and you could easily control it using Javascript. I hope this could help. Credits to @wasikuss posted answer.
// Load the IFrame Player API code asynchronously.
setTimeout(function() {
player.playVideo();
}, 20000);
var tag = document.createElement('script');
tag.src = "https://www.youtube.com/player_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
// Replace the 'ytplayer' element with an <iframe> and
// YouTube player after the API code downloads.
var player;
function onYouTubePlayerAPIReady() {
player = new YT.Player('ytplayer', {
height: '315',
width: '560',
videoId: 'iejOAPyooXs'
});
}
Reference https://developers.google.com/youtube/player_parameters