I have found a better way to do this.
Thanks @crazyphoton for hacking:
function onYouTubePlayerReady(playerId){ document.getElementById(playerId).playVideo(); document.getElementById(playerId).pauseVideo(); }
With this code, it is easy to remove the default button.
My question is adding my own button. This demo is the answer to this part. An image with position: absolute is a play / pause / repeat button that is oriented to the video.
source share