<video src="http://og09akxjj.bkt.clouddn.com/Avengers-Infinity-War.mp4" controls autoplay></video>

<p>
  <button type="button" class="js-playbackrate">change playbackRate 2x</button>
  <button type="button" class="js-defaultplaybackrate">change defaultPlaybackRate 2x</button>
  <button type="button" class="js-src">change src</button>
</p>

video {
  display: block;
  width: 480px;
  height: 300px;
  margin-bottom:20px;
}
const urls = [
  'http://og09akxjj.bkt.clouddn.com/QQ20170422-231806-HD.mp4',
  'http://og09akxjj.bkt.clouddn.com/Avengers-Infinity-War.mp4'
];

const video = document.querySelector('video');
document.querySelector('.js-playbackrate').addEventListener('click', () => {
   video.playbackRate = 2; 
});

document.querySelector('.js-defaultplaybackrate').addEventListener('click', () => {
   video.defaultPlaybackRate = 2; 
});
let i = 0;
document.querySelector('.js-src').addEventListener('click', () => {
   video.src = urls[i++ % 2];
   video.play();
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

This Pen doesn't use any external JavaScript resources.