change video speed

change.js

  var vid = document.getElementById("video1");

  function slowPlaySpeed() {
    vid.playbackRate = 0.5;
  }

  function normalPlaySpeed() {
    vid.playbackRate = 1;
  }

  function fastPlaySpeed() {
    vid.playbackRate = '2';
  }

  document.getElementById('slowPlaySpeed').addEventListener('click', () => {
    console.log('run slowPlaySpeed');
    slowPlaySpeed();
  });
  document.getElementById('normalPlaySpeed').addEventListener('click', () => {
    console.log('run normalPlaySpeed');
    normalPlaySpeed();
  });
  document.getElementById('fastPlaySpeed').addEventListener('click', () => {
    console.log('run fastPlaySpeed');
    fastPlaySpeed();
  });
  
// <button id="slowPlaySpeed">slowPlaySpeed</button>
// <button id="normalPlaySpeed">normalPlaySpeed</button>
// <button id="fastPlaySpeed">fastPlaySpeed</button>