Youtube iFrame APi不会触发onPlayerStateChange函数

Question

因此，当视频停止播放以下代码时，我正在使用Youtube iFrame API向我发出提醒：

<div id="player"></div>
<script type="text/javascript">
    var tag = document.createElement('script');

    tag.src = "https://www.youtube.com/iframe_api";
    var firstScriptTag = document.getElementsByTagName('script')[0];
    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

    var player;
    function onYouTubeIframeAPIReady() {
      player = new YT.Player('player', {
          height: '390',
          width: '640',
          videoId: '0Bmhjf0rKe8',
          playerVars: {
              'autoplay': 1,
              'controls': 1,
              'html5': 1
          },
          events: {
              'onReady': onPlayerReady,
              'onStateChange': onPlayerStateChange
          }
      });
    }

      var playerReady = false;
      // 4. The API will call this function when the video player is ready.
      function onPlayerReady(event) {
          playerReady = true;

      }


      // 5. The API calls this function when the player's state changes.
      //    The function indicates that when playing a video (state=1),
      //    the player should play for six seconds and then stop.
      function onPlayerStateChange(event) {
          if (event.data == YT.PlayerState.ENDED) {
              alert('done');

          }
      }

我在jsfiddle上尝试了相同的代码：（http://jsfiddle.net/QtBlueWaffle/8bpQ8/1/）并且在那里工作正常。但是在我的本地机器上不起作用。有任何想法吗？