tryhtml5_av_prop_texttracks 在线代码实例

 <button onclick="getTextTracks()" type="button">Get the number of available text tracks</button>
<br> 
<video id="video1" controls="controls">
  <source src="/statics/demosource/mov_bbb.mp4" type="video/mp4">
  <source src="/statics/demosource/mov_bbb.ogg" type="video/ogg">
  <track src="demo_sub.vtt">
  Your browser does not support HTML5 video.
</video>

<script>
myVid=document.getElementById("video1");
function getTextTracks()
  { 
  alert(myVid.textTracks.length);
  } 
</script> 

<p>Video courtesy of <a href="http://www.bigbuckbunny.org/" target="_blank">Big Buck Bunny</a>.</p>