在线运行代码 - 代码学院 www.codexy.cn

<!DOCTYPE html> 
<html> 
<head> 
<meta charset="utf-8"> 
<title>代码学院(codexy.cn)</title> 
</head> 
<body> 

<video id="myVideo" width="320" height="240" controls>
	<source src="movie.mp4" type="video/mp4">
  	<source src="movie.ogg" type="video/ogg">
  	您的浏览器不支持 video 标签。
</video><br>
<button onclick="getPlaySpeed()" type="button">默认播放速度？</button>
<button onclick="setPlaySpeed()" type="button">设置以慢速播放</button>
<script>
var x = document.getElementById("myVideo");
function getPlaySpeed(){ 
	alert(x.defaultPlaybackRate);
} 
function setPlaySpeed(){ 
	x.defaultPlaybackRate = 0.5;
  	x.load();
} 
</script> 

</body> 
</html>
源代码

动行结果
