为什么google chrome可以播放以下视频： http://www.w3schools.com/html/mov_bbb.mp4
但是当我尝试自己做的时候不是吗？
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
</head>
<body>
<video width="500" height="300" controls autoplay>
<source src="Videos/SampleVIDEO1.mp4" type="video/mp4">
Your browser doesn't support video, you may download the video instead: <a href="http://localhost:2421/Videos/SampleVIDEO1.mp4">Click</a>.
</video>
</body>
</html>