HTML5预载属性
为了防止在播放前加载HTML5视频，请使用preload属性。您可以尝试运行以下代码：
<!DOCTYPE html>
<html>
<body>
<video width = "350" height = "200" controls = "controls" preload = "none">
<source src = "movie.mp4" type = "video/mp4" />
<source src = "movie.ogg" type = "video/ogg" />
Your browser does not support the video tag.
</video>
</body>
</html>