我正在尝试在Mozilla Firefox 29.0.1中播放视频文件。从我找到here的解决方案，我的html是：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
</head>
<body>
<video width="320" height="240" controls>
<source src="wordpress.mp4" type="video/mp4">
<!--<source src="movie.ogg" type="video/ogg"> -->
Your browser does not support the video tag.
</video>
</body>
</html>
而.htaccess是：
# MIME types for Video
AddType video/mp4 mp4 m4v f4v f4p
AddType video/ogg ogv
AddType video/webm webm
AddType video/x-flv flv
但我仍然显示错误no video with supported format and mime type found！怎么了？