网上找的，因为最近要用，但还没试过
<!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>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head>
<body>
<p>
<object id="player" style="display:none" height="400" width="400" classid="CLSID:6BF52A52-394A-11d3-B153-00C04F79FAA6">
<param name="invokeURLs" value="-1">
<param NAME="AutoStart" VALUE="-1">
<param name="currentPosition" value="0">
<param name='uiMode' value='mini'>
<param NAME="url" VALUE="test.mpg">
</object>
</p>
<input name="submit" type="submit" onclick="getInfo()">
<p>
<script language="javascript">
var time;
function getInfo(){
var pl=document.getElementById("player");
time=pl.currentMedia.durationString;
alert(parseInt(pl.currentMedia.durationString.substring(0,2)*60));
//alert(parseInt(pl.currentMedia.durationString.substring(3,5)));
alert(parseInt(pl.currentMedia.durationString.substring(0,2)*60)+parseInt(pl.currentMedia.durationString.substring(3,5)));
}
</script>
</p>
</body>
</html>