下面的代码直接可以使用，获取视频的时长，然后可以根据业务再具体写逻辑
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>js获取视频时长</title>
</head>
<body>
<div>
<video src="https://vdept.bdstatic.com/4d7353594449333461724852716d4747/424253456e584b79/59d96f0aa420b86938e7ebaeb47553c871ed1a661934348af5651aa12986c93eab77ed9603a021062dd6be2c523d7ea4.mp4?auth_key=1583929206-0-0-0d2202f24b6757a116072d28b1c7ecae"
controls preload="auto" id="player"></video>
</div>
<input name="submit" type="submit" onclick="getInfo();">
<div>
<script language="javascript">
var time;
function getInfo(){
var pl=document.getElementById("player");
time = pl.duration;
var totalSecond = Math.floor(time);
// 得到分钟数加秒数
if (totalSecond > 60){
var minute = Math.floor(totalSecond / 60) ;
if (minute < 10) {
minute = "0" + minute;
}
console.info("second --> " + totalSecond % 60);
console.info("minute + second --> " + minute + ":" + totalSecond % 60);
}
alert(totalSecond);
}
</script>
</div>
</body>
</html>