for循环给class添加内容

[Tong0068]

主要代码如下，获取视频的时长，但在每个class上都会全部遍历出来，怎么让它只在对应的div里遍历呢，本人是初学者，小白一个，还希望能有大神来指点一二，感激不尽。
html:
<div class="video-content">
<div class="video-list">

<div class="video-top">
<video style="width: 100%; height:100%; object-fit: fill" oncanplaythrough="myFunction(this)">
<source src="http://www.runoob.com/try/demo_source/movie.ogg" type="video/mp4">
</video>
<div>
<img src="images/bofang2.png">
<p class="video-time getDuration"></p>
</div>
</div>

<div class="video-top">
<video style="width: 100%; height:100%; object-fit: fill" oncanplaythrough="myFunction(this)">
<source src="http://www.w3school.com.cn/i/movie.ogg" type="video/mp4">
</video>
<div>
<img src="images/bofang2.png">
<p class="video-time getDuration"></p>
</div>
</div>

</div>
<div>

js:
function myFunction(ele) {
var videolist = document.getElementsByClassName("video-list");
var getId = document.getElementsByClassName("getDuration");
var hour = parseInt((ele.duration) / 3600);
var minute = parseInt((ele.duration % 3600) / 60);
var second = Math.ceil(ele.duration % 60);
for (var i = 0; i < videolist.length; i++) {
if (hour == 0) {
getId[i].innerHTML += minute + ":" + second;
} else {
getId[i].innerHTML += hour + " : " + minute + ":" + second;
}
}

}
}

[Tong0068]

我知道这个问题很菜，但是拜托了，真的不知道问题在哪

[天际的海浪]

    function myFunction(ele) {
        var getId = ele.parentNode.getElementsByClassName("getDuration")[0];
        var hour = parseInt((ele.duration) / 3600);
        var minute = parseInt((ele.duration % 3600) / 60);
        var second = Math.ceil(ele.duration % 60);
        if (hour == 0) {
            getId.innerHTML = minute + ":" + second;
        } else {
            getId.innerHTML = hour + " : " + minute + ":" + second;
        }
    }