How to get input length of a video using javascript

Question

Here the code:

var myVideos = [];

    window.URL = window.URL || window.webkitURL;

    document.getElementById('form__video-upload').onchange = setFileInfo;

    function setFileInfo(){
        var files = this.files;
        myVideos.push(files[0]);
        var video = document.createElement('video');
        video.preload = 'metadata';

        video.onloadedmetadata = function (){
            window.URL.revokeObjectURL(video.src);

            var duration = Math.floor(video.duration).toString();
        
            myVideos[myVideos.length-1].duration = duration;
            updateInfos();
        }

        video.src = URL.createObjectURL(files[0]);
    }

    function minTommss(minutes){
        var sign = minutes < 0 ? "-":"";
        var min = Math.floor(Math.abs(minutes));
        var sec = Math.floor((Math.abs(minutes) * 60 ) % 60);
        return sign + (min < 10 ? "0" : "") + (sec < 10 ? "0" : "") + sec;
    }
    function updateInfos(){
        var infos = document.getElementById('infos');

        for(var i = 0; i < myVideos.length; i++){
            infos.value += myVideos[i].duration;
        }
    }

HTML PART:

 <input type="file" id="form__video-upload">

I want to do something like when the input file video is selected the length of the video will display. The code I wrote gives me wrong video length.