js获取本地音视频时长

//html
<input type='file' id='upload'  />

//js
document.querySelector('#upload').onchange = function(e){
	let file = this.files[0]
	let audio = new Audio()
    try{
        audio.srcObject = file
    }catch(err){
        audio.src = URL.createObjectURL(file)
    }
    audio.addEventListener('loadedmetadata', function(){    //监听音视频加载完毕
        console.log(audio.duration)
    })
}