pre有些页面声音总是太小，又不想调整系统音量，而video标签的volume属性最高只能调到1。于是在网上找到了一个方案：ref:https://atjiu.github.io/2021/05/10/video-above-1.0/ref:https://cwestblog.com/2017/08/17/html5-getting-more-volume-from-the-web-audio-api/codefunc