没啥废话，直接贴代码，哪里不懂的直接问，代码复制好浏览器F12切换为移动端看效果，下图为实现效果
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
* {
margin: 0;
padding: 0;
}
.wrapper {
position: relative;
}
.video-box {
position: relative;
margin: 0 auto;
width: 65%;
height: 80%;
}
#video-background {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
width: 100%;
height: 100%;
filter: blur(5px);
}
</style>
</head>
<body>
<div class="wrapper">
<canvas id="video-background"></canvas>
<div class="video-box">
<video
loop
muted
autoplay
controls
width="100%"
height="100%"
src="https://cdn.jsdelivr.net/gh/w157020087/CDN/video/%E5%BE%A1%E5%A7%90%E9%A3%8E.mp4"
></video>
</div>
</div>
</body>
</html>
<script>
var v = document.getElementsByTagName("video")[0];
var canvas = document.getElementById("video-background");
var context = canvas.getContext("2d");
var cw = Math.floor(canvas.clientWidth);
var ch = Math.floor(canvas.clientHeight);
document.getElementsByTagName("video")[0].play();
canvas.width = cw;
canvas.height = ch;
draw(v, context, cw, ch);
function draw(v, c, w, h) {
c.drawImage(v, 0, 0, w, h);
setTimeout(draw, 20, v, c, w, h);
}
</script>
