截取视频第一帧作为预览图片

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
</head>
<body>
<video id="video" controls="controls" width="400" height="300">
    <source src="myvideo.mp4">
</video>
<br><br>
视频第一帧图片:
<div id="output"></div>
<script type="text/javascript">
(function(){
var video, output;
var scale = 0.8;
var initialize = function() {
    output = document.getElementById("output");
    video = document.getElementById("video");
    video.addEventListener('loadeddata',captureImage);
};
var captureImage = function() {
    var canvas = document.createElement("canvas");
    canvas.width = video.videoWidth * scale;
    canvas.height = video.videoHeight * scale;
    canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height);
 
    var img = document.createElement("img");
    img.src = canvas.toDataURL("image/png");
    img.width = 400;
    img.height = 300;
    output.appendChild(img);
};
initialize();
})();
</script>
</body>
</html>
posted @ 2019-09-17 09:45  antball  阅读(458)  评论(0编辑  收藏  举报