canvas：绘制视频封面

一时失言乱红尘 2024-03-30 10:55 91阅读 0赞

一、需求：上传视频，同时截取视频某一帧作为视频的封面。

![5370713812261c266c980a9341d40029.png][]

二、实现思路：利用canvas绘制图像的功能，绘制图像某一帧，这里绘制了第一帧，很简单就实现了。  
三、代码：

<!DOCTYPE html>
    <html>
    <head>
        <meta charset="UTF-8">
        <title>capture screen</title>
        <style type="text/css">
            video,#container{width: 300px;height: 200px;}
            #container>img{width: 100%;}
        </style>
    </head>
    <body>
        <video id="video" controls="controls">
            <source src="video/video_test.mp4">
        </video>
        <div id="container"></div>
        <script type="text/javascript">
            (function() {
                var video, container;
                var scale = 0.8;
                var initialize = function() {
                    container = document.getElementById("container");
                    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");//转换成base64图片，地址拿出来就可以直接使用
                    container.appendChild(img);
                };
                initialize();
            })();
        </script>
    </body>
    </html>

四、本文转载至本人2018年博客

[javascript - canvas绘制视频封面 - 个人文章 - SegmentFault 思否][javascript - canvas_ - _ - SegmentFault]

五、欢迎交流指正，关注我，一起学习

[5370713812261c266c980a9341d40029.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/30/326bb432b4cd4072b2e9c992c5f1242b.png
[javascript - canvas_ - _ - SegmentFault]: https://segmentfault.com/a/1190000013126434