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<head><meta charset="UTF-8"><title>capture screen</title></head><body><video id="video" controls="controls"><source src="img/test.mp4"></video><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); // 用于向指定元素添加事件句柄。}; var captureImage = function() { var canvas = document.createElement("canvas"); // 创建一个画布 canvas.width = video.videoWidth * scale; canvas.height = video.videoHeight * scale; canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height); // getContext:设置画布环境；drawImage:画画 var img = document.createElement("img"); img.src = canvas.toDataURL("image/png"); // 获取图片的url output.appendChild(img);}; initialize();})();</script></body></html>