js+HTML5实现视频截图的方法

<video id="video" controls="controls">
<source src=".mp4" />
</video>
<button id="capture">Capture</button>
<div id="output"></div>

(function() {
"use strict";
var video, $output;
var scale = 0.25;
var initialize = function() {
$output = $("#output");
video = $("#video").get(0);
$("#capture").click(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();
$output.prepend(img);
};
$(initialize);
}());