Capture screenshot from html video element

snapshot.js

(function(window) {
  'use strict';
  window.snapshot = function snap(video, width, height, download) {
    video = video || window.document.getElementsByTagName('video')[0];
    width = video.width || video.videoWidth;
    height = video.height || video.videoHeight;

    var canvas = window.document.createElement('canvas');
    canvas.width = width;
    canvas.height = height;

    var context = canvas.getContext('2d');
    context.fillRect(0, 0, width, height);
    context.drawImage(video, 0, 0, width, height);

    var dataURI = canvas.toDataURL('image/jpeg');
    if (download) {
      dataURI = dataURI.replace('image/jpeg', 'image/octet-stream');
    }
    window.open(dataURI, '_blank').focus();
  };
}(this));