Video-CrossOrigin-set-to-anonymous-to-fix-CORS-error-with-video-screenshot-type-Javascript-primarily-for-twitch.user.js

// ==UserScript==
// @name         Video CrossOrigin set to anonymous to fix CORS error with video screenshot type Javascript, mainly for Twitch, may be useful for other sites
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  try to take over the world!
// @author       @tim1986
// @match        *://*.twitch.tv/*
// @exclude      http://clips.twitch.tv/*
// @exclude      https://clips.twitch.tv/*
// @exclude      https://www.twitch.tv/*/clip/*
// @run-at       document-start
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    let bodyElem = document.querySelector('body');
    let observer = new MutationObserver(mutations => {
        for(let mutation of mutations) {
            for(let node of mutation.addedNodes) {
                // For only video elements, skip other nodes
                if (node instanceof HTMLVideoElement) {
                    node.crossOrigin = "anonymous";
                    console.log('[Video CrossOrigin set to anonymous] Done.', node);
                }
            }
        }
    });

    observer.observe(bodyElem, {childList: true, subtree: true});
})();