AV1 Codec Blocker

Force websites to use alternative video codecs by blocking AV1.
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Wrap lines
// ==UserScript==
// @name                AV1 Codec Blocker
// @icon                https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @author              ElectroKnight22
// @namespace           electroknight22_av1_codec_blocker_namespace
// @version             1.0.0
// @description         Force websites to use alternative video codecs by blocking AV1.
// @match               *://*/*
// @run-at              document-start
// @grant               none
// @inject-into         page
// @license             MIT
// ==/UserScript==

/*jshint esversion: 11 */

(function () {
    'use strict';

    // Modern Logic
    if (window.MediaSource) {
        const originalIsTypeSupported = window.MediaSource.isTypeSupported;
        window.MediaSource.isTypeSupported = function (mime) {
            if (typeof mime === 'string' && (mime.includes('av01') || mime.includes('av1'))) return false;
            return originalIsTypeSupported.call(this, mime);
        };
    }

    // Legacy Fallback Logic
    const originalCanPlayType = window.HTMLMediaElement.prototype.canPlayType;
    window.HTMLMediaElement.prototype.canPlayType = function (mime) {
        if (typeof mime === 'string' && (mime.includes('av01') || mime.includes('av1'))) return '';
        return originalCanPlayType.call(this, mime);
    };

})();