Block AV1 & VP9

This userscript will force all videos to use the h.264 codec rather than VP9/AV1.

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         Block AV1 & VP9
// @version      1.0
// @description  This userscript will force all videos to use the h.264 codec rather than VP9/AV1.
// @author       TZ Shuhag
// @license MIT
// @match        *://www.youtube-nocookie.com/*
// @match        *://www.youtube.com/*
// @match        *://m.youtube.com/*
// @namespace    https://greasyfork.org/en/users/1495563
// @icon         https://raw.githubusercontent.com/tz-shuhag/HD.264/refs/heads/main/icons/video.png
// @run-at       document-idle
// @unwrap
// @grant        none
// ==/UserScript==
 
// Enable strict mode to catch common coding mistakes
"use strict";
 
// Force all videos to use h.264 (useful if you have a low spec machine when you load videos in 720p60)
 
var mse = window.MediaSource;
if (mse){
  // Set up replacement for MediaSource type support function
  var nativeITS = mse.isTypeSupported.bind(mse);
  mse.isTypeSupported = ourITS(nativeITS);
}
// Here's the replacement
function ourITS(fallback){
  // type is a string (hopefully!) sent by the page
  return function (type) {
    if (type === undefined) return '';
    // We only reject VP9
    if (type.toLowerCase().indexOf('vp9') > -1) return '';
    if (type.toLowerCase().indexOf('vp09') > -1) return ''; // Added 12/20/2019
    // Let Firefox handle everything else
    return fallback(type);
  };
}