Embedded YouTube Video Quality Preference

Set initial video quality for embedded YouTube videos based on a set of preferred video qualities, as well as minimum and maximum video qualities (configured in the script).

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

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

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

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

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

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

(I already have a user script manager, let me install it!)

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.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Embedded YouTube Video Quality Preference
// @namespace    https://greasyfork.org/en/users/85671-jcunews
// @version      1.0.1
// @license      AGPLv3
// @author       jcunews
// @description  Set initial video quality for embedded YouTube videos based on a set of preferred video qualities, as well as minimum and maximum video qualities (configured in the script).
// @match        *://www.youtube.com/embed/*
// @grant        none
// ==/UserScript==

(() => {

  //=== CONFIGURATION BEGIN ===

  //One or more video quality IDs. From most to least prioritized video quality.
  //e.g. if ["hd720", "medium"], try using "hd720" quality first. If not available, use "medium" quality. If it's also not available, use YouTube's default.
  var qualities = [""]; //Set to [] if no preference

  //Minimum video quality. Set it to "" to use lowest quality available.
  //If ID is not empty and is not available, use the available one which is a higher quality.
  var minQuality = "";

  //Maximum video quality. For slow network or low computer specifications. Set it to "" to use highest quality available.
  //If ID is not empty and is not available, use the available one which is a lower quality.
  var maxQuality = "";

  //minQuality and maxQuality have higher priority than the qualities variable.
  //e.g. if qualities is ["hd2160", "hd720"], minQuality is "hd1080", and maxQuality is "hd1440", YouTube's default will be used.
  //maxQuality rule is applied after minQuality rule has been aplied.
  //i.e. the rule priorities are: qualities, minQuality, then maxQuality.

  //To always use the maximum video quality available, set minQuality and maxQuality to "highres". The qualities variable will be ignored.

  //To always use the minimum video quality available, set minQuality and maxQuality to "tiny". The qualities variable will be ignored.

  /* Available video quality IDs:
    "tiny"     (144p)
    "small"    (240p)
    "medium"   (360p)
    "large"    (480p)
    "hd720"    (720p)
    "hd1080"  (1080p)
    "hd1440"  (1440p)
    "hd2160"  (2160p)
    "hd2880"  (2880p)
    "highres" (4320p; YouTube's highest resolution [2019 April])
  */

  //=== CONFIGURATION END ===

  var sb = document.querySelector(".ytp-settings-button");
  if (!sb) return;
  var sq = {
    "144p": "tiny", "240p": "small", "360p": "medium", "480p": "large", "720p": "hd720", "1080p": "hd1080",
    "1440p": "hd1440", "2160p": "hd2160", "2880p": "hd2880", "4320p": "highres"
  }, p = player.querySelector(".html5-video-player"), v = p.querySelector(".html5-main-video"), play = v.play, resm = {};
  ["tiny", "small", "medium", "large", "hd720", "hd1080", "hd1440", "hd2160", "highres"].forEach((r, i) => resm[r] = i);
  v.play = function() {
    var sty = document.head.appendChild(document.createElement("STYLE"));
    sty.innerHTML = '.ytp-settings-menu{display:none}';
    v.play = play;
    sb.click();
    document.querySelectorAll(".ytp-settings-menu .ytp-menuitem-label").forEach(l => {
      if (l.textContent !== "Quality") return;
      l.click();
      setTimeout(() => {
        var
          es = Array.from(document.querySelectorAll(".ytp-quality-menu .ytp-menuitem-label span")),
          qs = [], qsm = {}, esm = {}, cq = p.getPlaybackQuality(), q = cq;
        es.pop();
        es.reverse();
        var ss = es.map((e, s, n) => {
          s = e.firstChild.data;
          qs.push(n = sq[s]);
          qsm[n] = resm[n];
          esm[n] = e.parentNode;
          return s;
        });
        if (!minQuality || (qsm[minQuality] === undefined)) minQuality = qs[0];
        if (!maxQuality || (qsm[maxQuality] === undefined)) maxQuality = qs[qs.length - 1];
        qualities = qualities.filter(
          v => (qsm[v] !== undefined) && (resm[v] >= resm[minQuality]) && (resm[v] <= resm[maxQuality])
        );
        if (qualities.length) {
          q = qualities[0];
        } else {
          if (resm[cq] <= resm[minQuality]) q = minQuality;
          if (resm[cq] >= resm[maxQuality]) q = maxQuality;
        }
        if (q !== cq) {
          esm[q].click();
        } else v.play();
        sty.click();
        sty.remove();
      }, 0);
    });
  };
})();