Listen to only the audio on YouTube without loading the video.
// ==UserScript==
// @name Youtube Audio Mode
// @description Listen to only the audio on YouTube without loading the video.
// @version 1.2.2
// @include https://www.youtube.com/*
// @license GPL-3.0+; http://www.gnu.org/licenses/gpl-3.0.txt
// @run-at document-end
// @grant GM_xmlhttpRequest
// @grant GM.setValue
// @grant GM.getValue
// @noframes
// @namespace https://greatest.deepsurf.us/users/195276
// ==/UserScript==
(function(open) {
window.addEventListener("yt-navigate-finish", audioMode);
window.onYouTubeIframeAPIReady = audioMode();
async function audioMode() {
if (location.pathname == "/watch") {
let video = document.getElementsByTagName("video")[0];
let audioMode = await GM.getValue("ytAudioMode");
addToMenu(audioMode);
if (audioMode) {
setPoster(video, ["maxres", "hq", "sd"]);
watchStream(video);
}
}
}
// Watch the media streams so we can select the audio
function watchStream(video) {
XMLHttpRequest.prototype.open = function(method, url) {
let validStream = /^(?!.*live=1).+audio.+$/;
if (validStream.test(url) && ! video.src.includes("audio")) {
video.pause();
video.src = url.split("&range")[0];
video.play();
}
open.apply(this, arguments);
}
}
// Add audio mode to the settings menu
async function addToMenu(audioMode) {
let panel = document.getElementsByClassName("ytp-panel-menu")[0];
if (!panel.innerHTML.includes("Audio Mode")) {
panel.innerHTML += `
<div class="ytp-menuitem"
aria-checked="${audioMode}"
id="audio-mode">
<div class="ytp-menuitem-icon"></div>
<div class="ytp-menuitem-label">Audio Mode</div>
<div class="ytp-menuitem-content">
<div class="ytp-menuitem-toggle-checkbox">
</div>
</div>`;
// Toggle audio mode on or off
let audioToggle = document.getElementById("audio-mode");
audioToggle.onclick = async function() {
let audioMode = ! await GM.getValue("ytAudioMode");
this.setAttribute("aria-checked", audioMode);
GM.setValue("ytAudioMode", audioMode);
location.reload();
}
}
}
// Set the video poster from thumbnails with the best avaliable format
// https://developers.google.com/youtube/v3/docs/thumbnails
async function setPoster(video, fmts) {
let img = new Image();
let videoId = location.search.match(/v=(.+?)(&|$)/)[1];
img.src = `//i.ytimg.com/vi/${videoId}/${fmts.shift()}default.jpg`
img.onload = function() {
// A height 90 is YouTube"s not found image.
if (img.height <= 90) {
setPoster(video, fmts);
} else {
video.style.background = `url(${img.src}) no-repeat center`;
video.style.backgroundSize = "contain";
}
};
}
})(XMLHttpRequest.prototype.open);