Mimics stable volume control for YouTube.
// ==UserScript==
// @name Stable Volume Emulator
// @namespace http://tampermonkey.net/
// @version 1.4
// @description Mimics stable volume control for YouTube.
// @author InariOkami
// @match *://www.youtube.com/*
// @grant none
// @icon https://cdn.pixabay.com/photo/2021/10/02/23/20/logo-6676544_1280.png
// ==/UserScript==
(function() {
'use strict';
const volumeStorageKey = 'youtube_stable_volume';
const volumeNormalizationKey = 'youtube_volume_normalization';
let storedVolume = 1.0; // Set default volume to maximum
let volumeHistory = [];
function loadSettings() {
const savedVolume = localStorage.getItem(volumeStorageKey);
if (savedVolume !== null) {
storedVolume = parseFloat(savedVolume);
}
const savedHistory = localStorage.getItem(volumeNormalizationKey);
if (savedHistory !== null) {
volumeHistory = JSON.parse(savedHistory);
}
}
function saveVolume(volume) {
localStorage.setItem(volumeStorageKey, volume);
}
function saveVolumeHistory() {
localStorage.setItem(volumeNormalizationKey, JSON.stringify(volumeHistory));
}
function calculateAverageVolume() {
if (volumeHistory.length === 0) return storedVolume;
const total = volumeHistory.reduce((acc, val) => acc + val, 0);
return total / volumeHistory.length;
}
function applyVolume(video, volume) {
const boostedVolume = Math.min(volume, 1.0);
video.volume = boostedVolume;
volumeHistory.push(boostedVolume);
if (volumeHistory.length > 10) volumeHistory.shift();
saveVolumeHistory();
video.addEventListener('volumechange', () => {
saveVolume(video.volume);
volumeHistory.push(video.volume);
if (volumeHistory.length > 10) volumeHistory.shift();
saveVolumeHistory();
});
}
function handleVideo(video) {
if (video) {
const averageVolume = calculateAverageVolume();
applyVolume(video, averageVolume);
}
}
function observeDOMChanges() {
const observer = new MutationObserver(mutations => {
mutations.forEach(mutation => {
mutation.addedNodes.forEach(node => {
if (node.nodeName === 'VIDEO') {
handleVideo(node);
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
}
function checkStableVolumeAvailability(callback) {
const request = new XMLHttpRequest();
request.open('GET', 'https://update.greasyfork.org/scripts/508598/Stable%20Volume%20Emulator.meta.js', true);
request.onreadystatechange = function() {
if (request.readyState === XMLHttpRequest.DONE) {
if (request.status === 200) {
const responseText = request.responseText;
if (responseText.includes('Stable Volume')) {
callback(true);
} else {
callback(false);
}
} else {
callback(false);
}
}
};
request.send();
}
function init() {
checkStableVolumeAvailability(isAvailable => {
if (!isAvailable) {
loadSettings();
const video = document.querySelector('video');
handleVideo(video);
observeDOMChanges();
}
});
}
init();
})();