記住上次使用的播放速度，並改造YouTube的速度調整滑桿，最高支援8倍速。
// ==UserScript==
// @name Youtube Remember Speed
// @name:zh-TW YouTube 播放速度記憶
// @name:zh-CN YouTube 播放速度记忆
// @name:ja YouTube 再生速度メモリー
// @icon https://www.google.com/s2/favicons?domain=youtube.com
// @author ElectroKnight22
// @namespace electroknight22_youtube_remember_playback_rate_namespace
// @version 2.2.0
// @match *://www.youtube.com/*
// @match *://www.youtube-nocookie.com/*
// @exclude *://music.youtube.com/*
// @grant GM.getValue
// @grant GM.setValue
// @grant GM.deleteValue
// @grant GM.listValues
// @license MIT
// @description Remembers the speed that you last used. Now hijacks YouTube's custom speed slider and gives you up to 8x speed.
// @description:zh-TW 記住上次使用的播放速度，並改造YouTube的速度調整滑桿，最高支援8倍速。
// @description:zh-CN 记住上次使用的播放速度，并改造YouTube的速度调整滑杆，最高支持8倍速。
// @description:ja 最後に使った再生速度を覚えておき、YouTubeの速度スライダーを改造して最大8倍速まで対応させます。
// @homepageURL https://greasyfork.org/scripts/503771-youtube-remember-speed
// ==/UserScript==
/*jshint esversion: 11 */
(function () {
'use strict';
class SpeedOverrideManager {
constructor(maxSpeed, getSettings, setSpeed, updateSavedSpeed) {
this.maxSpeed = maxSpeed;
this.getSettings = getSettings;
this.setSpeed = setSpeed;
this.updateSavedSpeed = updateSavedSpeed;
this.DOM = {
speedTextElement: null,
speedLabel: null,
parentMenu: null,
};
this.mainObserver = null;
this.observerOptions = { childList: true, subtree: true, characterData: true };
}
disconnect() {
if (this.mainObserver) {
this.mainObserver.disconnect();
}
this.mainObserver = null;
}
overrideSpeedText(targetString) {
try {
if (!this.DOM.speedTextElement || !this.DOM.speedTextElement.isConnected) return;
const text = this.DOM.speedTextElement.textContent;
this.DOM.speedTextElement.textContent = /\(.*?\)/.test(text) ? text.replace(/\(.*?\)/, `(${targetString})`) : targetString;
} catch (error) {
console.error('Failed to set speed text.', error);
}
}
overrideSpeedLabel(sliderElement) {
try {
const speedLabel = this.DOM.speedLabel;
if (speedLabel?.isConnected && speedLabel.textContent && !speedLabel.textContent.includes(`(${sliderElement.value})`)) {
speedLabel.textContent = speedLabel.textContent.replace(/\(.*?\)/, `(${sliderElement.value})`);
}
} catch (error) {
console.error('Failed to override speed label.', error);
}
}
overrideSliderStyle(sliderElement) {
if (!sliderElement) return;
this.overrideSpeedLabel(sliderElement);
sliderElement.style = `--yt-slider-shape-gradient-percent: ${(sliderElement.value / this.maxSpeed) * 100}%;`;
const speedSliderText = document.querySelector('.ytp-speedslider-text');
if (speedSliderText) {
speedSliderText.textContent = sliderElement.value + 'x';
}
}
overrideCustomSpeedItem(sliderElement) {
const speedMenuItems = sliderElement.closest('.ytp-panel-menu');
if (!speedMenuItems) return;
const customSpeedItem = speedMenuItems.children[0];
if (!customSpeedItem) return;
if (!customSpeedItem.dataset.customSpeedClickListener) {
customSpeedItem.addEventListener('click', () => {
const newSpeed = parseFloat(sliderElement.value);
this.setSpeed(newSpeed);
this.updateSavedSpeed(newSpeed);
this.overrideSpeedText(newSpeed);
});
customSpeedItem.dataset.customSpeedClickListener = 'true';
}
if (customSpeedItem.classList.contains('ytp-menuitem-with-footer') && customSpeedItem.getAttribute('aria-checked') !== 'true') {
const currentActiveItem = speedMenuItems.querySelector('[aria-checked="true"]');
if (currentActiveItem && currentActiveItem !== customSpeedItem) {
currentActiveItem.setAttribute('aria-checked', 'false');
}
customSpeedItem.setAttribute('aria-checked', 'true');
}
}
overrideSliderFunction(sliderElement) {
sliderElement.addEventListener('input', () => {
try {
const newSpeed = parseFloat(sliderElement.value);
this.updateSavedSpeed(newSpeed);
this.setSpeed(newSpeed);
this.overrideSliderStyle(sliderElement);
this.overrideCustomSpeedItem(sliderElement);
} catch (error) {
console.error('Error during slider input event.', error);
}
});
sliderElement.addEventListener(
'change',
(event) => {
this.overrideSpeedText(sliderElement.value);
event.stopImmediatePropagation();
},
true,
);
}
setupSliderOnce(sliderElement) {
if (!sliderElement) return;
if (!sliderElement.dataset.listenerAttached) {
this.overrideSliderFunction(sliderElement);
sliderElement.dataset.listenerAttached = 'true';
}
sliderElement.max = this.maxSpeed.toString();
sliderElement.setAttribute('value', this.getSettings().targetSpeed.toString());
this.setSpeed(this.getSettings().targetSpeed);
this.DOM.speedLabel = sliderElement.closest('.ytp-menuitem-with-footer')?.querySelector('.ytp-menuitem-label');
}
async findSpeedTextElement() {
// We use a magic number to manually create a stable selector for the speed menu item.
const magicSpeedNumber = 1.05;
const pollForElement = () => {
const settingItems = document.querySelectorAll('.ytp-menuitem');
return Array.from(settingItems).find((item) => item.textContent.includes(magicSpeedNumber.toString()));
};
const targetSpeed = this.getSettings().targetSpeed;
const youtubeApi = document.querySelector('#movie_player');
// YouTube API must be called here regardless to allow the YouTube UI to updated normally. (reason unclear)
youtubeApi.setPlaybackRate(magicSpeedNumber);
let attempts = 0;
while (attempts < 50) {
const matchingItem = pollForElement();
if (matchingItem) {
this.DOM.speedTextElement = matchingItem.querySelector('.ytp-menuitem-content');
break;
}
await new Promise((resolve) => setTimeout(resolve, 10));
attempts++;
}
this.setSpeed(targetSpeed);
this.updateSavedSpeed(targetSpeed);
this.overrideSpeedText(targetSpeed);
}
_monitorUI() {
const sliderElement = document.querySelector('input.ytp-input-slider.ytp-speedslider');
if (sliderElement) {
if (!sliderElement.dataset.speedScriptSetup) {
this.setupSliderOnce(sliderElement);
sliderElement.dataset.speedScriptSetup = 'true';
}
if (!this.DOM.speedLabel || !this.DOM.speedLabel.isConnected) {
this.DOM.speedLabel = sliderElement.closest('.ytp-menuitem-with-footer')?.querySelector('.ytp-menuitem-label');
}
const speedLabel = this.DOM.speedLabel;
const expectedLabel = `(${sliderElement.value})`;
if (speedLabel && !speedLabel.textContent.includes(expectedLabel)) {
this.mainObserver.disconnect();
this.overrideSliderStyle(sliderElement);
this.overrideCustomSpeedItem(sliderElement);
this.mainObserver.observe(this.DOM.parentMenu, this.observerOptions);
}
return;
}
if (!this.DOM.speedTextElement || !this.DOM.speedTextElement.isConnected) {
this.findSpeedTextElement();
} else {
const currentText = this.DOM.speedTextElement.textContent;
const targetSpeed = this.getSettings().targetSpeed.toString();
if (!currentText.includes(targetSpeed)) {
this.mainObserver.disconnect();
this.overrideSpeedText(targetSpeed);
this.mainObserver.observe(this.DOM.parentMenu, this.observerOptions);
}
}
}
init() {
try {
this.DOM.parentMenu = document.querySelector('.ytp-popup.ytp-settings-menu');
if (!this.DOM.parentMenu) return;
this.mainObserver = new MutationObserver(this._monitorUI.bind(this));
this.mainObserver.observe(this.DOM.parentMenu, this.observerOptions);
} catch (error) {
console.error('Failed to initialize speed override manager.', error);
}
}
}
// --- Main Script Logic ---
const DEFAULT_SETTINGS = { targetSpeed: 1 };
let userSettings = { ...DEFAULT_SETTINGS };
const maxSpeed = 8;
let manager = null;
function setSpeed(targetSpeed) {
try {
const video = document.querySelector('video');
if (video && video.playbackRate !== targetSpeed) {
video.playbackRate = targetSpeed;
}
} catch (error) {
console.error('Failed to set playback speed.', error);
}
}
function updateSavedSpeed(speed) {
const newSpeed = parseFloat(speed);
if (userSettings.targetSpeed !== newSpeed) {
userSettings.targetSpeed = newSpeed;
GM.setValue('targetSpeed', userSettings.targetSpeed);
}
}
async function applySettings() {
try {
const storedSpeed = await GM.getValue('targetSpeed', DEFAULT_SETTINGS.targetSpeed);
userSettings.targetSpeed = storedSpeed;
} catch (error) {
console.error('Failed to apply stored settings.', error.message);
}
}
function handleNewVideoLoad() {
if (!manager) {
manager = new SpeedOverrideManager(maxSpeed, () => userSettings, setSpeed, updateSavedSpeed);
}
setSpeed(userSettings.targetSpeed);
manager.init();
const youtubeApi = document.querySelector('#movie_player');
if (youtubeApi && !youtubeApi.dataset.speedScriptListenerAttached) {
youtubeApi.addEventListener('onPlaybackRateChange', (newSpeed) => {
updateSavedSpeed(newSpeed);
if (manager) {
manager.overrideSpeedText(newSpeed);
}
});
youtubeApi.dataset.speedScriptListenerAttached = 'true';
}
}
function main() {
window.addEventListener(
'pageshow',
() => {
handleNewVideoLoad();
window.addEventListener(
'yt-player-updated',
() => {
if (manager) {
manager.disconnect();
manager = null;
}
handleNewVideoLoad();
},
true,
);
},
true,
);
}
applySettings().then(main);
})();