Youtube Automatic Min Quality

Set Youtube player automatically to min quality.

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴Greasemonkey 油猴子Violentmonkey 暴力猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴Violentmonkey 暴力猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴Userscripts ,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey 篡改猴,才能安装此脚本。

您需要先安装一款用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name         Youtube Automatic Min Quality
// @namespace    http://tampermonkey.net/
// @version      2024-03-08
// @description  Set Youtube player automatically to min quality.
// @author       Santeri Hetekivi
// @match        *://*.youtube.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        none
// @license      Apache-2.0
// ==/UserScript==

(function () {
    'use strict';
    // Base timeout.
    const TIMEOUT_MS = 100

    // Selector for player.
    const SELECTOR_PLAYER = ".html5-video-player"

    // Min quality.
    const MIN_QUALITY = "tiny"

    /**
     * Get element by selector.
     * @param {string} selector For this selector.
     * @param {function} callback Function to call with element.
     * @param {?string} key If given, use this key for data.
     */
    function getElementBySelector(selector, callback, key) {
        // Get element by selector.
        const element = document.querySelector(selector)

        // Init data.
        if (typeof getElementBySelector.data !== "object") {
            getElementBySelector.data = {}
        }

        // If key is undefined
        if (typeof key === "undefined") {
            // generate key that is not in use.
            do {
                key = (Math.random() + 1).toString(36).substring(2)
            } while (key in getElementBySelector.data)
        }
        // Else if key is not in use
        else if (!(key in getElementBySelector.data)) {
            // throw error.
            throw new Error("Key '" + key + "' not found in getElementBySelector.data!")
        }

        // Key has data.
        const keyHasData = (typeof getElementBySelector.data[key] === "object")

        // If element found.
        if (element) {
            // If key has data
            if (keyHasData) {
                // and timeout is number
                if (typeof getElementBySelector.data[key].timeout === "number") {
                    // clear timeout.
                    clearTimeout(getElementBySelector.data[key].timeout)
                }
                // delete data for key.
                delete getElementBySelector.data[key]
            }
            // Callback with element.
            callback(element)
        }
        // Else if element not found.
        else {
            // If key has no data
            if (!keyHasData) {
                // init data.
                getElementBySelector.data[key] = { counter: 0, timeout: null }
            }
            // After timeout
            getElementBySelector.data[key].timeout = setTimeout(
                function () {
                    // call again with same key.
                    getElementBySelector(selector, callback, key)
                },
                (
                    // Wait base timeout
                    TIMEOUT_MS
                    *
                    // times updated counter.
                    (getElementBySelector.data[key].counter++)
                )
            )
        }
    }

    // Init previous video id.
    let videoIdPrevious = null

    /**
     * Run on url change.
     */
    function onUrlChange() {
        // Get video id from url.
        const videoId = (new URLSearchParams(window.location.search)).get("v")
        // If
        if (
            // did not get video id
            videoId === null
            ||
            // or video id did not change
            videoId === videoIdPrevious
        ) {
            // just return.
            return
        }

        // Update previous video id.
        videoIdPrevious = videoId

        // Run for
        getElementBySelector(
            // video player
            SELECTOR_PLAYER,
            function (player) {
                // set min quality.
                player.setPlaybackQualityRange(MIN_QUALITY, MIN_QUALITY)
            }
        )
    }

    // Add event listener for
    window.addEventListener(
        // Youtube page data updated event.
        'yt-page-data-updated',
        function () {
            onUrlChange()
        }
    )

    // Run on url change once on first load.
    onUrlChange()
})();