YouTube Volume Assistant

Enhances the volume control on YouTube by providing additional information and features.

当前为 2023-05-21 提交的版本,查看 最新版本

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

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

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

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

您需要先安装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 Volume Assistant
// @namespace    http://tampermonkey.net/
// @version      0.1.2
// @description  Enhances the volume control on YouTube by providing additional information and features.
// @author       CY Fung
// @license      MIT License
// @match        https://www.youtube.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        none
// @run-at       document-start
// @unwrap
// @allFrames
// @inject-into page
// ==/UserScript==

(function () {
    'use strict';

    //    AudioContext.prototype._createGain = AudioContext.prototype.createGain;


    let wm = new WeakMap();
    /*
        AudioContext.prototype.createGain = function(...args){
            return this.createdGain || (this.createdGain = this._createGain(...args));
        }
    */

    function getMediaElementSource() {
        return wm.get(this) || null;
    }
    function getGainNode() {
        return wm.get(this) || null;
    }

    AudioContext.prototype._createMediaElementSource = AudioContext.prototype.createMediaElementSource;

    AudioContext.prototype.createMediaElementSource = function (video, ...args) {
        let createdMediaElementSource = wm.get(video);
        if (createdMediaElementSource) return createdMediaElementSource;
        wm.set(video, createdMediaElementSource = this._createMediaElementSource(video, ...args));
        video.getMediaElementSource = getMediaElementSource;
        return createdMediaElementSource;
    }


    MediaElementAudioSourceNode.prototype._connect = MediaElementAudioSourceNode.prototype.connect;

    MediaElementAudioSourceNode.prototype.connect = function (gainNode, ...args) {

        this._connect(gainNode, ...args);
        wm.set(this, gainNode);

        this.getGainNode = getGainNode;
    }




    let finished = false;
    const onNavigateFinish = () => {
        if (finished) return;
        finished = true;
    document.removeEventListener('yt-navigate-finish', onNavigateFinish, true);

        document.head.appendChild(document.createElement('style')).textContent = `
        .video-tip-offseted {
        margin-top:-1em;
        }
        .volume-tip-gain{
        opacity:0.52;
        }
        .volume-tip-normalized{
        opacity:0.4;
        }
        `;


        setTimeout(() => {

            let volumeSlider = document.querySelector('.ytp-volume-panel[role="slider"][title]');

            let volumeTitle = volumeSlider.getAttribute('title');



            function addDblTap(element, doubleClick) {
                // https://stackoverflow.com/questions/45804917/dblclick-doesnt-work-on-touch-devices

                let expired


                let doubleTouch = function (e) {
                    if (e.touches.length === 1) {
                        if (!expired) {
                            expired = e.timeStamp + 400
                        } else if (e.timeStamp <= expired) {
                            // remove the default of this event ( Zoom )
                            e.preventDefault()
                            doubleClick(e)
                            // then reset the variable for other "double Touches" event
                            expired = null
                        } else {
                            // if the second touch was expired, make it as it's the first
                            expired = e.timeStamp + 400
                        }
                    }
                }

                element.addEventListener('touchstart', doubleTouch)
                element.addEventListener('dblclick', doubleClick)
            }

            addDblTap(volumeSlider, (e) => {

                let target = null;
                try {
                    target = e.target.closest('.ytp-volume-area').querySelector('.ytp-mute-button');
                } catch (e) { }
                console.log(target)
                const e2 = new MouseEvent('contextmenu', {
                    bubbles: true,
                    cancelable: true,
                    view: window
                });

                if (target) target.dispatchEvent(e2);


            })



            let volumeSpan = null;
            let lastContent = null;



            let video = document.querySelector('#player video[src]');
            let source = null;
            let gainNode = null;
            video.addEventListener('volumechange', changeVolumeText, false)


            let ktid = 0;
            let template = document.createElement('template');

            function changeVolumeText() {

                let video = document.querySelector('#player video[src]');
                if (!video) return;

                if (gainNode === null) {

                    source = video.getMediaElementSource ? video.getMediaElementSource() : null;
                    if (source) {
                        gainNode = source.getGainNode ? source.getGainNode() : null;
                    }
                }

                let gainValue = (((gainNode || 0).gain || 0).value || 0);
                let m = gainValue || 1.0;

                let actualVolume = document.querySelector('ytd-player').player_.getVolume();
                let normalized = video.volume * 100;

                let gainText = gainValue ? `<span class="volume-tip-gain">Gain = ${+(gainValue.toFixed(2))}</span><br>` : '';

                template.innerHTML = `
                <span class="volume-tip-offset">
    ${gainText}
    <span class="volume-tip-volume">Volume: ${(m * actualVolume).toFixed(1)}% </span><br>
    <span class="volume-tip-normalized"> Normalized: ${(m * normalized).toFixed(1)}%</span>
    </span>`.trim();
                if (volumeSpan.textContent !== template.content.textContent && lastContent === volumeSpan.textContent) {

                    volumeSpan.innerHTML = template.innerHTML;
                    lastContent = volumeSpan.textContent;

                }
            }

            setInterval(() => {

                if (!volumeSpan) {
                    let elms = [...document.querySelectorAll('#player .ytp-tooltip div.ytp-tooltip-text-wrapper span.ytp-tooltip-text')];
                    elms = elms.filter(t => t.textContent === volumeTitle);

                    if (elms[0]) {
                        HTMLElement.prototype.closest.call(elms[0],'#player .ytp-tooltip').classList.add('video-tip-offseted');
                        volumeSpan = elms[0];
                        lastContent = volumeSpan.textContent;
                    }
                }

                if (volumeSpan && (!volumeSpan.isConnected || volumeSpan.textContent !== lastContent)) {
                    // volumeSpan.textContent = volumeTitle;
                    let p = document.querySelector('.video-tip-offseted');
                    if(p) p.classList.remove('video-tip-offseted');
                    let m = document.querySelector('.volume-tip-offset');
                    if(m) m.remove();
                    volumeSpan = null;
                    lastContent = null;
                }

                if (!volumeSpan) return;
                let tid = Date.now();
                ktid = tid;
                requestAnimationFrame(() => {
                    if (ktid !== tid) return;
                    changeVolumeText();

                });

            }, 80)

        }, 300);


    };
    document.addEventListener('yt-navigate-finish', onNavigateFinish, true);
    setTimeout(onNavigateFinish, 800);


})();