Control volume of playing media on any webpage
// ==UserScript==
// @name Volume Booster
// @namespace https://greasyfork.org/zh-CN/users/196399-xyabc120
// @version 2024-09-27
// @description Control volume of playing media on any webpage
// @author mr.zhao
// @match *://*.bilibili.com/*
// @icon https://www.bilibili.com/favicon.ico?v=1
// @grant GM_getValue
// @grant GM_setValue
// @license MIT
// ==/UserScript==
(function() {
'use strict';
const storageKeyName = "VOLUMN_BOOSTER_GAIN_INDEX";
let currentGainIndex = GM_getValue(storageKeyName, 0);
const gainValues = [1.0, 2.0, 3.0, 4.0, 5.0];
// 创建 AudioContext 和 GainNode
const audioContext = new (window.AudioContext || window.webkitAudioContext)();
const gainNode = audioContext.createGain();
gainNode.gain.value = gainValues[currentGainIndex];
let connectedVideo = null;
// 尝试连接现有视频元素
const connectMedia = () => {
const videoElement = document.querySelector('video');
if (videoElement && videoElement !== connectedVideo) {
if (connectedVideo) {
connectedVideo.srcObject = null;
}
const track = audioContext.createMediaElementSource(videoElement);
track.connect(gainNode);
gainNode.connect(audioContext.destination);
connectedVideo = videoElement;
}
};
// 监听 DOM 变化
const observer = new MutationObserver(connectMedia);
observer.observe(document.body, { childList: true, subtree: true });
// 可选：创建一个按钮来调整音量
const button = document.createElement('button');
button.textContent = `Volume Boost ${gainValues[currentGainIndex]}x`;
button.style.position = 'fixed';
button.style.top = '70px';
button.style.right = '10px';
button.style.zIndex = '9999';
button.style.padding = "1px 7px";
button.title = "左键点击增加音量倍数，右键重置";
document.body.appendChild(button);
const updateGain = (gainIndex) => {
currentGainIndex = gainIndex;
gainNode.gain.value = gainValues[currentGainIndex];
button.textContent = `Volume Boost ${gainValues[currentGainIndex]}x`;
GM_setValue(storageKeyName, gainIndex);
};
button.addEventListener('click', () => updateGain(++currentGainIndex % gainValues.length));
button.addEventListener('contextmenu', () => {
event.preventDefault();
updateGain(0);
});
})();