Boost Volume

Boost video volume on any site. Shortcuts: Alt-Shift-[+/-]

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

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

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

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

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         Boost Volume
// @namespace    http://greasyfork.org/
// @version      0.3
// @description  Boost video volume on any site. Shortcuts: Alt-Shift-[+/-]
// @author       rix
// @match        *://*/*
// @grant        none
// ==/UserScript==

(() => {
    const boostVolume = (() => {
        const sources = {};
        const context = new AudioContext();
        return (gain) => {
            for (let video of document.querySelectorAll('video')) {
                try {
                    const source = context.createMediaElementSource(video);
                    const gainNode = context.createGain(source);
                    source.connect(gainNode);
                    gainNode.connect(context.destination);
                    sources[video] = gainNode;
                } catch(e) {}
            }
            for (let [video, gainNode] of Object.entries(sources)) {
                try {
                    gainNode.gain.value = gain;
                } catch(e) {}
            }
        };
    })();
    let gain = 1;
    document.body.addEventListener('keyup', e => {
        if (!(e instanceof KeyboardEvent && e.type === 'keyup')) return;
        if (e.composed && e.altKey && !e.ctrlKey && !e.metaKey && e.shiftKey) {
            if (e.keyCode === 187) { // +
                gain++;
            }
            else if (e.keyCode === 189) { // -
                gain = Math.max(gain - 1, 1);
            }
            else return;
            boostVolume(gain);
        }
    });
})();