Youtube Audio Mode

Listen to only the audio on YouTube without loading the video.

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        Youtube Audio Mode
// @description Listen to only the audio on YouTube without loading the video.
// @version     1.2.2
// @include     https://www.youtube.com/*
// @license     GPL-3.0+; http://www.gnu.org/licenses/gpl-3.0.txt
// @run-at      document-end
// @grant       GM_xmlhttpRequest
// @grant       GM.setValue
// @grant       GM.getValue
// @noframes
// @namespace https://greatest.deepsurf.us/users/195276
// ==/UserScript==

(function(open) {
    window.addEventListener("yt-navigate-finish", audioMode);
    window.onYouTubeIframeAPIReady = audioMode();

    async function audioMode() {
        if (location.pathname == "/watch") {
            let video = document.getElementsByTagName("video")[0];
            let audioMode = await GM.getValue("ytAudioMode");
            addToMenu(audioMode);
            if (audioMode) {
                setPoster(video, ["maxres", "hq", "sd"]);
                watchStream(video);
            }
        }
    }

    // Watch the media streams so we can select the audio
    function watchStream(video) {
        XMLHttpRequest.prototype.open = function(method, url) {
            let validStream = /^(?!.*live=1).+audio.+$/;
            if (validStream.test(url) && ! video.src.includes("audio")) {
                video.pause();
                video.src = url.split("&range")[0];
                video.play();
            }
            open.apply(this, arguments);
        }
    }

    // Add audio mode to the settings menu
    async function addToMenu(audioMode) {
        let panel = document.getElementsByClassName("ytp-panel-menu")[0];
        if (!panel.innerHTML.includes("Audio Mode")) {
            panel.innerHTML += `
            <div class="ytp-menuitem"
                aria-checked="${audioMode}"
                id="audio-mode">
                <div class="ytp-menuitem-icon"></div>
                <div class="ytp-menuitem-label">Audio Mode</div>
                <div class="ytp-menuitem-content">
                    <div class="ytp-menuitem-toggle-checkbox">
                </div>
            </div>`;

            // Toggle audio mode on or off
            let audioToggle = document.getElementById("audio-mode");
            audioToggle.onclick = async function() {
                let audioMode = ! await GM.getValue("ytAudioMode");
                this.setAttribute("aria-checked", audioMode);
                GM.setValue("ytAudioMode", audioMode);
                location.reload();
            }
        }
    }

    // Set the video poster from thumbnails with the best avaliable format
    // https://developers.google.com/youtube/v3/docs/thumbnails
    async function setPoster(video, fmts) {
        let img = new Image();
        let videoId = location.search.match(/v=(.+?)(&|$)/)[1];
        img.src = `//i.ytimg.com/vi/${videoId}/${fmts.shift()}default.jpg`
        img.onload = function() {
            // A height 90 is YouTube"s not found image.
            if (img.height <= 90) {
                setPoster(video, fmts);
            } else {
                video.style.background = `url(${img.src}) no-repeat center`;
                video.style.backgroundSize = "contain";
            }
        };
    }
})(XMLHttpRequest.prototype.open);