Video Element Rate Controller Re-dux

Add keyboard shortcuts that will increase/decrease the playback rate for video elements.

As of 01. 06. 2023. See the latest version.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

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

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

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

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

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

(I already have a user script manager, let me install it!)

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.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Video Element Rate Controller Re-dux
// @namespace    https://github.com/mirnhoj/video-element-playbackrate-setter
// @version      2.3
// @description  Add keyboard shortcuts that will increase/decrease the playback rate for video elements.
// @include      http*://*.youtube.com/*
// @include      http*://*.gfycat.com/*
// @include      http*://*.vimeo.com/*
// @include      https://www.facebook.com/video.php*
// @include      https://www.facebook.com/*/videos/*
// @include      https://www.kickstarter.com/*
// @grant        GM_registerMenuCommand

// ==/UserScript==
/* jshint esversion: 6 */
//
// if you want to extend the functionality of this script to other sites
// besides youtube, add additional @include keys to the metadata block.
//
// if you want to change the default playback rate from 1x, change the line
// "var currentPlaybackRate = 1;" to equal something other than 1, like 1.3 to
// have all videos start playing at an increased speed, or 0.7 to have all
// videos start playing at a decreased speed.
//
// if you want change the granularity of the playback rate adjustment, change
// the line "var speedStep = 0.1;" to equal something other than 0.1, like 0.01
// for more granular adjustments, or 0.25 for less granular adjustments.


// These values are the default values for initialization
let speedStep = 0.1;
let displayTimeMilliSec = 1500;

let timeoutID = null;
const infobox = document.createElement('h1');
let showValuesOnVideo = true; // true to show new value on the video
let keyIncreaseSpeed = ']';
let keyReduceSpeed = '[';
let keyResetSpeed = '\\';

function getVal(variable) {
    let value;
    let storage = (localStorage || (sessionStorage ||
        (window.content.localStorage ? window.content.localStorage : null)));
    try {
        switch (variable) {
            case 'speedStep':
                value = storage.getItem('VERCRspeedStep');
                return Number(value);
            case 'displayTimeMilliSec':
                value = storage.getItem('VERCRdisplayTimeMS');
                return Number(value);
            case 'keyIncreaseSpeed':
                return value;
            case 'keyReduceSpeed':
                return value;
            case 'keyResetSpeed':
                return value;
            default:
                return null;
        }
    } catch (e) {
        if (e.name === 'NS_ERROR_FILE_CORRUPTED') {
            storage = sessionStorage || null; // set the new storage if fails
            storage.setItem('VERCRspeedStep', speedStep);
            storage.setItem('VERCRdisplayTimeMS', displayTimeMilliSec);
        }
    }
    //console.log('Variable "' + variable + '" is ' + value);
}

function setVal(variable, value) {
    let storage = (localStorage || (sessionStorage ||
        (window.content.localStorage ? window.content.localStorage : null)));
    try {
        switch (variable) {
        case 'speedStep':
            storage.setItem('VERCRspeedStep', Number(value));
            console.log(`Setting "${variable}" to ${value}`);
            return value;
        case 'displayTimeMilliSec':
            storage.setItem('VERCRdisplayTimeMS', Number(value));
            console.log(`Setting "${variable}" to ${value}`);
            return value;
        default:
            return null;
        }
    } catch (e) {
        if (e.name === 'NS_ERROR_FILE_CORRUPTED') {
            storage = sessionStorage || null; // set the new storage if fails
            storage.setItem('VERCRspeedStep', speedStep);
            storage.setItem('VERCRdisplayTimeMS', displayTimeMilliSec);
        }
    }
}

function GMsetup() {
    if (GM_registerMenuCommand) {
        GM_registerMenuCommand('Set adjustment rate', () => {
            const curEntry = getVal('speedStep');
            speedStep = prompt('New adjustment rate:\n(e.g., 0.1 = 10% faster)', curEntry);
            if (speedStep !== null) {
                while (isNaN(speedStep)) {
                    speedStep = prompt('Please input a valid number!\n\nNew adjustment rate:\n(e.g., 0.1 = 10% faster)', curEntry);
                }
                setVal('speedStep', speedStep);
            }
        });
        // GM_registerMenuCommand('Video Rate Re-dux: Set keyboard shortcuts', () => {
        //     const curEntry = `${getVal('keyIncreaseSpeed')}, ${getVal('keyReduceSpeed')}, ${getVal('keyResetSpeed')}`;
        //     // W.I.P.
        // });
        GM_registerMenuCommand('Set display timeout', () => {
            const curEntry = getVal('displayTimeMilliSec');
            displayTimeMilliSec = prompt('New display timeout length (in milliseconds):', curEntry);
            if (displayTimeMilliSec !== null) {
                while (isNaN(displayTimeMilliSec)) {
                    displayTimeMilliSec = prompt('Please input a valid number!\n\nNew display timeout length (in milliseconds):', curEntry);
                }
                setVal('displayTimeMilliSec', displayTimeMilliSec);
            }
        });
    }
}

function init() {
    let VERCRspeedStep = localStorage.getItem('VERCRspeedStep');
    let VERCRdisplayTimeMS = localStorage.getItem('VERCRdisplayTimeMS');
    if (!VERCRspeedStep) {
        VERCRspeedStep = speedStep;
        localStorage.setItem('VERCRspeedStep', Number(VERCRspeedStep));
    }
    if (!VERCRdisplayTimeMS) {
        VERCRdisplayTimeMS = displayTimeMilliSec;
        localStorage.setItem('VERCRdisplayTimeMS', Number(VERCRdisplayTimeMS));
    }
}

function showInfobox(rate) {
    // update rate indicator.
    infobox.innerHTML = `${rate}x`;
    // show infobox
    infobox.style.visibility = 'visible';
    // clear out any previous timers and have the infobox hide after the pre-set time period
    window.clearTimeout(timeoutID);
    timeoutID = window.setTimeout(() => {
        infobox.style.visibility = 'hidden';
    }, getVal('displayTimeMilliSec'));
}

function setPlaybackRate(rate, shouldShowInfobox) {
    // grab the video elements and set their playback rate.
    const videoElement = document.getElementsByTagName('video')[0];
    videoElement.playbackRate = rate;
    // add infobox to dom if it doesn't already exist.
    if (videoElement && !document.getElementById('playbackrate-indicator')) {
        videoElement.parentElement.appendChild(infobox);
    }
    if (shouldShowInfobox) {
        showInfobox(rate);

    }
}

// mimic vlc keyboard shortcuts
function addKeyListener() {
    window.addEventListener('keydown', (event) => {
        const key = event.key;
        const videoElement = document.getElementsByTagName('video')[0];
        let currentPlaybackRate = videoElement.playbackRate;
        speedStep = getVal('speedStep');
        if (key === keyReduceSpeed) {
            currentPlaybackRate = parseFloat((currentPlaybackRate - speedStep).toFixed(3));
            console.log(`Raising "currentPlaybackRate" to ${currentPlaybackRate}`);
            setPlaybackRate(currentPlaybackRate, showValuesOnVideo);
        } else if (key === keyIncreaseSpeed) {
            currentPlaybackRate = parseFloat((currentPlaybackRate + speedStep).toFixed(3));
            console.log(`Lowering "currentPlaybackRate" to ${currentPlaybackRate}`);
            setPlaybackRate(currentPlaybackRate, showValuesOnVideo);
        } else if (key === keyResetSpeed) {
            currentPlaybackRate = 1;
            setPlaybackRate(currentPlaybackRate, showValuesOnVideo);
        }
    });
}

function onReady() {
    addKeyListener();
}

function wait(time) {
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve();
        }, time);
    });
}

function main() {
    init();
    GMsetup();
    infobox.setAttribute('id', 'playbackrate-indicator');
    infobox.style.position = 'absolute';
    infobox.style.top = '10%';
    infobox.style.right = '10%';
    infobox.style.color = 'rgba(255, 0, 0, 1)';
    infobox.style.zIndex = '99999'; // ensures that it shows above other elements.
    infobox.style.visibility = 'hidden';
    infobox.style.marginTop = '3%';
    if (document.readyState !== 'loading') {
        onReady(); // Or setTimeout(onReady, 0); if you want it consistently async
    } else {
        document.addEventListener('DOMContentLoaded', onReady);
    }
}

main();