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Hover over a thumbnail to see images from the video
// ==UserScript==
// @name YT Thumbnails
// @namespace http://thegeeex.free.fr/
// @version 1.4.1
// @description Hover over a thumbnail to see images from the video
// @author Geeex
// @match https://www.youtube.com/*
// @grant none
// @run-at document-end
// ==/UserScript==
var prev, to,
path = 'https://i.ytimg.com/vi/',
ext = 'jpg';
document.body.addEventListener('mousemove', function(e) {
var img = e.target, id;
if (img.src && (match = img.src.match(/^https:\/\/i\.ytimg\.com\/\w+\/([\w-]+)\/\w+.+$/)) && !img.dataset.ytThumb) {
img.dataset.ytThumb = id = match[1];
img.style.backgroundColor = '#000';
img.style.backgroundImage = 'url(' + path + id + '/1.' + ext + ')';
img.style.backgroundSize = '100% 134%';
img.style.backgroundPosition = '0 50%';
preload(path + id + '/2.' + ext,
path + id + '/3.' + ext);
}
if (img == prev) return;
if (prev) {
prev.src = path + prev.dataset.ytThumb + '/mqdefault.' + ext;
prev = false;
}
if (img.tagName == 'IMG' && img.dataset.ytThumb) {
var loop = function() {
if (prev != img) return;
img.style.backgroundImage = img.style.backgroundImage.replace(/\/[123]\./, '/' + i + '.');
i = [1,2,3,1][i];
if (to) {
clearTimeout(to);
}
to = setTimeout(loop, 1000);
}, i = 1;
prev = img;
img.src = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7'; // 1px*1px transparent
loop();
return;
}
}, true);
// Preload an array of images
function preload(imgs) {
if (typeof imgs == 'string') imgs = [].slice.call(arguments);
var img = new Image();
img.onload = img.onerror = function() {
if (imgs.length) img.src = imgs.shift();
};
img.src = imgs.shift();
}