Video Preload

Minimal video optimizer: lightweight preload, ad blocking

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         Video Preload
// @namespace    none
// @version      0.1
// @description  Minimal video optimizer: lightweight preload, ad blocking
// @match        *://*/*
// @grant        none
// ==/UserScript==
Preload
(() => {
  'use strict';
  
  const AD_KEYWORDS = ['ad', 'sponsor', 'banner', 'promo'];
  const SCAN_DELAY = 3000;
  const OBSERVE_DELAY = 500;

  const isVideo = src => src && (src.includes('.mp4') || src.startsWith('blob:') || src.startsWith('data:'));
  const isAd = src => AD_KEYWORDS.some(k => src.toLowerCase().includes(k));

  function boost(video) {
    if (video.dataset.boosted) return;
    video.dataset.boosted = true;
    
    const src = video.currentSrc || video.src;
    if (!src || isAd(src)) return video.remove();
    if (isVideo(src) && src.startsWith('http')) {
      const link = document.createElement('link');
      link.rel = 'preload';
      link.as = 'video';
      link.href = src;
      document.head.append(link);
    }
    
    video.preload = 'auto';
    video.playsInline = true;
  }

  let lastScan = 0;
  const scan = () => {
    if (Date.now() - lastScan < SCAN_DELAY) return;
    lastScan = Date.now();
    document.querySelectorAll('video:not([data-boosted])').forEach(boost);
  };

  new MutationObserver(() => setTimeout(scan, OBSERVE_DELAY))
    .observe(document.body, { childList: true, subtree: true });

  window.addEventListener('DOMContentLoaded', scan);
  scan();
})();