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YouTube H.264 (h264ify)

https://github.com/erkserkserks/h264ify

当前为 2023-11-18 提交的版本，查看 最新版本。

// ==UserScript==
// @name YouTube H.264 (h264ify) 
// @name:ru YouTube H.264 (h264ify)
// @namespace https://www.youtube.com
// @version 18112023.1
// @description https://github.com/erkserkserks/h264ify
// @description:ru https://github.com/erkserkserks/h264ify
// @match *://*.youtube.com/*
// @match *://*.youtube-nocookie.com/*
// @match *://*.youtubekids.com/*
// @license MIT
// @grant none
// @run-at document-start
// ==/UserScript==

// false or true for 30fps
let block60fps = true;

function h264ify() {
    // Override video element canPlayType() function
    var videoElem = document.createElement('video');
    var origCanPlayType = videoElem.canPlayType.bind(videoElem);
    videoElem.__proto__.canPlayType = makeModifiedTypeChecker(origCanPlayType);

    // Override media source extension isTypeSupported() function
    var mse = window.MediaSource;
    // Check for MSE support before use
    if (mse === undefined) return;
    var origIsTypeSupported = mse.isTypeSupported.bind(mse);
    mse.isTypeSupported = makeModifiedTypeChecker(origIsTypeSupported);
}

  // return a custom MIME type checker that can defer to the original function 
function makeModifiedTypeChecker(origChecker) {
  // Check if a video type is allowed
  return function (type) {
    if (type === undefined) return '';
    var disallowed_types = ['webm', 'vp8', 'vp9', 'av01'];
    // If video type is in disallowed_types, say we don't support them
    for (var i = 0; i < disallowed_types.length; i++) {
      if (type.indexOf(disallowed_types[i]) !== -1) return '';
    }

    if (block60fps) {
      var match = /framerate=(\d+)/.exec(type);
      if (match && match[1] > 30) return '';
    }

    // Otherwise, ask the browser
    return origChecker(type);
  };
}

h264ify();