GDCBVD.user.js

// ==UserScript==
// @updateURL   https://gist.github.com/xNWDD/03cb0809b0d09c02e454d74d4846c574/raw/GDCBVD.user.js
// @downloadURL https://gist.github.com/xNWDD/03cb0809b0d09c02e454d74d4846c574/raw/GDCBVD.user.js
// @name         GDC Browse Video Downloader
// @description  Tested with Tampermonkey in Firefox, Should not work in Greasemonkey, May Freeze Violentmonkey
// @version      2019r1
// @include      /https?://www.gdcvault.com/*/
// @connect      cdnapisec.kaltura.com
// @connect      *.akamaihd.net
// @grant        GM_download
// @grant        GM_xmlhttpRequest
// ==/UserScript==
(function injector() {
	'use strict';
	if (document.body.querySelectorAll('a.session_item').length == 0)
		return setTimeout(injector,1000);
	[].slice.call(document.body.querySelectorAll('a.session_item')) //grab all talks
		.filter(v=>v.querySelector('.video')) //filter only videos
		.map(d=>({d:d,u:d.getAttribute("onclick")||d.href})) //pick href if no onclick
		.filter(o=>!o.u.startsWith("loginPopup(")) //don't show buttons for unaccessible vids.
		.map(o=>({d:o.d,i:o.u.match(/(play\/|cid=|\('[0-9]+',')([0-9]+)/)[2]})) //fetch the ids
		.map(o=>({d:o.d,u:location.protocol+"//"+location.host+"/play/"+o.i})) //generate urls from ids
		.forEach(o=>{
			const img = document.createElement("img"); //create download image
			img.src="/img/icon_play.png"; //use play icon as texture
			img.style="transform:rotate(90deg)"; //rotate it 90 deg clockwise
			img.addEventListener('click',(event)=>{ //start download process
                const origin = "https://www.gdcvault.com/play/0/GDCBVD";
				GM_xmlhttpRequest({method:"GET",headers:{Origin:origin,Referer:origin},url:o.u,onload:(r)=>{ //download talk page (html only)
                    const filename = r.responseText.match(/:title" content="(([^/>])+)\/>/)[1].replace(/[<|>|:|"|/|\|*|_| ]+/g," ").trim().replace(/[ |?]+/g,"_"); //generate valid win32 names
                    const iframe_path = r.responseText.match(/<iframe src="([^"]+)/i)[1]; //extract iframe address (evt/sevt)
                    GM_xmlhttpRequest({method:"GET",headers:{Origin:origin,Referer:origin},url:iframe_path,onload:(r)=>{ //download video page (html only)
                        const w = eval("("+r.responseText.match(/window.kalturaIframePackageData = ([^;]+)/i)[1]+")");
                        const video_redirect_url = "https://cdnapisec.kaltura.com/p/" + w.playerConfig.widgetId.substring(1) + "/sp/" + w.playerConfig.widgetId.substring(1) + "00/playManifest/entryId/" + w.playerConfig.entryId + "/flavorIds/" + w.entryResult.contextData.flavorAssets.filter(o=>o.fileExt == "mp4").sort((a,b)=>a.bitrate<b.bitrate)[0].id + "/format/url/protocol/http/a.mp4";
                        GM_xmlhttpRequest({timeout:2500,method:"GET",headers:{Origin:origin,Referer:origin},url:video_redirect_url,onerror:(r)=>{ //download video page (html only)
                            GM_download({url:r.error.match(/http.*?.mp4/i)[0],name:filename+".mp4",saveAs:true}); //open download popup to chose location
                        }});
                    }});
				}});
			event.preventDefault(); //prevent click from changing url
			event.stopPropagation(); //prevent click from triggering in parents
		});
		o.d.appendChild(img); //append download button
	});
})();