facebook lookback

by died

HTML

<textarea rows="4" cols="50" id="ta"></textarea>
<button id="btn" onclick="doit()">Click Me!</button>
<div id="res">1</div>

JavaScript

function doit() {
    var source = $("#ta").val();
    var start = source.indexOf("hd_src\\u002522\\u00253A\\u002522");
    var end = source.indexOf("\\u00252C",start)
    var url = source.substring(start+30,end-8);
    var x = url.replace(/\\u([\d\w]{4})/gi, function (match, grp) {
        return String.fromCharCode(parseInt(grp, 16)); } );
    url = unescape(x).replace(/\\/g,"");   
    $("#res").text(url);
    onDownload(url)
}

function onDownload(dataToDownload) {
    var a = document.createElement('a');
    a.setAttribute('download', 'lookback.mp4');
    a.href = dataToDownload;
    a.innerHTML = 'downloading';
    document.body.appendChild(a);
    a.click();
}