[Greasemonkey] YouTube ダウンロードリンク表示スクリプト

yagarさんのスクリプトが対応するまでの繋ぎということで、とりあえず動くところまでざっくりと。エラーチェックってなに？それおいしいの？ということでGitHubに上げておきました。人柱上等な方はどうぞ。youtube_adddownloadlinks.user.js

// ==UserScript==
// @name          YouTube_AddDownloadLinks
// @namespace     
// @description   Adding download links above the player region.
// @include       http://*youtube.com/watch*
// @version       0.1.0
// @author        outZider
// ==/UserScript==
(function() {
var formats = [
  {fmt: 37, dsc: "MP4(HD1080p H.264/AAC)", available: false},
  {fmt: 22, dsc: "MP4(HD720p H.264/AAC)", available: false},
  {fmt: 18, dsc: "MP4(iPod H.264/AAC)", available: true},
  {fmt: 35, dsc: "FLV(高 H.264/AAC)", available: false},
  {fmt: 34, dsc: "FLV(低 H.264/AAC)", available: false},
  {fmt:  6, dsc: "FLV(高-old H.263/MP3)", available: false},
  {fmt:  5, dsc: "FLV(低-old H.263/MP3)", available: true},
  {fmt: 17, dsc: "3GP(高 MPEG4/AAC)", available: true},
  {fmt: 13, dsc: "3GP(低 H.263/AMR)", available: true}
];
var t = "", video_id = "";
var flashvars = document.evaluate("id('movie_player')", document, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
var args = flashvars.snapshotItem(0).getAttribute("flashvars").split("&");
for (var i = 0; i < args.length; i++) {
  if (args[i].match(/^t=/)) {
    t = args[i].split("=")[1];
  }
  else if (args[i].match(/^video_id=/)) {
    video_id = args[i].split("=")[1];
  }
  else if (args[i].match(/^fmt_url_map=/)) {
    var fl = decodeURIComponent(args[i].split("=")[1]).split(",");
    for (var j = 0; j < fl.length; j++) {
      var v = parseInt(fl[j].split("|")[0]);
      for (var k = 0; k < formats.length; k++) {
        if (formats[k].fmt == v) {
          formats[k].available = true;
        }
      }
    }
  }
}
var al = document.createElement("div");
al.style.padding = "4px";
al.style.MozBorderRadius = "6px";
al.style.backgroundColor = "#ddd";
var ht = "";
for (var i = 0; i < formats.length; i++) {
  if (formats[i].available) {
    ht += "<a href='http://" + location.host + "/get_video?video_id=" + video_id + "&t=" + t + "&fmt=" + formats[i].fmt + "'>" + formats[i].dsc + "</a>";
  }
  else {
    ht += "<font color='#bbb'>" + formats[i].dsc + "</font>";
  }
  ht += "&nbsp;&nbsp;";
}
al.innerHTML = ht;
document.getElementById("watch-headline").appendChild(al);
})();