JS YouTube Download Userscript

jsyoutube

(function ()
{
    // Video Settings
    var VIDEO_TITLE = document.getElementById('eow-title').getAttribute('title');
    var VIDEO_ID = window.location.href.match(/v=[A-Za-z0-9-_]{11}/)[0].substring(2);

    // Script settings
    var SETTINGS = {
        "DEBUG_MODE": false,
        "SCRIPT_VERSION": "1.0.3",
        "QUALITY": {
            "5": "240p (FLV)",
            "34": "380p (FLV)",
            "35": "480p (FLV)",
            "18": "360p (MP4)",
            "22": "720p (MP4)",
            "37": "1080p (MP4)",
            "43": "360p (WebM)",
            "44": "480p (WebM)",
            "45": "720p (WebM)",
            "46": "1080p (WebM)",
            "102": "720p (WebM)",
            "100": "360p 3D(WebM)",
            "101": "480p 3D(WebM)"
        }
    };

    con(JSON.stringify(SETTINGS));

    // Create the main interface div box along with the download button
    createDownloadBox();

    // Get an array of all available download links
    links = getDownloadLinks();

    // Populate the combox box with available links
    populateList(links);

    // Download button is clicked
    document.getElementById('download-button').addEventListener('click', function (e)
    {
        con(e);
        window.location = document.getElementById('qualitySelect').value;
    });

    function createDownloadBox()
    {
        var headline = document.getElementById('watch-actions');

        // Create the main download widget box
        var box = document.createElement('div');
        var boxCSS = 'padding-top:15px';

        box.setAttribute('style', boxCSS);
        box.setAttribute('id', 'download-box');

        headline.appendChild(box);

        // Attach the script log
        var logoLink = document.createElement('a');
        var logoImg = document.createElement('img');
        logoImg.setAttribute('src', 'http://i40.tinypic.com/j7ax01.png');
        logoImg.setAttribute('class', 'yt-uix-tooltip-reverse yt-uix-tooltip');
        logoImg.setAttribute('data-tooltip-text', 'Visit YouTube + MP3 Script Website (opens a new window)');
        logoLink.href = 'http://userscripts.org/scripts/show/123836';
        logoLink.setAttribute('target', '_blank');
        logoLink.setAttribute('style', 'position:relative;top:6px;');
        logoLink.appendChild(logoImg);
        box.appendChild(logoLink);

        // Create the combo box
        var selector = document.createElement('select');
        selector.setAttribute('id', 'qualitySelect');
        selector.setAttribute('style', '');
        box.appendChild(document.createTextNode('Available Formats '));
        box.appendChild(selector);

        // Create the download button
        var button = document.createElement('button');
        button.setAttribute('class', 'yt-uix-button yt-uix-tooltip');
        button.setAttribute('id', 'download-button');
        button.setAttribute('style', 'position:relative;bottom:2px;left:10px;');
        button.appendChild(document.createTextNode('Download video'));
        box.appendChild(button);
        return box;
    }

    function getDownloadLinks()
    {
        var PAGE_SOURCE = document.body.innerHTML;
        var downloadLinks = [];
        var matches = PAGE_SOURCE.match(/m_map": "url=(.*?)", "/g)[0].split('url=');

        // Iterate through each valid download link and clean it up
        for (i = 0; i <= matches.length - 1; i++)
        {
            // Make sure it's a valid download link
            if (matches[i].indexOf('lscache') !== -1)
            {
                downloadLinks.push(unescape(matches[i]).replace(/(\\u0026quality.+|\\u0026type.+)/, ''));
            }
        }
        return downloadLinks;
    }

    function con(message)
    {
        if (SETTINGS.DEBUG_MODE) GM_log(message);
    }

    function populateList(list)
    {
        con('Populating combo box with ' + list.length + ' links.');
        var qSelect = document.getElementById('qualitySelect');

        // Append MP3 download link
        qSelect.innerHTML += '<option value="http://www.youtube-mp3.org/#v=' + VIDEO_ID + '"> MP3</option>';

        // iterate through the download link list and append it to the select combo box
        for (i = 0; i <= list.length - 1; i++)
        {
            // Attach the video's title to the download link
            var downloadLink = list[i] + "&title=" + VIDEO_TITLE;

            // Get the itag query string which indicates video format and quality
            var format = downloadLink.match(/itag=\d{1,3}/)[0].substr(5);
            var quality = SETTINGS.QUALITY[format];

            // SKIP unknown quality - FIXME
            if (typeof quality === 'undefined')
            {
                con("Ran into unknown quality: " + format + ". Skipping...");
                continue;
            }

            con('Video format: ' + format);
            qSelect.innerHTML += '<option value="' + downloadLink + '" >' + quality + '</option>';
            con('Link ' + (i + 1) + ' proccessed.');
        }
    }
})();