ytdl-core/lib/info.js

Youtube video downloader in pure javascript.

var qs       = require('querystring');
var _        = require('underscore');
var crequest = require('./crequest');
var util     = require('./util');
var sig      = require('./sig');


var INFO_URL = 'http://www.youtube.com/get_video_info?' +
'hl=en_US&el=detailpage&video_id=';
var VIDEO_URL = 'http://www.youtube.com/watch?v=';
var KEYS_TO_SPLIT = [
  'keywords',
  'fmt_list',
  'fexp',
  'watermark',
  'ad_channel_code_overlay'
];


/**
 * Gets info from a video.
 *
 * @param {String} link
 * @param {Object} requestOptions
 * @param {Function(Error, Object)} callback
 */
module.exports = function getInfo(link, requestOptions, callback) {
  if (typeof requestOptions === 'function') {
    callback = requestOptions;
    requestOptions = {};
  } else {
    requestOptions = _.clone(requestOptions);
  }

  var id = util.getVideoID(link);
  requestOptions.url = INFO_URL + id;
  link = VIDEO_URL + id;
  var downloadURL = requestOptions.downloadURL;
  delete requestOptions.downloadURL;

  crequest(requestOptions, function(err, body) {
    if (err) return callback(err);

    var info = qs.parse(body);

    if (info.status === 'fail') {
      callback(new Error('Error ' + info.errorcode + ': ' + info.reason));
      return;
    }

    // Split some keys by commas.
    KEYS_TO_SPLIT.forEach(function(key) {
      if (!info[key]) return;
      info[key] = info[key]
        .split(',')
        .filter(function(v) { return v !== ''; });
    });

    // Convert some strings to javascript numbers and booleans.
    Object.keys(info).forEach(function(key) {
      var val = info[key];
      var intVal = parseInt(val, 10);
      var floatVal = parseFloat(val, 10);

      if (intVal.toString() === val) {
        val = intVal;
      } else if (floatVal.toString() === val) {
        val = floatVal;
      } else if (val === 'True') {
        val = true;
      } else if (val === 'False') {
        val = false;
      }
      info[key] = val;
    });

    if (info.fmt_list) {
      info.fmt_list = info.fmt_list.map(function(format) {
        return format.split('/');
      });
    } else {
      info.fmt_list = [];
    }

    info.formats = util.parseFormats(info);

    if (info.video_verticals) {
      info.video_verticals = info.video_verticals
        .slice(1, -1)
        .split(', ')
        .filter(function(val) { return val !== ''; })
        .map(function(val) { return parseInt(val, 10); })
        ;
    }

    if (downloadURL) {
      sig.get(link, info, requestOptions.debug, callback);
    } else {
      callback(null, info);
    }
  });
};