code: function (callback) {
      var xhr = new XMLHttpRequest(),
          url = this.url,
          recording = this,
          contentLength = 0;
  
      xhr.onreadystatechange = function () {
        if (xhr.readyState === xhr.DONE) {
          if (xhr.status === 200 || xhr.status === 0) {
            if (xhr.responseText) {
  
              recording.finishLoad(xhr.responseText, callback);
  
            } else {
              console.error('Leap Playback: "' + url + '" seems to be unreachable or the file is empty.');
            }
          } else {
            console.error('Leap Playback: Couldn\'t load "' + url + '" (' + xhr.status + ')');
          }
        }
      };
  
      xhr.addEventListener('progress', function(oEvent){
  
        if ( recording.options.loadProgress ) {
  
          if (oEvent.lengthComputable) {
            var percentComplete = oEvent.loaded / oEvent.total;
            recording.options.loadProgress( recording, percentComplete, oEvent );
          }
  
        }
  
      });
  
      this.loading = true;
  
      xhr.open("GET", url, true);
      xhr.send(null);
    }
docs: optional callback once frames are loaded, will have a context of player