dAudioFirst)
          {
              mediasource_test(function(test, mediaElement, mediaSource)
              {
                  mediaElement.addEventListener("error", test.unreached_func("Unexpected event 'error'"));
                  MediaSourceUtil.fetchManifestAndData(test, manifestFilenameAudio, function (typeAudio, dataAudio)
                  {
                      MediaSourceUtil.fetchManifestAndData(test, manifestFilenameVideo, function (typeVideo, dataVideo)
                      {
           