rem: GError **error)
add: GError **error, guint32 *fourcc)
context: bacon_video_widget_open (BaconVideoWidget *bvw, const gchar *mrl,		GError **error){	GstElement *datasrc = NULL;		g_return_val_if_fail (bvw != NULL, FALSE);	g_return_val_if_fail (mrl != NULL, FALSE);	g_return_val_if_fail (BACON_IS_VIDEO_WIDGET (bvw), FALSE);	g_return_val_if_fail (bvw->priv->play != NULL, FALSE);	g_return_val_if_fail (bvw->priv->mrl == NULL, FALSE);	g_message ("bacon_video_widget_open: %s", mrl);	bvw->priv->mrl = g_strdup (mrl);	if (bvw->priv->vis_signal_blocked) {		g_signal_handler_unblock (	G_OBJECT(bvw->priv->play),									bvw->priv->vis_sig_handler);		bvw->priv->vis_signal_blocked = FALSE;	}		gst_play_connect_visualisation ( bvw->priv->play, TRUE);	gst_play_need_new_video_window ( bvw->priv->play);	if (g_file_test (mrl,G_FILE_TEST_EXISTS))	{		datasrc = gst_element_factory_make ("filesrc", "source");	} else {		datasrc = gst_element_factory_make ("gnomevfssrc", "source");	}	if (GST_IS_ELEMENT(datasrc))		gst_play_set_data_src (bvw->priv->play, datasrc);		bvw->priv->media_has_video = FALSE;	bvw->priv->stream_length = 0;		return gst_play_set_location (bvw->priv->play, mrl);;}