add: if (gtk_xine_can_set_volume (gtx) == FALSE) return 0;
context: gtk_xine_get_volume (GtkXine *gtx){	int volume = 0;	g_return_val_if_fail (gtx != NULL, 0);	g_return_val_if_fail (GTK_IS_XINE (gtx), 0);	g_return_val_if_fail (gtx->priv->xine != NULL, 0);	volume = xine_get_param (gtx->priv->stream,			XINE_PARAM_AUDIO_VOLUME);	return volume;}