A first gate and a second gate are preferably PMOS and NMOS transistors, respectively, formed in an n-type well and a p-type well. The valve has a carrier liquid duct and a chemical liquid duct opening into the carrier duct for interconnecting the inlet passage in a first rotative position of the valve, and the valve is capable of closing the inlet passages in a second rotative position of the valve. The method, electronic device and computer readable memory further apply the transition effect to the current and next media elements; and play the current and next media elements with the applied transition effect.