In this paper we propose SAVe, a real-time Stream Authentication scheme for Video streams. Each packet in the stream is authenticated to correspond to packet loss seen in UDP-based streaming. Since temporal and spatial compression techniques are adopted for video stream encoding, there are differences in the importance and dependencies between frames. Therefore to take the characteristics special to video into consideration, in SAVe the amount of redundancy distributed to each frame is adjusted according to the importance of each frame. Simulation results show that SAVe improves the playing rate 50% compared to previously proposed schemes.