Now

video delivery based on IP network is being used more and more. (Example: video phone and video conferences). But

since characteristics of IP network

packet loss that impairs quality of video delivery severely is inevitable. Reference Picture Selection (RPS) is a better way for error resilience. RPS does not necessarily mean extra delay in the encoder

but it need that a feedback channel can be set-up from the decoder to the encoder in order that the decoder can inform the encoder about which part of the transmitted information is corrupted by errors. RTCP (real time control protocol) is the control protocol of RTP (real-time transport protocol). RTCP provide a higher-level control information and a feedback channel. In this paper

by RPS and improved RTCP

we design and implement a mechanism that controls error in video delivery in order to reduce damage of packet loss. It has been found that this error control method can greatly improve the quality of the images transmitted on Packet network

for instance Internet.