目前视频图象在 IP分组网中的传输正被日益广泛地应用 (如 :视频电话、视频会议 ).但是，由于 IP分组网固有的特点，致使 IP分组包丢失的现象不可避免，并极大地影响了视频传输的服务质量.由于参考图象选择法RPS(Reference Picture Selection)是一种较好的视频图象差错复原的方法，因此，为了改善因分组包丢失而对视频传输带来的质量下降问题，利用 RTCP协议提供反馈信息和利用参考图象选择法进行视频图象复原，实现了一种在 IP分组网中进行视频传输的差错控制机制.实践证明，通过这种方法不仅可减小因分组包丢失而对视频图象信息带来的损害，而且可提高视频图象的传输质量，此方法适用于基于分组网的视频传输系统.

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.