Packet loss resilient videoconferencing using H.263+

Real-time video transmission over the Internet is becoming increasingly desirable for videoconferencing and other interactive applications. The reliable transport protocols used by the Internet were designed mainly for non-real time data, and cannot be used for delay critical applications, which must therefore be able to cope with packet loss. Motion compensated video coding is especially sensitive to loss because of temporal error propagation. In this paper, the effect of packet loss on H.263+ video transmitted using the real-time transport protocol (RIP) is assessed. Various algorithms are described to minimise or prevent temporal error propagation. These algorithms do not rely on retransmissions and do not introduce more than one frame delay, and are therefore suitable for real-time and multicast applications. It is shown that the robustness of H.263+ video can be greatly improved using these techniques. Such techniques can also be applied to other motion compensated video coding standards such as MPEG-4 and H.26L.