<title>Error-resilient video transmission over the Internet</title>

Abstract

Targeting multimedia communications over the Internet, this paper describes a technique in the direction of improved packet loss resiliency of video compressed streams. Aiming at a best trade-off between compression efficiency and packet loss resiliency, a procedure for adapting the video coding modes to varying network characteristics is introduced. The coding mode selection is based on a rate-distortion procedure with global distortion metrics incorporating channel characteristics under the form of a two states Markov model. This procedure has been incorporated in an MPEG-4 video encoder. It has been observed that, in error-free environments, the channel adaptive mode selection technique allows a significant gain with respect to simple conditional replenishment. On the other hand, under loss conditions, it is shown that this procedure significantly improves the encoder's performance with respect to the original MPEG-4 encoder, to approach the robustness of conditional replenishment mechanisms.