Adaptive two-layer MPEG-2 codec for video transmission over ATM

Classical approaches of video scalability may produce some problems for medium or high cell loss ratio and when traffic load on the transmission network is rapidly varying. In this paper, the standard MPEG-2 video codec is modified to manage packet losses during the transmission over an ATM network. A layered coding scheme is adopted, which uses an adaptive data-partition method (ADP) to generate two compressed video layers to be transmitted with different priority. The MPEG-P slice structure of the upper layer is completely redefined and a new synchronization procedure between the two layers is introduced. The experimental results prove the superiority of the two-layer model with respect to the standard approach, particularly for increasing values of cell loss probability.