DESIGN OF A TRANSPORT CODING SCHEME FOR HIGH-QUALITY VIDEO OVER ATM NETWORKS

In this paper, we explore the design of forward error control (FEC)-ba sed error concealment schemes for digital video transmission on ATM ne tworks. III particular, me study the impact of code selection on the o verall performance and provide a judicious code selection strategy, Th e use of FEC provides an active and powerful means of recovery from pa cket loss which is particularly useful when the encoded video material has high motion and scene changes, The best technique for applying FE C is tee throttle the source coding rate so that the overall transmiss ion rate after EEC application equals the original unprotected rate, H owever, the resulting performance then depends on the particular code selected, A well-chosen code provides good protection while allowing l ittle sacrifice in quality and at the same time satisfies specified de lay constraints, Our results show that a single code is generally insu fficient to provide good performance under all operating conditions, H owever, a small group of codes can be preselected, using the efficient code-selection strategy described here, which will provide efficient and robust performance over a wide range of channel conditions, We sho w that this simple code selection strategy is sufficient to select cod es judiciously for a nide range of operating conditions and constraint s, Employing this selection strategy, we demonstrate that moderate len gth codes are sufficient to provide good performance while meeting the imposed delay constraint.