An end-to-end approach for optimal mode selection in Internet videocommunication: theory and application

摘要

Rate-distortion (R-D) optimized mode selection is a fundamentalnproblem for video communication over packet-switched networks. Thenclassical R-D optimized mode selection only considers quantizationndistortion at the source. Such an approach is unable to achieve globalnoptimality under the error-prone environment since it does not considernthe packetization behavior at the source, the transport pathncharacteristics, and receiver behavior. This paper presents annend-to-end approach to generalize the classical theory of R-D optimizednmode selection for point-to-point video communication. We introduce annotion of global distortion by taking into consideration both the pathncharacteristics (i.e., packet loss) and the receiver behavior (i.e., thenerror concealment scheme), in addition to the source behavior (i.e.,nquantization distortion and packetization). We derive, for the firstntime, a set of accurate global distortion metrics for any packetizationnscheme. Equipped with the global distortion metrics, we design an R-Dnoptimized mode selection algorithm to provide the best tradeoff betweenncompression efficiency and error resilience. The theory developed innthis paper is general and is applicable to many video coding standards,nincluding H.261/263 and MPEG-1/2/4. As an application, we integrate ourntheory with point-to-point MPEG-4 video conferencing over the Internet,nwhere a feedback mechanism is employed to convey the pathncharacteristics (estimated at the receiver) and receiver behavior (errornconcealment scheme) to the source. Simulation results arendiscussed