Resource Allocations Protocols Impact on MPEG Sequence Quality
Slim Gara, Guy Pujolle · 1998
MPEG-2 video compression is the standard retained for video applications. Two encoding schemes are defined: open-loop and closed-loop. In this paper, some characteristics of the two MPEG encoding schemes are studied. We observe through the carried experiments that, with the same mean rate, open-loop encoding quality is better and less variable than closed-loop encoding quality. The ITU and ATM-Forum have defined ATM transfer capabilities in order to transport a wide variety of traffic classes. The impact of ATM contracts on the quality of a MPEG sequence is investigated. We show that the sequence quality is less damaged by reducing image size at the encoder level with ABT/DT contract than by a random cell loss inside the network with rt-VBR contract. Finally, we present a novel mechanism for real-time video transmission over ATM networks based on the elastic version of ABT/DT contract.