MPEG System Streams in Best-Effort Networks

The MPEG format is widely used and therefore an attractive vehicle for the distribution of video and audio material over the Internet. However, the hierarchical structure of MPEG systems complicates the task of delivering continuous, synchronized streams of video and audio in a best-effort environment (today’s Internet). If the network throws away packets on encountering congestion, the video and audio stream may loose synchronization for a number of frames. Therefore, adapting the resource demands of an MPEG system must be done by an entity that is knowledgeable of the MPEG system structure: an MPEG system filter. This paper describes the integration of such an MPEG system filter into a network. Our experience to date indicates that mid-range PCs can host such a filter, and that the filter succeeds in adapting the resource requirements of an MPEG system in response to changes in the network load.