Adaptive synchronization for continuous media storage in a multimedia communication system

The paper introduces and analyzes the synchronization concept used in a new B-ISDN multimedia communication system. The methods proposed have been simulated and then implemented in the actual prototype system. As opposed to the common time stamping concepts, we use a hierarchical approach that first smooths each stream timing and then synchronizes the streams to each other by delaying the "earlier" ones. The concept is based on the "Adaptive Method", but it has been extended and improved to support framed video and audio as well as unstructured, constant bit rate voice streams without additional framing overhead. Another interesting point is that the multimedia storage device can preserve the relative timing information between the streams, i.e. there is no difference whether the transmission is live or stored. It is also a convenience of this synchronization and storage concept, that the operating system can keep the stored video and audio tracks themselves, as well as their directory information on the same disk.