A Comparison of Streams and Time Advance As Paradigms for Multimedia Systems

A common model for multimedia systems is the stream, an abstraction representing the flow of continuous time-dependent data such as audio samples and video frames. The primary feature of streams is the ability to compose processes by making stream connections between them. An alternative time-advance model is related to discrete-event simulations. Data is computed in presentation order, but in advance of the actual presentation time. Timestamped, buffered data is subsequently output with low latency. The primary feature of time-advance systems is accurate output timing. Stream-based and time-advance systems are compared in terms of the programming model, flow control, buffering, support for interaction, synchronization, modularity issues, and real-time requirements. This research was performed by the Carnegie Mellon Information Technology Center and supported by the IBM Corporation.