Kaleido: an environment for composing networked multimedia applications

Kaleido is a system for flexible concurrent processing of multimedia flows where applications are decomposed into building blocks called "active buffers" whose computation and I/O requirements are characterized so as to allow reservation of CPU and bandwidth resources. The input and output ports of active buffers in a Kaleido application are connected by channels. The active buffers in an application may themselves be mapped either to a single compute node, or to multiple compute nodes connected by a network. The Kaleido runtime system software transparently handles the resulting local and remote channels by providing the abstraction of a distributed "active backplane". This "active backplane" also allows dynamic applications whose functional partitioning among compute nodes can be adapted to network, server, and terminal resources. The paper also describes I/O-centric hardware extensions that we have developed for efficient handling of concurrent multimedia streams in Kaleido.