Scheduling real-time multimedia tasks in network processors

Several companies have introduced powerful network processors (NP) that can be placed in active routers to execute application level tasks in the network. An NP consists of a number of on-chip processors to carry out packet level parallel processing operations. We propose to employ them for multimedia streaming (transcoding) to convert the incoming video streams to low bit-rate media units as per the requirements of the clients. To effectively schedule the parallel transcoding operations in an active router, we propose a static sequentialized batch-coscheduling (SSBC) scheme to meet both load balancing and real-time requirements for media streaming, based on divisible load theory (DLT). We first analyze the feasibility and optimality of the load distribution schemes from the theoretical perspectives, and then present separate solutions for non-delay-sensitive streams and delay-sensitive streams. Rigorous simulations and experiments have been carried out to evaluate the performance.