Real-time operating systems for multimedia processing

Real-time DSP operating systems have recently appeared in several commercial products that integrate multimedia processing into PCs. The DSP OSs, which run on DSP subsystems integrated on PC adapter cards, include admission control capabilities to ensure that timing guarantees are met and sufficient resources are available to handle the processing demands of a given mix of applications. Admission control is possible because the timing characteristics of the kernels are fully understood and real-time scheduling is used for all kernel resources. If a real-time approach is to be successful in host OSs, a similar approach must be followed. We compare the performance of the DSP OS and host OS approaches. We describe the DSP OS architectures and their admission control algorithms. We describe a general framework we have developed which models OSs for the purpose of admission control