EVALUATION OF A CPU SCHEDULING MECHANISM FOR MULTIMEDIA SYSTEMS

Multimedia applications handling audio and video data have to obey tim e characteristics of these media types. Besides a basic functionality to express time relations, correctness with respect to time constraint s requires mechanisms which lead to favoured processing of multimedia operations. CPU scheduling techniques based on the experience from rea l-time operating systems offer a solution and provide multimedia appli cations with the ability to meet time-related quality of service requi rements. This paper discusses mechanisms to express time in multimedia systems and describes an implementation of a CPU scheduler designed t o run under IBM's UNIX derivate AM. The evaluation of the implementati on based on measurements shows that the scheduler is able to support t he time requirements of multimedia applications and that such mechanis ms are indeed necessary since otherwise deadline violations occur.