OSs that support multimedia differs from the traditional ones (OSs that doesn't support multimedia) in the following three ways:
Let's discuss briefly about process scheduling.
The simplest type of video server is the one that can support the display of a fixed number of movies, all using the same frame rate, video resolution, data rate, and some other parameters.
In this model, the number of users changes as viewers come and go, frame sizes vary widely due to the video compression nature and different movies may have different resolutions, the scheduling of more than one competing processes, some/all of which have deadlines that must be met is called as real-time scheduling.
The classic static real-time scheduling algorithm for preemptable periodic processes is Rate Monotonic Scheduling or RMS in short.
The rate monotonic scheduling can be used for the processes that met the following five conditions:
Earliest deadline first is basically a dynamic algorithm that doesn't require the processes to be periodic as does the rate monotonic algorithm. Nor does it require the same run time per central processing unit burst, as does rate monotonic scheduling.