Minimizing memory requirement for a multi-rate continuous media server

In this paper, we examine and construct a mathematical model of buffer sharing problem for a multi-rate CM server, which supports media steams of different bit rates. On the basis of the developed model, we derive the maximal required buffer of a multi-rate CM server with different disk scheduling policies. Based on the observations from some experiments, we learn that not only the data retrieval timing for each stream but also the retrieval sequence of the streams has led to surprising impacts on the maximal buffer requirement of a multi-rate CM server. Therefore, we elaborate a novel disk scheduling scheme to obtain a better retrieval sequence, which can reduce the memory requirement of a multi-rate CM server by using memory sharing. According to the simulation results, the proposed method can reduce up to 36% memory buffer than that of the conventional non-sharing scheme, and about 15% than that of the worst case of the conventional buffer-sharing scheme.