Formal Veri cation and Analysis of Multimedia Systems

Sergio Campos Berthier Ribeiro-Neto Autran Macedo Luciano Bertini Computer Science Department Federal University of Minas Gerais Brazil Abstract In this work we discuss the use of formal methods tools, particularly symbolic model checking, in the veri cation and analysis of multimedia systems. We focus on the use of the Verus tool. Verus is based on symbolic model checking and has been used to verify a number of real-time applications. We show that it can be used not only to check the correctness of a multimedia system, but also to assist in the design of more e cient systems. In this work in particular, we apply Verus to the veri cation of a low cost video on demand server called ALMADEM-VoD. Modeling this server in Verus provides great insight into its design and its dynamic behavior. Using the quantitative estimates provided by Verus, we check the empirical results generated by our server. Such comparative analysis allows us to identify imperfections in the model and also to detect programming mistakes in the implementation of our server, which would have been di cult to detect otherwise. The correction of such mistakes leads to improved performance and increased reliability.