Automatic Verification of a Lip Synchronisation Algorithm Using UPPAAL

We present the formal speciication and veriication of a lip synchronisation algorithm using the real-time model checker UPPAAL. A number of speciications of this algorithm can be found in the literature, but this is the rst automatic veriication. We take a published speciication of the algorithm, code it up in the UPPAAL timed automata notation and then verify whether the algorithm satisses the key properties of jitter and skew. The veriication reveals some aws in the algorithm. In particular, it shows that for certain sound and video streams the algorithm can timelock before reaching a prescribed error state.