Section: Research Program

Semantics, Verification and Test of Mixed Scores

Participants : Jean-Louis Giavitto, Florent Jacquemard, Clément Poncelet.

We address the questions of functional reliability and temporal predictability in score-based interactive music systems such as Antescofo. On the one hand, checking these properties is difficult for these systems involving an amount of human interactions as well as timing constraints (for audio computations) beyond those of many other real-time applications such as embedded control. On the other hand, although they are expected to behave properly during public concerts, these systems are not safety critical, and therefore a complete formal certification is not strictly necessary in our case.

Our objective in this context is to provide techniques and tools to assist both programmers of scores (i.e. composers) and the developers of the system itself. [47], [46]. It should be outlined that the former are generally not experts in real-time programming, and we aim at giving them a clear view of what will be the outcome of the score that they are writing, and what are the limits of what is playable by the system. To help the development of Antescofo, we have built a framework for automated timed conformance testing. [14], [18], [58], [60], [59].

In both cases, it is important to be able to predict statically the behavior of the system in response to every possible musician input. This cannot be done manually and requires first a formal definition of the semantics of scores, and second using advanced symbolic state exploration techniques (model checking)  [43].