Master 2015 2016
Stages de la spécialité SAR
Visual Debugging Environment for Antescofo an Interactive Music System

Site : Team Mutant
Lieu : The internship will take place at the Institution of Research in Coordination Acoustic/Music (IRCAM) in the research team MuTant. Link to the team’s webSite:
Encadrant : Clément Poncelet Sanchez and Florent Jacquemard
Dates :from 03/2016 to 08/2016
Rémunération :Standard
Mots-clés : Master SAR, autre qu’ATIAM


The main problem of the internship can be summarized as : « How can we represent statically the execution states of an Interactive Music System ? »

The team MuTant is developing the Interactive Music System Antescofo ( whose purpose is to accompany musicians during live performances (acting like a real musician). This system plays during a performance by executing a program called augmented score. This program describes the electronics accompaniment according to the detected instrumental events. Then at runtime, the system detects the musician position (in the score) and its tempo, handles possible errors, and finally plays the electronic part of the score. These goals imply strong requirements of temporal reliability and a robustness to errors (from the musician and the detection algorithm). Indeed a main problem in music is that a musician performance is unique and so two performances are never the same ( The programmers must be able to anticipate the reactions to a variety of performances as large as possible.

Then we have a need for an authoring environment for editing and debugging augmented scores. Two approaches have been developed in the MuTant team to deal with these problems :

1- The graphical edition tool Ascograph [a] provides yet a representation of the augmented score (what the system has to detect and what it has to play). User Interfaces are a key point for this problem, because they deal with the presentation of the communications and the possible interactions between humans and systems. They are very important and has to be relevant and clearly presented to make easier the understanding of system behaviors. Thus for our context, aspects as the time, the dynamisms (runtime evolution) and the nondeterminism have to be shown in the interface which becomes hard to design [b]. Ascograph provides a « play mode » simulating an ideal performance (a perfect performance without error nor interpretation, like a robot playing the instrumental events of the score). In particular it cannot permit the simulation of other performances and cannot present an effective view of the system’s reactions according such kind of performance.

2- A framework for automatic test of Antescofo augmented scores [c]. It is based on formal models which have to properly describe the system interactions. It focus on the timed traces to capture the problem of time in the system and to improve its timed reliability with reference to durations. It includes an offline and online tools for the generation of sets of performances (called test cases) and executes them on Antescofo to output a verdict wether the system responses are on time or not (if the system behavior is conform to the model one). However this framework uses a command line interface and has few visualisations of the simulation done during the tests. Moreover the generation of performances is done automatically and makes a user decision impossible during the generation phase.

The internship subject is at the convergence of these two approaches.

The goal of this research work is to help the team researchers in the design of an unified environment centered on the performance generation. This environment has to be used for visualizing a performance and the system reactions, editing a performance and simulating/testing the system with it. The student will implement a debugging environment for Ascograph and complete the timed sequence view written in C++ using openFrameworks. An editor of input traces must be added to the existing implementation. The simulation requires communications with Antescofo which is done via Open Sound Control (OSC).

Note : The simulation of Antescofo can be done in real-time (like a real play) or in fast-foward (pass the time without waiting). The latter case uses a Virtual clock and raises problems when one wants to pass from one mode to the other. Student investigation will be encouraged to add this option in the debugging interface.

State-of-the-art :
- [IMS] : Interfaces [1-2-3]
- [Models] [4],,

KeyWords : C++ openFrameworks Mixed Music Visualization Model-Based testing


[a] T. Coffy, J-L Giavitto, A. Cont : AscoGraph : A User Interface for Sequencing and Score Following for Interactive Music. [b] G. Burloiu, A. Cont : Visualizing Timed, Hierarchical Code Structures in AscoGraph. [c] C. Poncelet, F. Jacquemard : Model Based Testing of an Interactive Music System. [1] D. Fober, Y. Orlarey, S. L. Inscore - an environment for the design of live music scores. [2] M. Puckette. Using pd as a score language. [3] J. Arias, M. Desainte-Catherine and C. Rueda. A framework for Composition, Verification and Real-time Performance of Multimedia Interactive Scenarios. [4] A. Hessel, K-G Larsen, M. Mikucionis, B. Nielsen, B. Pettersson and A. Skou. Testing Real-Time Systems Using UPPAAL.