Mot-clé : Real-time

2001

Real Time Musical Events Streaming over Internet

International Conference on WEB Delivering of Music, 2001, Firenze, Italy. pp.147-154

We present a new protocol to transmit time ordered events in real-time over Internet and to operate a correct time rendering on the receiver side. This protocol provides solutions to compensate for the network latency, to optimize the bandwidth use and to take account of the clock drift of the different stations involved in a transmission. It is particularly suitable to transmit musical events such as MIDI events. The implementation is based on the User Datagra... Lire la suite

We present a new protocol to transmit time ordered events in real-time over Internet and to operate a correct time rendering on the receiver side. This protocol provides solutions to compensate for the network latency, to optimize the bandwidth use and to take account of the clock drift of the different stations involved in a transmission. It is particularly suitable to transmit musical events such as MIDI events. The implementation is based on the User Datagram Protocol (UDP) however, the proposed solution is independant of the underlying network layers.

Dominique Fober, Yann Orlarey, Stéphane Letz

Mots-clés :
Internet, MIDI, Real-time

This paper presents inter processus communication (IPC) real-time performances measured on different operating systems, including GNU/Linux, Windows 98, 2000, NT 4.0 and MacOS X. The adopted point of view is based on a client / server model. The operating systems behavior and message transmission latency times are evaluated in different contexts: with one to ten clients for the server, with systems more or less busy with alternate tasks. As we wanted to measure... Lire la suite

This paper presents inter processus communication (IPC) real-time performances measured on different operating systems, including GNU/Linux, Windows 98, 2000, NT 4.0 and MacOS X. The adopted point of view is based on a client / server model. The operating systems behavior and message transmission latency times are evaluated in different contexts: with one to ten clients for the server, with systems more or less busy with alternate tasks. As we wanted to measure real world performances, the benchmarks have been applied to operating systems running standard default configurations. Each time it was possible, we compared the different systems on the base of local Unix sockets communication way. But above all, we choose the most efficient communication way per system to evaluate the overall best performances that one can expect in a client / server model.

Dominique Fober, Yann Orlarey, Stéphane Letz

Mots-clés :
IPC, Operating, Real-time, Systems

MidiShare is a portable software architecture for musical applications, based on a client/server model. Up to now and along all the supported operating systems (GNU/Linux, MacOS, Windows), it has always been implemented at low level operating system layer. This choice was dictated by efficiency and time constraints. The main drawback of using low level layers is the lack of portability and the complexity of the kernel extensions design. Recent evolutions of ope... Lire la suite

MidiShare is a portable software architecture for musical applications, based on a client/server model. Up to now and along all the supported operating systems (GNU/Linux, MacOS, Windows), it has always been implemented at low level operating system layer. This choice was dictated by efficiency and time constraints. The main drawback of using low level layers is the lack of portability and the complexity of the kernel extensions design. Recent evolutions of operating systems, combined with important technology improvements, have made possible to consider a more portable architecture for MidiShare. This document presents a proposed new architecture, based on a user level design.

Dominique Fober, Yann Orlarey, Stéphane Letz

Mots-clés :
Music, Operating, Real-time, Systems

Transmission d'événements musicaux en temps réel sur Internet

Journées d'Informatique Musicale, 2001, Bourges, France. pp.225-236

Nous présentons un nouveau protocole s'appuyant sur UDP, permettant de transmettre des événements datés en temps réel et fournissant au récepteur, les moyens d'une restitution temporelle correcte. Ce protocole inclus des mécanismes permettant de compenser la latence du réseau et d'optimiser l'utilisation de la bande passante. Il prend également en compte les dérives d'horloges des différentes machines impliquées dans une transmission. Il est particulièrement ad... Lire la suite

Nous présentons un nouveau protocole s'appuyant sur UDP, permettant de transmettre des événements datés en temps réel et fournissant au récepteur, les moyens d'une restitution temporelle correcte. Ce protocole inclus des mécanismes permettant de compenser la latence du réseau et d'optimiser l'utilisation de la bande passante. Il prend également en compte les dérives d'horloges des différentes machines impliquées dans une transmission. Il est particulièrement adapté à la transmission d'événements musicaux tels que les messages MIDI.

Dominique Fober, Yann Orlarey, Stéphane Letz

Mots-clés :
MIDI, Real-time, Streaming, UDP

2000

Real-time Composition in Elody

International Computer Music Conference, 2000, Berlin, Germany. pp.336-339

Elody was initially an environment for musical composition allowing the description and algorithmic manipulation of non real-time musical structures. To allow the definition of real-time transformation processes, we have added a new primitive in the language : the real-time input stream. This object can be manipulated and transformed like non real-time objects even before being known. Evaluating a real-time expression gives as result a command sequence which dr... Lire la suite

Elody was initially an environment for musical composition allowing the description and algorithmic manipulation of non real-time musical structures. To allow the definition of real-time transformation processes, we have added a new primitive in the language : the real-time input stream. This object can be manipulated and transformed like non real-time objects even before being known. Evaluating a real-time expression gives as result a command sequence which drives a transformation engine. This one transforms a real-time input stream in an output stream.

Stéphane Letz, Dominique Fober, Yann Orlarey

Mots-clés :
Composition, Elody, Real-time

1999

We developed an asynchronous transfer mode-based environment for distributed musical rehearsals in an immersive teleconference environment. This article describes the technical specifications of the installations and the organization and studio setup of these rehearsals. We present our implementation of the environment and give the results obtained from the organized distributed musical rehearsal trials.

Yann Orlarey, Olivier Carbonel, Dominique Konstantas, Simon Gibbs

Mots-clés :
Distributed system, Music, Real-time

1997

Distributed Musical Rehearsal

International Computer Music Conference, 1997, Thessaloniki, Greece. pp.279-282

Bringing together a group of musicians and a conductor for a musical rehearsal requires advance planning and an important budget in order to cover travel and subsidiary costs. We have developed an ATM based telepresence environment allowing small groups of musicians that are located in different sites to rehearse as if they were present in the same room and have organized a first distributed musical rehearsal trial. The trial allowed us to test and evaluate the... Lire la suite

Bringing together a group of musicians and a conductor for a musical rehearsal requires advance planning and an important budget in order to cover travel and subsidiary costs. We have developed an ATM based telepresence environment allowing small groups of musicians that are located in different sites to rehearse as if they were present in the same room and have organized a first distributed musical rehearsal trial. The trial allowed us to test and evaluate the system, according to a methodology we developed and to draw first conclusions regarding its performance and usability.

Dominique Konstantas, Yann Orlarey, Simon Gibbs, Olivier Carbonel

Mots-clés :
Distributed system, Music, Real-time

1996

Recent developments of MidiShare

International Computer Music Conference, 1996, Hong Kong, China. pp.40-42

MidiShare is a real-time multi-tasks musical operating system first presented at the ICMC 89. Based on a client/server model, MidiShare offers fast and accurate real-time performances, multi-platform support, powerful inter-application communications, while considerably simplifying the development of complex real-time musical applications. MidiShare has been used by our institution for internal developments for more than 7 years. It was awarded by the Apple Tro... Lire la suite

MidiShare is a real-time multi-tasks musical operating system first presented at the ICMC 89. Based on a client/server model, MidiShare offers fast and accurate real-time performances, multi-platform support, powerful inter-application communications, while considerably simplifying the development of complex real-time musical applications. MidiShare has been used by our institution for internal developments for more than 7 years. It was awarded by the Apple Trophy 89 and the Paris-Cité 90 prize. Today, it is evolving toward a distributed multi-platform environment. The poster session will present and demonstrate its recent developments: the MidiShare environment, the developer's kit and documentation, multi-platform development issues, libraries, Ethernet support, compatibility with other systems and third parties applications.

Dominique Fober, Stéphane Letz, Yann Orlarey

Mots-clés :
MidiShare, Operating, Real-time, System

1995

Real Time Functional Languages

International Computer Music Conference, 1995, Banff, Canada. pp.549-552

This paper introduces two real-time functional programming languages. The first one aims to describe temporal trajectories. The second allows the manipulation of both real-time and deferred time streams. We shall describe the architecture of the real-time reduction machine used for evaluation. We shall also review the expected consequences of this approach.

Stéphane Letz, Yann Orlarey, Dominique Fober

Mots-clés :
Functional programming, Real-time

1990

An Efficient Scheduling Algorithm for Real-Time Musical Systems

International Computer Music Conference, 1990, Glasgow, United Kingdom. pp.194-198

Scheduling problems hold an important place in most real-time musical systems. We here present an algorithm allowing to solve these problems efficiently and ensuring a bounded low scheduling cost per event in any circumstances. Its principle is to maintain events all the better sorted out as their running time gets closer.

Yann Orlarey

Mots-clés :
Real-time, Scheduling

1989

MidiShare : a Real Time multi-tasks software module for Midi applications

International Computer Music Conference, 1989, Colombus, United States. pp.234-237

This paper introduces MidiShare, a real time software module meant for the development of Midi applications in a multi-tasks context. MidiShare brings facility in most of the fields concerned with the development of musical applications: communications management, precise time control, tasks scheduling. The originality of MidiShare lies in its capacity to deal with multiple Midi applications running at the same time. Besides, MidiShare offers some interesting p... Lire la suite

This paper introduces MidiShare, a real time software module meant for the development of Midi applications in a multi-tasks context. MidiShare brings facility in most of the fields concerned with the development of musical applications: communications management, precise time control, tasks scheduling. The originality of MidiShare lies in its capacity to deal with multiple Midi applications running at the same time. Besides, MidiShare offers some interesting possibilities, particularly the one consisting in a dynamic connection between Midi applications through internal links. MidiShare was at first designed for the Macintosh under MultiFinder, it is now available on other machines.

Yann Orlarey, Hervé Lequay

Mots-clés :
Communication, MIDI, Operating, Real-time, System