Proceedings of the Linux Audio Conference 2010 May 1st – 4th, 2010 Hogeschool voor de Kunsten Utrecht Utrecht, The Netherlands Published by Hogeschool voor de Kunsten, Utrecht, The Netherlands May 2010 All copyrights remain with the authors http://lac.linuxaudio.org/2010 Credits Cover design: Tijs Ham Layout: Frank Neumann Editor: Maurits Lamers Typesetting: LaTeX and pdfLaTeX About the cover The cover text is created using a PureData patch. When you play the patch, you should get an idea of what the penguin at the bottom is singing... Thanks to: Martin Monperrus for his webpage ”Creating proceedings from PDF files” Printed in Hilversum by Print service ”de Toekomst” http://www.detoekomst.nl ii Partners and Sponsors Hogeschool voor de Kunsten Loohuis Consulting Linux Weekly News Linuxaudio.org Elastique Tonehammer Muziekinstituut MultiMedia iii LAC 2010: a Linux Audio Conference Since 2003 the Linux Audio Conference has become a yearly recurring international event where users and developers of open source music software and Linux Audio in particular get together. This year the LAC, as it is known by some, is hosted by the Hogeschool voor de Kunsten Utrecht. The HKU offers bachelor and master programmes for various disciplines such as Music, Theatre, Design, Media, Games, Interaction and Music & Technology. Students and alumni of the HKU participate in the organisation and contribute to the conference. So why is the HKU doing this? And why am I doing this? To answer the first question: because the HKU recognises the importance of Open Source Software for education and, vice versa, by involving the generations that will shape the future we hope to enrich the Linux Audio community. As for the second question: I’m doing this because I am a long time Linux Audio user, an Open Source advocate, a lecturer at the HKU and I need the freedom that Open Source Software gives me. Oh, and because at last year’s LAC in Parma, Italy, I said to someone in the pub how nice it would be to host this conference in a different country or even continent every year. From that moment on my fate was sealed: I was going to get this party to Utrecht. Originally a Linux Audio developers meeting, the LAC has developed into a conference that comprises not only Linux Audio but also other Open Source Music Software and Open Content. Of course, with Linux being a true Open Source platform, Linux Audio remains the backbone of the venue. The Linux Audio community is more alive than ever, as is demonstrated by this book with its collection of high-standard papers. The conference offers enough diversity to attract people with different backgrounds and one common denominator: their devotion to open systems. With over 75 scheduled events such as presentations, workshops, discussion panels and concerts, there are lots of opportunities for everyone to participate, learn and find new inspiration, work relations and even friends. My personal hope for the LAC 2010 is that it will contribute to the acceptance and use of open systems for creating, producing, understanding and enjoying music. To conclude I would like to thank Ad Wisman for giving his approval and Jan IJzermans and Rens Machielse for backing me up. During the entire process, Robin Gareus and Frank Neumann did a tremendous job with advice, support, creating nifty solutions and handling the entire process from papers to proceedings. Thanks guys, I owe you one! Ico Bukvic, thanks for keeping the server up and running. Thank you Farida Ayojil for all your support with respect to the location, security and catering. v And then there are Than van Nispen tot Pannerden and Bertus van Dalen who generated lots of ideas, helped out in numerous situations and gave a whole new dimension to this conference. To all the others I didn’t mention: your contributions are highly appreciated. I wish you all a very good LAC 2010 and hope you enjoy your stay in Utrecht! Marc Groenewegen vi Special thanks to ... Conference Organisation Marc Groenewegen Robin Gareus Frank Neumann Marcel Wierckx Than van Nispen tot Pannerden Bertus van Dalen Program Marc Groenewegen Than van Nispen tot Pannerden Bertus van Dalen Robin Gareus Frank Neumann Streaming Jorn¨ Nettingsmeier Christian Thater¨ Emile Bijk Herman Robak Wouter Verwijlen Raffaella Traniello Ernst Roza T-shirt Design Tijs Ham Public Relations Marc Groenewegen Femke Langebaerd Conference Website Marc Groenewegen Robin Gareus Logo Design Niek Kok Tamara Houtveen Timetable database and web front-end Robin Gareus Marc Groenewegen vii Concert Organisation Marc Groenewegen Concert Sound Stefan Janssen Composition Contest ”150 Years of Music Technology” Than van Nispen tot Pannerden Magazine ”The LAC Times” Niek Kok Sander Oskamp Marc Groenewegen Than van Nispen tot Pannerden Bertus van Dalen Maarten Brinkering Marcel Wierckx Consulting and Assistance Luc Nieland Than van Nispen tot Pannerden Bertus van Dalen Danique Kamp Farida Ayojil Henk Schraa Jos Bertens Roderick van Toor Sanne Smits Maurits Lamers Armijn Hemel Marije Baalman Fons Adriaensen viii Operational team as known by April 25, 2010 Bertus van Dalen Ciska Vriezenga Daan van Hasselt Danique Kamp Eric Magnee Farida Ayojil Frank Neumann Giel Dekkers Harry van Haaren Henk Schraa Johan Rietveld Jos Bertens Luc Nieland Marcel Wierckx Mario van Etten Martijn van Gessel Maurits Lamers Roald van Dillewijn Roderick van Toor Sanne Smits Simon Johanning Stefan Janssen Than van Nispen tot Pannerden Thijs Koerselman Tijs Ham Photography Brendon Heinst Paper Administration and Proceedings Frank Neumann ...and to everyone else who helped in numerous places after the editorial deadline of this publication. ix Review Committee Fons Adriaensen Casa della Musica, Parma, Italy Marije Baalman Concordia University, Montreal, Canada Frank Barknecht Footils, Cologne, Germany Ico Bukvic Virginia Tech, Blacksburg, VA, United States Gotz¨ Dipper ZKM, Karlsruhe, Germany Florian Faber Marburg, Germany Robin Gareus University of Paris, France Marc Groenewegen Hogeschool voor de Kunsten Utrecht, Utrecht, The Netherlands Frank Neumann Harman International, Karlsbad, Germany Yann Orlarey GRAME, Lyon, France Dave Philipps United States Martin Rumori Academy of Media Arts, Cologne, Germany Pieter Suurmond Hogeschool voor de Kunsten Utrecht, Utrecht, The Netherlands Victor Lazzarini NUI Maynooth, Ireland Music Jury Hans Timmermans Than van Nispen tot Pannerden Bertus van Dalen Pieter Suurmond Marc Groenewegen x Table of Contents QuteCsound, a Csound Frontend 1 • Andres´ Cabrera Implementing a Polyphonic MIDI Software Synthesizer using Coroutines, • Realtime Garbage Collection, Closures, Auto-Allocated Variables, Dynamic Scoping, and Continuation Passing Style Programming 7 Kjetil Matheussen Writing Audio Applications using GStreamer 15 • Stefan Kost Emulating a Combo Organ Using Faust 21 • Sampo Savolainen LuaAV: Extensibility and Heterogeneity for Audiovisual Computing 31 • Graham Wakefield, Wesley Smith, Charles Roberts The WFS system at La Casa del Suono, Parma 39 • Fons Adriaensen General-purpose Ambisonic playback systems for electroacoustic • concerts - a practical approach 47 Jorn¨ Nettingsmeier Real-Time Kernel for Audio and Visual Applications 57 • John Kacur Re-Generating Stockhausen’s ”Studie II” in Csound 65 • Joachim Heintz Using open source music software to teach live electronics in pre-college • music education 75 Hans Roels Field Report: A pop production in Ambisonics 83 • Jorn¨ Nettingsmeier 5 years of using SuperCollider in real-time interactive performances and • installations - retrospective analysis of Schwelle, Chronotopia and Semblance 91 Marije Baalman Applications of Blocked Signal Processing (BSP) in Pd 99 • Frank Barknecht OrchestralLily: A Package for Professional Music Publishing with • LilyPond and LaTeX 109 Reinhold Kainhofer Term Rewriting Extensions for the Faust Programming Language 117 • Albert Graf¨ xi Openmixer: a routing mixer for multichannel studios 123 • Fernando Lopez-Lezcano, Jason Sadural Best Practices for Open Sound Control 131 • Andrew Schmeder, Adrian Freed, David Wessel Supernova - a multiprocessor-aware synthesis server for SuperCollider 141 • Tim Blechmann Work Stealing Scheduler for Automatic Parallelization in Faust 147 • Stephane Letz, Yann Orlarey, Dominique Fober A MusicXML Test Suite and a Discussion of Issues in MusicXML 2.0 153 • Reinhold Kainhofer 3DEV: A tool for the control of multiple directional sound source • trajectories in a 3D space 161 Oscar Pablo Di Liscia, Esteban Calcagno Sense/Stage - low cost, open source wireless sensor and data sharing • infrastructure for live performance and interactive realtime environments 167 Marije Baalman, Joseph Malloch, Harry Smoak, Joseph Thibodeau, Vincent De Bellebal, Marcelo Wanderley, Brett Bergmann, Christopher Salter Education on Music and Technology, a Program for a Professional • Education 177 Hans Timmermanns, Jan IJzermans, Rens Machielse, Gerard van Wolferen, Jeroen van Iterson Concerts 181 • Workshops 187 • xii QuteCsound, a Csound Frontend Andr´esCABRERA Sonic Arts Research Centre Queen’s University Belfast UK [email protected] Abstract QuteCsound is a front-end application for Csound written using the Qt toolkit. It has been developed since 2008, and is now part of the Csound distri- bution for Windows and OS X. It is a code editor for Csound, and provides many features for real-time control of the Csound engine, through graphical con- trol interfaces and live score processing. Keywords Csound, Front-end, Qt, Widgets, Interface builder