Proceedings of the Linux Audio Conference 2019 March 23rd – 26th, 2019 Center for Computer Research in Music and Acoustics (CCRMA) Stanford University, USA “In Ping(uins) e trust! Published by CCRMA, Stanford University, California, US March 2019 All copyrights remain with the authors http://lac.linuxaudio.org/2019 ISBN 978-0-359-46387-9 Credits Layout: Frank Neumann and Romain Michon Typesetting: LATEX and pdfLaTeX Logo Design: The Linuxaudio.org logo and its variations copyright Thorsten Wilms c 2006, imported into "LAC 2014" logo by Robin Gareus Thanks to: Martin Monperrus for his webpage "Creating proceedings from PDF files" ii Partners and Sponsors Linuxaudio.org iii iv Foreword Welcome everyone to LAC 2019 at CCRMA! For the second time in its seventeen year history, the Linux Audio Conference (LAC) is hosted in the United Stated of America by the Center for Computer Research in Mu- sic and Acoustics (CCRMA) at Stanford University. With its informal workshop-like at- mosphere, LAC is a blend of scientific and technical papers, tutorials, sound installations, and concerts centered on the free GNU/Linux operating system and open-source free soft- ware for audio, multimedia, and musical applications. LAC is a unique platform during which members of this community gather to exchange ideas, draft new projects, and see old friends. In these times of increasing political tensions and of rising extremism throughout the world, we believe that emphasizing and promoting the universality of this type of event is of the utmost importance. The Linux audio community exists worldwide; we believe it should remain a priority to diversify LAC’s geographical location from year to year for the benefit of those who can’t afford to travel to the other side of the world. This year, a large portion of presenters and performers is coming from the Americas and Asia. LAC-19 features six paper sessions, five concerts, four workshops, one keynote, as well as various posters, demos, and side events happening in various locations on Stanford University campus. We wish you a pleasant stay at Stanford and we hope that you will enjoy the conference! Romain Michon (LAC-19 Co-Chair) CCRMA, Stanford University (USA) & GRAME-CNCM, Lyon (France) v vi Conference Organization Core Team • Romain Michon – Co-Chair & Organizer • Fernando Lopez-Lezcano – Co-Chair & Organizer • Constantin Basica – Music Chair & Organizer • Elliot Canfield-Dafilou – Organizer • Carlos Sanchez – CCRMA System Administrator & Organizer • Matthew Wright – CCRMA Technical Director & Organizer • Nette Worthey – CCRMA Administrator • Chris Chafe – CCRMA Director • Bruno Ruviaro – Organizer Volunteers • Alex Chechile • David Goedicke • Benjamin J. Josie • Kyle O. Laviana • Vidya Rangasayee • Travis Skare • Xingxing Yang Paper Chair/Administration and Proceedings • Frank Neumann Stream Team • David Kerr • Carlos Sanchez vii Keynote Speaker • Fernando Lopez-Lezcano Also Thanks to • Session Chairs: – Chris Chafe – Albert Gräf – Elliot Kermit Canfield-Dafilou – Fernando Lopez-Lezcano – Yann Orlarey – Julius O. Smith • Santa Clara University Laptop Orchestra (SCLOrk) viii Review Committee Joachim Heintz University for Music Drama and Media Hanover, Germany IOhannes Zmölnig IEM, University of Music and Performing Arts (KUG), Graz, Austria Elliot Canfield-Dafilou CCRMA, Stanford University, United States Robin Gareus Germany Martin Rumori Institute of Electronic Music and Acoustics, Graz, Austria Orchisama Das CCRMA, Stanford University, United States Henrik von Coler Technische Universität Berlin, Germany Mark Rau CCRMA, Stanford University, United States Stéphane Letz GRAME-CNCM, France Romain Michon GRAME-CNCM, France & CCRMA - Stanford University, USA Jörn Nettingsmeier Netherlands David Runge Native Instruments, Germany Fons Adriaensen Huawei Research, Germany Harry van Haaren OpenAV, Ireland Steven Yi United States ix x Table of Contents Papers • Creating a sonified Spacecraft Game using Happybrackets and Stellarium 1 Angelo Fraietta, Ollie Bown • Browser-based Sonification 9 Chris Chafe • Sequoia: A Library for Generative Musical Sequencers 17 Chris Chronopoulos • A JACK Sound Server Backend to synchronize to an IEEE1722 AVTP Mediaclock Stream 21 Christoph Kuhr, Alexander Carôt • tpf-tools - a multi-instance JackTrip clone 29 Roman Haefeli, Johannes Schütt • A Cross-Platform Development Toolchain for JIT-compilation in Multimedia Software 37 Jean-Michaël Celerier • Bringing the GRAIL to the CCRMA Stage 43 Fernando Lopez-Lezcano, Christopher Jette • Rendering of Heterogeneous Spatial Audio Scenes 51 Nicolas Bouillot, Michał Seta, Émile Ouellet-Delorme, Zack Settel, Emmanuel Durand • A JACK-based Application for Spectro-Spatial Additive Synthesis 57 Henrik von Coler • GPU-Accelerated Modal Processors and Digital Waveguides 63 Travis Skare, Jonathan Abel • CPU consumption for AM/FM audio effects 71 Antonio Jose Homsi Goulart, Marcelo Queiroz, Joseph Timoney, Victor Lazzarini • Formalizing Mass-Interaction Physical Modeling in Faust 75 James Leonard and Jérôme Villeneuve, Romain Michon, Yann Orlarey and Stéphane Letz • Are Praat’s default settings optimal for Infant Cry Analysis? 83 Giulio Gabrieli, Leck Wan Qing, Andrea Bizzego, Gianluca Esposito • Isochronous Control + Audio Streams for Acoustic Interfaces 89 Max Neupert, Clemens Wegener xi • Game|lan:Co-Designing and Co-Creating an Orchestra of Digital Musical Instruments within the Fab Lab Network 95 Alexandros Kontogeorgakopoulos, Olivia Kotsifa • Finding Shimi’s voice: fostering human-robot communication with music and a NVIDIA Jetson TX2 101 Richard Savery, Ryan Rose, Gil Weinberg • A Scalable Haptic Floor dedicated to large Immersive Spaces 107 Nicolas Bouillot, Michał Seta • midizap: Controlling Multimedia Applications with MIDI 113 Albert Gräf • sc-hacks: A Live Coding Framework for Gestural Performance and Electroacoustic Music 121 Iannis Zannos Posters • Bipscript: A Simple Scripting Language For Interactive Music 129 John Hammen • Switching "Le SCRIME" over to Linux as a complete novice 133 Thibauld Keller, Jean-Michaël Celerier • SoundPrism: A Real-Time Sound Analysis Server and Dashboard 135 Michael Simpson xii Proceedings of the 17th Linux Audio Conference (LAC-19), CCRMA, Stanford University, USA, March 23–26, 2019 CREATING A SONIFIED SPACECRAFT GAME USING HAPPYBRACKETS AND STELLARIUM Angelo Fraietta Ollie Bown UNSW Art and Design UNSW Art and Design University of New South Wales, Australia University of New South Wales, Australia [email protected] [email protected] ABSTRACT the field of view. For example, Figure 2 shows how the player might view Saturn from Earth, while Figure 3 shows how the player may This paper presents the development of a virtual spacecraft simula- view Saturn from their spacecraft. The sonic poi generates sound tor game, where the goal for the player is to navigate their way to that is indicative of the player’s field of view. Additionally, the poi various planetary or stellar objects in the sky with a sonified poi. provides audible feedback when the player zooms in or out. The project utilises various open source hardware and software plat- forms including Stellarium, Raspberry Pi, HappyBrackets and the Azul Zulu Java Virtual Machine. The resulting research could be used as a springboard for developing an interactive science game to facilitate the understanding of the cosmos for children. We will describe the challenges related to hardware, software and network integration and the strategies we employed to overcome them. 1. INTRODUCTION HappyBrackets is an open source Java based programming environ- ment for creative coding of multimedia systems using Internet of Things (IoT) technologies [1]. Although HappyBrackets has focused primarily on audio digital signal processing—including synthesis, sampling, granular sample playback, and a suite of basic effects–we Figure 2: Saturn viewed from the ground from Stellarium. created a virtual spacecraft game that added the functionality of con- trolling a planetarium display through the use of WiFi enabled Rasp- berry Pis. The player manoeuvres the spacecraft by manipulating a sonic poi1, which is usually played in the manner shown in Figure 1. The poi contains an inertial measurement unit (IMU), consisting of an accelerometer and gyroscope; and a single button. The goal of the Figure 3: A closer view of Saturn from Stellarium. The University of New South Wales required a display for their open day to showcase some of the work conducted in the Interactive Figure 1: The conventional way of playing a sonic poi. Media Lab. The opportunity to develop an environment whereby vis- itors could engage with the technology we were developing would not only facilitate attracting possible future students, it was also a game is for a player to choose an astronomical object, for example a way to develop and test the integration of various research compo- planet or star, and to fly towards that object. This enables the player nents we were conducting. Many managers and business seek to en- to view other objects, including planets, moons, stars and galaxies in gage new customers through gamification [3]—in this case, prospec- 1"Poi spinning is a performance art, related to juggling, where weights on tive customers were potential students. Furthermore, research indi- the ends of short chains are swung to make interesting patterns." [2, p. 173] cates that visualisation and interpretation of software behaviour de- 1 Proceedings of the 17th Linux Audio Conference (LAC-19), CCRMA, Stanford