I have uploaded a small piece of software which allows users to find a specific audio marker in audio streams. It is mainly practical to synchronise a camera (audio/video) recording with other audio with the same marker. The marker is a set of three beeps. These three beeps are found with millisecond accurate precision within the audio streams under analysis. By comparing the timing of marker synchronization becomes possible. It can be regarded as an alternative for the movie clapper boards.
With the goal in mind to reduce common runner injuries we first need to measure some running style characteristics. Therefore, we have developed a sensor to measure how hard a runners foot repeatedly hits the ground. This sensor has been compared with laboratory equipment which proofs that its measurements are valid and can be repeated. The main advantages of our sensor is that it can be used ‘in the wild’, outside the lab on the runners regular tours. We want to use this sensor to provide real-time biofeedback in order to change running style and ultimately reduce injury risk.
Studies seeking to determine the effects of gait retraining through biofeedback on peak tibial acceleration (PTA) assume that this biometric trait is a valid measure of impact loading that is reliable both within and between sessions. However, reliability and validity data were lacking for axial and resultant PTAs along the speed range of over-ground endurance running. A wearable system was developed to continuously measure 3D tibial accelerations and to detect PTAs in real-time. Thirteen rearfoot runners ran at 2.55, 3.20 and 5.10 m*s-1 over an instrumented runway in two sessions with re-attachment of the system. Intraclass correlation coefficients (ICCs) were used to determine within-session reliability. Repeatability was evaluated by paired T-tests and ICCs. Concerning validity, axial and resultant PTAs were correlated to the peak vertical impact loading rate (LR) of the ground reaction force. Additionally, speed should affect impact loading magnitude. Hence, magnitudes were compared across speeds by RM-ANOVA. Within a session, ICCs were over 0.90 and reasonable for clinical measurements. Between sessions, the magnitudes remained statistically similar with ICCs ranging from 0.50 to 0.59 for axial PTA and from 0.53 to 0.81 for resultant PTA. Peak accelerations of the lower leg segment correlated to LR with larger coefficients for axial PTA (r range: 0.64–0.84) than for the resultant PTA per speed condition. The magnitude of each impact measure increased with speed. These data suggest that PTAs registered per stand-alone system can be useful during level, over-ground rearfoot running to evaluate impact loading in the time domain when force platforms are unavailable in studies with repeated measurements.
‘Team Scheire’ is a Flemish TV program with a similar concept as BBC Two’s ‘The Big Life Fix’. In the program, makers create ingenious new solutions to everyday problems and build life-changing solutions for people in desperate need.
One of the cases is Ben. Ben loves to run but has a recurring running related injury. To monitor Ben’s running and determine a maximum training length a sensor was developed that measures the impact and the amount of steps taken. The program makers were interested in the results of the Nano4Sports project at UGent. One of the aims of that project is to build those type of sensors and knowhow related to correct interpretation of data and use of such devices. Below a video with some background information can be found:
Thanks to the support of a travel grant by the faculty of Arts and Philosophy of Ghent University I was able to attend the ISMIR 2018 conference. A conference on Music Information Retrieval. I am co author on a contribution for the the Late-Breaking / Demos session
The structure of musical scales has been proposed to reflect universal acoustic principles based on simple integer ratios. However, some studying tuning in small samples of non-Western cultures have argued that such ratios are not universal but specific to Western music. To address this debate, we applied an algorithm that could automatically analyze and cross-culturally compare scale tunings to a global sample of 50 music recordings, including both instrumental and vocal pieces. Although we found great cross-cultural diversity in most scale degrees, these preliminary results also suggest a strong tendency to include the simplest possible integer ratio within the octave (perfect fifth, 3:2 ratio, ~700 cents) in both Western and non-Western cultures. This suggests that cultural diversity in musical scales is not without limit, but is constrained by universal psycho-acoustic principles that may shed light on the evolution of human music.
Recently I have published a small library on github called JGaborator. The library calculates fine grained constant-Q spectral representations of audio signals quickly from Java. The calculation of a Gabor transform is done by a C++ library named Gaborator. A Java native interface (JNI) bridge to the C++ Gaborator is provided. A combination of Gaborator and a fast FFT library (such as pfft) allows fine grained constant-Q transforms at a rate of about 200 times real-time on moderate hardware. It can serve as a front-end for several audio processing or MIR applications.
While the gaborator allows reversible transforms, only a forward transform (from time domain to the spectral domain) is currently supported from Java.A spectral visualization tool for sprectral information is part of this package. See below for a screenshot:
Claims made in many Music Information Retrieval (MIR) publications are hard to verify due to the fact that (i) often only a textual description is made available and code remains unpublished – leaving many implementation issues uncovered; (ii) copyrights on music limit the sharing of datasets; and (iii) incentives to put effort into reproducible research – publishing and documenting code and specifics on data – is lacking. In this article the problems around reproducibility are illustrated by replicating an MIR work. The system and evaluation described in ‘A Highly Robust Audio Fingerprinting System’ is replicated as closely as possible. The replication is done with several goals in mind: to describe difficulties in replicating the work and subsequently reflect on guidelines around reproducible research. Added contributions are the verification of the reported work, a publicly available implementation and an evaluation method that is reproducible.
A philologist’s approach to heritage is traditionally based on the curation of documents, such as text, audio and video. However, with the advent of interactive multimedia, heritage becomes floating and volatile, and not easily captured in documents. We propose an approach to heritage that goes beyond documents. We consider the crucial role of institutes for interactive multimedia (as motor of a living culture of interaction) and propose that the digital philologist’s task will be to promote the collective/shared responsibility of (interactive) documenting, engage engineering in developing interactive approaches to heritage, and keep interaction-heritage alive through the education of citizens.
I was kindly invited by SoundCloud to give a presentation on “Acoustic fingerprinting in research”. The presentation took place during one of the “MIR Meetups” in Berlin on Monday, April 23, 2018. Before my presentation there was a presentation by Derek and Josh (both SoundCloud engineers) detailing the state of the internal fingerprinting system of SoundCloud.
During my presentation I gave an overview of various applications of acoustic fingerprinting in a music research environment and detailed how these applications can be handled and are implemented in Panako: an open source fingerprinting system
Below the slides used during the presentation can be found:
The presentation during my defense was meant for a broader audience. During the presentation I gave examples of the research topics I have been working and focused on how these are connected. The presentation titled Engineering systematic musicology can be seen by following the previous link and is included below. The slide with the live spectrogram and the slide with the map need to be started by double clicking otherwise they remain empty.
The presentation is essentially an interactive HTML5 website build with the reveal.js framework. This has the advantage that multimedia is well supported and all kinds of interactions can be scripted. The presentation above, for example, uses the web audio API for live audio visualization and the google maps API for interactive maps. Video integration is also seamless. It would be a struggle to achieve similar multi-media heavy presentations with other presentation software packages such as Impress, Keynote or Powerpoint.
I often need audio and video material embedded into presentations. I have had bad experiences with powerpoint/keynote and especially the LaTeX beamer package and multimedia: audio/video material does not start playing or at the wrong moment, finicky on codecs, limited compatibility, a clunky UX (whoever came up with the idea to show multimedia controls while hovering over e.g. an audio thumbnail should be reoriented towards back-end programming) all contribute to errors while handling audio/video. Moreover the interactive capabilities are limiting.
“Since 2005, the Italian Research Conference on Digital Libraries has served as an important national forum focused on digital libraries and associated technical, practical, and social issues. IRCDL encompasses the many meanings of the term “digital libraries”, including new forms of information institutions; operational information systems with all manner of digital content; new means of selecting, collecting, organizing, and distributing digital content…"
The 26th of January Federica presented our joint contribution titled “Applications of Duplicate Detection in Music Archives: from Metadata Comparison to Storage Optimisation”. The work focuses on applications of duplicate detection for managing digital music archives. It aims to make this mature music information retrieval (MIR) technology better known to archivists and provide clear suggestions on how this technology can be used in practice. More specifically applications are discussed to complement meta-data, to link or merge digital music archives, to improve listening experiences and to re-use segmentation data.
This weekend the University Hamburg – Institute for Systematic Musicology and more specifically Christian D. Koehn organized the International Symposium on Computational Ethnomusicological Archiving. The symposium featured a broad selection of research topics (physical modelling of instruments, MIR research, 3D scanning techniques, technology for (re)spacialisation of music, library sciences) which all had a relation with archiving musics of the world:
How could existing digital technologies in the field of music information retrieval, artificial intelligence, and data networking be efficiently implemented with regard to digital music archives? How might current and future developments in these fields benefit researchers in ethnomusicology? How can analytical data about musical sound and descriptive data about musical culture be more comprehensively integrated?
In this presentation we describe our experience of working with computational analysis on digitized wax cylinder recordings. The audio quality of these recordings is limited which poses challenges for standard MIR tools. Unclear recording and playback speeds further hinder some types of audio analysis. Moreover, due to a lack of systematical meta-data notation it is often uncertain where a single recording originates or when exactly it was recorded. However, being the oldest available sound recordings, they are invaluable witnesses of various musical practices and they are opportunities to improve the understanding of these practices. Next to sketching these general concerns, we present results of the analysis of pitch content of 400 wax cylinder recordings from Indiana University (USA) and from the Royal Museum from Central Africa (Belgium). The scales of the 400 recordings are mapped and analyzed as a set. It is found that the fifth is almost always present and that scales with four and five pitch classes are organized similarly and differ from those with six and seven pitch classes, latter center around intervals of 170 cents, and former around 240 cents.
I have contributed to the 4th International Digital Libraries for Musicology workshop (DLfM 2017) which was organized in Shanghai, China. It was a satellite event of the ISMIR 2017 conference. Unfortunately I did not mange to find funding to attend the workshop, I did however contribute as co-author to two proceeding papers. Both were presented by Reinier de Valk (thanks again).
This study is a call for action for the music information retrieval (MIR) community to pay more attention to collaboration with digital music archives. The study, which resulted from an interdisciplinary workshop and subsequent discussion, matches the demand for MIR technologies from various archives with what is already supplied by the MIR community. We conclude that the expressed demands can only be served sustainably through closer collaborations. Whereas MIR systems are described in scientific publications, usable implementations are often absent. If there is a runnable system, user documentation is often sparse—-posing a huge hurdle for archivists to employ it. This study sheds light on the current limitations and opportunities of MIR research in the context of music archives by means of examples, and highlights available tools. As a basic guideline for collaboration, we propose to interpret MIR research as part of a value chain. We identify the following benefits of collaboration between MIR researchers and music archives: new perspectives for content access in archives, more diverse evaluation data and methods, and a more application-oriented MIR research workflow.
This work focuses on applications of duplicate detection for managing digital music archives. It aims to make this mature music information retrieval (MIR) technology better known to archivists and provide clear suggestions on how this technology can be used in practice. More specifically applications are discussed to complement meta-data, to link or merge digital music archives, to improve listening experiences and to re-use segmentation data. The IPEM archive, a digitized music archive containing early electronic music, provides a case study.
The active listening demo movie above should explain the aim system succinctly. It shows two different ways to provide ‘context’ to audio playing in the room. In the first instance beats information is used to synchronize smartphones and flash the screen, the second demo shows a tactile feedback device responding to beats. The device is a soundbrenner pulse tactile metronome and was kindly sponsored by the company that sells these.
On Saturday the eight of April I gave a workshop on the ESP 32 micro controller at Newline, the yearly hackerspace conference of Hackerspace Ghent. The aim was to provide a hands-on introduction. The participants had to program to make the ESP execute the following:
Connecting to wifi
Sending data from the ESP32
Sending data using TCP
Broadcast data over UDP
Broadcast data using OSC over UDP
Broadcasting sensor data over UDP and OSC
At the start of the workshop I gave a presention as an introduction.
It was attended by a mix of (Ethno)musicologists, archivists, computer scientists and people identifying themselves as more than one of these categories by varying degrees. This mix ensured a healthy discussion and talks by Frans Wiering, Willard McCarthy, Emilia Gomez, and may more provided ample source material to discuss. These discussions ranged from the abstracts around schemata down to concrete of software tools for archive management.
On a more personal side the workshop did provide useful insights to contextualize my research and help form ideas that can be condensed in my PhD dissertation.
The xOSC board by x-io technologies looks like a very nice solution in many interactive wireless setups. Judging from the specifications and documentation it offers a lot of value. It is basically a small WiFi transmitter with some sensors and a battery attached to it. The board also has some drawbacks. 1) It is expensive at about € 180. This is especially problematic if you need about five or so for your application.2) It seems that it is also hard to add extra sensors via SPI or I²C. 3)The battery needs to be removed to charge, which makes it harder to build into a fixed enclosure. This post describes an alternative based on the ESP32 platform that addresses these shortcomings.
The ESP32 is a micro-controller with a WiFi transmitter which can be programmed using the Arduino environment. Sparkfun has a thing called the ESP32 Thing which contains the ESP32 chip. It can be used to build an xOSC alternative.
It costs about 20$, when you add a battery 5$ and a sensor 20$ (IMU) you end up with a 45$ price tag. The price of course depends on which exact sensor/battery you need for your application. A 500mAh lasts about two hours when sending 66 messages per second over WiFi (using UDP).
The ESP32 Thing supports the Arduino environment which potentially allows you to use all available Arduino libraries and supported sensors. However, some libraries do contain hardware specific instructions which are often not ported yet. Since the hardware is rather new – large scale production started only 3 months ago – not many libraries have been ported. Fortunately a lot of libraries simply work without any changes. At hackaday they have been testing a few: ESP32 and Arduino libraries. I had success with the BNO55 library, it did not need any changes. The OSC library did need some small changes to operate as expected.
The Thing contains a battery charging circuit. Once embedded into an enclosure the battery can stay in place. The software running on the device even keeps running when changing power sources.
Attached to this post you can find modifications to the Andriod OSC library that enable it to run on the ESP32: ESP32-Arduino-OSC-library together with a patch that sends random data over OSC. This should enable you to build an xOSC alternative.
Some drawbacks of the ESP32 is that the supporting software is quite immature. There is a Bluetooth chip on the ESP32 which is currently not supported in the Arduino environment. The setup can be somewhat challenging. The documentation can be improved. Some of the ESP32 Things seem to be unable to connect to old WiFi routers which can be problematic.
Last Saturday, October eight 2016, IPEM was present at the opening event of the digital week. A small video report was made for VRT news, unfortunately our contribution did not make the cut.
Van 8 tot en met 16 oktober 2016 loopt de elfde editie van de De Digitale Week. Plaatselijke organisaties in heel Vlaanderen en Brussel organiseren tijdens deze week diverse laagdrempelige activiteiten waarbij het gebruik van multimedia centraal staat, steeds gratis of zeer goedkoop, en open voor zowel beginners als mensen met wat meer ervaring. Daarnaast loopt er tijdens de Digitale Week een grote publiciteitscampagne die aandacht vraagt voor de thema’s e-inclusie en mediawijsheid.
This weekend IPEM, the research institute in musicology of University Ghent, was present at Parklife 2016. Parklife is a music festival with a special focus on interactive music installations aimed at children. Two of those were provided by IPEM.
The first installation was a trampoline that triggered sounds. Two trampoline were provided with a pressure sensor. An Axoloti provides the sonic feedback. A simple but fun experience especially for younger children.
The second installation was more involved. It consisted of a bike – controlled by a first participant – that provided the speed of falling blocks that a second participant had to step on. When the second participant triggered the blocks on time a melody appeared. The video above makes it more clear.