Morning session


Torben Hohn e.a.

Netjack – Remote music collaboration with electronic sequencers on the Internet

The JACK audio server with its ability to process audio streams of numerous applications with realtime priority, has major signi=0Ccance in context with audio processing on Linux driven personal computers. Although the Soundjack and the Jacktrip project already use JACK in terms of remote handmade music collaboration, there is currently no technology available, which supports the interconnection of electronic music sequencers.
This paper introduces the Netjack tool, which achieves sample accurate timeline synchronization by applying the delayed feedback approach (DFA) and in turn represents first solution towards this goal.


Free Ekanayaka, Daniel James

Transmission – Linux Audio goes mobile

Transmission is a custom GNU/Linux distribution designed for real=C2=ADtime audio production on mobile computing platforms, including Intel ‘Ultra Mobile devices. It was developed on behalf of Trinity Audio Group by 64 Studio Ltd. and was released to the public in the summer of 2008.


John ffitch – Keynote Speech


IOhannes Zmölnig

Reflection in Pure data

One of the more prominent realtime computer music languages on linux is Pure Data. While Pure data provides ample constructs for signal domain specific programming, it has only limited capabilities for metaprogramming. In this paper we present “iemguts”, a collection of objects that add (amongst other things) reflection capabilities to Pure Data.

Afternoon session


Albert Graef

Signal Processing in the Pure Programming Language

This paper introduces the author’s new functional programming language Pure and discusses its use as a scripting language in signal processing applications. Pure has a IT compiler based on the LLVM compiler framework which makes execution reasonably fast and interfacing to C very easy. A built-in GSL matrix type makes it possible to handle numeric signals in an efficient way, and a Pure plugin for Miller Puckette’s Pd provides the necessary infrastructure for realtime signal processing. The paper gives a brief overview of the language and the Pd interface, and presents some examples.


Victor Lazzarini

A Distortion Synthesis Tutorial

In this article, we will be surveying the area of distortion synthesis, using the Csound language to provide tutorial examples of the different techniques. The text will discuss various methods from the classic algorithms to newer approaches. The article will concentrate on less well-known techniques as well as more recent developments, which have been less often explored in the literature. The main aims of the article are to provide a general overview of the area with some tutorial implementations of various correlate techniques.


Jürgen Reuter

Considering Transient Effect in Spectrum Analyis

Signal processing with discrete Fourier transform (DFT) works well in standard settings, but is unsatisfying for rapid changes in signal spectra. We illustrate and analyze this phenomenon, develop a novel transform and prove its close relation to the Laplace transform. We deploy our transform for deriving a replacement for the sliding window DFT. Our approach features transient effect and hence shows more natural response to rapid spectral changes.


Hans Fugal

Optimizing the Constant-Q Transform in Octave

Abstract The constant-Q transform calculates the log-frequency spectrum and is therefore better suited to many computer music tasks than the DFT, which computes the linear-frequency spectrum. The direct calculation of the constant-Q transform is computationally inefficient, and so the efficient constant-Q transform algorithm is often used. The constant-Q transform and the efficient constant-Q transform algorithm are implemented and benchmarked in Octave. The efficient algorithm is not faster than the direct algorithm for a low minimum frequency. Additional vectorization of the algorithm is slower under most circumstances, and using sparse matrices gives marginal speedup.