VisibleSound/AudibleImage is a workshop and performance series by Derek
Holzer and Sara Kolster which focuses on the interrelation of sound and
The workshop component is a four day overview of Pure Data, GEM and PDP,
a collection of Free + Open Source Softwares available for Linux and Mac
OSX 10.3 which allow image, sound and data to be synthesized and
manipulated in the same environment. Participants will learn the basic
"grammar" and "vocabulary" of Pure Data, upon which objects for sound,
3D and video will be added. Emphasis will be placed on direct
connections between sound and image through three different methods:
influence of sound on image, influence of image on sound and the use of
common "control data" for both image and sound.
Time: 24. - 28. may 2005
Place: BEK, C. Sundtsgt. 55, 5004 Bergen, Norway
To apply send a short CV to firstname.lastname@example.org
before 16. may.
1) Introduction: Why PD & Why Free + Open Source Software?
Our decision to use Pure Data has been motivated by several factors.
First and foremost is the need for a modular environment where audio and
video processing is possible without the intrusion of negative elements
such as a predetermined Graphical User Environment, cross-platform
issues and restrictive licenses. We will discuss these issues, and why
it is more important than ever that artists take Free + Open Source
Software seriously as tools for creative expression.
2) Installation Clinic
The first part of the workshop will be devoted to installing Pure Data,
GEM, PDP and several other externals on the participants' computers. Mac
OSX 10.3 and most Linux distributions can be accomodated. While PD and
GEM support Windows, PDP and several other externals do not, so Windows
users will be encouraged to use a live Linux CD such as Dynebolic during
the workshop. (BEK will provide some Linux and OSX machines for those who
don't bring their own laptops).
3) Pure Data as a Language
Like learning any new language, PD starts with learning vocabulary and
grammer. In this case, we will learn the names of many common objects
and the syntax of how to use them, in a clear "Geek-to-English"
translation which makes the complex data-flow operations of PD
understandable to non-technicians and artists.
4) Pure Data for Sound Synthesis
PD has powerful signal-processing abilities, and we will explore these
by building a simple, monophonic synthesizer controllable from either a
MIDI device or from the keyboard of your computer. Different types of
sound sythesis, such as Additive, Subtractive, Amplitude Modulation,
Frequency Modulation and Wavetable Synthesis will be covered, along with
the use of filters and delays for a variety of effects.
1) Pure Data for Sample Manipulation
Because PD uses a range of very basic building-blocks to store and
playback sampled sound, a wide range of manipulations are possible.
Here, we will explore pitchshifting, time stretching, looping and basic
granular synthesis. Other uses of data stored in tables for control
purposes will also be touched on.
2) Pure Data for 3D: GEM
GEM is an external library used in PD for moving 3D graphics under the
OpenGL protocol. It is also an ideal environment for VJ mixing. We will
explore how to create and manipulate simple 3D objects, how to texture
them with images, how to playback and mix video clips in GEM and how to
use a live camera input.
3) Pure Data for Physical Modelling: PMPD
PMPD is an external library for PD which allows the creation of physical
models, consisting of units of mass and force, which can be used to
control both sound and image. We will look at different examples of
physical modelling using the sound-processing of PD as well as 3D
graphics from GEM to sonify and visualize our "virtual objects".
1) Pure Data for Audio Analysis
We continue our investigation of the audio side of Pure Data by looking
at different methods of analyzing sound signals for pitch and amplitude
information. The data we extract from the audio can be used to either
(re)synthesize new sounds or to control 3D or video graphics manipulations.
2) Pure Data for Video: PDP
PDP (Pure Data Packet) is another external library in PD which is used
primarily for video playback and effects filters. We will investigate
PDP for direct video synthesis, for the playback and mixing of
(audio)visual clips and for the processing of a live camera input. PDP
includes several tools for the analysis of video for movement, change
and color, which in turn can be used to control sound playback and other
events in PD.
1) Pure Practical Examples
Now that the workshop participants have the background to understand
more complex PD patches, we will spend the morning looking at various
demos and performance patches to see how different artists and
programmers have developed their own environments for live audiovisual
2) Pure Data Practice
Workshop participants will put what they have learned into practice by
working in small groups, pairing sound artists together with video
artists to create simple audiovisual performance tools, with an emphasis
on the interrelation of sound and image.
1) Workshop Presentation
Public presentation by instructors and workshop participants of tools
created during the week, covering the importance of Free + Open Source
Software, as well as the practical examples of its use.