David Bullock - mail@davidbullock.uk

III. Installation - Technical Overview

With the invaluable help of the team at Soundbeam I have been exploring a means to interface the Soundbeam system with Flash technology. Soundbeam is first and foremost a system for creating music. At the heart of Soundbeam is a MIDI (Musical Instrument Digital Interface) system which can process inputs from a variety of MIDI devices and up to four Soundbeam ultrasonic sensors. Each sensor works by emitting an ultrasonic beam which detects and measures physical interruptions such as a person passing through the beam. The measurements are converted digitally and passed to a sound module or synthesiser which generates corresponding musical sounds. For example moving towards the sensor might produce a higher tone and moving away a lower tone. This could either be continuous or stepped as in a musical scale. The PC acts as a control device for Soundbeam through which all system parameters are set. A typical system configuration can be seen in the diagram below.

Standard Soundbeam configuration for musical applications

The set-up I wanted required the addition of a digital projector which could project the movies. As I had no plans to use a MIDI soundtrack (all the sounds I have used are embedded AIFF files) it meant I could dispense with the sound module. It should be noted that the team at Soundbeam already use a similar configuration to create video-augmented sound performances. The primary difference in my case is that the movies I have produced are dynamically interactive rather than linear video, triggered by MIDI events.

Soundbeam configured for video installations

As I mentioned before Soundbeam is primarily for musical purposes and hence uses MIDI protocol to transfer data, whereas Flash being a multimedia application does not. However, I realised that if I could get Flash to somehow recognise MIDI data it would be possible to use this data to control parameters within Flash Movies. The challenge therefore was to find a means to enable MIDI data to “talk” to Flash. Fortunately I managed to track down a German company called VLIGHT who made a couple of VJ (Video Jockey) packages based around Flash technology. One of these packages, VLIGHT.CTRLv1.5, enabled data to be taken from MIDI to control Flash movies, which was exactly what I needed for the project.

To establish connection between Flash and Soundbeam it was necessary to embed some code in Flash that hooks up with the VLIGHT.CTRLv1.5 application (see left). The VLIGHT.CTRLv1.5 acted as a conduit between the MIDI data output from Soundbeam and the embedded code in Flash. It was then possible to use the embedded code as a variable within customised action scripts to control the desired parameters.