Tag Archives: locative media

‘The swamp that was’ – a bicycle opera from the ground of Ganda (part 5)

The Bicycle Opera is now live, get your bikes from the Snoepwinkel, Sint-Pietersnieuwstraat 21:

A bicycle opera in Ghent! British sound artist Kaffe Matthews records urban sounds such as music, singing and street sounds. As she combines these with elements from the past, she creates an unseen urban opera. A mobile composition, written for cyclists. You can rent an “audio bike” to explore the streets of Ghent. As you ride past certain spots, sound recordings are played on the speakers of your bike, uncovering the soundtrack of the city piece by piece.

Here is a visualisation of the zones (including the moving ghost zones) across the city.

More music from bikes (part 4)

The last few days has seen intense work on Kaffe Matthews’ Ghent Bicycle Opera which goes live in a few days, lots of new stuff on the git repo for Beagle Board/GPS powered sample playback.


(image from Timelab/Kaffe’s site)

The main problem with the version we tested in June was that all the samples needed to be preloaded, fixing us to <512Mb total sample data. The sample loading was also extremely slow, meaning it could take up to 10 minutes after starting up till the bikes were usable. This slowness turned out to be uncompressing the ogg samples into memory on the not so fast ARM processor. Seeing as they needed to be entirely uncompressed to play anyway, there was little point in compressing them (we have no shortage of storage memory on the SD cards). Now the zones (which link areas of the city to audio samples) are surrounded by a couple of hundred metres of loading/unloading area - crossing into this area causes the sample to start loading, exiting frees it from memory. We can now fit all samples for all the routes (collections of zones for different parts of the city) onto a single system - much more than the total memory on the boards. Other significant improvements include a more data-driven sample playback, where zones are given a naming convention that describe if the sample needs to loop, be panned to come from a specific compass direction (based on the calculated direction of the cyclist, from GPS data) of if they need to be a special mysterious type of zone - called a "ghost zone". Ghost zones are programmed to travel across the city over time - blending between a start and end shape/position, so in the morning they might be heard in different places to the afternoon. You'll be able to experience The swamp that was, a bicycle opera at Electrified III: The Responsive City, in Ghent from this weekend.

Borrowed Scenery tendrils reach out

Some serious connecting work going on with borrowed scenery for joining physical and imaginary worlds together. A new Boskoi database is up and running, giving us a place to put all kinds of story elements and plants found in the city. Boskoi uses the Ushahidi platform, which provides an API the game is now using to pull all items tagged in the map (which can come from the Android app or web app) into the game where they can interact with players or other entities.

More of Theun’s artwork has gone in, including a magician tarot avatar on the left while the three plants in the screenshot above represent those tagged on the map below. Getting everything in the right place (map lat/long coordinates vs game location coordinates and then aligning the map) took a lot of time to get right!

Location based sound, part two

Our first public test for the The swamp that was, a bicycle opera takes place next weekend, so I’ve been working on the on-bike software and getting more experience with the BeagleBoard while Kaffe builds up the sound pieces. In order to test the software, I’ve made a local map I can play with:

Each coloured zone represents a different audio sample. We are also experimenting with direction, panning each sound depending on your direction and that of the sound source. For example it’s possible to set a sound to come from the north, which pans it to the left if you are heading in an easterly direction and the reverse. Using this test map, I can run the system on battery while out walking the dog: