I reworked the cyclepix/cycletile modulation image generation algorithm to run on the GPU, handles 60fps easily on my machine 'zebimus' (compared to 9fps for a matju-made-it-faster (TM) CPU-based Pd+GF implementation), and not much noticeable slowdown at higher resolutions. Features one shader to make a tiled image which gets converted to sound, and rendered with another shader to smooth the transition to black (sharp edges make lossy encoders cry).
The real-time mode uses JACK for audio, this JACK tutorial was helpful, as was this DC blocker algorithm. The non-realtime mode just writes raw files, I've been joining them together manually with Audacity so far but will look into sound file libraries at some point soon.
dr1 is a collection of audio(-visual) ambient/drone works in progress:
git clone http://code.mathr.co.uk/dr1.git
The original PureData + GridFlow audio-visual prototype: CycleTile Sonification #1.