Final programming refinements

17 06 2010

I’ve been working through some final refinements to the Pd patch that I will be using for the installation. My main concern was determing a way to adjust the ambient noise versus heart beat noise in my audio interactive installation. Basically, I wanted to be sure that the heartbeat sound didn’t dominate over the ambient noise and vice versa when causing the moving image to pulse. After a couple of intense days with Ed Kelly from the London College of Communication I now have this final revision of the Pd patch!

Some recent and notable additions to this patch include an ambient sound calibrator and an audio playing object that allows for tempo and pitch adjustment of the heartbeat. The ‘wiring’ of this patch is now set up a little differently. My previous versions of this program had a direct link between the pulse of the videos and the audio that came in from the microphone. I added a ‘metronome’ and ‘drunk’ object to a’translateXYZ’  object to create a simple zoom effect on the videos that zoomed in depending on the pitch of the sounds the mic picked up. This was effective in a quiet space when all one heard was my looped heartbeat sound, but I knew the installation would be noisy at times which could cause the video to shake erratically.

With some key guidance and advice the patch now wires a direct number stream from the heartbeat wav file so that it doesn’t have to pass through the mic (brilliant idea Ed, and no, I don’t think this is cheating). I’ve kept the mic audio input part of the patch but have lessened its influence on the video through a set of objects that auto-calibrate for ambient sound (thank you for all your help with this one too Ed). Also, the fade between the videos is now linked to the heart beat sound directly. In effect what will happen is that the noisier the ambient sound is the less of video 2 (the text) you will see, that is until the auto-calibration kicks in. If it is silent or if noise levels maintain at a steady hum, the text will pulse and become more legible. If ambient noise is erratic all you will see is the video 1 (the traffic light themed images) pulsing with the heart beat and loud sounds in the environment.

Another thing that is newly added is adjustability to the patch’s sensitivity so that when I set up the installation I can digitally fiddle around with things until I have the output as I would like. My previous plan was to fiddle around with the position of the mic and speakers but this way allows for more fine tuning. In the end, I can still adjust the hardware side if I so choose 😉

I’ve also worked out how to eliminate the choppiness in the playback of the videos. I changed the compression of the video to  H.1263 codec which suits Macs and I reduced the file size by opting not to go HD. As a result the video plays better and is more reactive to sound. My previous videos were using 324% of my CPU (when running the program) and I have now reduced that to 36%!

I have also resolved a simple way to show the video fullscreen. I will set up using two screens: 1. my work screen  and 2. the projector screen. I’ll link the two screens on Pd then simply drag the video window into the projector screen. After that I can unplug my work screen and all that will be left is the playing video. Voila!

Hope this all makes sense. My head is still reeling from the stuff I picked up from the last two days with Ed!





Tweaking the Pd Patch

20 05 2010

I have been working on refining the Pd patch I designed as an image engine/video mixer for the project. So far I am quite happy with how it is looking.  As patches go, it’s not overly complicated: mainly a video mixer and an audio feed for a contact mic. The rest is connecting the dots and getting creative with where I put the mic. If anything, I could work on smoothening out the ‘pulsing’ effect. I’ll do this once I’ve settled on the mic/speaker combination I am going to go with and how it all works within the environment of a suitcase.

PD sketch for Final Piece