“Variations on the theme of videoconferencing, audio and visual connections between remote sites, are often referred to as telepresence in an art context. Related terms compete for bandwidth. Communicating a poetic sense of what is concealed has been referred to as teleabsence (Lozano-Hemmer 1997), and other projects are more appropriately designated as telerobotics, indicating action at a distance, and telepistemology, referring to knowledge at a distance (Goldberg 2001). The term telematic (Roy Ascott 2005) broadens the scope because it is not pinned to presence or to the visual. Telematics permits fo a play across absence and presence, as well as range of dynamic impulses, both human and nonhuman. The suffix “matics” is quantly mid-twentieth-century (evoking “modern” kitchen appliances like “blend-o-matic”) is infused with enough ambiguity for it to be open to diverse underspecified interactions. [...] How are the human senses of intimacy and physical connection dependent on playing across what is revealed and what is concealed (rather then simply on what is visually displayed) – not just presence, not just absencem not just action, not just knowledge — all of these and more.”
– Susan Kozel in “CLOSER – perfomance, technologies, phenomenology”
To be able to watch and participate in Transmittance performance only a modern browser is required – we recomend Firefox with versions 3.5 and above. Chrome/chromium and Opera 10.50 are also good candidates. Unsupported browsers are Internet Explorer and Safari, so if you are using one of these please download Firefox. It’s free. Read more about compatibility with Theora video.
After asking for some help on Linux Audio Users and Stream-ring concerning skipping chunks of video, and after doing some of my own tests lowering the resolution and quality, it seems that there are two factors influencing the flow of stream: CPU spikes and bandwidth spikes.
As Robin Gareus writes via lau-list:
> Panning and zooming puts addidtional some strain on the encoder
> (motion compensation calc) and also produces bandwidth spikes….
> AT LAC, we were able to kick out some remote-participants with quick
> camera panning due to bandwith spikes so we tried to avoid those
Robin also writes about cpu-friendly scaling to multiples of 16(8):
> Down-scaling the video decreases CPU usage of the encoder, but
> requires a few CPU cycles to perform the scaling, in particular if
> scaling to non multiples of 16: try `-x 384 -y 288 -aspect 4:3`
> instead of ` -x 393 -y 288` (it /should/ not make a difference since
> Theora requires the geometry to be multiples of 8 (or 16?), but
> ffmpeg2theora may just be scaling/cropping/expanding twice?!).
Lluis Gomez i Bigorda via stream-ring also pointed at CPU usage andpoints to the “–speedlevel” option. So we are now using the following command line to steam from a DVcamera and it looks quite stable:
dvgrab --format raw - | ffmpeg2theora -f dv -x 384 -y 288 -v 3 --speedlevel 2 --no-skeleton -o /dev/stdout - | oggfwd icecastserver 8000 pass /mount.ogv
simple slideshow in PD/GEM
For the needs of displaying various images from a folder I wrote a simple slideshow “player” in GEM. The part I’m particularly proud of is the code that takes the dimensions of the image (WxH) in pixels, calculates ratio and is then able to calculate the resizing factor in order for the image to stay within bounds of a traditional computer screen or projections (4:3). For an experienced coder this might have been trivial, but for a self-thought artist-programmer like me it took me a bit of time.
Here’s a patch and a screenshot.
I was playing with various transformation of image, in fact, with a particular transformation and distortion of image using `metapixel` tool. In order to find a good combination of parameters (because metapixel is a command-line tool) I’ve written a bash script that cycles through some numbers and throws out about 30 permutations (metapixelations) of each image processed. The results are most of the time quite interesting (for me at least).
Here’s a the script and an image.
WIRELESS FEELINGS are MANAGING YOUR PRIVACY in the SETTINGS OF THE SOLITUDE.
I’m PROCESSING A LIE while VERIFYING YOUR SKIN in LIMITED STORAGE
YOU ARE PERMITTED TO MY ACCESS so therefore LOAD ME
I’m DOWNLOADING MY BEHAVIOR
DESIRE OF SHARING is OFF so you can ALLOW USERS TO KNOW ME
SET UP NEW HEART DEVICE and DISABLE AUTOMATIC KINDNESS
Than you can LOG OUT AFTER COMPASSION
DRAG CATEGORIES OF YOUR MANKIND and REVEAL EXPANDED PRIVATE ITEMS
KEEP EXPANDING IF POSSIBLE
LEAVE MY FILES ALONE before you TRASH ME
SYSTEMIZE ME if you can
PUT ME TO SLEEP WHEN INACTIVE FOR 7 MINUTES
And on the end make sure you HIDE YOUR DETAILS
Hey there, what’s up? Leaves an auto replay: Away. Several long minutes later: Oh 1 sec. The pleasure of waiting and being waited for. Not much. Browsing around the familiarities of strangers. Seeking for help. How about u? A lazy respond as Same here can cause an acceleration of the particular event. Today that is not a case. Have you been OK lately? seems more generous and my fingertips sweat from the excitement of offering an answer. I’ve been away for a while, I had a need to look deep in myself and realize that I am doing well. Yeah… I missed you, and all your celebrity lies. Its OK to be missed once in a while. Listen to the words that come from a stranger and take them, they aren’t candies, but do taste sweet and I have to run to disturb the bitterness of your behavior. Oh… Don’t worry I am able to spend time on my own talking to birds and insects. It is OK to leave. With closed mouth and knotted tongue I sing Bye Bye while waiting for another, perhaps more inspiring encounter. Away.
Solved mysteries of streaming skipping chunks. Seems like the culprit could be in the upload bandwidth. If it’s too small (and it needs alot of space for overhead!), then chunks start to happen. When I lowered quality and resolution to 160×128 no cuts were appearing in the stream. Not sure what it means when we raise upload speed from 265k to 785k.
I also improved quite a lot the interaction interface – where audence of transmittance perfomance can chat, watch the stream and see the menu options change – what is available to choose. It looks quite neat now.
I happily discovered that the whole collection of “digital beauties” managed to get itself down through torrent. I improved a little bash script that makes number of different distortions of a single image with help of metapixel program. This should be fun!.
That’s a short report from deViator’s lab.