To make it simple to illuminate the matrix, there are three protocols that are all supported:
Receives UDP packets with a raw PPM file (P6) on port 1337 in a
single datagram per image.
A ppm file has a simple text header followed by the binary RGB image data.
We add another feature: 'offset'; since the header is already defined in a
fixed way, we add a footer after the binary image data to be backward compatible.
A 10x10 image looks like this (header + data + optional footer). End-of-line
comments in the header are allowed with # character:
P6 # Magic number
10 10 # width height (decimal, number in ASCII)
255 # values per color (fixed). After newline, 10 * 10 * 3 bytes RGB data follows
5 # optional x offset
5 # optional y offset
0 # optional z offset.
The optional offset determines where the image is displayed on the
Flaschen Taschen display relative to the top left corner (provided in the
remote Flaschen Taschen class as a SetOffset(x, y, z) method).
The (x,y) offset allows to place an image at an arbitrary position - good for animations or having non-overlapping areas on the screen.
The z offset represents a layer above the background. Zero is the background image, layers above that are overlaying content if there is a color set (black in layers not the background are regarded transparent). That way, it is possible to write games simply (consider typical arcade games with slow moving background, a little faster moving middelground and a fast moving character in the front. This allows for full screen sprites essentially).
Or you can overlay, say a message over the currently running content. The nice thing is is that you don't need to know what the current background is - a fully networked composite display essentially :) Note: layers above the background (z=0) will auomatically turn transparent again if they stick around for a while without being updated.
Since the server accepts a standard PPM format, sending an image is as simple as this; you can make use of the convenient pnm-tools:
# This works in the bash shell providing the pseudo-files /dev/udp/host/port
bash$ jpegtopnm color.jpg | pnmscale -xysize 20 20 > /dev/udp/ft.noise/1337
# replace 'ft.noise' with 'localhost' if you have
# a locally running server, e.g. terminal basedIf you're not using bash, then the /dev/udp/... path won't work, then
you can use the network-swiss army knife socat
$ jpegtopnm color.jpg | pnmscale -xysize 20 20 | socat STDIO UDP-SENDTO:ft.noise:1337
You find more in the client directory to directly send content to the server, including a convenient class that provides an implementation on the client side.
The http://openpixelcontrol.org/ socket listens on standard port 7890
(Simulated layout row 0: left-right, row 1: right-left, row 2: left-right...;
this is what their standard wall.py script assumes).
Provides pixel pusher control via standard beacon (this is cool to be used together with processing, there are libs that support it). (Simulated layout: 10 strips starting on the left with 10 pixels each; pretty much like a standard framebuffer).
Within Noisebridge, the hostname is ft.noise.