Following on from the previous post on revisiting convolution in processing and trying to tie that in with my previous explorations of the desktop as a performance space and feedback generator wouldnt it be good if there was a way to pass the desktop as video into processing scripts in a similar way to that in which ffmpegs' x11grab allows us to open a window which follows the mouse focus around the desktop like a virtual webcam ?
Turns out there is. A friend had told me about V4l2loopback previously, a way of creating virtual webcams in Linux and then thinking about it the other day I came across this post which describes how to do it https://narok.io/creating-a-virtual-webcam-on-linux/ but that author streams a video file rather than what I want which is the same input as I get from x11grab. Why ? If we can create a virtual webcam we can use that as an input for processing so we can extend the possibilites of desktop feedback loops .
TLDR: do this on Debian based systems
install this
sudo apt install v4l2loopback-dkms
run this command
sudo modprobe v4l2loopback devices=1 video_nr=10 max_buffers=2 exclusive_caps=1 card_label="Default WebCam"
then this
ffmpeg -f x11grab -follow_mouse centered -framerate 10 -video_size 640x480 -i :0.0 -f v4l2 -vcodec rawvideo -s 640x480 /dev/video10
Then open a script in processing which uses a webcam for input ( ie the convolution scripts ive been working on ) and experiment.
