Sorry, I realize I missed you are using a USB ZED camera. So the right command would be:
gst-launch-1.0 v4l2src device=/dev/video1 ! video/x-raw, format=YUY2 ! videoconvert ! xvimagesink
assuming that /dev/video1 is the video node for your ZED (should appear a few seconds after you plug it in). If you don’t have any CSI camera connected, it may be video0.
About custom lib, nvivafilter plugin uses a library providing a function for processing one frame. The original lib is the one you’ve found. But it doesn’t do so much for cuda-process, so you would want to rebuild your own (you would download sources for this), and provide location of this lib as nvivafilter option customer-lib-name as you did in post #5. If you provide a bad location and nvivafilter cannot find this lib, it would silently fall back to use the lib in /usr/lib/aarch64…