Capturing, displaying and getting a raw frame matrix to work from, with gstreamer

I am trying to capture video in a Jetson_nano with a Raspberry pi 2 camera, using python and gstreamer. I am new to gstreamer and did not find examples for this application, capturing a frame , display it, and getting a raw array of the frame to work with it.
I tried initially to record the frame and I used :

gst-launch-1.0 -vvv videotestsrc ! tee name=t ! queue ! x264enc ! mp4mux ! filesink location=xyz1.mp4

but it only worked with videotestsrc, i need to use nvarguscamerasrc, but didn´t work

How can I do that?
How can I get a raw matrix (in GBR or RBG) to work with?
I need help…