@sheko
As I see your standard camera parameters are: 1080x1280 120fps
And as it configured in python script for first step try:
cap = cv2.VideoCapture('v4l2src device=/dev/video0')
if still failing try with passing parameters to gstreamer:
cap = cv2.VideoCapture('v4l2src device=/dev/video0 ! video/x-raw,format=UYVY, width=1080, height=1280,framerate=120/1 ! videoconvert ! video/x-raw,format=GRAY8 ! appsink sync=1')
or from command line to check if gstreamer works without python
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,format=UYVY, width=1080, height=1280,framerate=120/1 ! videoconvert ! video/x-raw,format=GRAY8 ! appsink sync=1
if still failing try RAW8 format
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,format=RAW8, width=1080, height=1280,framerate=120/1 ! appsink sync=1
if still failing, can't help, I don't have this sensor.