Nvidia NX reset video core

is there a way to reset the video core via a command or C lib ?

For video core, do you mean video encoding/encoding engine NVENC or NVDEC? Not sure what video core exactly means and would like to clarify this first.

The V4l2 device drive ? For a camera with a const FPS We are having issue where after we call VIDIOC_QBUF and VIDIOC_DQBUF for a few times we are seeing the timestamp is varying randomly but the seq num is continues, even if we reset the app the problem still persist, the only way to fix this is to do give a reboot command, so we are suspecting that the driver has memory leak.

If your camera source goes through Argus, you can try

$ sudo service nvargus-daemon stop
$ sudo service nvargus-daemon start