How to get camera intrinsics and extrinsics in openni2?

Question

I have a primesense carmine 1.08 and carmine 1.09. I need the intrinsic parameters for the RGB and the IR camera and the extrinsics between the two. I use pcl with openni2 support. So I need to know the sensor parameters used by openni2/pcl.

Is there a way in openni2 to find the intrinsics and the extrinsics using openni2/pcl? Libfreenect2 has option to get IR and color camera intrinsics, but are these parameters same as that in openni? Are all these parameters extracated from sensor during runtime?

I tried to get it via pcl, but i get nan for the focal length and the principal points

int main (int argc, char** argv)
{
std::string device_id ("");
pcl::io::OpenNI2Grabber::Mode depth_mode =
pcl::io::OpenNI2Grabber::OpenNI_Default_Mode;
pcl::io::OpenNI2Grabber::Mode image_mode =
pcl::io::OpenNI2Grabber::OpenNI_Default_Mode;

pcl::io::OpenNI2Grabber grabber (device_id, depth_mode, image_mode);
grabber.start();

double fx,fy,px,py;

grabber.getDepthCameraIntrinsics(fx,fy,px,py);

cout << "fx=" << fx << endl;
cout << "fy=" << fy << endl;
cout << "px=" << px << endl;
cout << "py=" << px << endl;

return (0);
} 

A similar question has been asked here https://stackoverflow.com/questions/41110791/openni-intrinsic-and-extrinsic-calibration. However it hasnt recieved any answers.