calling OpenCV calibration functions to calculate rotation vector and translation vector

calling OpenCV calibration functions to calculate rotation vector and
translation vector

I am developing an AR application on android.I use eclipse ide. I have the
4 corner coordinate of the marker which virual object must augment on it.
my question is how can I call OpenCV calibration function to calculate the
camera's extrinsic parameters including rotation vector and translation
vector? I would really appreciate it if you answer me quickly :-) I am new
in opencv.