OpenNI + NiTE: New user registration without callback

edit

I am programming a simple skeleton tracker using OpenNI 1.5.4.10 and NiTE to be executed in ROS Hydro. I want to detect the skeleton from a single user recorded in an ONI file. This user does not perform init gestures, and although I have the callbacks for the User object registered, the "New User" callback is not executing. When I try to detect the skeleton, the method detects 0 users and I do not obtain any data from the user skeleton.

Which are the options to solve this problem? How can I register the user I have without a callback?

Thank you in advance,

regards