Although Zdenek Katal himself was against it, but the source codes of his algorithm for tracking objects in a video stream Tracking-Learning-Detection (aka Predator) still got into open access. Apparently, they were posted for some time on the author's website and someone managed to make a copy. And since the code was published under the GPL 2.0 license, there were no obstacles for its further distribution.
The main part is made on Matlab and can be relatively easily translated to C in a couple of days. ')
The tracking itself is carried out by the method of Lucas-Canada and with the help of OpenCV.