dets = detector(frame, 0)
dets = [list(rect_to_bb(dets[0]))]
print(dets)
[[277, 294, 150, 149]]

faces = cascade.detectMultiScale(gray, 1.3, 5)
print(faces)
[[259 264 182 182]]

_, landmarks = facemark.fit(gray, dets)
TypeError: Expected cv::UMat for argument 'faces'