code: def process_frames_face(self, frames):
          
          detector = dlib.get_frontal_face_detector()
          predictor = dlib.shape_predictor(self.face_predictor_path)
          mouth_frames = self.get_frames_mouth(detector, predictor, frames)
          self.face = np.array(frames)
          self.mouth = np.array(mouth_frames)
          if mouth_frames[0] is not None:
              self.set_data(mouth_frames)
docs: Preprocess from frames using face detector