dlib for video face detection

[notknowchild]

I recently used dlib_video_face_detection for video face detection, (https://github.com/bertolechi/faceswap-GAN).
My input video is 1280 * 720. When min_face_scale = 1/50., The output face image size is not uniform. At first, it was 52 * 51, and later it became 52 * 52. Will you have encountered this situation? ? Thanks for answering！