Gen2 NN sync output freezes if there is no input

[dhruvmsheth]

The Gen2 NN Sync inferencing basically freezes if the face_frame is none, because the loop gets stuck on the place if there is no face detected in the first frame -

            while q_land.has():
                face_frame = face_q.get()
                out = frame_norm(face_frame, q_land.get().getFirstLayerFp16())
                cv2.circle(face_frame, tuple(out[:2]), 1, (255, 255, 0))  # Right eye
                cv2.circle(face_frame, tuple(out[2:4]), 1, (255, 255, 0))  # Left eye
                cv2.circle(face_frame, tuple(out[4:6]), 1, (255, 255, 0))  # Nose
                cv2.circle(face_frame, tuple(out[6:8]), 1, (255, 255, 0))  # Right mouth
                cv2.circle(face_frame, tuple(out[8:]), 1, (255, 255, 0))  # Left mouth
                cv2.imshow("face", face_frame)

An alternative could be using threading, so even though face_frame is not extracted, the main loop could continue to work.
@VanDavv

[Luxonis-Brandon]

Thanks for the report!