我正在尝试从流式视频中获取图像，并且花了几分钟，但是随后出现以下错误：cv2.error：OpenCV（4.1.1）C：\ projects \ opencv-python \ opencv \ modules \ imgproc \ src \ resize.cpp：3720：错误：（-215：断言失败）！函数'cv :: resize'中的ssize.empty（） 我的代码：

while True:

ret,frame = video_capture.read()


small_frame = cv2.resize(frame,(0,0),fx=0.25,fy=0.25)


rgb_small_frame = small_frame[:,:,::-1]

#
if process_this_frame:

    face_locations = face_recognition.face_locations(rgb_small_frame,number_of_times_to_upsample=2)
    face_encodings = face_recognition.face_encodings(rgb_small_frame,face_locations)

    face_names = []
    for face_encoding in face_encodings:

        matches = face_recognition.compare_faces(known_face_encodings,face_encoding)
        name = "None"

        # #
        # if True in matches:
        #     first_match_index = matches.index(True)
        #     name = known_face_names[first_match_index]

        face_distances = face_recognition.face_distance(known_face_encodings,face_encoding)
        best_match_index = np.argmin(face_distances)
        if matches[best_match_index]:
            name = known_face_names[best_match_index]

        face_names.append(name)
        if matches[best_match_index]:
            adicionar_json()

process_this_frame = not process_this_frame

font = cv2.FONT_ITALIC





for (top,right,bottom,left),name in zip(face_locations,face_names):

    top *= 4
    right *= 4
    bottom *= 4
    left *= 4

我正在尝试从rtsp摄像机获取视频流