Python 使用 pyvirtualcam 时出错：'NoneType' 对象没有属性 'send'

我正在试着修复我的网络摄像头，它里面有一条水平的绿线，我使用OpenCV来嵌入这条线，使用pyVirtualcam来创建一个虚拟摄像头，并在Discorde和Google Meet等应用程序中使用它. 使用OpenCV的图像处理工作正常，但在try 创建虚拟凸轮时出现以下错误:

Traceback (most recent call last):
  File "...\webcamfix\camfix.py", line 37, in <module>     
    cam.send(frame)
  File "...\pyvirtualcam\camera.py", line 349, in send
    self._backend.send(frame)
    ^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'send'

以下是我的代码:

import cv2
import pyvirtualcam
from pyvirtualcam import PixelFormat

# Read webcam
webcam = cv2.VideoCapture(0)

# Set width to 1280 and height to 720
webcam.set(3, 1280)
webcam.set(4, 720)

# Read mask
mask = cv2.imread('mask.jpg', cv2.IMREAD_GRAYSCALE)

# Start virtual cam with 1280x720 30fps
with pyvirtualcam.Camera(1280, 720, 30, fmt=PixelFormat.BGR) as cam:
    print('Virtual camera device: ' + cam.device)


if webcam.isOpened():
    sucess, frame = webcam.read()
    while sucess:
        sucess, frame = webcam.read()

        # Inpainting frame where mask limits using TELEA technique
        frame = cv2.inpaint(frame, mask, 3, cv2.INPAINT_NS)
        
        # Fliping image
        frame = cv2.flip(frame, 1)

        # Displaying video and closing the window if ESC is pressed
        cv2.imshow("webcamfix", frame)
        key = cv2.waitKey(5)
        if key == 27: # ESC
            break

        cam.send(frame)
        cam.sleep_until_next_frame()

正如pyVirtualcam文档建议的那样，我使用的是OBS虚拟摄像头和Unity Video Capture.如果有什么更简单的方法可以在Windows上用python创建一个虚拟相机，我会很高兴知道的.