环境是python+opencv
摄像头：
显示黑屏
测试代码网上找的：
import cv2
import numpy as np
cap = cv2.VideoCapture(0)
# ret = cap.set(3, 320)
# ret = cap.set(4, 240)
# 设置摄像头分辨率
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)
cap.set(cv2.CAP_PROP_FOURCC, cv2.VideoWriter.fourcc("M","J","P","G")) #?1为啥要重设
i = 0
while cap.isOpened():
ret, frame = cap.read(0)
#print(frame)
left_img = frame[:, 0:640, :]
right_img = frame[:, 640:1280, :]
if ret:
# 显示两幅图片合成的图片
cv2.imshow('img', frame)
# 显示左摄像头视图
cv2.imshow('left', left_img)
# 显示右摄像头视图
cv2.imshow('right', right_img)
key = cv2.waitKey(delay=2)
if key == ord('t'):
cv2.imwrite('./img/test' + str(i) + '.jpg', frame) #
i += 1
if key == ord("q") or key == 27:
break
cap.release()
cv2.destroyAllWindows()
请问是摄像头有问题还是代码要怎么设置？

附：只能左侧的摄像头能正常使用