CV2.视频捕获不返回帧

Question

我正在尝试用wx按钮保存网络摄像头视频。这是我的代码

def OnRecord(self, evt):
    capture = cv2.VideoCapture(0)
    if (not capture.isOpened()):
       print "Error"
    # video recorder
    fourcc = cv2.cv.CV_FOURCC('D', 'I', 'V', 'X')  # cv2.VideoWriter_fourcc() does not exist
    out = cv2.VideoWriter("output.avi", fourcc, 9.0, (640, 480), True)
    # record video
    while (capture.isOpened()):
        ret, frame = capture.read()
        if not ret:
            print "Capture Failed"
        else:
            out.write(frame)
            cv2.imshow('Video', frame)

但它会打印Capture Failed，直到我自己关闭python外壳。所以，我猜capture.read()不会返回帧。原因可能是什么？

我怎样才能让它工作？希望得到一些专家建议：）

Answer 1

在读取捕获之前尝试初始化计数器例如：

i = 0
while i < 0:
     ret, frame = capture.read()
     if ret:
          out.write(frame)
     else:
          print "Error"