该方法通过基于 cv2.VideoCapture 能够获取视频流入（rtmp/rtsp等）实时帧，能够解决由于图像处理速度不够等原因造成帧堆积的问题。

class ThreadedCamera(object):

def init(self, source=0):

global cap

self.capture = cv2.VideoCapture(source)

self.thread = Thread(target=self.update, args=())

self.thread.daemon = True # 防止主线程挂掉，子线变成程僵尸进程

self.thread.start()

self.status = False

self.frame = None

def update(self):

while True:

if self.capture.isOpened():

(self.status, self.frame) = self.capture.read()

def grab_frame(self):

if self.status:

return (self.status,self.frame)

return (None,None)

streamer = ThreadedCamera(args.video)

while True:#cv.waitKey(1) != 'q':

has_frame, show = streamer.grab_frame()