Read rst gstreamer with nvidia acceleration

i try to use gstreamer to read rstp without latency as below:

import cv2

url = "rtsp://admin:abcd1234@"
pipeline = 'rtspsrc location=%s latency=0 ! decodebin ! ' % url

cvt_pipeline = (
                'videoscale ! '
                'video/x-raw, width=(int)%d, height=(int)%d !'
                'videoconvert ! appsink sync=false'
                % (1920, 1080)
cap = cv2.VideoCapture(pipeline + cvt_pipeline, cv2.CAP_GSTREAMER)

while True:
      ret,frame =
      if not ret:
        print('empty frame')

it is work, but it use cpu too much.
i find out that, i can use gstreamer with nvcodec. (Install NVDEC and NVENC as GStreamer plugins · GitHub)
but don’t know how to implement it. Could you guide me to do it?