how to flip the image or video stream from CSI camera on jetson

Hello ,i use the jetson AGX Xavier,when i use deepstream 4.0.1 to run demo, i get the image or video stream is fliped to 180,that is,it is upside down

because,my camera is onboard CSIcamera, it is installed upside down!
so how to flip the video stream and i can get the normal orientation image!

thank you!!!

Please check the sample in: