CCTV RTSP URL realtime accessing

My aim is to access cctv livestream using rtsp url on axon and process it using npu and apply models and get the processed output displayed on the screen. I have tried ffmpeg opencv for this and when its running, I’m getting corrupted frames (gray and stuck with little edges somewhere) where nothing is visible properly being happening randomly and frequently and I’m not getting my desired output with that. I also found that gstreamer also does this, but its headless and its not showing any output display. So I want to know if there is any method i should follow for getting the correct video streamed and decoding them correctly. I have been using the same os which came installed and I havent flashed anything yet. Please guide me how to proceed.