Hi,
Using python + OpenCV should be fine, there are samples for reference:
Increasing play speed decoding from mp4 file - #9 by DaneLLL
Doesn't work nvv4l2decoder for decoding RTSP in gstreamer + opencv - #3 by DaneLLL
Displaying to the screen with OpenCV and GStreamer - #9 by DaneLLL
Stream processed video with OpenCV on Jetson TX2 - #5 by DaneLLL