Hello,
Delphi-ONVIF-master is around, never used it.
I wrote some code to use ONVIF for PTZ control. Did not use the video portion of the ONVIF specifiation
For video, most cameras our customers use are MJPEG or RTSP and the video portion of ONVIF did not add any value.
At the time ONVIF PTZ compliance was...marketed but not 100%. Still made it work. 🙂
Good luck,
Mark