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As Kuesquillio mentioned, this tutorial is a 2-step approach. Pi streams video to a PC. PC presents the video as an ONVIF camera. At the time this page was written this was a good way.There is now a 100% Pi solution and full ONVIF Server that runs on the Pi. It is a NodeJS project called RPOS (Raspberry Pi ONVIF Server). The project is hosted at https://github.com/BreeeZe/rpos and will stream H264 video from a Pi Camera to ONVIF viewing software.