Another method that most cameras support (if you want the bare basics of record video/audio) is accessing an RTSP stream from the camera. In fact RTSP streams are the primary way you get video into frigate specifically. Some of the more fancy cam manufacturers (axis), are just now starting to support encrypted RTSP , but most of it is unencrypted. you can enable authentication, however in general if you’re doing this over the Internet you do it over a VPN via un encrypted rtsp

Onvif is the keyword, if it’s supported it works with frigate. I think most of the industrial cams are not as locked down as you might think. They are infrastructure so vendors aren’t going to force customers to tear down their existing setup.