My application will stream rtsp from a Pelco encoder fine using opencv. But when I point it at an Axis encoder, wireshark shows that it contacts port 80 and gets "No session ID specified" instead of 554. If I point it at another Axis encoder of a slightly different type, it goes back to port 554. The difference in the rtsp urls between the two Axis encoders is a single digit in the ips; that's it. I did not provide anything different between the two.
If I specify 554 directly in the url, it will connect to 554, but only issues rtsp Continuation, no OPTION/DESCRIBE/SETUP etc.
Does anyone have any ideas why?
Windows Server 2016 OpenCV 4.2.0 RTSP/H264