Indeed the http port is not required.
However there is no configuration for "media port" in the dvr (DS-7104HWI-SL), only "RTSP Port" which is 554 (by default). Do you think there is any configuration i might be missing, for this "media port"?
I checked the traffic, using wireshark and it looks like it only uses 81 and 554 ports, there are no requests to port 8000.