Following worked for my setup.
Device: NVR4-7000 (Link)
I have managed to find the RTSP option in the menu.
This post helped to figure it out:
For example:
FrontDoor / IP Camera 1
Main Stream: rtsp://admin:[email protected]:554/Streaming/Channels/101
Sub Stream: rtsp://admin:[email protected]:554/Streaming/Channels/102
I had the same problem with Swann NVR8-7400, until an hour ago.
I then read this article NVR-7400 Help · Issue #250 · thirtythreeforty/neolink · GitHub
I now have a Reolink RLN8-410 system 
It took 3 minutes. You will need to use password 12345 to pick up the cameras.
The Reolink integration then effortless imports the cameras to Home Assistant.
I’m very impressed. If you use DDNS on SwannView app, then it’s an easy change…otherwise you can download the Reolink app for your phone.
Good Luck
I have a DVR8-4680RN on FW V8.2.2-20240820 and i got mine working with
rtsp://user:password@IP:554/rtsp/streaming?channel=01&subtype=0
Hope that helps someone else 
Hey @Spiz67 did you manage to get this working at all? I have DVR8-4600T with no RTSP options just like you. Been trying all sorts of stuff for days now and I’m basically out of ideas.
I can see my DVR streams on Reolink mobile app and SwannView (desktop) but I can’t for the life of me get any links to work in VLC let alone Home Assistant.
Wise forum people, please guide me. If I don’t have an RTSP enabled DVR am I out of luck? Can’t seem to get anywhere using HTTP links.
Did you check out the links previously provided?
One person was able to enable RTSP by flashing Reolink firmware to their Swann NVR:
As you saw in the reply from @paulpretorius, the connection parameters vary widely so also check out:
How to Access Swann Cameras Remotely Without SwannView | Flynsarmy
Edit: Also make sure the user account you are using doesn’t have any special characters (such as ‘@’ , ‘.’, or ‘:’) that may interfere with connection.
