I don’t know if this could be of any help, but recently I struggled as well with a DVR which I don’t remember the brand because it was not mine . Any way, what I did was:
Connect using Internet Explorer, it might require some Active X control available only in Iexplorer.
Activate upnp in routerboard. The DVR I was configuring, after successful login, was opening other ports for streaming and other for controlling it.
That will only work from the internet. If you are trying it from a localnet computer, it won’t work without a hairpin nat. http://wiki.mikrotik.com/wiki/Hairpin_NAT
@SurferTim I think I already did it, but I am not pretty sure because I am a beginner in this, I am using winbox and I have created two NAT rules placed in this order: