Yes, I've tried that though I'm not really sure if I did it correctly.
Here's what I have:
Ip address that I have in my DVR which is also shown in my router
--192.168.100.4--
On the list option "Application" list, I didn't saw "H.264 DVR" as what I can see in my DVR. But what caught my attention is this option (File1). 34567 for with TCP/UDP and another for 80 with TCP/UDP. I also tried 34567 with TCP and UDP separate. same goes with 80. I put the same with my DVR's network settings. Then I tried to check if it successfully open a port via "Canyouseeme.org" but, still, I failed.
Thank you for your response.