we have Q-See NVR model QC828 and Q-see DVR model QC448. So they are came from same series which is QC series. SO i guess they came from same Chinese manufacturer. I have both system on same LAN. In NVR when i do Remote device and do auto search, it detected the IP of the DVR, then I can add this DVR to the NVR and show the analog camera in the NVR. So the answer is YES, you can add video from DVR to the NVR as long as they are from same manufacturer.