You can get the video stream from Atlas DVR via RTSP.
Please try it with newest F/W.
rtsp://ID:password@IP address:RTSP port/live/main0
rtsp://ID:password@IP address:RTSP port/live/second0
For example,
rtsp://ADMIN:1234@192.168.0.25:5554/live/main0 - main stream ch1
rtsp://ADMIN:1234@192.168.0.25:5554/live/second0 - sub stream ch1
rtsp://ADMIN:1234@192.168.0.25:5554/live/main1 - main stream ch2
rtsp://ADMIN:1234@192.168.0.25:5554/live/second1 - sub stream ch2
when you use RTSP on Nuvis NVR, write as below at stream path
/live/main0
/live/second0