I noticed that our QSS301-04L-P4 Security NVR has an RTSP service. I thought if it would be easy enough to access the live stream via RTSP and capture an image.
Turns out, it’s not that difficult and can be performed using ffmpeg. Once you have ffmpeg binary available for your platform, execute it like so.
ffmpeg -y -i rtsp://username:firstname.lastname@example.org:554/unicast/c1/s0/live -vframes 1 image-capture.jpg
The above example will capture image from c1 (Channel 1) and s0 (Stream 0 = main high resolution stream).