QT rtsp:// mp4 streams are a big problem. You can try to change mdatrtsp:// onto rtsp:// and then use the link in HiDownload, MovRecorder, VLC player, MPlayer.

I would give 95% that it can only be recorded with screen video capture software.

p.s.
Related thread: Manage MovRecorder or other stream recorder to record rtsp:// .mov QT streaming video