Can't work out how to capture this stream

[gctwnl]

I have been looking at capturing an rtsp:// stream but I am unable to find out how. Apparently, I do not understand the GUI (Mac). I tried opening it and select save settings, but it doesn't work and instead displays very choppy stuff in a small window.

Example stream URL: rtsp://mp4streams.omroep.nl/ceres/1/nos/rest/2011/11act0504Herdenking2/bb.20110504.m4v

What am I doing wrong? Or more precisely: what exactly should I do when I want to save this stream for offline viewing?

Thanks,

G