how to download encrypted rtmp stream?

i have tried jaksta, the first few pages of google and nearly all of the chrome and firefox extensions for downloading vids. While they work with youtube, they do not download encrypted rtmp stream videos. Anyone know a way to do this besides screenrecording (on mac)?

Thanks

HINT: I remember using a while ago something called RTMPDump
It was working fine for me, but i was on a PC not MAC