DRM protected channels won't work without Telerising (SD streams are possible without HDCP enforcement, there's no stream at all with HDCP enforced by the provider). At this moment, the German RTL channels are affected by these restrictions in Switzerland, and most of the private channels use DRM via Zattoo DE/AT. In case someone would like to try this to watch German channels.
Interesting! I had no idea German channels had this kind of issue.
Well, it's still possible to use telerising in the setup I mentioned: you just replace the direct zattoo link with the one telerising provides in the m3u, eg. http://<telerising_ip>:5050/api/zch/live/cnn-international, and it works beautifully without stutter.
(feature request: add the streamlink option instead of ffmpeg. It would make setup much easier!).
Indeed when I was looking for solutions, I tested teleboy (which streamlink does not directly support) using tvheadend+streamlink, and it worked really well until... they blocked my VPN which forced me to check zattoo again. (I guess I could have set up a personal proxy via vps2day, but why paying for one more service when I can re-use my VPN?)