at german jurisdiction streams from other countries should be lower than 2% of the whole listeners. I´ve found the geoblocking thread and you said it is not possible. I´ve found an icecast script, which make it very easily possible: https://gist.github.com/anthonyeden/7cc90e4d9fed0a84701d6f36ffb43d05
All you´ve to do is:
- add an extra field at the icecast-xml conf file
- a few input fields, radio buttons at centova itself to execute create the php based geoblocking.