Holy crap!
I finally made a thing work .. mostly.

- set up icecast2 server
- stream to it (hard)
- pair this audio with @asciinema live-stream

The icecast2 stuff was "fairly" straightforward, until I entered the TLS swamp (required so that https pages from asciinema don't freak out your browser).

Eventually cobbled together a series of pipes that works:
ffmpeg | oggenc | shout

secret-sauce on "shout" is "--tlsmode rfc2818". Probably needs a blog-post 🤔
Next-stop live-stream coding??