Happily surprised to find that I can #stream stereo #radio using #OpenWrt out of the box on a #Mango Mini Wireless Router (the GL-MT300N-V2).
#libopus is only using 40-50% CPU.
I also tried with #lame for #mp3 by the way - which was hopeless. Every possible configuration I could find immediately maxes out the CPU, causing constant overruns.
This is the comand I used:
arecord -q -f S16_LE -c2 -r48000 | \
opusenc --quiet --comp [0-9] --raw --raw-rate 48000 --raw-chan 2 --bitrate 128 - - | \
oggfwd ICECASE_SERVER_IP 8000 hackme stream
You can also get away with higher values for comp (at comp 9 I get about 90% CPU usage, comp 10 is too much for it) bitrate of 256 is also working.
https://www.gl-inet.com/products/gl-mt300n-v2/
Thanks @rafael2k for pointers!