I have TV connected by optical toslink to speakers. But thay have no remote control. So I bought hifiberry with input/output toslinks. What I want to do is just set volume with rpi.
Everything works, but can't find how to connect input and output with working volume control.
What works for me is alsaloop, which resends data from input to output.
alsaloop -C hw:0,0 -P hw:0,0
But this command do not send data to mixer, so I cannot regulate volume.
Does anybody know how to solve this?