Hello,
I am searching for a way how to cast audio to Home assistant without any additional device. I would like to press the cast on my android phone and have the audio going from Rpi4 audio output. I am running home assistant OS on Rpi.
Is there an integration/addon to to this?
Thank you! 
Did you ever find a solution? I have a friend with a whole home audio system connected to a dumb amplifier, which sits in a closet where the Raspberry pi running home assistant is… I want to have the RPi connected to the amp and be the sole source of audio, with all the other devices just casting to the RPi