Amplifier volume control

[markferry]

Zones with amplifiers controllable via HDMI or Network should allow routing of volume control all the way through from app (e.g. Spotify) to Amplifier bypassing all software volume controls.

• HDMI CEC

  • https://github.com/lautis/cec-alsa-volume
    • nodejs dep :C (~10MB)
  • if shared with Kodi would need to use kodi-send
  • CEC only supports Volume Up, Down and Mute. It does not support setting a specific volume.

• Networked amp

  • https://www.alsa-project.org/wiki/Matrix:Module-aloop
  • alsactl monitor hw:2
  • a script to abstract amp protocol (e.g. calls onkyo-eiscp)
  • would let a user hit HomeAssistant API