Control ARC device volum?

[colemickens]

Hi,

This is a really weird one. I have a Bravia tv and have recently purchased a not-so-smart soundbar. It is hooked up via HDMI ARC. This passes through vol-up/vol-down commands to the soundbar from the tv remote.

I think it makes sense even that this isn't controllable via the default api/control, but I'm wondering if you know -- is there an API to maybe manipulate the ARC volume? It seems like the TV doesn't read the volume level out of arc device (not sure if that's even possible) but maybe there's still a way to remotely volume up/down as if it were the remote pointed at the TV?