iTunes and hardware volume control with RPi

I'm in the process of knocking together a streamer using IanCanada's fifpi, DAC and transformer output, that will be driving an NCore NC122MP. I've got the rPi 7" touchscreen and I'm working on a case design to be CNC'ed. Now I'm working on the software at the moment.

My main system consists of a Naim Uniti Atom (driving Quad 2912's), and I use that streamer in two ways. The first is pretty straightforward. I have a 4TB disk with all my ripped music and some high res music on it. I use the naim app on a tablet or my phone to control what is playing volume etc. But a lot of the time I airplay from my phone or one of two Mac computers running iTunes. I have carefully groomed all my music in iTunes and it's been working well as my streaming hub for years. The Naim hardware volume and iTunes stay in sync beautifully, if I use the iTunes volume slider, it changes on the naim. If I use the naim remote, the volume knob on the unit, or the app, the volume in iTunes moves with any of those other adjustment methods. IT's like they are all tied together.

I have taken that symbiosis for granted, and with the RPi hardware I can change the volume in hardware using the web interface, but the airplay link is really dumb. There is no track info or cover art, and iTunes volume control is blind to the changes I've made in the app. There's no back and forth communication.

I've been looking into shairport-sync and it appears that a lot of the functionality I am missing on the RPi solution can be implemented, but it's a bit of a rocky road to do it. I'm more than willing to work on it, but I'm wondering if I'm the only one here that would like that functionality or is this a common gripe about what seems to be a half-baked airplay implementation in these various pre-packaged RPi music streamer distributions?

I love doing the DIY thing, but the Naim Uniti Atom is so nice and works so seamlessly that I might have to bail on this project and just get a second one for the shop.

In summary, I want bi-directional volume info to and from iTunes (apple music) to the RPi so the volume controls everywhere are in sync. I'd also like more metadata broadcast as well.

Does anybody else want this or am I a lone voice in the wilderness?

Sheldon
 
This this thread has been such a resounding success, I thought I'd follow up by saying that I am abandoning iTunes after 15+ years and using Roon for all my streaming needs. It's so much better for music discovery and very impressive in many other ways. I resisted it for a long time because it's not free or included on my machines, but I have to say that for me, it's worth it.

Sheldon