Headphone volume button to control ubuntu volume?

Question

Background

I am using bluetooth audio a lot at work to play music to my wireless headphones. It could be spotify or other tools such as youtube, local video playback, etc. As headphones goes as a much used peripheral for my part, I want it working in a certain way.

Question

Is it possible to adjust the Ubuntu volume slider by using the headphone volume controls? It varies from distro and operating system and phones, that some connected devices actually adjusts the "system" volume instead of the built-in volume in the headphones.

When i tap volume up, i want the ubuntu volume to increase and not the volume available in my headset. Because if i have 20% sound on ubuntu, my headphones can only vary between 20% and 0% - I can't increase it.

Are there any known workarounds for my issue? I tried looking it up but my searches gave no results.

System info

Ubuntu 18.04, Lenovo Thinkpad X1 Carbon 6th Gen.

Answer 1

This Feature is called "absolute volume". Windows brought it in it's April 2018 Update [1]

For PulseAudio¹, this seems to be a work in progress. [2] [3]

¹ PulseAudio is the default sound-server on almost every major linux-distribution including ubuntu. It manages volume-control and audio-transmission to bluetooth-devices.

[1] https://mspoweruser.com/the-windows-10-april-2018-update-is-a-massive-upgrade-for-bluetooth-in-windows-10/
[2] https://patchwork.freedesktop.org/patch/76558/
[3] https://patchwork.freedesktop.org/patch/257674/

Update 2021-01-25: There is a MR[4] in the meanwhile. It seems that there is still a lot of work but it's in active development.

[4] https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/239

Update 2021-09-07: PipeWire has it! I couldn't become it working under ubuntu 20.04, even with pipewire from [5], I think bluez is too old :(. But it works fine on fedora 34 :)

[5] https://pipewire-debian.github.io/pipewire-debian/