Volume control doesn't catch processes from different inputs

[Jeremy2131]

Hello, so I bought a new headset and the problem is I can route different apps through different inputs (Game/Media/Chat) but Volume control catches processes only from the Game input because Game is the default one
Can it be counted as a bug or a feature to be introduced?

[Dregu]

Yep seems like if you use the "App volume and device preferences" in W10 to set a non-default output for an app, VolumeControl will just adjust sessions in the default device for everything anyway. Except if you launch the other app first and then restart VolumeControl it will properly find the session on the other device and can even jump between sessions on different output devices, so clearly there's support for this, it's just bugged.

Edit: After snooping around it looks more like there isn't support for multiple sessions on the same process and the workaround just work by accident for me, because the non-default device is initialized first on launch by chance. After the other app is reopened, the sessions are created in a different order and this time VC picks the silent one.

Only some apps are broken for me (firefox and ffplay) because they are creating sessions on both devices (default + user defined) but only playing sound on the second one. This might be a quirk of how W10 does things with these non-default outputs. Then again spotify works just fine with VC when routed to the alternative device exactly the same way 🤷🏻.

A good fix might be to adjust volume on all open sessions for the process, or just the ones making sounds recently...

[Dregu]

Looks like changing AddSession() to compare the actual SessionIdentifier for duplicates instead of only PIDs does add multiple-devices-per-process support and fixes my main issue, but needs some more work to filter out the sessions in disabled state in the notification/hotkey iteration. Or maybe only hide the disabled sessions from processes that also have active sessions. I don't see any reason to quickly adjust the volume of any app/session that isn't currently producing sound though.

I might make a PR for some of these things later...

[teadrinker2015]

I'm not quite understand the circumstance you're describing. I'll elaborate mine anyway, to facilitate the replication of this issue hopefully.

• Foobar2000's output set to a speaker, Firefox output to the default device. At the beginning, default device is also that speaker.
• Then, I connect to a bluetooth headphone. consequently, it become the default now, and Firefox is redirect to the headphone, perfectly. Then I adjust volume.
• Everything is broken.

Sorry, I'm not intend to make a joke, but I can't remember the exact problem I had encountered. I recently replaced my bluetooth adapter to an audio-only bluetooth adapter, which act as an always-on audio output device, ignorant of which and whether my haedphone is connected. I just realized this change solved my problem.
That's just the last piece of my whole workaround solutions package. Maybe I just want to share this to people.

If you're using a generic normal bluetooth adapter, buy another one. (as previously described)