[pulseaudio-discuss] RFC: Change the device-restore database to allow per-port volumes

[Arun Raghavan]

On Wed, 2011-08-24 at 22:58 +0100, Colin Guthrie wrote:
> Hi,
> 
> This is a patch set that will likely mostly interest David, but also
> solves one of the remaining niggles I have for 1.0 - the fact that
> volumes are not set properly on port changes.
> 
> Now this only "solves" that niggle when the module-device-restore is used,
> but I'm happy enough to rely on that for now seeing as it's the default
> on 99.999% of desktop installs.
> 
> The overall benefit of this patch is that it allows different volumes
> to be saved and restored for different ports. Combine this with David's
> work on making jack-detection work (which triggers port changes) and you
> automatically get different volumes on headphones vs. speakers.

My main concern is the following scenario:

0. Say we start with built-in speaker and headphone port and equal
(maybe 70%) volume
1. With headphones plugged in, I've got the volume turned up while
playing something that's naturally not very loud
2. I pull out headphones, start playing something that's quite loud, I
turn down the volume
3. I put the headphones back, find the output too loud (since the port
volume was turned up for the previous stream)

While the current scenario isn't ideal, it's easy for users to wrap
their head around (different devices have different loudness levels). If
we don't handle this sort of case in the per-port-volume case, IMO the
behaviour is potentially confusing/frustrating to users.

Maybe there's a simple way to handle this that I'm missing ...

-- Arun