[sound] Subwoofer slider works in mysterious ways

[David Henningsson]

Sometimes it follows master volume and sometimes it doesn't.

Same as:
https://bugzilla.gnome.org/show_bug.cgi?id=753847

Also raised by OEM team.

[David Henningsson (diwic)]

Hi Seb,

With my proposed fix, the subwoofer slider will work as follows:

Slider all the way to the left = no subwoofer
Slider in the middle = subwoofer / other speakers equal volume
Slider all the way to the right = only subwoofer

That will make the subwoofer slider behave consistently with the other sliders, with also fade away a set of speakers when sliders are moved from the middle towards either side.

Any problems with that before I go coding on it? The PulseAudio part of it is already in PulseAudio git master, just the u-c-c pieces remain.

[David Henningsson (diwic)]

Note to self - these are the commits we need to cherrypick into Ubuntu for the PulseAudio pieces:

http://cgit.freedesktop.org/pulseaudio/pulseaudio/commit/?id=9fecb6eb32d19b5f2dfc194426b7b3cd678a7520
http://cgit.freedesktop.org/pulseaudio/pulseaudio/commit/?id=387a244cd92061ecedd3cc97c6f87ece44b65a91

[Sebastien Bacher (seb128)]

the pulseaudio changes are in the current version