Disable PulseAudio flat volumes to prevent it from pushing volume level to max

[kendell clark]

hi
I can second this. Currently we do this in sonar on versions after
2015.3, which have to be built atm. There are two applications off the
top of my head I know of that will currently do this. They are, kodi
media center, and qemu virtualization software, if you emulate a sound
card of anything other than es1370. I'll add your voip application to
this list, though I don't know what it's called. To disable flat
volumes, edit /etc/pulse/daemon.conf, and change the "flat volumes" line
from yes to no, and remove the semicolon, which is the comment. Then
restart pulseaudio, either by killing pulseaudio, causing it to respawn
or restart your computer.
I'm not sure what should be done to prevent this. Usually, the only
applications that do this are applications that are not pulse audio
aware. Applications that are use the pulse audio API, and thus don't
jump the volume. I completely agree, this requires a change to pulse
audio, but I've had no luck contacting the pulse audio devs. I go onto
their irc channel, and there's literally no response to queries.
Thanks
Kendell clark


On 09/17/2015 01:59 PM, Germano Massullo wrote:
> =======
> Definition of flat-volumes from [1] : it scales the device-volume with
> the volume of the "loudest" application. For example, raising the VoIP
> call volume will raise the hardware volume and adjust the music-player
> volume so it stays where it was, without having to lower the volume of
> the music-player manually.
> =======
> 
> Today I had a scary experience with the audio of my computer.
> I was listening to music with Amarok, using my headphones... The KMix
> volume level was ~ 35%. When I logged into a video conference
> application, the volume suddenly reached the 100%. I was shocked, having
> the maximum audio level shooted in your ears is a painful experience.
> The conference application that triggered PulseAudio pushing volume to
> maximum level probably should have never asked the system for a 100%
> audio level, but on the other hand, PulseAudio should never allow an
> application to make such sudden changes.
> To avoid that, you have to set
> flat-volumes = no
> in /etc/pulse/daemon.conf
> 
> I found many users stories complaining about this default setting [2]
> [3] [4] and you can easily find other by searching "pulseaudio flat
> volumes".
> I completely agree with user gaggra comment at [3]
> 
> <<This is an interesting issue because it is one of the rare times
> misbehaving software can /physically hurt you/. You would think that
> once that was understood, the design of this sort of behaviour would be
> treated in a very conservative, careful manner.>>
> 
> Moreover this default setting can cause sound crackling [5].
> 
> So I would like to start a discussion about disabling this default
> behaviour for the mentioned reasons.
> 
> 
> [1] https://wiki.archlinux.org/index.php/PulseAudio
> [2]
> https://major.io/2015/06/08/pulseaudio-popping-with-multiple-sounds-in-fedora-22/
> [3]
> https://www.reddit.com/r/linux/comments/2rjiaa/horrible_decisions_flat_volumes_in_pulseaudio_a/
> [4]
> http://awesomelinux.blogspot.it/2013/06/pulseaudios-dynamic-volume-levels-are.html
> [5] https://bugzilla.redhat.com/show_bug.cgi?id=1264177
> 
>