When I plug in a USB camera then the volume levels are changed to some preset values. It also happens sometimes when I start some audio playback from a different SW (e.g. radiotray or mplayer). I don't want this automatic volume changing. I have XUbuntu 14.04 and I suspect PulseAudio but I can't figure out how to disable it.
Stream output volume is a feature which allows individual stream properties based on applications.
For streams it is controlled by the pulseaudio module
module-stream-restore, for audio devices it is controlled by
module-device-restore, and for sound cards (if multiple) it is
To test whether our issue is resolved we can temporarily unload any of these modules (which should be loaded from our
pacmd unload-module module-stream-restore
The module will be re-loaded by restarting the pulseaudio sound server with
If after unloading the issue was resolved we can prevent loading this module by commenting out the line in our
default.pa (located in
~/.config/pulse/ like this: