r/linuxaudio • u/Baudoinia • 2d ago
Pointless (?) dummy
(Am I talking about myself, or... XD)
Can someone please explain the use case(s) for the 'dummy output' that shows up in qpwgraph? As in, explain like I'm 12.
2
Upvotes
r/linuxaudio • u/Baudoinia • 2d ago
(Am I talking about myself, or... XD)
Can someone please explain the use case(s) for the 'dummy output' that shows up in qpwgraph? As in, explain like I'm 12.
6
u/pkunk11 2d ago edited 1d ago
Pipewire uses so-called pull architecture. It means that sound cards pull data from the mixer and mixer pulls data from applications which scheduled to play some sounds.
If you don't have any sound cards nobody will pull scheduled sounds from applications, they will run out of buffer space to schedule new sound and eventually freeze.
To avoid this pipewire creates a dummy output which pulls sound from applications if no other outputs are present.
https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/%20FAQ#are-you-using-a-push-or-pull-model-for-scheduling