Crackling sound & lagging screencast in OBS

[Raphaël Pinson]

Since updating to Ubuntu 22.04, OBS (27.2.3+dfsg1-1) has become unusable for recording:

- the screen capture (pipewire with xdg-desktop-portal) is very laggy: when passing slides on the captured screen, OBS stays stuck on previous frames
- the sound input (pulseaudio) is crackling, even though it works perfectly well when recording the same source with pw-record.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: obs-studio 27.2.3+dfsg1-1
ProcVersionSignature: Ubuntu 5.15.0-27.28-generic 5.15.30
Uname: Linux 5.15.0-27-generic x86_64
ApportVersion: 2.20.11-0ubuntu82
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue May 3 23:36:52 2022
InstallationDate: Installed on 2022-02-25 (66 days ago)
InstallationMedia: Ubuntu 21.10 "Impish Indri" - Release amd64 (20211012)
SourcePackage: obs-studio
UpgradeStatus: Upgraded to jammy on 2022-04-21 (12 days ago)

[Raphaël Pinson (raphink)]

Notes:

- I tried to switch to Xorg: the screen capture works well, but the sound crackling is even worse (probably because the CPU is used more heavily under Xorg due to fractional scaling)
- Everything worked fine under Ubuntu 21.10 (with OBS 27.0.1+dfsg1-1)

[Raphaël Pinson (raphink)]

I tried using Alsa Capture Device instead of PipeWire and got good results:
- sound is fine (when using Default device, got no sound at all when choosing device manually in lsit)
- screen capture is reactive

[Raphaël Pinson (raphink)]

Scratch that previous comment. Switching to Alsa Capture Device solves the sound problem only. The screen capture issue is only solved by switching to Xorg instead of Wayland (but then the CPU suffers from the fractional scaling).