Can't see the Start Virtual Camera option with OBS Studio 28.1.2

b1zzu

New Member
Hi,
I would like to use the Virtual Camera to share my screen in meetings, but I can't find the button to start it.

I saw some videos and read some blogs and everyone says that it should just be under Controls, but I don't have it:
1670925992416.png


I'm using Fedora 37 with Wayland and I've installed OBS from Flathub.

Do I need to enable some settings for it to work?

Thanks for the help in advance,
Davide
 

AaronD

Active Member
everyone says that it should just be under Controls
Yes, it should. And your screenshot doesn't show it. Its settings are supposed to be in the Tools menu. Do you have that? Maybe it needs to be enabled from there before the button appears.

Or maybe the flatpak just doesn't have it. Try snap or apt/rpm instead. (apt is for Ubuntu and other Debian-based distros, Fedora has rpm)
 

Tuna

Member
The previous post has it all wrong. Don't use snap, it is known to cause issues. Also the settings are not in the tools menu.

One should have installed the v4l2loopback module. If it still does not show up, try loading the module manually before starting OBS.
 

AaronD

Active Member
Don't use snap, it is known to cause issues.
What kind of issues? I've used it before, and it worked just fine for me. There were a boatload of permissions that I had to set, so it could use things that were outside of its sandbox (one of snap's "features", and all documented on the same page that I linked to), but once that was done, it was great. It had a bunch of plugins preinstalled and "just working" that I had a bear of a time getting to work piecemeal.

Not saying there *aren't* any issues, just that I never saw any.

Also the settings are not in the tools menu.
Okay, you're right on that one. v28 has them here:
1671116997749.png

I think a previous version does have them in the toolbar, when it was still an external plugin like all the others, so I was going off of memory from that.

One should have installed the v4l2loopback module. If it still does not show up, try loading the module manually before starting OBS.
That could do it too. Though if that's the problem, I might call it a minor bug for OBS to not show it at all. I think it should show it, and then show an error when you try to use it. That would make it much easier to troubleshoot.

However, my v28.1.2 of OBS would ask for my password on first start (why???) and then the VCam would work. A bit of googling told me that it was trying to load that module in the background and needed root permission to do it, hence the password. So I dug through the source code to see exactly what it was doing there, and copy/pasted that line into a system startup script that I made to run as root. (in Ubuntu, sudo crontab, @reboot) No more password prompt.

That line is:
Bash:
modprobe v4l2loopback exclusive_caps=1 card_label='OBS Virtual Camera'

There are other ways to load a module on startup, but this works too. And I like to keep my modifications all in one place if I can, so I can copy them later to another build.
Most of what I find as the "right" or intended way to do it, is all over the place for each different thing. Some in ~/.config, others in /etc/<something>, still more somewhere else, etc. Makes it hard to set up a similar system from scratch, because I KNOW I'll forget one and then wonder why it doesn't work. A script that runs on startup and has all the commands in it (two actually, for me: one as root and one as user) is much easier to copy.
 
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AaronD

Active Member
@AaronD thx !!! that did my trick as well :-)
Just FYI: I don't do it that way anymore. I use Ubuntu Studio now, which has an old version (v27) of OBS preinstalled natively and working. Add the PPA per the sticky thread in this forum (still works), and then the normal update process gets you the latest, which also works.
sudo apt-add-repository ppa:obsproject/obs-studio

THEN build your rig on the updated version. If you build a bunch and then update, you'll lose it all and have to start over, because of a graphics change from v27 to v28 that causes a bunch of plugins to not load, and then their settings are wiped out because they didn't load. Gone forever, even if you downgrade back to what it was.

So update FIRST and THEN build your rig. See what plugins are available for the current version, and what functionality is native now and doesn't need a plugin, etc.

I still have the modprobe line in a startup script as root. That's still needed. Though I added a bit to keep it from rearranging my other captures:
Bash:
modprobe v4l2loopback exclusive_caps=1 card_label='OBS Virtual Camera' video_nr=99
 
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