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Snow-Sudo

Member

Registered: 2020-09-13

Posts: 15

[SOLVED] Unable to view Youtube videos in fullscreen through Firefox

I'm using KDE Plasma as my desktop environment and Firefox as my primary browser. Whenever I full screen a Youtube video on my secondary monitor, the video goes black, but I can hear the audio play. I still see my cursor when this happens and can leave full screen by clicking on the bottom right corner. This only happens on my secondary monitor but not on my first one. I reinstalled Firefox and also reinstalled the nvidia drivers to see if that would solve the issue but it didn't.

I've posted a short clip of it on imgur here: https://imgur.com/a/ajAmUhf

Last edited by Snow-Sudo (2020-11-13 23:35:38)

sm0x

Member

Registered: 2014-01-13

Posts: 4

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

I cannot help you, but I have the exact same problem on my OpenSUSE Tumbleweed Workstation. Same setup. NVidia, YouTube, and only the second Monitor.

Last edited by sm0x (2020-11-09 08:45:55)

Snow-Sudo

Member

Registered: 2020-09-13

Posts: 15

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

@sm0x Go to Compositor in the settings and uncheck the Enable compositor on startup. This seems to solve the issue.

Last edited by Snow-Sudo (2020-11-13 23:35:49)

patrioticparadox

Member

Registered: 2020-11-29

Posts: 3

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

I was also facing this issue. (side note: I was experiencing this issue with many video players (all I tried) from a variety of webpages)

In "Compositor" settings I changed "Rendering backend" from OpenGL 3.1 back to OpenGL 2.0.
After applying and without restarting either the system OR Firefox I could fullscreen the video and it rendered fullscreen video correctly.
Interestingly, I then changed "Rendering backend" BACK to OpenGL 3.1 and could still fullscreen videos as expected.
I did not adjust "Enable compositor on startup up" from its default state of enabled.

I restarted my system with OpenGL 3.1 and "enable compositor on startup" still set to default(on) to see if the issue would reoccur and it did not. I can still go fullscreen with videos within Firefox with expected behavior.

Hopefully, someone smarter that I can provide some reasoning behind this. Regardless, hope it helps someone else as this post is a high ranked result from Googling.

Last edited by patrioticparadox (2020-11-29 23:41:39)

rockybulwinkle

Member

Registered: 2013-11-09

Posts: 3

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

I saw the issue too, but patrioticparadox's suggestion didn't help me. I haven't had a chance to try disabling the compositor on startup.

For me, it seems it had to do with applications overriding the compositor. I unchecked the "allow applications to block compositing" and that fixed it for me without needing to restart anything.

Edit: I also need to have the rendering backend on OpenGL 2.0. OpenGL 3.1 with the "allow applications to block compositing" unchecked still causes the error.

Last edited by rockybulwinkle (2020-12-04 19:33:59)

rockybulwinkle

Member

Registered: 2013-11-09

Posts: 3

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

Actually, I'm seeing the issue come back after a while. It seems like I have to just change "something" in those settings, then hit apply. It's like something with the compositor gets in a bad state, but updating the settings gets it out of the bad state.

LeeJunFan

Member

Registered: 2020-09-06

Posts: 5

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

I found it. There's an effect "Full Screen" in "Desktop Effects" that needs to be disabled. It's supposed to do some kind of animation for windows going into and leaving full screen mode.

rockybulwinkle

Member

Registered: 2013-11-09

Posts: 3

Re: [SOLVED] Unable to view Youtube videos in fullscreen through Firefox

Thanks, yeah I was about to come here to post that same answer

I'm gonna post a bug report on KDE's bug tracker.

EDIT: someone already reported it:
https://bugs.kde.org/show_bug.cgi?id=428166

Last edited by rockybulwinkle (2020-12-18 15:20:03)