Video vsync issue

English Multimedia
1

Hi,
Small issue here, I’ve installed Leap 15 recently, along with the multimedia codecs.
The problem is that when playing video, it appears that the vsync is not working properly, resulting in an horizontal bar in the middle of the screen.
I have a Nvidia gtx 970, and I’ve tried setting the vsync option to “full screen repaints” in the compositor settings menu with no success.
I’ve also tried disabling the vsync in the Nvidia X server settings, also with no success.
I’ve downloaded the codecs from this website.

Any suggestion?

Thanks in advance!

2

Which video player are you using?

3

Just in case the following is helpful here…

Do you have the vdpau driver installed?

zypper se -si vdpau

Is your player configured to use vdpau?

4 
** 
$** zypper se -si vdpau

S  | Name             | Type    | Version           | Arch   | Repository             
---+------------------+---------+-------------------+--------+-----------------------
i+ | libvdpau1        | package | 1.1.1-lp150.1.9   | x86_64 | openSUSE-Leap-15.0-Oss
i+ | libvdpau_nouveau | package | 18.0.2-lp150.17.2 | x86_64 | openSUSE-Leap-15.0-Oss
i+ | vlc-vdpau        | package | 3.0.2-lp150.3.2   | x86_64 | packman                
i+ | vlc-vdpau        | package | 3.0.2-lp150.3.2   | x86_64 | Packman Repository

I forgot to mention that I have this problem while playing video in VLC (or any other player) and online.

Thanks!

5

With VLC you can set the video output via Tools > Preferences > Video. What is set there. Have you tried experimenting with these. In particular, perhaps try setting VDPAU Output explicitly?

Try launching mpv (video player) from a terminal and play a video file.

mpv /path/to/your/video/file

Any error messages?

6

this could also depend on the type of file you’re opening
you could try running

vdpauinfo

to see what your gpu can handle in hardware and

mediainfo /path/to/file/you.re/playing.mp4

to see more information about the media ie video and audio encoding and profiles and the used container format
mediainfo is not installed by default

zypper in mediainfo

not everything is supported in hardware if the media uses an unsupported profile then decoding is done in software and that could cause sync issues one way around this is letting vlc (or your preferred player) drop frames

7

Thanks everybody, problem solved!
I created ‘/etc/profile.d/kwin.sh’ with the line ‘export KWIN_TRIPLE_BUFFER=1’.
If I understand correctly, it enforces the vsync no matter what.

Even though it works, do you agree with this solution?
Are there some consequences I should worry about?

8

I don’t own computers using nvidia graphics hardware, but I do note this is a common suggestion for such screen tearing symptoms with nvidia hardware , so if it works for you then great!

https://devtalk.nvidia.com/default/topic/828962/screen-tearing/
https://forums.opensuse.org/showthread.php/502227-Screen-tearing-in-KDE-with-nvidia-proprietary-drivers
https://www.reddit.com/r/kde/comments/88aejd/is_anyone_here_using_kde_on_proprietary_nvidia/