GNOME 40 Mutter Lands Wayland Presentation-Time Support

[Mez']

Previously I used X.Org but now I have a bug where I can't move windows by dragging the the titlebar so I had to switch to Wayland which does not suffer from this bug.

Fyi, it's already been solved.
https://bugs.launchpad.net/ubuntu/+s...r/+bug/1917926

[pracedru]

Year of the linux desktop was 2007 for me.
I ditched Windows and have been very happy with Linux since.

[Linuxxx]

That link gave in past post was also for intel graphics and person having problems.

I'm truly sorry to say this, but You really have no clue! (Well, at least when it comes to the topic on hand.)

That random link with the random person having random problems with mpv is also precisely because of this: HE HAS NO CLUE!
He was trying to run 4K videos with his severely outdated & underperforming Intel Haswell 7.5 Gen iGPU with dscale=mitchell & cscale=ewa_lanczos - of course his machine is going to drop frames like crazy, anything else would have quite literally been a miracle!
And yes, watching full length films without a single dropped or even delayed frame on X11 with mpv is absolutely possible, as I have been doing for many years already! (With display-resample & activated frame interpolation.)

Speaking of interpolation:
aufkrawall
Are you still using sphinx?
If so, could You try tscale-window=kaiser with tscale-radius @ it's default (so most likely 1.0 or simply not setting the value at all)?
Maybe even do some of that special screenshot benchmarking of Yours?

[oiaohm]

Why not post a picture of a banana instead, it might be closer to the actual topic...
I btw. had perfect playback on gemini lake with xf-86-intel ddx, please try to bullsh*t somebody else...

Really try to bullsh*t someone else aufkrawall gemini lake with the Intel ddx with x.org at best is 1 frame out of sync as in the video is one frame behind the audio with mpv. Mpv on wayland had a stutter badly with presentation time due to the Wayland version not having the extra frame so maths were out in mpv.

https://ppaalanen.blogspot.com/2014/...n-wayland.html

The X11 Present extension has a known bug documented by Keith made it. Yes like it or not gemini lake Intel can also turn choppy on X.org X11 because it has the same X11 Present bug . Just you have not seen it yet.

Display-resample is not fixing all the issues like it or not with mpv. Moving to wayland presentation time allowing usage of correct information to know exactly when is on frame not +-1 frame as X11 Present gives

The better information wayland present time gives allows software with right processing to keep playback right at a higher CPU load level than the X11 present does.

Yes aufkrawall you just did a works of me arguement without the knowledge to see that its not working right and not understanding the issues that will come. That link gave in past post was also for intel graphics and person having problems. You just have not been doing the load on your system to make the problem visible but the problem is absolutely there with gemini lake.

Wayland Presentation time and X11 present time both same objective make it less likely for video/audio to end up badly out of sync. Of course Wayland presentation time higher accuracy as long as there are no bugs in the software means it has a lower risk of going out of sync compared to X11 present time that has a lower accuracy of its information.

Getting the video and audio correctly synced turns out to be quite a hard process. Along the way different developers have goofed things up.

[aufkrawall]

https://bbs.archlinux.org/viewtopic.php?id=261550

Its not that straight forwards. display-resample is not fixing all the issues for everyone with Xorg. Turns out getting stable frame pacing is not a simple process.

Why not post a picture of a banana instead, it might be closer to the actual topic...
I btw. had perfect playback on gemini lake with xf-86-intel ddx, please try to bullsh*t somebody else...

[oiaohm]

Hard for me to understand why we need this. I have been playing videos for a long time on Gnome wayland and never noticed sync issues. Is this about videos occasionally going out of sync in some circumstances, or is there some fraction-of-a-second sync issues that I'm simply not noticing?

The regular problem here minor going out of sync for some fraction of a second sync issues you will not notice here. "if something can go wrong, it will", from sod law absolutely applies. If all those minor out of syncs stack up you will end up in some circumstances majorly out of sync. So those things you are simply not noticing stack up to at times to cause bigger visible issues in more of a random way. Of course while the sync issue is minor the corrections can be done in minor ways that can be completely invisible to the end user if the playback software can know about it.. Yes to do corrections you need to know the problem has happened this is where presentation time information comes in so player software support it can find out things are going wrong and do corrections before they are bad enough to be noticeable by user.

Video playback and keeping the playback defects not noticeable to the end user is not a simple problem. Yes this is why you get a lot of works for me claims that under closer inspection its not in fact working for them they just are not seeing the stack up events of the defects can happen yet so they are ignoring the minor defects to claim its working right.

[RahulSundaram]

Hard for me to understand why we need this. I have been playing videos for a long time on Gnome wayland and never noticed sync issues. Is this about videos occasionally going out of sync in some circumstances, or is there some fraction-of-a-second sync issues that I'm simply not noticing?

The original blog post goes into some details

https://ppaalanen.blogspot.com/2014/...n-wayland.html

It is unlikely you are going to notice it on a typical desktop system.

[sarmad]

Hard for me to understand why we need this. I have been playing videos for a long time on Gnome wayland and never noticed sync issues. Is this about videos occasionally going out of sync in some circumstances, or is there some fraction-of-a-second sync issues that I'm simply not noticing?

[oiaohm]

Yet playback is perfect with mpv's --video-sync=display-resample on Xorg. Very easy to test, just dub some judder test video with an audio track...

https://bbs.archlinux.org/viewtopic.php?id=261550

Its not that straight forwards. display-resample is not fixing all the issues for everyone with Xorg. Turns out getting stable frame pacing is not a simple process.

[aufkrawall]

Yet playback is perfect with mpv's --video-sync=display-resample on Xorg. Very easy to test, just dub some judder test video with an audio track...