1770728 - Stutter while scrolling a 60FPS video (Was:Scrolling on https://www.home.saxo/ is quite stuttery (in the middle of the page))

Status: RESOLVED DUPLICATE of bug 1767185

(Core :: Graphics: WebRender, enhancement)

Description

[Mayank Bansal]

Go to https://www.home.saxo/
Start scrolling down.
Roughly in the middle just below "Analyse, optimise and" there is some large animation thingy
Scrolling while that animation thingy is visible on the page is very stuttery.

https://share.firefox.dev/3Nrg5Li

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Mayank Bansal]

If I set gfx.webrender.dcomp-video-overlay-win= False , the page doesnt stutter
Profile : https://share.firefox.dev/3MIOSE2

Comment 3

[Mayank Bansal]

It looks like the animation thingy is a 60FPS AVC1 video.

Comment 4

[Mayank Bansal]

Attachment: Global-Frontpage-2021-Platform-Animation-D.mp4

This is the video that causes stutters.
STR:

1. Open this video in a Nightly tab
2. Pinch-zoom the page a lot so that vertical scroll-bars appear on the tab
3. Start the video
4. Try to scroll in the tab
   ER: Stuttery scroll
   https://share.firefox.dev/3lAFtSN

Comment 5

[Sotaro Ikeda [:sotaro]]

(In reply to Mayank Bansal from comment #4)

Created attachment 9277775 [details]
Global-Frontpage-2021-Platform-Animation-D.mp4

This is the video that causes stutters.
STR:

1. Open this video in a Nightly tab
2. Pinch-zoom the page a lot so that vertical scroll-bars appear on the tab
3. Start the video
4. Try to scroll in the tab
   ER: Stuttery scroll
   https://share.firefox.dev/3lAFtSN

Wait happened at DirectComposition::CDevice::Commit(). It seemed that DirectComposition was very busy.