1946657 - Resizing the PiP on youtube videos flickers

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Mayank Bansal]

Attachment: bandicam 2025-02-07 13-22-46-873.mp4

enable layer compositor
Enable PiP if not enabled
Go to youtube (https://www.youtube.com/watch?v=unSQ6dS9yQw&t=36s)
Put the video in PiP mode
Resize the PiP by dragging on the edge with mouse

AR: the PiP flickers.
ER: Not so

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Mayank Bansal]

This repros on youtube, and a local video file. But does NOT repro on Netflix.
Make what you will of this.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

:gw, since you are the author of the regressor, bug 1945683, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 4

[Mayank Bansal]

The flickering continues till you get a error in gfx-notes in about:support:

Failure Log
(#0) GP+[GFX1-]: Sw video swapchain present is slow

Once you get this, the flickering stops.
So maybe some interaction between the layer compositor and overlay?

Comment 5

[Mayank Bansal]

More issues:

1. if you scroll this page up, the preview/thumbnail of the video appears on top of the search-bar UI, where it is not supposed to.
2. If you pinch-zoom on the page while the preview/thumbnail is visible, the video flickers.
3. With gfx.webrender.debug.dcomp-redraw-regions = TRUE, the whole youtube page is redrawn. Compare this with Layer compositor disabled, where only the video area is redrawn (with occasional redraw of some additional area)

Comment 6

[Mayank Bansal]

Glenn, hopefully you can fix all of these symptoms in this bug itself, rather than posting patches in the other confidential bugs. That way, there will be an open-to-public bug with patches that anyone can see in the future.

Comment 7

[Mayank Bansal]

Not fixed by bug 1946487

Comment 8

[Sotaro Ikeda [:sotaro]]

The videos flickers seemed to happen by recreating video swap chain. During recreating video swap chain, there could be a timing that rendering video does not exist.

We might need to revive workaround of video swap chain that was removed by Bug 1940023. But we need to prevent Bug 1940023 regression.

Comment 9

[Sotaro Ikeda [:sotaro]]

Attachment: Bug 1946657 - Re-add workaround of video overlay's SwapChain Present()

Comment 10

[Mayank Bansal]

With the try build, the flicker of PiP is fixed. Also seems to fix bug 1949116 and bug 1946655
But there is a lot of stutter https://uditmahajan.com/ : https://share.firefox.dev/42ZrAVn

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1a8a6a295027
Re-add workaround of video overlay's SwapChain Present() r=gfx-reviewers,lsalzman

Comment 12

[Sotaro Ikeda [:sotaro]]

(In reply to Mayank Bansal from comment #10)

With the try build, the flicker of PiP is fixed. Also seems to fix bug 1949116 and bug 1946655
But there is a lot of stutter https://uditmahajan.com/ : https://share.firefox.dev/42ZrAVn

Thank you for checking! The fix has some workaround for the stutter, but it was not enough. Going to create a new bug for it.

Comment 13

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/1a8a6a295027

Comment 14

[Mayank Bansal]

This is fixed for me.