1709493 - The entire screen flashes white when playing a Youtube video.

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Alice0775 White]

[Tracking Requested - why for this release]: The entire screen flashes white

Several people have reported bugs on Mozillazine.
(see http://forums.mozillazine.org/viewtopic.php?f=23&t=3074418 )

Reproducible: yes

Steps To reproduce:

1. Start Nightly90.0a1
2. Load Youtube video in a tab
3. Start playback the video

Actual Results:
Screen flashing(UI and contents).

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=5a74388d847a9487593a0fe28a706015ac353220&tochange=a57a18bd5034b718955a35fecea22727d556e35f

Suspect: Bug 1708590

Comment 1

[Lee Salzman [:lsalzman]]

Please post your about:support information so I have an idea of what platform this is occurring on

Comment 2

[Alice0775 White]

Attachment: about:support

Comment 3

[Lee Salzman [:lsalzman]]

I am not able to reproduce this locally at all on Linux. Sotaro, are you able to reproduce this on any platform and/or have an idea why this might be occurring?

Upon further investigation, I misunderstood, this doesn't seem to affect SW-WR, even though we made that change for SW-WR.

I don't quite have the right platform to test and reproduce locally, but I suspect this is because our HW-WR RenderCompositors (RenderCompositorANGLE and probably enderCompositorNative as well) don't recognize that no surfaces have been added and try to render a frame. But since this frame has no surfaces, you just see blankness...

Comment 4

[Alice0775 White]

Screencast: https://youtu.be/cwjDsZhzOHM (The bug appears around 0:11-0:13 in this screencast.)

Comment 5

[Lee Salzman [:lsalzman]]

Attachment: Bug 1709493 - Don't call compositor begin_frame/end_frame unless actually rendering. r?sotaro

If we're not actually rendering a frame, calling begin_frame/end_frame on the compositor without
adding surfaces can cause us to render a blank frame. Avoid calling begin_frame/end_frame as well
in this situation so that we don't cacidentally do this.

Comment 6

[Lee Salzman [:lsalzman]]

Alice0775, I put up a patch that might fix this. I can't quite test it myself, but could you try these builds to see if it solves it for you?

https://treeherder.mozilla.org/#/jobs?repo=try&revision=bbf2b8f53004d2158b58ac5a2aa1b5bc1428760a

Comment 7

[Alice0775 White]

(In reply to Lee Salzman [:lsalzman] from comment #6)

Alice0775, I put up a patch that might fix this. I can't quite test it myself, but could you try these builds to see if it solves it for you?

https://treeherder.mozilla.org/#/jobs?repo=try&revision=bbf2b8f53004d2158b58ac5a2aa1b5bc1428760a

Yes, the try opt build fixes the problem on Windows10 :)

Comment 8

[Sotaro Ikeda [:sotaro]]

(In reply to Lee Salzman [:lsalzman] from comment #3)

I am not able to reproduce this locally at all on Linux. Sotaro, are you able to reproduce this on any platform and/or have an idea why this might be occurring?

Sorry for slow response. Japan was in public holidays.

Yes, I could reproduce the problem with youtube 4K video. You already have D114316 for addressing the problem. I confirmed it addressed the problem for me on Win10 PC.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ec86658fae7f
Don't call compositor begin_frame/end_frame unless actually rendering. r=sotaro,gfx-reviewers,gw

Comment 10

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/ec86658fae7f

Comment 11

[Alice0775 White]

I can reproduce the problem on Nightly90.0a1(build id: 20210506092558) Windows10.
And I have verified that the problem is fixed on Nightly90.0a1(build id: 20210507095221) Windows10.