1679232 - Very slow fullscreen video on YouTube (wr-sr)

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P3)

Description

[Asif Youssuff]

Played back https://www.youtube.com/watch?v=zQluQs-GEGg in fullscreen 1080p.

Saw massive lag. See profile: https://share.firefox.dev/3pYORAB

Comment 1

[Jeff Muizelaar [:jrmuizel]]

This is hitting the video slow path. Do you see the same on all videos?

Comment 2

[Asif Youssuff]

Also seeing slow playback on https://vimeo.com/210599507

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Is this a regression perhaps? Can you try a slightly older build?

Comment 4

[Asif Youssuff]

This seems better for both videos on the build from 2020-11-01, but still noticeably bad. Did you have any timeframe in mind (is the beginning of the month too old)?

Comment 5

[Jeff Muizelaar [:jrmuizel]]

Can you get a profile from 2020-11-01 build?

Comment 6

[Asif Youssuff]

Here you go: https://share.firefox.dev/37f1gbo

Comment 7

[Jeff Muizelaar [:jrmuizel]]

Yeah, that profile is what I'd expect things to look like. Are you able to get a regression window for the performance regression?
If the "Renderer" is calling CompositeYUV that's the fast path, if it's calling composite_TEXTURE_RECT_YUV_frag::sample_yuv that's the slow path.

Comment 8

[Matt Woodrow (:mattwoodrow)]

Attachment: Bug 1679232 - Remove shadowed variable. r?lsalzman

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/31ac73e59b78
Remove shadowed variable. r=lsalzman

Comment 10

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/31ac73e59b78