1708989 - flashing during animation

Status: RESOLVED FIXED

(Core :: Graphics: Color Management, defect)

Description

[Timothy Nikkel (:tnikkel)]

Load https://weather.gc.ca/satellite/satellite_anim_e.html?sat=goes&area=wcan&type=1070 and click play.

Comment 1

[Timothy Nikkel (:tnikkel)]

We sync decode so macOS is doing some async when it color converts the surface to the screen or something?

Comment 2

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

Set release status flags based on info from the regressing bug 1701760

Comment 3

[Pascal Chevrel:pascalc (PTO until April 26)]

Jeff, is that something that needs fixing in the 89 timeframe?

Comment 4

[Jeff Muizelaar [:jrmuizel]]

We should probably just back out bug 1701760 from 89 to buy us more time.

Comment 5

[Pascal Chevrel:pascalc (PTO until April 26)]

89 fixed by backout of bug 1701760

Comment 6

[Julien Cristau [:jcristau]]

Now also backed out from trunk (91) and beta (90).

Comment 7

[Jeff Muizelaar [:jrmuizel]]

This page appears to be drawing each image to a canvas while also having visible it in the DOM.

Comment 8

[Jeff Muizelaar [:jrmuizel]]

Setting image.decode-sync.enabled=true makes the problem go away.

Comment 9

[Jeff Muizelaar [:jrmuizel]]

Timothy/Andrew, can either of you hypothesize what's happening here from imagelib's point of view? Is having decode requests with FLAG_DECODE_TO_SRGB_COLORSPACE set and unset messing with something that would otherwise prevent the flicker?

Comment 10

[Timothy Nikkel (:tnikkel)]

I think the page is using drawing to a canvas to force a sync decode of the image so that when they switch to it in the DOM it is decoded and there is no flash. After bug 1701760 we request SRGB and that means we store the decoded image for the canvas with the srgb flag, separately from the decoded image without the srgb flag in the surface cache. So when we draw to the screen we don't ask for the srgb image and we have to decode it anew.

Bug 1701760 is effectively removing the ability to use canvas.drawImage to sync decode an image that the author wants to draw to the screen using the normal dom drawing path.