1335488 - Severe YouTube flickering on OS X with HWA disabled

Status: UNCONFIRMED

(Core :: Graphics, defect, P3)

Description

[AJ Jordan [:strugee] (he/they)]

I'm experiencing relatively severe flickering on video controls when I watch a YouTube video. With the new site design (which somehow I only get in my main profile?), I also see flickering on the autocomplete suggestions.

I'm on Nightly built January 31st, 2017, but this bug has been present for many months and I've just been too lazy to do anything about it. I've experienced this with "Use hardware acceleration when available" checked and unchecked, but I can't reproduce this in a fresh profile.

I'll attach my about:support and a video of the bug.

Comment 1

[AJ Jordan [:strugee] (he/they)]

Attachment: about:support

Comment 2

[AJ Jordan [:strugee] (he/they)]

Attachment: screencast

Comment 3

[AJ Jordan [:strugee] (he/they)]

It's in the about:support, but for posterity, I'm on OS X 10.11.6 on a early 2011 15-inch MacBook Pro.

I should also mention that I'm willing and able to test patches and/or find regression ranges.

Comment 4

[Loic]

(In reply to Alex Jordan [:strugee] from comment #3)
> I should also mention that I'm willing and able to test patches and/or find
> regression ranges.

You can use mozregression for that: http://mozilla.github.io/mozregression/

Comment 5

[AJ Jordan [:strugee] (he/they)]

(In reply to Loic from comment #4)

> You can use mozregression for that: http://mozilla.github.io/mozregression/

Wow, didn't know about mozregression. That's _super_ useful, thank you! I assume a regression range would be useful here?

Comment 6

[Loic]

Yes, that's the aim! :)

On OSX, you need python 2.7 to run mozregression. Then run the command "mozregression --good=50" by assuming FF50 build was good.

Comment 7

[AJ Jordan [:strugee] (he/they)]

Aaaand I don't seem to be able to reproduce this anymore :/

If it crops up again I'll try to find a regression range.

Comment 8

[AJ Jordan [:strugee] (he/they)]

Oh, weird - I thought this was present regardless of the hardware acceleration setting, but I guess I made a mistake since it appears that turning acceleration *off* causes this bug.

Comment 9

[AJ Jordan [:strugee] (he/they)]

Here's the mozregression result:

> 27:46.94 INFO: Last good revision: f5bfd9e3ebcfc81eed53001c0d5235ca8c1d4a6c
> 27:46.94 INFO: First bad revision: 52fa735c7cec7333737999f62a43856e7306f6ba
>  27:46.94 INFO: Pushlog:
>  https://hg.mozilla.org/integration/fx-team/pushloghtml?fromchange=f5bfd9e3ebcfc81eed53001c0d5235ca8c1d4a6c&tochange=52fa735c7cec7333737999f62a43856e7306f6ba
> 
> 27:48.90 INFO: Looks like the following bug has the changes which introduced the regression:
> https://bugzilla.mozilla.org/show_bug.cgi?id=1282070

I'll also attach an abbreviated prefs.js file that can be copied into a new profile to reproduce the bug.

Comment 10

[AJ Jordan [:strugee] (he/they)]

Attachment: known-bad prefs.js

I can reproduce the bug by creating a new profile, quitting Nightly, replacing the new prefs.js with this file, reopening Nightly, and visiting https://www.youtube.com/watch?v=8N4sb-SEpcg.

Comment 11

[AJ Jordan [:strugee] (he/they)]

So, I can also reproduce this on http://rochester.edu/. It appears to be related to the <video> tag with the boat animation, since I couldn't reproduce this when I tried saving a copy on the Wayback Machine (for the purposes of this bug), which didn't seem to save the video.

I reproduced this in my usual profile started in Safe Mode, which has layers.acceleration.disabled set to false in about:config. I haven't yet confirmed whether this happens in different configurations or whether it matches the same regression window I found above.

Comment 12

[Loic]

So it happens only with HWA disabled?

Comment 13

[AJ Jordan [:strugee] (he/they)]

Forgot to mention the above result happened in Safe Mode in the stable channel. Sadly I can no longer reproduce the result I mentioned since U of Rochester changed their home page.

I can confirm that when creating a fresh profile under a Nightly built 2017-04-18, the bug does not occur, but when I go into about:preferences and uncheck "use hardware acceleration when available" and restart, I can reproduce.