1763585 - Opening/exiting in fullscreen is working very slow for HDR videos on macOS 11

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Raluca Popovici, Desktop QA]

Note: This issue happens only on Fx 100.0b2

Affected version: Firefox 100.0b2

Affected Platform:
MacOS 11

Steps to reproduce:

1. Open Firefox
2. Access: https://drive.google.com/drive/u/0/folders/1S-E4WeKO6y6UySHnSWvfAuCB7N6URdCj and download The World in HDR file locally on your computer.
3. Drag and drop the video saved at previous step to the Firefox window
4. Click on FullScreen

Actual result:
A black window is maximized for 4~5 seconds after the video is loading.

Expected result:
Fullscreen on the HDR video should work without delays.

Note: The same behaviour happens on exiting fullscreen.

Comment 1

[Raluca Popovici, Desktop QA]

Attachment: original-AD5B5E7D-16EC-425E-A635-091E4B6B2AA0.mp4

Comment 2

[Marco Castelluccio [:marco]]

(In reply to Ralu from comment #0)

Note: This issue happens only on Fx 100.0b2

So it is a regression?

Comment 5

[strobe]

In my experience, the source of the jank is MacOS WindowServer which gets really janky (at least on Intel chips) when transitioning from all-SDR to any-HDR rendering, or the reverse. (I don't have an ARM Mac yet; hopefully this is fixed on those devices!) It looks like the delay comes from this happening twice on a fullscreen transition - going HDR to SDR when tearing down the old surface and then back to HDR after the resize. A way to avoid this might be to keep an HDR surface on screen the whole time during the transition.

Comment 6

[Markus Stange [:mstange]]

Does setting full-screen-api.macos-native-full-screen to true on about:config fix this? It should keep the video on screen during the transition.