1677618 - Firefox perceived frame rate is lower than expected in full-screen videos only (hardware acceleration turned off)

Status: UNCONFIRMED

(Core :: Graphics, defect)

Description

[geoleven]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:82.0) Gecko/20100101 Firefox/82.0

Steps to reproduce:

While playing any video in full-screen mode on various major video sites (YouTube for example) the video will have lower perceived frame rate although the video statistics log no frame drops.

Actual results:

The perceived frame rate is notably lower than anticipated or than what is played while not in full-screen mode.

Expected results:

Have the same frame rate in full-screen and non full-screen mode.

Comment 1

[Andrei Purice]

Hey geoleven,
I tried to reproduce this issue on the latest versions of Firefox Nightly 85.0a1 (2020-11-19), beta 84.0b3 and release 83.0 but the frame rate was the same in fullscreen as it was in a windowed session.

Can you test the issue while in Safe Mode? You can find helpful info here : https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode .
Also a fresh new profile could help. You can find more about creating a new profile here : https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems#w_6-create-a-new-firefox-profile .
If possible, you can test this issue on the nightly build as well. Download the build from : https://www.mozilla.org/en-US/firefox/nightly/all/ .

Comment 2

[geoleven]

Hello Andrei,

Following your instructions I tried to reproduce it in a safe mode instance of the application and it seems to still be there.

Some more, probably much needed info that you may need but I didn't provide previously due to the way the questions were asked in the bug submission form are that:

1. The reason that I am running with hardware acceleration off is that this specific setup has a pretty old GPU with minimal support for recent technologies (ATI HD 5850).
2. As such, my GPU drivers are really dated. They are the last legacy drivers supporting this card:
   • Driver Packaging Version : 15.301.1901-160226a-318062E
   • 2D Driver Version : 8.01.01.1533
   • Direct3D Version : 9.14.10.01171
   • OpenGL Version : 6.14.10.13417
   • Mantle Driver Version : 9.1.10.0099
   • AMD Catalyst Control Center Version : 2015.0804.21.41908

As my current setup in this machine is extremely "fragile" I would like to refrain from installing a beta version.

Other related entries that about:config shows as NOT default:
layers.acceleration.disabled True
layers.mlgpu.sanity-test-failed False
gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle true
gfx.direct3d.last_used_feature_level_idx 0
gfx.crash-guard.d3d11layers.appVersion 56.0
gfx.crash-guard.d3d11layers.deviceID 0x06c0
gfx.crash-guard.d3d11layers.driverVersion 22.21.13.8233
gfx.crash-guard.d3d11layers.feature-d2d true
gfx.crash-guard.d3d11layers.feature-d3d11 true
gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle true
gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle true
gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11 false
gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp false
gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11 true
gfx.crash-guard.status.d3d11layers 2
gfx.crash-guard.status.d3d11video 2
gfx.crash-guard.status.d3d9video 2
gfx.crash-guard.status.glcontext 3
gfx.direct3d.last_used_feature_level_idx 0
gfx.driver-init.appVersion 42.0
gfx.driver-init.deviceID 0x9440
gfx.driver-init.driverVersion 8.970.100.1100
gfx.driver-init.feature-d2d true
gfx.driver-init.feature-d3d11 true
gfx.driver-init.status 2
services.blocklist.gfx.checked 1605881031
browser.newtabpage.activity-stream.prerender false
sanity-test.webrender.force-disabled false

Inform me if you want more info.

Comment 3

[geoleven]

A small personal opinion note, as I have seen such behavior in the past, it could be related to the render used for videos.

Comment 4

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

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 5

[Jamie Nicol [:jnicol]]

Hi Geoleven, could you please attach a copy of your about:support information? Thanks.