1960732 - Grey horizontal stripe in Netflix player in fullscreen mode

Status: NEW

(Core :: Audio/Video, defect)

Description

[maik.diessner]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.0) Gecko/20100101 Firefox/137.0

Steps to reproduce:

1. Open https://www.netflix.com/
2. Choose any profile
3. Open "Black Mirror" S7E1
4. Click fullscreen button

Actual results:

There is a grey horizontal stripe at the top. In Google Chrome 135.0.7049.42 (64-Bit) this bug does not occur (just cannot show video/screenshot because screenrecording blacked in Chrome).

Expected results:

No grey horizontal stripe shown at the top.

Comment 1

[maik.diessner]

Attachment: Viewport.png

Comment 2

[maik.diessner]

Attachment: About Support.txt

Comment 3

[maik.diessner]

Attachment: Screenshot.png

Comment 4

[maik.diessner]

Attachment: Video.mp4

Comment 5

[Mark Striemer [:mstriemer]]

Is this for all videos or specifically that black mirror episode? That episode looked fine for me on macOS and Windows in a VM

Comment 6

[maik.diessner]

It only occurs with some videos (but only in Firefox browser - Chrome is fine).

Comment 7

[az [:az]]

Could you please give Nightly a try with a new user profile and see if this fixes your error? With any luck, a patch is in the process of making its way to the next version of Firefox that'll fix the issue for you. Does disabling hardware acceleration clear the issue up? Does this happen with any other video sites?

Also, if you could capture a profile of the bug in action, that would be helpful. To do so:

1. Start Firefox with no other tabs open - this is important, the more tabs that are open, the harder it will be to diagnose the issue.
2. Go to the about:logging page.
3. Click "Logging preset" and choose Media Playback.
4. Click "Set Log Modules".
5. Enable "Stack Traces for Log Messages".
6. Click Start Logging.
7. Open a new tab and repeat the steps that cause the issue. Once you reproduce the issue, close the tab, then go back to the about:logging page and click Stop Logging.
8. The Firefox Profiler should launch itself automatically.
9. Click Upload Local Profile using the button in the top right. It will give you a share link - paste it here.

The tutorial to get the logs is here: https://www.loom.com/share/24ea3a8e3a054c478de94643a0ea8620?sid=87b0ffaa-c4ea-43ce-8107-639f24b747a8 or https://paul.cx/public/about-logging-presentation.webm .

If this is new behavior which still occurs on Nightly with a clean profile, you could also give mozregression a try to help track down the exact change which caused this problem to crop up.

Thanks!

Comment 8

[maik.diessner]

Disabling hardware acceleration fixes the issue. So far I've only seen this issue with certain Netflix videos if I remember correctly.

Do I still need to check the issue in Nightly and doing a profile capture then?

Comment 9

[az [:az]]

Testing the issue on nightly would be helpful because there could be a fix for your issue there already on the way to being included in the next Firefox release - if it's fixed there, then we're in good shape. However, if you still encounter the same issue on nightly, capturing the profile as per the directions above would be useful to diagnose further. Thanks!

Comment 10

[maik.diessner]

It's not fixed in Nightly 139.0a1. See attached video "Video-Nightly139a1.mp4".

Profile: https://share.firefox.dev/44tLPLJ

Comment 11

[maik.diessner]

Attachment: Video-Nightly139a1.mp4

Comment 12

[Francesco Lodolo [:flod]]

Is your background gray? Because I'm seeing the same problem here, but it's showing a line from the background.

YouTube works fine at full screen, Netflix shows this line on any video at full screen. Disabling hardware acceleration and restarting makes the video work as expected.

Comment 13

[Francesco Lodolo [:flod]]

Attachment: about:support raw data

Comment 14

[Francesco Lodolo [:flod]]

Also, worth noting that this started recently. On release, my previous update is from April 16 (and Widevine April 12), so I have a feeling something changed on Netflix side to trigger this.

Comment 15

[maik.diessner]

My desktop background is black. Firefox using system (light) theme. Here is only occurs with some Netflix movies. Also I've seen this bug for quite some time (not a recent change).

Comment 16

[Francesco Lodolo [:flod]]

One additional info: for me, it happens only on some videos, not all (e.g. it happens consistently on Ozark, but not Breaking Bad), so I'm guessing it depends on the video format.