1657128 - LinkedIn audio doesn’t correspond with the actual video time after playing with the seek bar

Status: NEW

(Core :: Audio/Video, defect, P3)

Description

[Maria Berlinger [:mberlinger], Services QA]

Suggested severity

• S2

Affected versions

• 79.0
• 80.0b3
• 81.0a1 (2020-08-04)

Affected platforms

• Windows 10x64
• Windows 7x64
• macOS 10.15

Steps to reproduce

1. Launch Firefox.
2. Go to https://www.linkedin.com/
3. Log in.
4. Access the https://www.linkedin.com/learning/activate-connections-that-will-transform-your-career webpage.
5. Click anywhere on the seekbar to forward or backward the video.
6. Observe the audio and the video from the

Expected result

• The audio corresponds with the actual video time.

Actual result

• Audio doesn’t correspond with the actual time of the video

Regression range

• This is not a recent regression since it is reproducible on Nightly 67.0a1 (2019-02-05), I’ll come with a regression range asap.

Additional notes

• This issue doesn’t on Ubuntu 18.04x64
• By clicking on pause and then play again everything works fine.

Comment 1

[Alastor Wu [:alwu]]

I can reproduce this issue and here is the profiled result [1], let's wait for the regression range to see if we can find the root cause.

[1] https://share.firefox.dev/31k7lAg

Comment 2

[Alice0775 White]

I can reproduce the issue on Nightly81.0a1 and Firefox 53 Windows10 as well.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=502977d27c2806e7bcaf7703c9f6ae8686912fed&tochange=efb08fa7d183891ab0381cb84f30f2ceaf990f9d

Before landing Bug 1309516 : When you click on the seek bar to move the elapsed time, Progress bar and audio is moved to a slightly earlier time. But the video image is paused at correct time until the audio reaches the time. After that, the A/V sync works as expected.

After landing Bug 1309516 : When you click on the seek bar to move the elapsed time, the audio is moved to a slightly earlier time. But the video image is moved at correct time. so A/V sync is broken.

Comment 3

[Alastor Wu [:alwu]]

Do you have the bandwidth to investigate this issue?

Comment 4

[Jeronimo Torti (Please send NI request to Brindusa Tot)]

Hi,
I tested this issue on Windows 10 and 7, on Firefox Nightly 87.0a1 (2021-02-17) (64-bit), and Release 85.0 (64-bit) , but I was unable to reproduce this issue on my end.

If you are still able to reproduce it, please, share further information with us, like screenshots, screen recording, or more specific steps.

Thanks

Comment 5

[Nils Ohlmeier [:drno]]

Lowering severity based on comment #4