1659932 - [Ubuntu] Videos from nytimes in picture-in-picture mode freeze while scrolling down the page

Status: NEW

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

Description

[Oana Botisan, Desktop Release QA]

Attachment: peekTOZEP0.webm

Affected versions

• Firefox 80.0
• Firefox 81.0a1

Affected platforms

• Ubuntu 18.04 x64

Steps to reproduce

1. Go to https://www.nytimes.com/.
2. Put a video in picture-in-picture mode.
3. Scroll down the page and observe the video's behaviour.

Expected result

• The video is working properly.

Actual result

• The video stops for a few seconds, but the sound still work.

Regression range

• If this is a regression, I will find it as soon as possible.

Additional notes

• Please look at the attached gif.

Suggested severity

• S3

Comment 1

[Oana Botisan, Desktop Release QA]

I can reproduce it on an older version of Nightly (2020-11-15), so I don't think this is a regression.

Comment 2

[Bryce Seager van Dyk (:bryce)]

Does the video start playing if you stop scrolling, or does it remain stuck? Does the sound continue playing even when the video has stopped?

Could you gather a profile of the issue happening using the media profile preset and share the link here, please?

Comment 3

[Clara Guerrero]

Attachment: slow scrolling with pip enabled

I can also reproduce in aarch64, in latest nightly 81.0a1 (2020-08-19) (64-bit) in this link https://www.webmd.com/coronavirus-in-context/video/paul-offit-vaccine. Notice that audio keeps playing, image is stuck.

Comment 4

[Darkspirit]

(In reply to Oana Botisan, Desktop Release QA from comment #0)
Can this problem be fixed by setting gfx.webrender.force-disabled to true and restarting Nightly? If yes, please attach your about:support.

Comment 5

[Oana Botisan, Desktop Release QA]

(In reply to Bryce Seager van Dyk (:bryce) from comment #2)

Does the video start playing if you stop scrolling, or does it remain stuck? Does the sound continue playing even when the video has stopped?

1. The video starts playing if the scrolling stops.
2. The sound continues to play without an issue.

Could you gather a profile of the issue happening using the media profile preset and share the link here, please?

This is the link from the profiler: https://profiler.firefox.com/from-addon/calltree/?globalTrackOrder=7-8-9-10-0-1-2-3-4-5-6&hiddenGlobalTracks=2-3&localTrackOrderByPid=4098-1-2-0~5025-0~4784-0~4680-0~4924-0~4888-0~4742-0-1~&thread=2&v=5

Comment 6

[Oana Botisan, Desktop Release QA]

Attachment: raw data

(In reply to Darkspirit, Servo QA from comment #4)

(In reply to Oana Botisan, Desktop Release QA from comment #0)
Can this problem be fixed by setting gfx.webrender.force-disabled to true and restarting Nightly? If yes, please attach your about:support.

Yes, the issue is reproducing even if the gfx.webrender.force-disabled is set to true.

Comment 7

[Bryce Seager van Dyk (:bryce)]

(In reply to Oana Botisan, Desktop Release QA from comment #5)

(In reply to Bryce Seager van Dyk (:bryce) from comment #2)

Does the video start playing if you stop scrolling, or does it remain stuck? Does the sound continue playing even when the video has stopped?

1. The video starts playing if the scrolling stops.
2. The sound continues to play without an issue.

Could you gather a profile of the issue happening using the media profile preset and share the link here, please?

This is the link from the profiler: https://profiler.firefox.com/from-addon/calltree/?globalTrackOrder=7-8-9-10-0-1-2-3-4-5-6&hiddenGlobalTracks=2-3&localTrackOrderByPid=4098-1-2-0~5025-0~4784-0~4680-0~4924-0~4888-0~4742-0-1~&thread=2&v=5

Could you use the share button on a captured profile and paste that here?

Comment 8

[Oana Botisan, Desktop Release QA]

Is this link better: https://share.firefox.dev/3gmgjlL?

Comment 9

[Bryce Seager van Dyk (:bryce)]

(In reply to Oana Botisan, Desktop Release QA from comment #8)

Is this link better: https://share.firefox.dev/3gmgjlL?

It is, thanks.

It looks like there's a lot going on in the profile. We're spending a lot of time compositing, as well as a lot of time in JS and layout. My suspicion is that the page is putting Firefox under a lot of load as we scroll and video gets clobbered as a result.

Was the above profile gathered using the 'Media' preset? It looks like it's missing media threads. If you could gather another profile with the preset it would help to show if we're decoding video or not. We may be decoding video, but failing to render it since the composition part of the pipeline seems under so much load.

Comment 10

[Bryce Seager van Dyk (:bryce)]

Should the dependency on bug 1661015 have gone on another bug? It seems unrelated to this.