1540519 - youtube buffer reset in fullscreen

Status: NEW

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

Description

[AJ]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:67.0) Gecko/20100101 Firefox/67.0

Steps to reproduce:

i was just watching youtube as usual but after some time when i opened a video which was preloaded(buffered) got reset when i go fullscreen.

Actual results:

all the prebuffered(preloaded) videos in youtube are reset and loading again when go to fullscreen everytime

Expected results:

the videos should have same preloaded buffer when we go fullscreen instead of reseting buffer.

Comment 1

[AJ]

Attachment: 1.png

in this attachment 1 [details] [diff] [review].png the preloaded buffer video can be seen which will get reset when i go full screen.

Comment 2

[AJ]

Attachment: 2.png

so in this 2nd attachment when i got to fullscreen the preloaded video got reset and got loading again this is the main problem where it should not.

Comment 3

[Michael Froman [:mjf]]

Jean-Yves, any thoughts on this?

Comment 4

[Jean-Yves Avenard [:jya]]

That's YouTube choice.

Comment 5

[Andreas Pehrson [:pehrsons]]

Closing as invalid per comment 4. Please bring this up with Youtube instead.

Comment 6

[AJ]

how can it be youtube's problem when it occurs in firefox beta?? now i'm on public version and the issue is not here, so it was problem in firefox beta not youtube.

Comment 7

[Jean-Yves Avenard [:jya]]

If you could run the mozregression utility and identify the culprit then, thanks.

Comment 8

[Jean-Yves Avenard [:jya]]

And if you fake your user-agent from 67 back to 66 do you see the issue still?

YouTube is serving the AV1 codec and use a new API that allows to change codec on the fly.

It may well be that this is what you are seeing.

Comment 9

[Paul_B]

I verified this issue on all the latest Firefox version across OS-es.
Unfortunately, I was not able to reproduce the mentioned behavior on Windows 10 or Ubuntu 18.04.

I was, however, able to observe it on Windows 7 ( on the Nightly build and Firefox release build) and on all the latest Firefox versions on Mac OS 10.14.5.

Running mozregression tool on Windows 7, pointed to the following pushlog that could contain the regression: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=70a50fe09a18b2516e9ffdb2083debfab7de720d&tochange=a5a5ddfb5178f8a2b30d186d3cf478da38f324ba

@Aj, given that your report points to Windows 10, could you please try to run the same tool and maybe see if you get the same results as mine?
Information on the tool is available at http://mozilla.github.io/mozregression/.

Comment 10

[AJ]

ok @Paul_B i will run and give log asap.

Comment 11

[Alice0775 White]

I can reproduce on Nightly68.0a1, 67.0RC1 and 66.0.3 Windows10.

VP9 @720

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=83598ee9b2e8378bc141c46bd9acdce730dc4fd9&tochange=9f49631d6536a27752469cac43e60ed1f19eed55

Triggered by: 9f49631d6536a27752469cac43e60ed1f19eed55 Jean-Yves Avenard — Bug 1524119 - Properly get VP9 benchmark value. r=bryce

Comment 12

[KillerQ13]

Setting media.benchmark.vp9.fps to the same value as media.benchmark.vp9.threshold (150 and 150) is working great as a temporary fix for me. :P

Comment 13

[Liz Henry (:lizzard) (relman/hg->git project)]

:jya, can you take another look, as it looks like this may be a regression from bug 1524119? Thanks!

Comment 14

[Jean-Yves Avenard [:jya]]

It is not a regression caused by bug 1524119. It only cause us to get in a different YT codepath where before they would have served h264 and now they serve VP9.

There's nothing we can do here. It's a YouTube site issue

Comment 15

[Liz Henry (:lizzard) (relman/hg->git project)]

Thanks for making that clear! I can reach out to YT tomorrow.

Comment 16

[Liz Henry (:lizzard) (relman/hg->git project)]

Paul, can you try this: reproduce the issue, then right-click on the player, choose Copy Debug Info, and provide the result. Thanks!