1237772 - Video playback stalls during the first few seconds of playback

Status: RESOLVED WORKSFORME

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

Description

[Johannes]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0
Build ID: 20160105164030

Steps to reproduce:

A few weeks ago, supposedly since the 43.0.3 release, video playback on YouTube (and other pages like Vimeo) stalls for the first ~5 seconds and the continues as normal. During this period, the YouTube progress indicator is also not updated (but the cache indicator is), but sound from the video is still heard. The progress bar then jumps to 5 seconds once the video unfreezes.
I suppose this started to happen at the same time as "On some Windows configurations, improve the decoding of some videos on YouTube"  was fixed according to the Firefox release notes.
I'm running Firefox on Windows 7.

Comment 1

[Johannes]

Note: "A few weeks ago" should be "Since about a week".

Comment 2

[Ralph Giles (:rillian)]

Can you please attach the contents of your about:support? We need some information about your graphics card to diagnose the problem.

Comment 3

[Johannes]

Attachment: about:support

Done. Note that I'm using switchable graphics (pre-Optimus era), and Firfefox has shown video playback issues when switching between Intel and AMD graphics while Firefox was running, but this particular issue also arises when only using AMD FirGL V5700 card.

Comment 4

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Try a Firefox nightly 46 on the AMD card. Check if there is an updated driver for the Intel card.

Comment 5

[Johannes]

Lenovo hasn't released any updated drivers for this laptop and due to the switchable graphics feature it's not possible to just use "normal" Intel/AMD drivers. I'll check out the nightly build ASAP.

Comment 6

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Can you please paste in the graphics section of about:support so we know what hardware/drivers you have?

Comment 7

[Johannes]

I already did, see attached file.

Comment 8

[Ralph Giles (:rillian)]

about:support indicates hardware video decoding is supported but disabled, so it looks like we've blocked the driver. Same with layers acceleration. Hopefully this will be addressed if Lenovo updates their driver. Until then there's little we can do.

Comment 9

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

You don't have accelerated layers and therefore don't have accelerated video. This is because the Intel driver is blacklisted. You might get those if you select the discrete graphics card in your BIOS. It will increase battery usage but may give you better performance.

Comment 10

[Johannes]

Video playback worked flawlessly until this very latest Firefox release. Lenovo does no longer update graphics drivers for this model.
Hardware video acceleration might have been disabled by myself.

Anthony, I am already using the AMD graphics when I'm stationary, but need switchable graphics for when I'm mobile. Thus, as said, the AMD graphics driver is actually activated while I'm using Firefox. Why would Firefox disable acceleration when the Intel driver is not even active?

Comment 11

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

(In reply to Johannes from comment #10)
> Video playback worked flawlessly until this very latest Firefox release.
> Lenovo does no longer update graphics drivers for this model.
> Hardware video acceleration might have been disabled by myself.

If layers is disabled then video is also disabled.

> Anthony, I am already using the AMD graphics when I'm stationary, but need
> switchable graphics for when I'm mobile. Thus, as said, the AMD graphics
> driver is actually activated while I'm using Firefox. Why would Firefox
> disable acceleration when the Intel driver is not even active?

Jeff - am I barking up the wrong tree?

Comment 12

[Jeff Muizelaar [:jrmuizel]]

You should be able to determine exactly what caused this change by finding a regression window using mozregression (http://mozilla.github.io/mozregression/)

Could you also share the make and model number of the computer that you're using? Finally, it would be great if you could post a link to a crash from about:crashes. If you don't have any crashes there, you should be able to force a crash by running this executable http://people.mozilla.org/~jmuizelaar/crash-firefox.exe.

Comment 13

[Johannes]

The problem seems to have effectively disappeared with the Firefox 44 update last week. I'll add the new about:support content for comparison, but after a quick diff it seems that accelerated layers are enabled again.
The computer is a Lenovo W500 with FireGL V5700 + Intel integrated graphics (with manual switching - not done automatically like in later Optimus/etc. devices).

Comment 14

[Johannes]

Attachment: about:support for Firefox 44