1454930 - Firefox on macOS - viewing 1080p video at 60 frames per second causes occasional pauses

Status: UNCONFIRMED

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

Description

[staraffinity]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:59.0) Gecko/20100101 Firefox/59.0
Build ID: 20180323154952

Steps to reproduce:

Viewing for example this video: https://youtu.be/qlyzo9ll9Vw
Change the quality (cogwheel in lower right corner of the video) to be 1080p60. Playback will be smooth overall, but if you let the video run and look carefully it will stutter at times and pause/hiccup in places where it shouldn't (major pause here at 0:34 https://youtu.be/qlyzo9ll9Vw?t=31). Playback works fine for me if switching to 720p60 but it doesn't seem related to hardware limitations as I don't see this in Windows 10 on the same computer.


Actual results:

Pause/hiccup in video during playback.


Expected results:

No pause/hiccup during video playback.

Comment 1

[ovidiu boca[:Ovidiu]]

Hi staraffinity,

I tested this issue on Mac OS X 10.12 with FF Nightly 61.0a1(2018-04-23) and I can't reproduce it. Please note that I used a new profile with no add-ons installed. 

If you have add-on on your profile can you please retest this issue in safe mode? Here is a link that can help you:
https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode

If that doesn't resolve your problem can you please download Firefox Nightly from here: https://nightly.mozilla.org/ and retest the problem?

Comment 2

[staraffinity]

I will try, but thinking maybe macOS Sierra (10.12) isn’t affected?

Comment 3

[staraffinity]

No difference with safe mode in Firefox 59.0.2 or Firefox Nightly 61.0a1(2018-04-23).

The thing is – it doesn't seem to happen with Intel GPUs, so if that's what you have you won't see the problem. But both AMD and Nvidia GPUs are affected (as far as I understand, I only have easy access to graphics cards from Nvidia and Intel.

Comment 4

[ovidiu boca[:Ovidiu]]

Hi staraffinity,

I tested again this issue on iMac OS X 10.13.3 with GPU - NVIDIA GeForce GT 640 M 512 MB with FF Nightly 61.0a1(2018-04-23) and FF 59 release and I can't reproduce it, in my case the video is smooth. I will assign a component and maybe someone from there has more info about this. Thanks for your help.

Comment 5

[staraffinity]

Hmm… things are getting more complicated. I don't see the problem on a MacBook Pro (Late 2013) when turning off the Intel GPU and going for Nvidia GT 750M. But I see it on a desktop Mac Pro (Mid 2010) with a GTX 970. This requires Nvidias so called Web Driver, but according to them (I've been in contact with Nvidia) it also happens with an AMD 5770 GPU in a Mac Pro with the macOS built-in graphics drivers for that card. I'll do some more research and see if I can narrow things down…

Comment 6

[ovidiu boca[:Ovidiu]]

Thanks staraffinity for your effort and please add here any update that you consider to be relevant to this issue.

Comment 7

[staraffinity]

Sure, no problem. :) Would be good if we can conclude that it is related to the Nvidia Web Driver (which I first thought it wasn't) but if that's the case I'm sorry I have taken time you could have spent on better things… :/ :)

Comment 8

[staraffinity]

It seems this issue is related to some software in MacOS specific to (at least some models of) the Mac Pro (I have one from 2010). Not sure if it's related to the graphics drivers, but it happens on both Nvidia and AMD GPUs. There is a bug report filed with Apple about it, so maybe they will do something to fix it (I guess probably not if it only happens in Firefox). Oh, well…

Comment 9

[Nils Ohlmeier [:drno]]

On my 2013 MacBook Pro with 10.13 the sample video also plays fine for me with 1080@60. No hickups or pauses at all.

One thing to point out though is that Firefox on MacOS and Windows might end up using different codecs for the video playback. See https://support.mozilla.org/en-US/kb/firefox-4k-ultra-high-definition-youtube-videos for details

Can you check in the "stats for nerds" if you get the same codec on both OS's?

Comment 10

[staraffinity]

Yes, Firefox on Windows and MacOS seem to use different codes for that video (https://youtu.be/qlyzo9ll9Vw) on YouTube and also Safari on MacOS uses different codecs than the other two:

Firefox 61.0.1 on MacOS
Codes: avc1.64002a (299) / opus (251)

Firefox 61.0.1 Windows:
Codecs: vp9 (303) / opus (251)

Safari 11.1.1 on MacOS:
Codecs: avc1.4d401f (135) / mp4a.40.2 (140)

I guess that has got got to do with the problem I'm seeing?


Here's another example:
https://www.gamespot.com/reviews/wreckfest-review-crashing-the-party/1900-6416935/

Playback works fine and smooth in Firefox for some time then it hitches for a few seconds. I have no problems like this when playing back in Safari – smooth all the time.