1387358 - YouTube 4K playback is very choppy even with hardware acceleration and windows power plan

Status: NEW

(Core :: Audio/Video: Playback, defect, P2)

Description

[Jean-Yves Avenard [:jya]]

From bug 1292374 comment 50

I downloaded and tested Firefox 55.0beta from
https://www.mozilla.org/en-US/firefox/channel/desktop/ and tested with the
YouTube 4K video I referred to

https://www.youtube.com/watch?v=tO01J-M3g0U&t

as well as other videos.  I double checked the about:config vp9 settings and
Firefox 55.0beta enabled everything for hardware acceleration on my machine.  I
can confirm that now CPU utilization and RAM usage are indicative of VP9
hardware acceleration and similar to what I see in Edge and Chrome.

But... there still is a major problem.  Every YouTube 4K video I tested has
very choppy playback and less than acceptable responsiveness in 4K full-screen
mode.  Its not as bad as in Firefox 54 and previous versions when it doesn't
have VP9 acceleration but it's still so choppy that it's unwatchable.  The
exact same videos in Edge and Chrome have buttery smooth playback.  Not sure
what this issue is now since it's choppy even when you can tell from CPU
utilization and memory usage that hardware acceleration is taking place.

Comment 1

[Jean-Yves Avenard [:jya]]

Could you try with Nightly https://www.mozilla.org/en-US/firefox/channel/desktop/

Comment 2

[Leandro]

I found the source of the issue Jean-Yves, my machine is a laptop (HP ZBook 15 G4) and when I'm using battery that's when it is choppy/has jitter.  I'm using production Firefox 55.0.1 now.  Once I plug in the laptop, even in the middle of YouTube video playback, the jitter goes completely away.  I have the following settings:

Intel HD Graphics Control Panel

On Battery:
- Power Plan: Maximum Battery Life
- Display Power Saving Mode: Enable
- Bar set to one notch to the right of Maximum Quality
- Enhanced Power Saving Mode: Enable
- Extended Battery Life for Gaming: Enable

My Windows Power Plan

- Multimedia Settings
-- Video playback quality bias
--- On battery: Video playback power-saving bias
-- When playing video
--- On battery: Optimize power savings

I still think this issue is worth looking into since with Edge and Chrome, using battery and the settings I have above, there is no playback jitter whatsoever.

Comment 3

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

Are you using an external or internal 4K display?

Comment 4

[Leandro]

(In reply to Anthony Jones (:kentuckyfriedtakahe, :k17e) from comment #3)
> Are you using an external or internal 4K display?

Internal 4K display

Comment 5

[Blake Wu [:bwu][:blakewu]]

Leandro, 
Can you still see this problem on Firefox 57?

Comment 6

[Leandro]

(In reply to Blake Wu [:bwu][:blakewu] from comment #5)
> Leandro, 
> Can you still see this problem on Firefox 57?

Hi Blake,

Yes, with the new Firefox 57 it's just as choppy/jittery if not worse.

To restate the details of the issue, when I play a YouTube 4K video on my 4K laptop display using battery power there is very choppy playback with the above Intel HD Graphics and Windows Power Plan battery settings related to graphics and video.  This issue happens only in YouTube fullscreen mode on 4K, when it's in default or theater mode it doesn't happen.  When I plug the laptop in during video playback the choppy playback stops, and when I disconnect the power it immediately comes back.  This issue doesn't occur in Edge or Chrome.

Comment 7

[Leandro]

I want to follow up and confirm that this issue still exists.  I've reproduced the issue on a new laptop with 4K/UHD display.  I've been able to isolate the source, as mentioned above the laptop should be running on battery power and using the iGPU.  When I go into the Intel Graphics Settings -> Power -> On Battery -> and select Maximum Battery Life then 4K Youtube videos in full screen mode will be very choppy.  The moment I select Balanced or better in the Intel Graphics Control Panel then the choppiness goes away. This issue doesn't occur in Edge or Chrome in the same situation, so maybe they are ignoring certain graphics power settings.

Comment 8

[bug.zilla]

I, too, can replicate this on a AMD Ryzen 5 2500U laptop connected to a 4K display.
Activating "Stats for nerds" I can see around 10% dropped frames in full screen mode.

This does not happen with Edge which shows no dropped frames.

Comment 9

[bug.zilla]

EDIT: possibly related to / duplicate of these:
https://bugzilla.mozilla.org/buglist.cgi?quicksearch=4k+youtube