1912567 - Youtube videos (pretty much any codec) will drop frames on start-up, freeze or briefly choppy

Status: UNCONFIRMED

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

Description

[Chobits1717]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Firefox/128.0

Steps to reproduce:

Logged profile: https://share.firefox.dev/3yzmKkG

Load up any high quality video, regardless of codec (happens most on VP09, though). Tends to happen most often when jumping to video from search results.

Watch the frames drop, tends to vary in amount. Doesn't seem to happen on a refresh of the browser tab the video is running in.

Actual results:

20+ frames dropped, resulting in a noticeably choppy first 5 or so seconds of the video. One video even drops 292 frames on start, resulting in a 4 second freeze.

Expected results:

Video performance should be consistent

Comment 1

[Chobits1717]

Did some more testing, this is (seemingly) only on VP09 videos. Some frames are still sometimes dropped even on refresh but it is nowhere near as severe.

Comment 2

[Paul Adenot (:padenot)]

Alastor, can you check the profile? I'm seeing quite a lot of destruction / creation of decoder in the GPU process, and very long decode time, does that ring a bell?

Comment 3

[Alastor Wu [:alwu]]

By checking the profiled result in the comment0, I saw a lot of size changes which seems triggering recreating new decoders.

Here is the first time we sent the video frame. Just for one sample, we created decoder three times, which is really strange. I saw only one config change which would trigger decoder recreation, but I don't understand how other decoder recreation was triggered. If those creation were triggered by VPXChangeMonitor, then we should be able to see these markers. But none of them are shown in the result.

---

chobits, could you constantly reproduce this issue on the same video? if so, could you provide an example video link to us so that we can try to reproduce the issue? Thanks!

Comment 4

[Chobits1717]

Here's a good one! I've noticed that it happens more often if you load it from youtube's search results, so give that a shot as well.

https://www.youtube.com/watch?v=C9trkTjUlxA

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit BugBot documentation.

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit BugBot documentation.

Comment 7

[Jim Mathies [:jimm]]

needs profile analysis.

Comment 8

[Chobits1717]

Any updates on this? Not sure if its just the laptop GPU or Firefox itself

Comment 9

[Alastor Wu [:alwu]]

Would you mind to capture a profile on the latest Nightly (follow this instruction)? We've added more markers which might help us understand this issue better. Thanks!

Comment 10

[Chobits1717]

(In reply to Alastor Wu [:alwu] from comment #9)

Would you mind to capture a profile on the latest Nightly (follow this instruction)? We've added more markers which might help us understand this issue better. Thanks!

You're welcome! I'll do it when I get home! :)

Comment 11

[Volodymyr]

I also have the problem with frames drop, but not from the very beginning of playback, but after some time (5-10 minutes).
The problem exists on YouTube and Twitch.

Here are some recorded profiles:
https://share.firefox.dev/4gL9iL4
https://share.firefox.dev/4grXVbg

This is what it looks like:
https://youtu.be/GaHH8W2XgWc

Comment 12

[joharr2k18]

I'm also having the same issue, particularly on YouTube, and especially with live streams.
When I right-click on a video, and click "Stats for nerds", in the "Viewport/Frames" section, I can see that there are a lot of frames that are dropping. It usually will not happen immediately, but after a couple of minutes or so of playing the video.

I've also noticed that it's more likely to happen on AVC1 codec videos than VP9 on YouTube.

Here's my profile:
https://share.firefox.dev/4gvEGNS

Comment 13

[Chobits1717]

New profile: https://share.firefox.dev/4mBGDfi

Dropped frames at beginning of playback