1905424 - Youtube Live video endless buffering

Status: UNCONFIRMED

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

Description

[Chris]

version 127.0.2 on a macbook pro.

Steps to reproduce:

1. Extra info at bottom of this description. Youtube videos and google photo videos buffer at the start, won't play for a long time (1-10 minutes), then start, but then will soon buffer again. e.g. https://www.youtube.com/watch?v=RAH02SE9jyo

Actual Results:
Starts buffering but doesnt play for around 5 minutes. After it starts video stops after for a while. But audio is playing.
Profiler log: https://share.firefox.dev/4aEXK8R

When the buffer length reaches 0s, the image seems to stop without recovery.

Extra info: If you switch themes in youtube between light and dark, it will play instantly like it used to before the VP9 issue. Then may buffer again.

Comment 1

[Alastor Wu [:alwu]]

Hello, Chris, would you mind to follow this instruction to capture a profile? Only the profile captured by that way will contain the debug logs we need, thank you.

Comment 2

[Chris]

Hi Alastor. Sure!

https://share.firefox.dev/4bwMPyw

Comment 3

[Alastor Wu [:alwu]]

Hello, Chris, do you find a way to robustly reproduce this issue? Because when capturing a profile, we would need to start capturing early enough in order to see how Youtube appends the data, which usually would happen several seconds before the issue happens. The one you provided in the comment2 is started too late, so it doesn't contain the important information we need.

Does this issue usually happen after seeking? If so, it might be the same problem with bug 1904937. Thanks!

Comment 4

[Chris]

Here's another. I waited a while, played a tab with the instruction video linked above, then opened youtube and you can see the issue happen again.

https://share.firefox.dev/4cjfQyE

Comment 5

[Alastor Wu [:alwu]]

Hello, by checking you profile, I'm assuming the data Youtube provided have flaws, but I would like to confirm that with another profile, would you mind to help me capture another profile again by using different log modules?

Follow the instruction here, after selecting media playback preset, please use timestamp,HTMLMediaElement:4,HTMLMediaElementEvents:4,cubeb:5,PlatformDecoderModule:5,AudioSink:5,AudioSinkWrapper:5,MediaDecoder:5,MediaFormatReader:5,GMP:5,EME:5,MediaSource:5,MediaSourceSamples:5 to replace the current log modules. After doing that, all steps are the same.

Thank you!

Comment 6

[Chris]

Here's the additonal info that you requested.

I also noticed that videos from Google Photos does the same thing and is part of this log

https://share.firefox.dev/45Wsy4f

Comment 7

[Alastor Wu [:alwu]]

The google photo bug is filed in 1904938, and I hope the bug 1904937 and bug 1906342 can address the rest of infinite buffering problems.

Comment 8

[Chris]

Are you saying the bug entered 4 days ago can address this bug opened 10 days ago? lol OK

Comment 9

[Alastor Wu [:alwu]]

I don't know why the open date is matter. Bug 1906342 is a follow up of bug 1904937, which is even filed earlier than this bug.

Comment 10

[Chris]

Because you are saying all of the work I've done here to help fix this was for nothing and this is all a COMPLETE waste of my time and just waved it away. Why would I even bother.

Comment 11

[Chris]

And the other bug 12 days ago is not even the same bug.

Comment 12

[Alastor Wu [:alwu]]

Sorry to make you feel that, I didn't mean that. I've carefully examined the profiled result you provided before, I just didn't update more information about that, because I couldn't see why Youtube stopped appending data in your case. However, it's not waste of time, because your profile shows another good example of Youtube not appending the data they should have appended, and that is similar with other bugs I've been working.

The API used for streaming is called Media Source Extension (MSE), and for that API, it's all website's responsibility to control the size of buffered data. To be clear, the bug 1906342 and bug 1904937 are used to fix the Youtube's own bug, and we've even reported the issue to Youtube but didn't get any response from them. Those two bugs can mitigate the issue for our users even when Youtube doesn't handle the issue in their side.

As I can't certain about what exact reason is causing the issue you've been encountering, that is why I said I hope this can fix this issue as well. We don't need the bug to be the same, just need to fix the root cause which causes all of them.

Comment 13

[Alastor Wu [:alwu]]

FYI the fixes for Youtube (bug 1904937 and bug 1906342) has both been deployed to Nightly today. Feel free to check the latest Nightly to see if the issue still presents or not. If that fixes the issue, the solution will ride the train of Fx129. Thanks!