1773120 - Video doesn't play on twitch.tv

Status: VERIFIED FIXED

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

Description

[Ksenia Berezina [:ksenia]]

This was originally reported in https://github.com/webcompat/web-bugs/issues/105377

To reproduce, visit https://www.twitch.tv/videos/637388605 in Firefox Nightly and observe the video.
The original reporter is experiencing this problem on Linux and I was able to reproduce it on MacOS.

Expected:
Video plays

Actual:
"This video is either unavailable or not supported in this browser. (Error #4000)" error is displayed

This seem to be the only video that has this error, another stream from the same user plays fine.

Comment 1

[Ksenia Berezina [:ksenia]]

I run mozregression on MacOS and Windows and it points to https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=af0c1ff4ce299c32cf252f510dc54c452a080033&tochange=6f97064ebae745b0a85cab06a1e81782ef66c2f1

On Linux it doesn't seem to be a recent regression as it is showing the error in a build from a year ago.

Comment 2

[Ksenia Berezina [:ksenia]]

Hi Zaggy, wonder if you could take a look at this, please?

Comment 3

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

Set release status flags based on info from the regressing bug 1757861

Comment 4

[Zaggy1024]

I wasn't aware that Twitch has AV1 videos available, thanks for reporting this. Looks like they're using "video/mp4;codecs="av01.0.31M.08"" as their mimetype, which specifies level 31, which as indicated by spec should be equivalent to the highest level parameters available. Not sure why they're using it, but it highlights something I missed in the spec.

I believe the solution for this would be to check for level == 31 here and change that to the maximum actual valid level (23 if spec is never revised).

I'm setting up my development environment again now, so I can get to this in a while if nobody else can add in that quick fix.

Comment 5

[Zaggy1024]

Actually, after another look at the spec, it seems like it needs to be changed to accept level == 31 and store it internally, I'll have to check whether there are any other places that may break it. The quote from spec:

If seq_level_idx is equal to 31 (indicating the maximum parameters level), then there are no level-based constraints on the
bitstream.

Self-assigning this so that I can create a patch once my development environment is ready.

Comment 6

[Zaggy1024]

Attachment: Bug 1773120 - Accept AV1 level 31 in codec parameter strings. r=alwu

Fixes an issue where AV1 test videos on twitch.tv would be unable to play.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9fb58db3c3f1
Accept AV1 level 31 in codec parameter strings. r=alwu

Comment 8

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/9fb58db3c3f1

Comment 9

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

The patch landed in nightly and beta is affected.
:Zaggy1024, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox102 to wontfix.

For more information, please visit auto_nag documentation.

Comment 10

[Pascal Chevrel:pascalc (PTO until April 26)]

Alastor, that looks like something we should uplift in 102, what do you think?

Comment 11

[Alastor Wu [:alwu]]

Comment on attachment 9280555 [details]
Bug 1773120 - Accept AV1 level 31 in codec parameter strings. r=alwu

Beta/Release Uplift Approval Request

• User impact if declined: Some AV1 video can't be played
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: See comment0.
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): This patch doesn't introduce any new feature or structural change, it simply allows us to support AV1 video with profile level 31.
• String changes made/needed:
• Is Android affected?: Yes

Comment 12

[Pascal Chevrel:pascalc (PTO until April 26)]

Comment on attachment 9280555 [details]
Bug 1773120 - Accept AV1 level 31 in codec parameter strings. r=alwu

Approved for 102 beta 8, thanks.

Comment 13

[Pascal Chevrel:pascalc (PTO until April 26)]

https://hg.mozilla.org/releases/mozilla-beta/rev/b31cbfa0d929

Comment 14

[Catalin Sasca, Desktop QA [:csasca]]

Reproduced the issue on Firefox 103.0a1 (2022-06-07) under macOS 12.4 by following the STR from Comment 0.

The issue is fixed on latest Firefox 103.0a1 (2022-06-14) and Firefox 102.0b8 (treeherder build). Tests were performed on macOS 12.4, Ubuntu 22.04 and Windows 11.