1957119 - Firefox incorrectly flushes HEVC decoded samples due to a false detection of an in-band configuration change.

Status: RESOLVED FIXED

(Core :: Audio/Video: Playback, defect, P1)

Description

[Alastor Wu [:alwu]]

This results in slight frame drops for certain HEVC streams.

Comment 1

[Alastor Wu [:alwu]]

Attachment: Bug 1957119 - part1 : correct SPSIterator::IsValid().

In H265::CompareExtraData(), SPSIterator::IsValid() is used as a
boolean expression to determine whether two SPS NALUs should be
compared. If it returns an incorrect result, it can lead to a false
detection of a configuration change, causing decoded frames to be
discarded.

Comment 2

[Alastor Wu [:alwu]]

Attachment: Bug 1957119 - part2 : update loggings.

Depends on D243528

Comment 3

[Alastor Wu [:alwu]]

[Tracking Requested - why for this release]:

Comment 4

[Alastor Wu [:alwu]]

I'm still investigating whether this is worth to uplift to 137.

Comment 5

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 1942404

Comment 6

[Alastor Wu [:alwu]]

We should uplift this to Fx137 in order to prevent video stuttering on Netflix HEVC videos.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b5704200b8f6
part1 : correct SPSIterator::IsValid(). r=media-playback-reviewers,jolin
https://hg.mozilla.org/integration/autoland/rev/224815c39101
part2 : update loggings. r=media-playback-reviewers,jolin

Comment 8

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/b5704200b8f6
https://hg.mozilla.org/mozilla-central/rev/224815c39101

Comment 9

[Alastor Wu [:alwu]]

Comment on attachment 9475473 [details]
Bug 1957119 - part1 : correct SPSIterator::IsValid().

Beta/Release Uplift Approval Request

• User impact if declined/Reason for urgency: It affects Release Netflix users (or other content stream providers) when they watch HEVC video, some video will regularly lost several per 5-6 seconds. As we're actively collaborating this feature with Netflix, it will be great to have this change on Release in order not to affect the Release users.
• 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: Following this link
  https://docs.google.com/document/d/1Eh2yLIjy9JmHa1BrxWR0Mw8WBcj__xZVBONlrb-K12k/edit?usp=sharing
• 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 only fixes a small condition check for the inband config change, it doesn't introduce any big changes and new function.
• String changes made/needed: No
• Is Android affected?: No

Comment 10

[Alastor Wu [:alwu]]

After some discussion with Netflix, this issue isn't seen on Release again, so we should be good to keep the fix on 138 and no need to be rush.

---

[update] this is still seen on Release, and Netflix disabled the PlayReady testing due to this problem.

Comment 11

[Alastor Wu [:alwu]]

Comment on attachment 9475473 [details]
Bug 1957119 - part1 : correct SPSIterator::IsValid().

Beta/Release Uplift Approval Request

• User impact if declined/Reason for urgency: After further discussions with Netflix, they have decided to disable 4K playback for users until this issue is resolved. As a result, our Netflix users will no longer be able to watch content in 4K and may experience stuttering during HEVC video playback. This issue could also affect playback from other content providers that use the HEVC format.
• 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: Following this link
  https://docs.google.com/document/d/1Eh2yLIjy9JmHa1BrxWR0Mw8WBcj__xZVBONlrb-K12k/edit?usp=sharing
• 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 only fixes a small condition check for the inband config change, it doesn't introduce any big changes and new function.
• String changes made/needed: No
• Is Android affected?: No

Comment 12

[Ciprian Georgiu, Desktop QA]

We’ve tried to reproduce the problem described in the document provided for QA (comment 11), but unfortunately, after talking with Alastor Wu, it appears to be a hardware-specific issue. On the tested Windows 11 (22H2 or later versions) machines, none of them seem to support HEVC.

Given this, I don’t think we can verify the fix on our end. I'm going to remove the qe+ flag.

Comment 13

[Pascal Chevrel (relman team) -> :pascalc|PTO until Sept 2]

Alastor, regarding your comment #10, is it something we need to fix in 137 (release)? It's not clear to me if this is an issue we hit with Netflix on production and is important to have in our 137.0.2 dot release next week or if it can just ride the 138 train (end of month). Thanks!

Comment 14

[Alastor Wu [:alwu]]

Sorry for the confusion, the comment 10 isn't valid anymore, as Netflix was able to reproduce the issue on their side on the Release. So yes, it will be great to have this landed on Fx137 as well, because this is a blocker for us to allow our users to use PlayReady.

Comment 15

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-release/rev/4bcab6ad081c