1590997 - Set MediaRecorder's mimeType async after start()

Status: RESOLVED FIXED

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

Description

[Andreas Pehrson [:pehrsons]]

In bug 1512175 we landed new mimeType behavior that was up to spec.

The spec is about to change in PR #190 to set the mimeType async just before firing "start".

This matches our old (pre-71) behavior better. We should defer setting the mimeType per the new proposal to avoid flip-flopping this behavior between 70-71-72 (assuming the spec change lands and our fixes land in 72), considering the annoyances such changes would bring to developers.

Comment 1

[Andreas Pehrson [:pehrsons]]

The spec PR has been merged.

Comment 2

[Pascal Chevrel:pascalc]

Andreas, what are your plans wrt to 71? Any uplift needed?

Comment 3

[Andreas Pehrson [:pehrsons]]

Yes, the fix will be quite simple and I'd much prefer to get it uplifted to 71. I just need to dig up some time to write it.

Comment 4

[Pascal Chevrel:pascalc]

Andreas, when do you plan to land a patcha and request an uplift to beta? We are at beta 8 out of 12. Thanks.

Comment 5

[Andreas Pehrson [:pehrsons]]

Yep, sorry. I've been bogged down by other work. I'll try to get this prioritized.

Comment 6

[Andreas Pehrson [:pehrsons]]

Attachment: Bug 1590997 - Update tests for new MediaRecorder mimetype-at-start-event behavior. r?jib

Comment 7

[Andreas Pehrson [:pehrsons]]

Attachment: Bug 1590997 - Defer setting MediaRecorder mimeType attribute until firing start event. r?jib

Depends on D52255

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/42f9a49ed38f
Update tests for new MediaRecorder mimetype-at-start-event behavior. r=jib
https://hg.mozilla.org/integration/autoland/rev/550c2f8bde45
Defer setting MediaRecorder mimeType attribute until firing start event. r=jib

Comment 9

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/20171 for changes under testing/web-platform/tests

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 11

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/42f9a49ed38f
https://hg.mozilla.org/mozilla-central/rev/550c2f8bde45

Comment 12

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 13

[Andreas Pehrson [:pehrsons]]

Comment on attachment 9107347 [details]
Bug 1590997 - Defer setting MediaRecorder mimeType attribute until firing start event. r?jib

Beta/Release Uplift Approval Request

• User impact if declined: We ship new behavior for MediaRecorder in 71 that we immediately in 72 return back to being on par with pre-71.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): No threading changes, no lifetime changes. We're just moving the setting of a member on main thread to a later point in time. The biggest risk I see is in setting the member when we're not supposed to, because the class has already been reset. However we are handling such cases explicitly so I still consider that low risk.
• String changes made/needed:

Comment 14

[Pascal Chevrel:pascalc]

Comment on attachment 9107347 [details]
Bug 1590997 - Defer setting MediaRecorder mimeType attribute until firing start event. r?jib

Low risk Mediarecorder change with tests, uplift approved for 71 beta 9, thanks.

Comment 15

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/releases/mozilla-beta/rev/bc3e7578b5d4
https://hg.mozilla.org/releases/mozilla-beta/rev/b0f372da1c94