845452 - Lower volume of media mochitest tests

Status: RESOLVED FIXED

(Testing :: Mochitest, defect)

Description

[Henrik Skupin [:whimboo][⌚️UTC+2]]

As it came up on bug 837458 and by a full testrun on my own machine which blew me away the ears, we should mute the media mochitests if possible:

>(In reply to Henrik Skupin (:whimboo) from comment #21)
>> Clint, I run all the media mochitests lately and none of the media tests
>> muted audio. Not sure why that is but lets ask Roc if we should follow-up on
>> that separately.
>
>Yes I think we should.
>
>Ideally the test machines would be muted at the system level somehow.

Muting at the system level will only work for our test machines but not if you have to run the tests on your own machine while you want keep e.g. other music running. It's really distracting.

Comment 1

[Jeff Walden [:Waldo]]

Given that the code paths followed for full-mute might reasonably be different from with normal volume, I don't think muting is a good idea.  10% volume, or some suitably small fraction that doesn't kill volume entirely, seems like the right thing to do.  Perhaps a volume-scaling pref set during test runs (defaulting to 1.0 otherwise) would be a reasonable way to do this.

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

We already have media.volume_scale. Just set that.

Comment 3

[Jason Smith [:jsmith]]

(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #2)
> We already have media.volume_scale. Just set that.

Back over to Core::WebRTC then. We could just add a simple one line patch to head.js runTest to set this pref.

For those of us who don't know the pref - what value would we set it to? "0.0"?

Comment 4

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Not sure why you moved that to WebRTC. This is a bug covering all media tests and has to rely as initially filed in the Mochitest component. Moving back so we might want to get this addressed as a default preference set by the framework.

Comment 5

[Jason Smith [:jsmith]]

(In reply to Henrik Skupin (:whimboo) from comment #4)
> Not sure why you moved that to WebRTC. This is a bug covering all media
> tests and has to rely as initially filed in the Mochitest component. Moving
> back so we might want to get this addressed as a default preference set by
> the framework.

Didn't realize you were targeting all mochitests originally when I wrote that comment.

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

(In reply to Jason Smith [:jsmith] from comment #3)
> For those of us who don't know the pref - what value would we set it to?
> "0.0"?

Just to be on the safe side (i.e. make sure we don't take any shortcut codepaths that hide bugs), I'd set it to 0.01 or something like that.

Comment 7

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Attachment: Patch v1

This patch implements what has been suggested in that bug. We do not completely silence the tests but scale the volume down. '0.01' seems to be a good candidate here. Asking for review from roc for the media tests, and ted for the build system.

Comment 8

[Jason Smith [:jsmith]]

Just for safety, we might want to get a try run here just to make sure nothing blows up setting this pref.

Comment 9

[Henrik Skupin [:whimboo][⌚️UTC+2]]

A try run has already been submitted but I missed to add this to my last comment: https://tbpl.mozilla.org/?tree=Try&rev=ee22a32a8461

Comment 10

[Henrik Skupin [:whimboo][⌚️UTC+2]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/fe50e7d880ff

Comment 11

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/fe50e7d880ff