1195061 - Mono Audio unplayable in Windows 10

Status: RESOLVED FIXED

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

Description

[Paul17041993]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0
Build ID: 20150812163655

Steps to reproduce:

Attempt to play a mono OGG file


Actual results:

Play button will change, but nothing else occurs


Expected results:

Playback should start

Comment 1

[Paul17041993]

still working on whether it's specific to OGG or mono files, occurs with 5.1 speaker setups but not stereo.

Comment 2

[Loic]

Attach an audio sample if possible.

Comment 3

[Paul17041993]

confirmed mono-audio specific and the problem is inside cubeb again

example sources;
https://commons.wikimedia.org/wiki/File:Fennec_Singing.ogg
https://www.youtube.com/watch?v=mEN7DTdHbAU

working on a possible patch now

Comment 4

[Paul17041993]

Attachment: win10monAudFix.patch

windows 10 sees the removal of mono support entirely for > 2 channel setups, so we have to give it stereo regardless.

no idea about sources > 2 channels, but I don't think we support that yet anyway?

Comment 5

[Paul17041993]

I would consider the lack of playback for a common format to be at least major

Comment 6

[Matthew Gregan [:kinetik]]

I can reproduce this locally.

In handle_channel_layout, we pass a mix format with nChannels == 1 to IsFormatSupported and receive AUDCLNT_E_UNSUPPORTED_FORMAT, which causes us to fall back to using the hardware mix format retrieved from GetMixFormat.  Passing that to Initialize causes it to fail with AUDCLNT_E_UNSUPPORTED_FORMAT again and cubeb_stream_init eventually returns CUBEB_ERROR.

In theory, we'd expect initializing a stream with the format reported by GetMixFormat to succeed and we'd then up/down mix and resample as necessary.  It fails because we change dwChannelMask to (in this case) KSAUDIO_SPEAKER_MONO before testing IsFormatSupported and when reverting the mix format to the version received from GetMixFormat we only reset the WAVEFORMATEX members rather than the complete WAVEFORMATEXTENSIBLE structure (which includes dwChannelMask).

Comment 7

[Matthew Gregan [:kinetik]]

Attachment: fix v0

Comment 8

[Paul17041993]

well that explains why it wasn't accepting the hardware default, not sure how I overlooked that, but I can confirm it fixes the bug. Quite odd though that it wasn't a problem until now...

Comment 9

[Matthew Gregan [:kinetik]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3a784fc318c1

Comment 10

[Matthew Gregan [:kinetik]]

Comment on attachment 8648566 [details] [diff] [review]
fix v0

Approval Request Comment
[Feature/regressing bug #]: bug always present, exposed by Windows 10 behaviour changes
[User impact if declined]: some audio formats unplayable on Windows 10 (mono audio)
[Describe test coverage new/current, TreeHerder]: n/a
[Risks and why]: very low, trivial fix
[String/UUID change made/needed]: none

Comment 11

[Matthew Gregan [:kinetik]]

(In reply to Paul17041993 from comment #8)
> well that explains why it wasn't accepting the hardware default, not sure
> how I overlooked that, but I can confirm it fixes the bug. Quite odd though
> that it wasn't a problem until now...

Thanks for verifying the fix!

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/3a784fc318c1

Comment 13

[Paul17041993]

we should push this as far back as 40 if it's not a problem, of which it shouldn't be as the function hasn't been touched since some distant version...

Comment 14

[Sylvestre Ledru [:Sylvestre]]

Comment on attachment 8648566 [details] [diff] [review]
fix v0

Windows 10 regression, taking the fix.

Comment 15

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/7f7c33477122

Comment 16

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/releases/mozilla-beta/rev/51fd00199355