VLC 3.0.1 shows unnecessary error for each video

[zhgutov]

Hello.

I have multichannel digital audio interface (RME Digiface USB) for which VLC shows error for each video.
Actually VLC plays everything as desired. But this error is disturbing.

The error looks like this:

https://zhgutov.files.wordpress.com/201 ... -error.png

This is Audio MIDI Setup:

https://zhgutov.files.wordpress.com/201 ... output.png

This is channel layout (which is set to Stereo):

https://zhgutov.files.wordpress.com/201 ... layout.png

Is there any way to disable this error? Or maybe this is some kind of bug?

[zhgutov]

Related topic: https://forum.videolan.org/viewtopic.php?f=12&t=143650

[zhgutov]

VLC 2.2.8 works fine without such error message.

[vr_driver]

Yes, I have exactly the same problem with my PreSonus Studio192.
It's been driving me crazy.

"Audio device is not configured
You should configure your speaker layout with "Audio Midi Setup" in /Applications/Utilities. VLC will output Stereo only."

Version 3.0.1 Vetinari (Intel 64bit)
Compiled by d-fu with clang 9.0.0 (clang-900.0.39.2) (Feb 26 2018 21:02:37)

I've also tried the latest nightly build too, with the same result.
Version 4.0.0-dev Otto Chriek (Intel 64bit)
Compiled by jenkins with clang 9.0.0 (clang-900.0.37) (Apr 16 2018 04:02:46)


Have now gone back to version 2.2.8 with no problems. Thanks for the help.

[tguillem]

hello,

This bug should be fixed in 3.0.2 (the warning should be shown only the first time): could you try with the last vlc nightly: http://nightlies.videolan.org/build/mac ... 6-0645.dmg

[zhgutov]

Yes, this works exactly like you describe.
It shows that error only once after start.

But I still don't understand why it shows that error at all.
Yes, my interface have more channels than required for stereo, but it is configured correctly.
I set up channel mapping for stereo, what's wrong with that?
And what will happen if I have two videos with different channels count?
In that case I will probably expect some behaviour like convert 5.1 to stereo,
or play stereo to the front left and right only, or something else which may present in options.
And in that case I still don't understand where is the error.
Maybe I need to set up such behaviour once, and after that this error should not appear anymore.

[zhgutov]

Oh, just mentioned that when I run the application again it does not show this error anymore.
Maybe it's okay.

[zhgutov]

I have one question. When I go back and forth between 3.0.x and 2.2.8 I always notice that 3.0.x sounds more smooth with AAC, and 2.2.8 is slightly more harsh.
Have you changed something in decoding or processing, or maybe this is some kind of illusion?

[tguillem]

But I still don't understand why it shows that error at all.

With usb surround sound card, it seems that there is no distinction between configured for stereo and not configured.
I think it's a regression from VLC 2.2.x but now I don't have a surround usb sound card to do my tests, so I can't be sure (there is no problem with HDMI audio).

I have one question. When I go back and forth between 3.0.x and 2.2.8 I always notice that 3.0.x sounds more smooth with AAC, and 2.2.8 is slightly more harsh.
Have you changed something in decoding or processing, or maybe this is some kind of illusion?

We changed and updated a lot of things, so yes it's possible.

[zhgutov]

With usb surround sound card, it seems that there is no distinction between configured for stereo and not configured.
I think it's a regression from VLC 2.2.x but now I don't have a surround usb sound card to do my tests, so I can't be sure (there is no problem with HDMI audio).

This is not consumer-like surround sound card, which usually have standard channel mapping (I suppose HDMI audio is the similar thing, and strictly follows the standard).
This is a sound card with free channel mapping, so it is possible the channel mapping is stored somewhere in a different place.
But this mapping definitely should be stored somewhere, because it may be changed via Audio MIDI Setup.
If you look at the setup dialog, you will notice there is more "depth" in settings.
Not only channels, but also channel groups (streams), so probably such things are supposed to be used in a different way.

[zhgutov]

Oh, just a guess. Never used any API in Mac OS X yet, so maybe I will tell something weird.

You can swap channels in built-in output via Audio MIDI Setup.
To do this you need to reassign channels in the similar dialog.
But probably you will see this channels via API in the same way as channel 1 and channel 2 (or Left and Right, I don't know).
If so, this means there is a standard channel layout, where channel 1 or channel 2 are used as stereo Left and Right by default,
but may be reassigned to different channels of the sound card in Audio MIDI Setup.
Maybe if the sound card has more channels available, you will (may) see them always, but they can be silently remapped via different programming interface.

Anyway, if I have channel array, this does not mean I use (or should use) them all.
Particularly in my case I can use two channels for stereo, and six channels for 5.1 with the same channel array.
You can output stereo files to channels 1-2, 5.1 to channels 1-6, 7.1 to 1-8, and this will be correct (just an example).
Because I can configure internal mixer of the sound card in any way, for example, I can mix that channels and always output them to stereo.
Or I can expect this job done by VLC. Or I can expect the stereo signal to be transformed to 5.1, and 5.1 signal is sent as is.
That's why I asked about such options in my post above. This can make such error unnecessary.