Strange and Interesting KDE Pseudo-Dependency

[John R. Graham]

The first part of this is probably just ignorance on my part. I discovered that PulseAudio provides the plumbing that allows for automatic recognition of my USB headset in KDE (and perhaps elsewhere). With PulseAudio (media-sound/pulseaudio) installed, it Just Works™.

The second part is what's strange and interesting. I've been living with what I considered a minor bug. On a relatively new laptop that's now my "Daily Driver", the speaker / volume control icon that KMix puts in the System Tray was very dark and low contrast and didn't match the brightness and coloration of the other icons: it was there, but you had to look closely to see that it was there. However, after installing PulseAudio, the KMix icon is now bright, easy to see, and matches the color theme of the other System Tray icons.

It's an unexpected kind of, sort of dependency and probably worth a note in the Wiki, which I plan to make.

- John
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[eccerr0r]

Though Pulseaudio is Poettering Poo... I don't really think it really deserves the shunning. Yes it was very clunky in its infancy but now it's pretty mature. It's actually very useful and makes things work well when it's installed correctly.

Granted it was made specifically for GUI control and all the device/filter/... names are very keyboard unfriendly... CLI control of pulseaudio gets very hairy.

I have a random Bluetooth receiver that supports A2DP, I was quite shocked it "Just Works™" too. Can switch my local speakers to my stereo system speakers in another room with pavucontrol, probably the exact same way as one would switch to USB headsets.

It *is* CPU overhead, but what isn't. But if you have the CPU and like the ability to switch inputs/outputs and mix audio at whim with a GUI, it's worth using.
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Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

[asturm]

Assuming you are talking about media-sound/pulseaudio-daemon, this is not reproducible here with media-video/pipewire[sound-server] installed instead of media-sound/pulseaudio-daemon.

As far as dependencies are concerned, kmix[pulseaudio] correctly depends on media-libs/libpulse - which in turn ensures a sound server is installed via

[John R. Graham]

@asturm, that's interesting, but I didn't have the pulseaudio USE flag set, which may be what's causing KMix to misbehave. What I didn't have installed—that I installed to address my issue—was media-sound/pulseaudio. I then set the pulseaudio USE flag globally and updated @world with --reinstall=changed-use. Let me reverse these changes to make sure my old issue is reproducible.

- John
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I can confirm that I have received between 0 and 499 National Security Letters.

[asturm]

If your system relied on pulseaudio to have *any* sound device available on your system, the behavior of the icon might make sense, albeit I haven't seen that yet. But kmix certainly does not need pulseaudio with USE=-pulseaudio and alsa set up.

With pipewire instead of plain alsa now I'm using kde-plasma/plasma-pa instead of kmix, which only kind of still exists as legacy fallback.

[John R. Graham]

Yeah, it's a little confusing. I had alsa set up, had the pulseaudio USE flag globally unset (although I'm unsure of whether it's set by some ebuilds, but I doubt it), and was getting audio in KDE just fine, albeit with the limitations I described in my original post.

- John
_________________
I can confirm that I have received between 0 and 499 National Security Letters.

[Goverp]

If you read the emerge output for kmix on a system with plasma and USE=pulseaudio, it says "plasma-pa is the default volume control".
I had two volume controls on my laptop until I removed kmix, though the message doesn't say you have to remove kmix.
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Greybeard

[asturm]

Yes, removal is not necessary. kmix can simply be closed at runtime to not start at the next session. But it could still be used in a different environment.

[John R. Graham]

I'm somewhat frustrated to report that I can't reproduce my original condition. No matter what I do now, the KMix icon is not messed up, although removing pulseaudio completely (and restarting the display-manager service), of course does remove the code that auto-recognizes USB audio devices like my headset.

- John
_________________
I can confirm that I have received between 0 and 499 National Security Letters.

[steve_v]