How can I enable video for Zoom, Skype, Doxy for MDs in KDE linux?
So far nothing I've tried has had any success enabling video from the USB connected Creative Live! Optia AF webcam, aka 041e:4058 in the UVC database.

Here is a check I did:
jim@tabby7:~$ dmesg | grep -i "Camera"
[ 3.959210] uvcvideo 1-1:1.0: Entity type for entity Camera 1 was not initialized!
[ 3.959290] input: UVC Camera (041e:4058) as /devices/pci0000:00/0000:00:01.2/0000:01:00.0/0000:02:08.0/0000:06:00.1/usb1/1-1/1-1:1.0/input/input6

So the system knows the camera is there. The Optia camera shines with a blue glow in its base but no picture is displayed except when running web tests under Win 10.
I want it to work in KDE Neon.

I installed Kamoso, webcamoid, and cheese. None of them made a viable connection with the Optia AF.

In Plasma's System Settings there no longer is a section on "Multimedia - Audio and Video," due, I think to underlying changes in the base linux and Qt software.

I hope some people know enough about how to enable use of the webcam by Zoom and Skype, for example.

(I decided not to try Kmix yet, because the last time I did on my older system, my system crashed.)
(Also how can I get sound out of line out 3.5 mm jack--I do have USB headset sound. Maybe that is related.)

Thanks in advance.

I checked to see what is installed under the heading "phonon" in Muon package manager.
Only three packages:
libphonon4qt5-4
phonon4qt5-backend-vlc
libphonon4qt5-bin

I was tempted to install phonon and other packages, but I guess phonon is superceded somehow, and, I have no idea of what the developers think should be there.

An update.
I think I am involved in a hopeless quest although I have one more ploy I am pursuing. See below.

Fedora people noted about 2011-2014 that the Optia AF driver had failed. Eventually they decided to forget about it. It seems there was no live connection to the Linux driver development people, I assume. (Fedora tested the Optia AF repeatedly between about 2011 and 2014, but never tried to fix the problem, and found it did not work each time.
https://bugzilla.redhat.com/show_bug.cgi?id=739448 )
.
Meanwhile Creative has issued End of Life for the Optia AF. Note that the Optia AF Windows driver still works. (I checked on an older machine on which I replaced two CPU cooler fans yesterday.)

By then I tried a bunch more Linux webcam apps, none of which worked.
I turned to a buddy in a local Linux User Group and have bounced ideas back and forth. Whatever he suggests I try--without success.

I checked out the VLC forum hoping they had found a way. I found a request like mine that got blown away by a moderator who insisted the problem was due to the poster's OS. I sent a private message to that disappointed person to see if he/she ever got a fix.

My latest idea is to return to the Win10 guest in VirtualBox under Neon and install Skype and see if I can get it to use the Windows Optia AF driver. (I had tried this about a week ago and got just a black screen using the Linux driver.)
My intuition is it will not work yet again.
I overcame the initial problems of getting the addon package to VB installed that you need for reaching the webcam and getting Skype running.
Neither sound input nor output work yet and video is not working. I will see what is possible. Chances are I can get sound to work....

Meanwhile in the retail channel, Logitech's supply of their popular webcams is all sold out and used versions on Amazon are for sale at 3-4 times their new price--i.e., gouging in a time of pandemic.
There are offbrand models for sale with future deliveries from China expected at roughly double their August prices.

I am a weakly experienced VirtualBox user--mainly for evaluation of various Linux distros.
I installed Win10 in VB because that is the only way I could get it up and running on my new hardware. So I am essentially a pragmatic, persistent, but impatient hacker googling for fixes in a last ditch effort to get a workaround given the bit rot that disabled the Linux Optia AF driver.

I wish the picture were more upbeat, but it looks like the Optia AF is unusable under Linux. If luck is with me I hope to contradict that hunch.
If there are better ideas I welcome them.

Update: over a week ago I gave my best effort using the repository version 5 of VirtualBox. I got sound to work but failed with video.
I did not install version 6 of VirtualBox but think it would not have given greater capability.

I invested in an offbrand new webcam at only double the usual cost. One Unix user reported good luck with it. It should arrive mid-May.