qemu, webcam, VM can't access

English Virtualization
1

I made a fresh installation of the 15.3
then
I installed with Yast KVM and KVM tools
then
with https://software.opensuse.org/package/virglrenderer

I updated QEMU to 6.0.0 according to get libvirglrenderer >= 0.8.2 (0.9.1 in fact) with

https://download.opensuse.org/repositories/home:regataos/openSUSE_Leap_15.3/home:regataos.repo

no problem with my 15.2 for the VM accessing to the webcam.

When I invoke the VM with

qemu-kvm -enable-kvm
-m 2048 -smp 2 -cpu host
-device virtio-vga,virgl=on -display gtk,gl=on,zoom-to-fit=off
-device usb-ehci
-device usb-kbd
-device usb-mouse
-device usb-tablet
-device ich9-intel-hda
-device hda-duplex,audiodev=snd0
-audiodev pa,id=snd0
-device usb-host,vendorid=0x046d,productid=0x081b
-boot menu=on
-nic bridge
~/QEMU_VM/android_x86_7.1-r5.img \

When I launch the “opencamera” app, I get an error:

Fails to open the webcam
The webcam may be used by another app?
ID:0

Also, I get an error using WhatsApp video call.

This webcam (-device usb-host,vendorid=0x046d,productid=0x081b ) is a dedicated webcam. I get another webcam for Skype and other ones under openSuse.
I checked that webcam is good.

Deprecated feature, removed feature, syntax, ACL, anything else ?

Thanks

2

I get this

@localhost:~> sudo ls -l /dev/video*
[sudo] Mot de passe de root :
crw-rw----+ 1 root video 81, 0 23 sept. 10:21 /dev/video0
crw-rw----+ 1 root video 81, 1 23 sept. 10:21 /dev/video1
crw-rw----+ 1 root video 81, 2 23 sept. 10:21 /dev/video2
crw-rw----+ 1 root video 81, 3 23 sept. 10:21 /dev/video3

It is strange because I get only 2 webcams.

Also, VLC supplies these 4 dev names. I also knew this with 15.2, and I was surprised, but all was working well.

With VLC
I can read on vide0 and video2
I can’t read on video1 and video3

3

I forgot something.

To use a webcam, you must :

  • be a member of “kvm” group

  • add the rule

<vendor name> <model name>

SUBSYSTEMS==“usb”, ATTRS{idVendor}=="<vendorid>", ATTRS{idProduct}=="<porductid>", GROUP=“kvm”, MODE=“0664”

in a file named “50.qemu.rules” and put in /etc/udev/rules.d/

But this time there is, I assume, another troublemaker, which is pipewire
[li]. Happily yesterday there was an update to pipewire 0.3.37 and today tada i can use the webcam with qemu.[/li]
[*] I use opensuse Argon 15.3 then Pipewire replaces pulseaudio but not only. Pipewire manages audio and video streams between numerous sources and destinations in the PC.