Two /dev/video* after device upgrade[SOLVED]

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

Recently I bought a new webcam. The new camera is working fine.
Now I got two /dev/video*, o and 1 - Skype picks the wrong webcam.
I forgot how to delete the old webcam.

Anon-E-moose · Posted: Thu May 30, 2019 12:23 pm Post subject:

Probably a udev rule
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EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

Gotta set one because there is no udev rule for it.
I have two files in /etc/udev/rules.de/ :
10-local.rules
99-dev-input-group.rules
That´ s it.

NeddySeagoon · Posted: Thu May 30, 2019 7:40 pm Post subject:

transsib,

/dev/video* entries are normally generated in response to hardware being detected.
That suggests that you have two devices connected. Is that intentional?

/dev/video* nodes are not just webcams. Any wideo capture device will do, sometimes even scanners.

If the /dev/video* entries are symlinks, they are added by udev after the kernel DEVTMPFS adds the real device nodes.
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

Hi Neddy, no other video capture device are connected.
Gonna see to it tomorrow. I have shut down box for today.

Annotation
Morning all, the udev rule I have set in 10-local.rules seems to work.
I still have two video devices in dev but Skype seems to pick the
proper device.
I still need to find out what results in 2 /dev/video.
Following Neddy ... could be the scanner device of my multifulti printer.

javeree · Guru Joined: 29 Jan 2006 Posts: 453

I have the same thing with my webcam, but so far ignored it because I could not find any downside so far.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

On my Windows 10 OS I have two entries in Device Manager for image processing:
the webcam and the scanner function of my printer/copier/scanner - laser printer.

On Gentoo my multifunctional printer is being controlled by a Linux driver coded by the
printer manufacturer, but Linux creates the device. One of those /dev/video devices
never works with skype or any other application that needs a webcam.

Does any webcam application work with either /dev/video device on your system?

NeddySeagoon · Posted: Sat Jun 01, 2019 10:34 am Post subject:

transsib,

dmesg should show both video devices being detected, along with the Vendor and Device IDs
It may even show device drivers being loaded.

You should be able to tell them apart from that.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

I cannot tell yet, Neddy. The printer is a networked device in my local network.
If none of us uses it it is powered down. So I gotta wait until I or any other user
on my local network needs the printer.

It´s gotta be the scanner function here; you´re certainly right about this.

Gonna post here as soon as I know. You know, when the printer is on I fail to ask
dmesg because if it´s on there´s something important to get done and I forget
about dev device nodes as long as printing, scanning, copying and fax works.

NeddySeagoon · Posted: Sat Jun 01, 2019 9:03 pm Post subject:

transsib,

I wouldn't expect Skype to work with a scanner. Its Microsoft after all. :)
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NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

NeddySeagoon · Posted: Sun Jun 02, 2019 9:30 am Post subject:

transsib,

If its a network printer/scanner/whatever, you won't get a /dev entry. It won't appear in dmesg either as the kernel won't see it come and go.
Its just something you talk to over the network, like any other system on the network.

Your webcam has a built in stereo microphone, so I would expect it to get several device nodes.
/dev/video* for the video and some entries in /dev/snd/ for the microphone. snd_usb_audio should load to take care of the USB audio device.

/dev/snd/ should get a new controlC* for the controls and pcmCxD0c for the audio stream itself.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

NeddySeagoon · Posted: Sun Jun 02, 2019 10:03 am Post subject:

transsib,

You are in good company.
When I first got a webcam about 20 years ago, it took me about three weeks to work out that trying to play sound through the webcam mic was a bad idea. :)
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

Which sounds ? :wink:

Never liked the idea of a webcam. I had an older model but rarely used it: grainy picture
plus not being photogenic, security concerns... hugh
Now I got myself a newer, better camera because Skype is somehow fun too. But when it´s not in use
I turn it around so that it faces the wall

NeddySeagoon · Posted: Sun Jun 02, 2019 3:07 pm Post subject:

transsib,

I still have that 20 year old webcam. Its in a box in a cupboard somewhere.
I had the idea to use it with the family but none of them liked the idea, so it never happened.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

EasterParade · l33t Joined: 26 Jul 2003 Posts: 938

I´m sorry to hear that, Neddy.

Too bad, so many good things lying in boxes in some cupboard.