Two USB webcams will not work at the same time in the same scene.

[irisch]

I am wondering if anybody else is having this problem.
I have two webcams plugged into different USB ports on my PC and OBS sees both of them, and when I add a new Video Capture Device I see both webcams. So far so good. If I set them both up one will display and the other will not. Now if I switch scene collection and then come back to the one I have set up both webcams the one that was working okay stop working and the other one works. In other words, I can not get them both to work in the same scene collection.
The same thing happens when I end and then restart OBS. The webcam will do the same thing as switching scenes. I went on a Windows machine and it does not do this, only in Linux (Ubuntu 20.04 with Gnome desktop.)

 

[RadioInfoCite]

Hi,
to get two Webcams or more you need a computer with a very good USB bus,
this mean balace your share bandwidth.

First you need to look at your webcam, which resolution you wish to get.
Because two full HD on the same I/O chip will not working on many motherboard.

first solution to test is change the location of one webcam to see if you have multiple I/O bus or a single one.

You may need to add a extra card in the computer to get more USB bus, ideally it will be a card with multiple chips on-it.

To let's you see, we have run a Intel i5 Gen.3 / 16GB and running 5 webcam at the same time,
and we have connected 8 cameras ready.

Good luck.

 

[irisch]

I have Linux and Windows running on the same computer. If I boot into Window and run OBS, I can use both USB webcams, but if I boot into Linux (which I use all the time) and run OBS, I have this problem.

 

[Tuna]

We would like to see a log. Else it's speculation.

Most likely USB bandwidth. The issue is that on Windows you won't notice when cameras transmit JPEG instead of raw images (iirc). On Linux you would have check the supported color formats of your cameras. Only the ones that show an "emulated" in their names will internally use JPEG transmission over the USB bus. With raw images you will exhaust USB bandwidth quickly.

 

[irisch]

Thanks, for all the help. I have a workaround if anyone is interested. I have a few old android phones laying around so I install the app "irirun" on them and installed the program from http://iriun.com/ on the computer end. As long as you are on the same network they see each other and work great as webcams. This works for all platforms, (Windows, Mac, and Linux). There is a Howto in setting this up. YouTube Howto

 

[Filip S]

Thanks, for all the help. I have a workaround if anyone is interested. I have a few old android phones laying around so I install the app "irirun" on them and installed the program from http://iriun.com/ on the computer end. As long as you are on the same network they see each other and work great as webcams. This works for all platforms, (Windows, Mac, and Linux). There is a Howto in setting this up. YouTube Howto

Today your workaround is with vdo.ninja / obs.ninja but it does not solve the problem with usb bandwidth - I have also had problems with more usb cams on USB hub.