How to identify hidden video capture devices?

Programming Help
1

Hello

I’m interested in using PTB to perform video capture from a FLIR Chameleon 3 camera. It is connected via USB 3 and I am running Windows 10. I am using the following version of PTB: '3.0.17 - Flavor: beta - Corresponds to SVN Revision 12135. My version of Matlab is: ‘9.10.0.1649659 (R2021a) Update 1’.

When I execute Screen(‘VideoCaptureDevices’), the camera is not found. The website (http://psychtoolbox.org/docs/Screen-OpenVideoCapture) explains that this can happen with some devices and it provides information about how to pass information to PTB about hidden devices so video capture can proceed. However, I can’t find any information about how to identify the camera. How do I determine the camera’s name or ID? I’d appreciate any suggestions on how to do this or if you could point me to the resource that describes this process. I looked around on the website, the forum, and the github issues, but I couldn’t find anything. If I missed it, I’m sorry. Thank you so much for your time and have a good day!

~Nick

2

You asked the same question in a GitHub issue a month ago, i explained priority support to you as an option of getting help, you fell silent, so i will close that issue now.

-mario

3

Hi Mario,

Thanks for that update! I was sidetracked by other issues, so that is why I had not pursued this question further. When I came back to it yesterday and it still had not been answered, I decided to follow your suggestion and move the question here.

Since information appears in the software guide on how to deal with hidden cameras, I thought people would have some tips on how to identify the hidden cameras. Perhaps this is a complex problem that is much more system specific than I had anticipated, which is why you are suggesting using paid support.

I’d appreciate any advice anyone has with this problem. Thanks!

~Nick

4

Try reading the documentation for GStreamer and for Windows. For linux, video devices are found by listing /dev/ — a really nice feature of Linux where everything is exposed as a “file”, even hardware devices. My vague recollection is clicking around in device manager USB section in Windows?

Also doesn’t Teledyne have some software you can use to configure your camera etc.?

5

Has this problem been resolved? If so, i guess others might appreciate some feedback that might help them in similar situations.

-mario

6

Unfortunately, no. I’ve worked on it a bit this morning, but I still can’t get it to work. I’ve found numerous names and IDs in the device manager properties for the camera. I’ve tried ~15, but with no success. I’ve looked around online to see if there is anything about device IDs, but most of that information is in relation to identifying drivers. Perhaps if I had more information about where the device ID and name come from in PTB, that might help.

Whenever I try to open the device with an ID or name I found in the device manager properties, I get the following error from PTB:

PTB-ERROR: Statechange failed with GST_STATE_CHANGE_FAILURE!
Error in function OpenVideoCapture: Usage error
In OpenVideoCapture: Opening the video capture device failed during camerabin pipeline zero → ready. Reason given above.

I’d appreciate any other information or suggestions people might have. Thanks!

~Nick