[SOLVED] Web Cam issue

GRS63 · 08-15-2021, 12:57 AM

Fedora 33 64 bit OS Fully updated. 8GB RAM
Web cam Logitech C615

I can plug this camera in and open Cheese to see the Video. Sometmes the Video is present for a few seconds before I see a Message "There was an error playing from Webcam". Other times it might run for 30 minutes before it stops and I get the same message. It does not seem to be influenced by what resolution is used but it does seem to be a bit more unstable when trying to use 1920 by 1080 resolution. If I try to use Zoom the whole computer just freezes with a still frame video and the sound repeating itself for teh last few seconds. Have to do a hard reboot as the mouse and keyboard do not respond.
Sometimes all will seem to be running fine and stable but just on the odd accassion if I shift the camera it will stop and give the mesage above under cheese. It s NOT the cable or a loose connection in the camera as I have verified that by using the camera, with no issues at all on a Windows machine.
A thought I has was thet the noie of shifting the camera may have overloaded the sound channel in some was and that caused the error message. However that does NOT occure when the cam is bing used on he windows machine.
I have also tried using another cam, a J Burrows CM200 Autofocus HD Webcam, and I get the same results.
Wondering if anyone has had the same issue or has any ideas as to where to look to find out what is causing this issue.
Thanks

ondoho · 08-15-2021, 02:48 AM

How could the noise have anything to do with it?
Anyhow, I don't think too loud microphone sound makes software crash.

What you can try to get more info:

You want to see how your Linux system reacts to a certain peripheral being plugged in (smartphone, monitor, USB stick etc.).

Code:

dmesg

can provide that information, but one needs to separate it from previous messages.
Here's how:

Make sure the device in question is unplugged.
Open a terminal, maximise it.
Enter
Code:
```
dmesg -w
```
or --follow (wait for new messages).
Some systems require elevated privileges for
Code:
```
dmesg
```
, if so prepend
Code:
```
sudo
```
or become superuser first.
After
Code:
```
dmesg -w
```
spat out lots of stuff and has hopefully settled down (if it hasn't that could point to a different problem), press <Enter> until your terminal window is blank.
Now insert the peripheral you want information about and wait a few seconds.
Reproduce the rpoblematic behaviour
Copy all the new output that is visible now.

Also find out what the command line is to start Cheese (chances are it's just 'cheese'). Start it from the terminal, reproduce the problem and show us the output.

GRS63 · 08-16-2021, 05:08 PM

Thanks for the information.
I have atatched two files. The first dmesg.txt is the dmesg -w file. It was done as follows.
the computer was rebooted. No Cam was connected.
Treminal was opened and dmesg -w run. At the end of the display a put a few spaces on the screen to show where one actioned ended and the next started.
I the plugged in the CAM.
at the end of the messages, for that action, which came up I put a few more spaces in.

I then started cheese.

I then introduced the fault where I ge tthe cheese screen saying "There was an error playing from Webcam".

I then saved the file dmesg.txt.

The second file is the terminal screen fom starting cheese and the readout when the cam plays up and gives "There was an error playing from Webcam".

this is the file cheese.txt

If there is anything further please advise.
Thanks

ondoho · 08-17-2021, 01:51 AM

In the future I have to make it more clear that we are not interested in a complete dmesg output.
This is the relevant part as per my instructions:

Code:

[   67.321897] usb 1-5: new high-speed USB device number 5 using xhci_hcd
[   67.639392] usb 1-5: New USB device found, idVendor=046d, idProduct=082c, bcdDevice= 0.11
[   67.639396] usb 1-5: New USB device strings: Mfr=0, Product=2, SerialNumber=1
[   67.639397] usb 1-5: Product: HD Webcam C615
[   67.639398] usb 1-5: SerialNumber: 60E4D060
[   67.664874] mc: Linux media interface: v0.10
[   67.689234] videodev: Linux video capture interface: v2.00
[   67.979647] usbcore: registered new interface driver snd-usb-audio
[   67.979706] usb 1-5: Found UVC 1.00 device HD Webcam C615 (046d:082c)
[   68.017068] input: HD Webcam C615 as /devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5:1.2/input/input18
[   68.017222] usbcore: registered new interface driver uvcvideo

[   79.665404] usb 1-5: reset high-speed USB device number 5 using xhci_hcd

[  100.661920] usb 1-5: USB disconnect, device number 5
[  100.663722] uvcvideo 1-5:1.3: Failed to resubmit video URB (-19).
[  100.667685] uvcvideo 1-5:1.3: Failed to resubmit video URB (-19).
[  100.671688] uvcvideo 1-5:1.3: Failed to resubmit video URB (-19).
[  100.675682] uvcvideo 1-5:1.3: Failed to resubmit video URB (-19).
[  100.930560] usb 1-5: new high-speed USB device number 6 using xhci_hcd
[  101.885607] usb usb1-port5: Cannot enable. Maybe the USB cable is bad?
[  102.681587] usb 1-5: new high-speed USB device number 7 using xhci_hcd
[  103.006662] usb 1-5: New USB device found, idVendor=046d, idProduct=082c, bcdDevice= 0.11
[  103.006674] usb 1-5: New USB device strings: Mfr=0, Product=2, SerialNumber=1
[  103.006680] usb 1-5: Product: HD Webcam C615
[  103.006683] usb 1-5: SerialNumber: 60E4D060
[  103.335967] usb 1-5: Found UVC 1.00 device HD Webcam C615 (046d:082c)
[  103.375143] input: HD Webcam C615 as /devices/pci0000:00/0000:00:14.0/usb1/1-5/1-5:1.2/input/input19

Strangely, it looks like the device has been disconnected and unsuccesfully reconnected when you started cheese.
I have no idea why.

A web search for what I think is the most relevant error message seems to suggest kernel issues... maybe you can find more there, maybe add the keyword fedora + webcam device name., so: https://www.startpage.com/sp/search?...ideo+URB+(-19)

Cheese output is just this:

Code:

(cheese:186426): cheese-WARNING **: 12:33:04.308: Could not read from resource.: ../sys/v4l2/gstv4l2bufferpool.c(1132): gst_v4l2_buffer_pool_poll (): /GstCameraBin:camerabin/GstWrapperCameraBinSrc:camera_source/GstBin:bin35/GstV4l2Src:v4l2src1:
poll error 1: Invalid argument (22)

Not sure it's even relevant...

GRS63 · 08-19-2021, 05:44 PM

Thanks for the information and links. Went throught it all but got nowhere except that on going through the links and links off those I came across an article where a person had had an intermittent issue with his cam. I disassembled the cam and found that some of the metalised material that is used to place a shield around the cable as it goes through to the inside of the plastic case was not seated smoothly and secure. Fixed all that and Cam now works with no problems. So the matrial must have been loose enough that it caused an intermittent short internally which was enough to cause the problem I reported. It must have been pure luck that the cam worked on other computers.
But during all of this there was also another hardware fault so I had two faults. The second fault was in the USB port I was using to test the cam. Originally I had the cam plugged in to a USB port on the rear of the computer and I got the fault as reported. For testing I used a USB port on the front of the computer, for convenience, and this port turned out to have a fault in the socket. Pulled the board out and resoldered the connections. All OK now.
Oh for having more than one USB port.

Thanks for the help you information was very helpful andI learnt more about linux andsits diagnostic tools.
Solved. with thanks

ondoho · 08-19-2021, 11:14 PM

Quote:

Originally Posted by ondoho

it looks like the device has been disconnected and unsuccesfully reconnected when you started cheese.

So this was it after all.

Great it's SOLVED now!

FWIW...

Quote:

Originally Posted by GRS63

It must have been pure luck that the cam worked on other computers.

This is an easy psychological trap to fall into, coming to the wrong conclusions based on what one thinks is the weakest link, happened to me too.