Using USB webcam with a USB Extender and a USB Hub

Forum for questions and support relating to the 1.24.x releases only.
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ZonedOut
Posts: 8
Joined: Sat Nov 27, 2010 9:50 pm

Using USB webcam with a USB Extender and a USB Hub

Post by ZonedOut »

Yes, I know, that might be asking for trouble. But with a PC with only 2 usb ports (and ony one free), and desired webcam locations nowhere near my PC I can see no option but to use an usb hig and usb extender.

Unsurprisingly, Im having a little grief.

Here is the problem :

I cannot get a USB webcam to work when connected to a USB extender via a USB hub, It wont even work in xawtv or cheese.

However, here's what does work in XAWTV, cheese and zoneminder :

Plugging the same webcam and USB extener directly into the USB port.
Plugging up (identical) USB webcams into the USB hub (they all work fine in zoneminder).
Plugging the USB extender into the USB hub and into a Windows XP PC (and testing with Skype)

It just seems that the combination of USB extender and USB hub is not popular in Linux.

Can anyone suggest what I might try to get this to work ? Ive exhauted all of my ideas :-)

Can anybody suggest how I migh be able to make this work, or what I might try even ?
ZonedOut
Posts: 8
Joined: Sat Nov 27, 2010 9:50 pm

Post by ZonedOut »

Hmm. interesting - I would have thought a USB hub and USB extenders would be a common requirement for zoneminder, but maybe Im pushing the boundaries !

If anyone is able to help out, I have further discovered that :

YawCam in windows (similar but less sophisticated product) copes with all possible combinations of cameras, hubs and extenders.

XWATV on Ubuntu 10 complains as follows :
v4l-conf had some trouble, trying to continue anyway
Warning: Cannot convert string "-*-ledfixed-medium-r-*--39-*-*-*-c-*-*-*" to type FontStruct
ioctl: VIDIOC_G_STD(std=0x1 [PAL_B]): Invalid argument
libv4l2: error turning on stream: No space left on device
ioctl: VIDIOC_STREAMON(int=1): No space left on device
ioctl: VIDIOC_S_STD(std=0x0 []): Invalid argument
v4l2: oops: select timeout
libv4l2: error turning on stream: Device or resource busy
And Zoneminder is complaining of exit with status code 6. But if xawtv isnt working, then its not really a zoneminder issue as such, so it would complain.

I think this means the Ubuntu driver cant cope with the usb extender and hub combination, whereas that on windows can. I think this means that you cant use a USB extender and usb hub on Ubuntu.

I just find that surprising, especially goven a usb hub is a pretty dumb device (yes, mine is powered and will happily run 4 webcams - just so long as none of them are on usb extenders).

Can anyone share their similar experiences or wisdom with ubuntu, usb hubs, extenders and webcams ?
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