ZoneMinder Forums

Phil: Kudos on an excellent piece of software.

The old Logitech QuickCam Express cameras work pretty well under Linux (Fedora Core 3, Kernel 2.6.9 - 2.6.11 tested) with the usb driver from http://qce-ga.sourceforge.net. Since there are many versions of this camera on the market, I should mention that I'm talking about the white 'eyeball' shaped camera with the grey focus ring and the triangular base. I have close to two dozen of these cameras working with multiple ZM installations, and they get the job done pretty well.

Thanks for the information. Do you ever use more than one camera per USB bus? If so do you need to supply options to the driver to manage bandwidth or does it do it automagically (unlike the cpia and ov511 ones)?

Phil

zoneminder wrote:Do you ever use more than one camera per USB bus?

I started out with that, actually - trying to use two cameras on a single bus. And where with one camera I was able to get 13fps, with two the framerates dropped to between 5-6fps.

zoneminder wrote:If so do you need to supply options to the driver to manage bandwidth or does it do it automagically (unlike the cpia and ov511 ones)?

So the answer seems to be that this is done automagically- or to be precise, it is done whether you want it to happen or not. If you want the bus bandwidth to be shared asymmetrically, that'd require the passing of options.

To be honest, I didn't like the performance of the cameras in this mode. I was kind of comparing apples to oranges (I'd become used to my Axis cameras ), but still, it seemed to make the image... kinda choppy. Giving them each their own bus made the issue disappear, and thats the way I have them setup now.

And to anyone following this thread and trying to set this camera up, note that the 2.6.11 kernel requires the > 0.6.3 release of the qc-usb driver. 2.6.9 and 2.6.10 worked fine with 0.6.2, but 2.6.11 did not and I had to go to the CVS tree until they released 0.6.3.

zoneminder wrote:Do you ever use more than one camera per USB bus?

I did some more tests on this: it turns out that the cameras were all on separate USB bus'es.
So I forced two cameras onto a single USB bus (verified this with 'cat /proc/video/quickcam/videoX') and I noticed some interesting behavior. Now keep in mind that all the cams are identical units- when cams 1 and 2 are used together on a single bus, I see no noticeable difference. But when cams 2 and 4 are put through the same process, they start to step all over each other - images are overwritten in one case.

A little googling' of the problem led me to this link:
http://cvs.freax.be/cgi-bin/viewcvs.cgi ... AQ?rev=1.2
And the specific quote:
A single USB 2.0 bus may or may not work with multiple cameras. It appears to depend on the vendor.

Just as an FYI, I'm using a 4-port USB Controller: Agere Systems (former Lucent Microelectronics) USS-344S USB Controller (rev 11). This uses the OHCI kernel module. I've seen some reports of problems with OHCI on the quickcam express devel lists.

With multiple Logitech QuickCams then, it seems that the best bet is to go with a multi-port PCI USB card, which uses the UHCI module - and to give each camera its' own port - which translates into 'its' own bus', to get the best results possible.

Hi,

I have one of those cameras (Logitech Quickcam Express), most of the time I view the camera it seems corrupted (see image).



This doesn't happen all of the time, but it does most times I view the cam.

Have you come across this before and do you know how to fix it?

Thank you in advance.

What did you pick for mode and resolution? Try switching between PAL and NTSC and various resolutions.

how do you switch modes and resolutions?