It would seem that the Logitech (C500 etc) two camera issue is to do
with excess bandwidth device allocation of the USB bus. ie its not a
motion problem as such. I'd just like to mention what I have been
doing and would welcome any feedback from those who have been
In my experiments a week plus ago I had two cameras working on two
USB buses (ie an extra PCI USB2 card in addition to the MB one) I
had the uvcvideo quirks=128 enabled and was happily running YUYV
1280x1024. Was working well.. There is no way I could run it on one
Until I updated the kernel.. to 18.104.22.168 (SuSE 11.2). Yes that
kernel is a little old.. (Sorry I cant remember the prior version.)
One of the cameras (on the MB port) would now continually
disconnect/reconnect and shift to USB1.1 mode, regardless of motion
running. I'd actually suspect hardware and am looking for another
USB2 PCI card. I did however need to get it going so I removed the
quirks and switched both cameras to MJPEG palette. Still had
problems with disconnect/connects and most of my hair fell out!
You wont believe it but changing the PCI USB card to YUYV and
leaving the one on the MB port at 800x600 USB1.1 works without
fault! Yes real weird! I wonder if two camera MJPEG mode has some
kind of issue.?
(quirks = 128 makes the MJPEG palette non working)
I am sure I'll eventually crack this. The next step is some more
USB2 PCI cards. I also need to look more into running two cameras in
MJPEG mode on the once bus. Don't know how to do that just yet. I
wonder if something with the same USB device ID gets things into
trouble. I think a latest kernel will be a step in there somewhere.
And here is a question. I am also running a PAL-DK camera into a
BT878 card. v4l-info says that the max image size is 924X576, which
is not 4:3. Its kind of a half widescreen thing. (924 becoming 912
with modulo 16) Is changing the 912 to 768 the right way to do this?
I mean it fixes the aspect ratio but I worry about any loss of
Cheers Bob (Australia)