[V4L] usb webcam III and v4l on redhat 6.2 (2.2.16)

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Hello,
	I have installed the usb-backport from www.suse.cz and
ov511's driver version 1.25 from alpha.dyndns.org for a USB
creative Webcam III. Besides usb-uhci complaining when I modprobe
it with the webcam connected,
   #modprobe usbcore
   #modprobe usb-uhci
   usb-uhci.c: Detected 2 ports
   usb.c: This device is not recognized by any installed USB
      driver
   #modprobe videodev
   #modprobe ov511

everything works fine. I'd like to have 2 USB ports, but my
laptop has only one, and I don't know what the second
warning/error message means.
 
When I remove modules I get some error messages from usb-uhci
again:
   #rmmod usb-uhci
   kmem_shrink: Invalid cache addr c3fdfaa0
   usb-uhci.c: uhci_desc_kmem remained
   kmem_shrink: Invalid cache addr c3fdfb00
   usb-uhci.c: urb_priv_kmem remained

Now, I need to set v4l capture parameters and make it work for
our projects (Digital Comms Research Lab, National University of
Cordoba, Argentina).

After opening the device (/dev/video):

ioctl (fd, VIDIOCGCAP, &capab) says:
	name: OV511 USB Camera
	it can capture to memory and subcapture.
	max size: 640 x 480
	min size: 32x16
	only one channel
Unfortunately there's no SELECT capability.


ioctl (fd, VIDIOCGCHAN, &chan) says:
	there's channel 0 called Camera
	VIDEO_TYPE is Camera
	norm: 49151	(I don't know what this number means,
			 PAL, NTSC, ...)

ioctl (fd, VIDIOCGPICT, &pict) says:
	depth, colour, palette, etc.


I need to get YUV420 QCIF (176x144 pixels) frames at max frame
rate, aprox 20 fps according to Mark McClelland, so:

pict.palette=VIDEO_PALETTE_YUV420;
ioctl (fd, VIDIOCSPICT, &pict);

Then,

ioctl (fd, VIDIOCGCAPTURE, &capture);
capture.x=0;
capture.y=0;
capture.width=176;
capture.heigth=144;
capture.flags=ODD|EVEN;
capture.decimation=0;	/*I don't know what this is*/
ioctl (fd, VIDIOCSCAPTURE, &capture);

but it would't accept odd and even frames. It only accepts odd
frames. Is this what I have to set to capture 176x144 frames? How
can I get them all, odd and even?

As far as I understood, then I have to mmap the device. Ok? How?
Am I on the rigth path to capture YUV420 QCIF at full speed?

Any comments will be appreciated.

Thank you,
Matias.





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