xawtv and v4lctl with usbvision kernel driver

[Sietse Achterop <s.achterop@rug.nl>]

    Dear all,

Context:
 debian/lenny with usb frame grabber:
     Zoran Co. Personal Media Division (Nogatech) Hauppauge WinTV Pro (PAL/SECAM)
 This uses the usbvision driver.

The problem is that while xawtv works OK with color, v4lctl ONLY shows the frames
in black-and-white.

I understood that the usbvision driver needs some attention, e.g. a command like
"v4lctl setinput 2" is not working, it will keep using setting 0.
Because I need 2 (S-video) I patched the driver to always use 2 by setting
channel=2 in "usbvision_muxsel" to permanently select that channel.
With that usbvision module loaded I am getting pictures, but in BLACK_AND_WHITE,
as mentioned.

When starting "xawtv", it works fine!

With a simple opencv application I do an
	CvCapture* capture = cvCaptureFromCAM( cnum );
                 ...
	cam = (CvCaptureCAM_V4L*)capture;
                 ...
        ioctl(cam->deviceHandle,VIDIOC_G_FMT,&format))
                 ...
and find that the format is YV12, but the picture is black-and-white.
But YV12 is a color format.

The question is, how to get proper color pictures when using v4lctl or other
simple applications with this driver.

  Thanks in advance,
    Sietse Achterop