On Sun, Nov 9, 2008 at 11:28 PM, Laurent Pinchart <
[EMAIL PROTECTED]> wrote:

> Hi Michael,
>
> On Thursday 06 November 2008, Michael wrote:
> > Hey
> >
> > I'm trying to use video4linux2 to control a Logitech QuickCam Pro 9000.
> The
> > camera supports UVC and I can get the image just fine. However, I'm
> having
> > issues with the controls.
> >
> > Luvcview reports the following controls:
> >
> > V4L2_CID_BASE         (predefined controls):
> >  index:9963776    name:Brightness                       type:1 min:0
> > max:255   step:1     def:128   now:128
> >  index:9963777    name:Contrast                         type:1 min:0
> > max:255   step:1     def:32    now:32
> >  index:9963778    name:Saturation                       type:1 min:0
> > max:255   step:1     def:32    now:32
> >  index:9963788    name:White Balance Temperature, Auto  type:2 min:0
> > max:1     step:1     def:1     now:1
> >  index:9963795    name:Gain                             type:1 min:0
> > max:255   step:1     def:0     now:0
> >
> >
> > There are no driver specific controls. The problem is that there are some
> > missing. There should also be Auto Exposure on/off, manual exposure,
> > autofocus on/off and manual focus.
> >
> > The strange thing is that luvcview will let me turn off auto exposure
> > (strangely by pressing the on button), and will also let me set the
> > exposure manually.
> >
> > I would like to know if there is a way to access these controls using
> > video4linux?
>
> Yes there is. luvcview uses an old control enumeration method that results
> in
> controls being missed. It should instead use the V4L2_CTRL_FLAG_NEXT_CTRL
> flag as explained in the V4L2 specification.
>
> Regardless of enumeration issues, controls can be accessed through
> VIDIOC_G_CTRL and VIDIOC_S_CTRL.
>
> Best regards,
>
> Laurent Pinchart


Hi Laurent

Thanks for that. After looking through the code, I am enumerating the
controls in the same way luvcview does. I was just following a code example
from the V4L2 api documentation (perhaps I was looking at an old version of
the docs).

Anyway I'll have a look at the V4L2_CTRL_FLAG_NEXT_CTRL tomorrow.

Cheers
Michael
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