On Mon, Nov 10, 2008 at 12:14 AM, Michael <[EMAIL PROTECTED]>wrote:

> 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


Hi

I've modified how my code enumerates the controls for the camera.
Auto/manual exposure controls are now appearing, but manual focus is not. A
quick Google only finds mailing list posts from about a year ago dealing
with focus issues:


> - If I want to change the focus manually, than I have to do it by my own
> in a userspace program, as mentioned in some previous posts.

Right.

> Is the a code snippet available?

Not yet but soon :-) A userspace tool to handle vendor-specific controls is on
the way. It will be announced on the mailing list.

Best regards,

Laurent Pinchart


I would like to know if this is still the case? Am I able to set the
focus of the camera using Video4Linux2?

Thanks
Michael
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