[ros-users] uvc_camera not publishing width and height on /camera_info topic

[Patrick Goebel]

Hi Eric,

On 12/19/2010 02:17 PM, Eric Perko wrote:

> Were there any errors in the terminal you started guvcview from when
> changing to auto or shutter priority? They definitely shouldn't work the
> same as manual mode. If I recall correctly, when guvcview fails to set a
> control to a certain value, the webcam keeps the previous setting. You
> may have just been still in manual mode if there were errors setting the
> control.

You are exactly right. I watched the terminal this time while changing 
exposure modes in guvcview and it turns out that only modes 1 and 3 
(Manual and Aperture Priority) are valid for the Logitech QuickCam 9000.

> I've not debugged it, but often on the first launch, it will throw
> errors about failing to set most all of the controls. If I then close
> and relaunch, it should only fail to set one of them... "gamma"
> perhaps... since the Webcam 9000 I use doesn't support that control.

Yeah, I was able to confirm that too.

>     [ WARN] [1292778385.643706002]: Reconfigure callback failed with
>     exception couldn't set format:

> Hrm... that's odd... I don't usually see that as long as the default
> format is correct (it should default to MODE_RGB). I'll have to look
> into this one as well.

This might be a problem only with my Logitech camera as I am not having 
the same issue with a Philips SPC 1300NC.

> It is intentional right now, as I don't have any idea what the valid
> ranges for the different controls actually are. They also seem to vary
> from camera model to camera model when I load things up in guvcview. The
> best case would be some sort of way for a node using a dynamic
> reconfigure to set whether a control is supported and it's ranges
> dynamically at runtime.

Understood.

> Again, thanks for the report. This will definitely be useful info to
> keep in mind while working towards "the one, true USB camera ROS driver" :)

It was great to see that effort launched yesterday.  In the meantime, I 
am functioning fine now so thanks for all your help.

--patrick