Re: [Linux-uvc-devel] [SVN] Added preliminary pan/tilt support for Quickcam Orbit MP

[michel X. <mx...@ma...>]

Le Lundi 6 Février 2006 17:23, Laurent Pinchart a écrit :
> Hi everybody,
>
> thanks to Logitech that sent a Quickcam Orbit MP, you can find a
> preliminary pan/tilt support in the latest SVN release. Preliminary means
> that pan/tilt works as expected, but the interface will change in the near
> future as I rewrite the UVC controls handling code.
>
> As this is a brand new feature, you probably won't find any application
> supporting it yet. For those of you who would like to play with pan/tilt,
> here's the API.
>
> Pan/tilt is currently implemented with the following controls (refer to the
> V4L2 API for details regarding how to use VIDIOC_S_CTRL) :
>
> - V4L2_CID_PANTILT_RELATIVE (V4L2_CID_PRIVATE_BASE+7) commands the pan/tilt
> motion. The argument is a 4 bytes array formatted as a 32 bits number.
>
> Offset	Field		Size	Value		Description
> ---------------------------------------------------------------------------
>-- 0	wPanRelative	2	Signed Number	Pan relative rotation
> 2	wTiltRelative	2	SignedNumber	Tilt relative rotation
>
>
> - V4L2_CID_PANTILT_RESET (V4L2_CID_PRIVATE_BASE+8) resets pan/tilt to their
> default value. The argument is a bit field formatted as a 32 bits number.
>
> Offset	Field		Size	Value		Description
> ---------------------------------------------------------------------------
>-- 0	bReset		1	Number		D0: 	0 No action
> 							1 Reset Pan position
> 						D1: 	0 No action
> 							1 Reset Tilt position
> 						D2..D7: Not used (set to 0)
>
> The interface *will* change in a future release, but in the meantime you
> can start implementing a motion-tracking algorithm :-)
>
> Laurent Pinchart
> _______________________________________________
Well another question I use :
int err =0;
    queryctrl->id = control;
    if ((err= ioctl(vd->fd, VIDIOC_QUERYCTRL, queryctrl)) < 0) {
	printf("ioctl querycontrol error %d \n",err);
to verify the control V4L2_CID_PANTILT_RESET  exist
 for some strange reason the ioctl return -EPERM ?
-- 
Michel Xhaard
http://mxhaard.free.fr