Gilles, Please have a look at guvcview code: http://guvcview.berlios.de There is an implementation in a GTK GUI of these controls.
Best regards Paulo 2009/2/8 Gilles GIGAN <[email protected]>: > Hi, > I have checked out the latest v4l code from the mercurial repository on > linuxtv.org, and successfully compiled and loaded the uvcvideo module, which > I tested with a logitech quickcam sphere af (046d:0994). I have comments and > questions regarding the V4L2 controls to pilot the pan and tilt motors: > After mapping the dynamic controls (with uvcdynctrl), the following controls > become available: > - Pan Reset: min: 0, max: 1, step: 1, type: integer > - Tilt Reset: min 0, max: 1, step: 0, type: integer (note the step value of > 0 which should really be 1 here) > - Pan (Relative): min: 4480, max: 4480, step: 1, type: integer > - Tilt (Relative): min: 1920, max: 1920, step: 1, type: integer > - Pan/tilt Reset: min: 0, max: 3, step: 1, type: integer > Creating a user interface based on these controls is quite hard because of > their types and step values: > Trying to set a value of 0 on any of the Reset controls fails, even though 0 > is reported as an acceptable value. > Setting a value of 1 on either Pan (Relative) or Tilt (Relative) succeeds > but results in no movement. > Keeping the GUI up-to-date is not possible because calling > ioctl(VIDIOC_G_CTRL) on any of these controls fails (which makes sense when > you know what the controls are). But from a programming point of view, if > you try to create an interface that will work with any controls, the way > these are reported (integers) makes it almost impossible to keep track of. > I have a couple of suggestions to improve this, and would appreciate > comments on them: > - Reporting the Pan/Tilt Reset control as a menu and Pan Reset and Tilt > Reset as buttons instead of integers, will solve the previously mentioned > issues. > - Change the Pan (Relative) and Tilt (relative) step value to one that > actually results in a slight movement of the camera. > Is there a way to make these changes when mapping the controls, or do they > have to be coded in the driver itself ? > Thanks > Gilles > > > _______________________________________________ > Linux-uvc-devel mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/linux-uvc-devel > > _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
