ioctl(int device, v4l2_operation request, ref v4l2_queryctrl argp);
public DeviceControl QueryControl(Control ctrl) {
v4l2_queryctrl query = new v4l2_queryctrl();
query.id = (uint)ctrl;
int ret = ioControl.QueryControl(ref query);
if(ret < 0) { throw new Exception("VIDIOC_QUERYCTRL: " + ret.ToString()); }
DeviceControl control = new DeviceControl() {
Id = ctrl,
Name = query.name,
Min = query.minimum,
Max = query.maximum,
Step = query.step,
Default = query.default_value,
Type = query.type,
Flags = query.flags,
};
control.Value = GetControlValue(ctrl);
if(control.Type == v4l2_ctrl_type.Menu || control.Type == v4l2_ctrl_type.IntegerMenu) {
v4l2_querymenu qmenu = new v4l2_querymenu();
qmenu.id = (uint)ctrl;
control.MenuItems = new List<Tuple<int, string>>();
for(int i = control.Min; i <= control.Max; i++) {
qmenu.index = (uint)i;
//Console.WriteLine("qmenu.index={0}", qmenu.index);
if(ioControl.QueryMenu(ref qmenu) != 0) { continue; }
//Console.WriteLine("MenuItem: {0}", qmenu.name);
control.MenuItems.Add(new Tuple<int, string>(i, qmenu.name));
}
}
return control;
}
/// <summary>
/// Calls VIDIOC_QUERYCTRL
/// </summary>
public int QueryControl(ref v4l2_queryctrl control)
{
return ioctl(deviceHandle, v4l2_operation.QueryControl, ref control);
}