A question in DShow.Net

[Ali]

How can I use DIrectshow library for

1. changing the properties of the video
(hue,brightness,contrast,........) or display properties page

2. change the video source because my tvtuner (pixel view) give three
video sources tuner , composie, s-video

3.for the Dxsnapshot example in Dshow.net library at sourcefrog.com it
give error in

COMExeption was unhandled

public Capture(int iDeviceNum, int iWidth, int iHeight, short iBPP,
Control hControl)
{
DsDevice [] capDevices;

// Get the collection of video devices
capDevices =
DsDevice.GetDevicesOfCat(FilterCategory.VideoInputDevice);

if (iDeviceNum + 1 > capDevices.Length)
{
throw new Exception("No video capture devices found
at
that index!");
}

try
{
// Set up the capture graph
SetupGraph( capDevices[iDeviceNum], iWidth, iHeight,
iBPP, hControl);

// tell the callback to ignore new images
m_PictureReady = new ManualResetEvent(false);
}
catch
{
Dispose();
throw;
}
}

and point in throw() how can I solve this problem