webcam, Video Source dialog comes up - windows

Question

So have seen a ton of people with the same issue's but no answers. My SendMessage pop's up the "Video Source" dialog box on a windows 7 laptop with one camera. I have Cyber Link YouCam installed.
If I uninstall Cyber Link YouCam the "Video Source" dialog goes away. It appears to be the OS is acting as though YouCam is a second driver for the same device. My question is how do I stop the dialog box for "Video Source" from appearing? Once I choose an option in the dialog I don't get the dialog box (until I restart the application) so there must be a setting somewhere being set.
Though debugging found this bit of code (see whole section below) is the one that seems to be the one that calls the dialog box - SendMessage (deviceHandle, WM_CAP_CONNECT, deviceno, ((IntPtr) 0).ToInt32 ())
public void StartWebCam (int height, int width, int handleofthepicturebox, int deviceno)
{
string deviceIndex = "" + deviceno;
deviceHandle = capCreateCaptureWindowA (ref deviceIndex, WS_VISIBLE | WS_CHILD, 0, 0, width, height, handleofthepicturebox, 0);
if (SendMessage (deviceHandle, WM_CAP_CONNECT, deviceno, ((IntPtr) 0).ToInt32 ()) > 0)
{
SendMessage (deviceHandle, WM_CAP_SET_SCALE, -1, 0);
SendMessage (deviceHandle, WM_CAP_SET_PREVIEWRATE, 0x42, 0);
SendMessage (deviceHandle, WM_CAP_SET_PREVIEW, -1, 0);
}
else
{
// nothing failed maybe some clean up needed
}
}
So again the question is - how do I stop the dialog box for "Video Source" from appearing?

Answer 1

I developed a form to display two live captures with avicap32 on Windows XP. There is a chance the fix I found in my case also applies to yours.
In the case of avicap, it is possible to programmatically manage your webcams, and all that is registry-based. Here is the thread I found to guide me and achieve what I wanted.
In this thread, the role of the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources\msvideo\MSVideo.VFWWDM\DevicePath registry key is highlighted for the selection of the active webcam.
And here is maybe a helpful piece of info: I had to set the value in lowercase to avoid the Video Source dialog popping up.
I determined it by monitoring the registry key before and after the call to SendMessage with WM_CAP_CONNECT.
To the best of my knowledge (and googling), nobody else has offered a fix, so even though I might be answering a little late, it would be great if you could tell us whether it worked for you as well.

Answer 2

Finally I Found a solution for this.
The problem happens in Windows 7 / 8
First you need this API function
Private Declare Function GetTickCount Lib "kernel32" () As Long
Then... after you call capCreateCaptureWindowA() you have to wait 1 second processing events, (note: sleep don't work the same)
IniTime = GetTickCount()
While GetTickCount() < (IniTime + 1000)
DoEvents
Wend
then you call WM_CAP_DRIVER_CONNECT (maybe a couple of times).. and THAT's IT ... no more video source dialog

Answer 3

With this solution it works perfect. The GetTickCount() waiting for events worked along with calling the function until it returned true.
Private Sub PreviewVideo(ByVal pbCtrl As PictureBox)
hWnd = capCreateCaptureWindowA(VideoSource, WS_VISIBLE Or WS_CHILD, 0, 0, 0,
0, pbCtrl.Handle.ToInt64, 0)
Dim IniTime As Long = GetTickCount()
While GetTickCount() < (IniTime + 1000)
Application.DoEvents()
End While
Dim OKAnswer As Boolean = False
For xretries As Integer = 1 To 10
' I'll give you Only 10 tries to connect, otherwise I AM LEAVING MICROSOFT!
OKAnswer = SendMessage(hWnd, WM_CAP_DRIVER_CONNECT, VideoSource, 0)
If OKAnswer Then
Exit For
End If
Next
If okanswer Then
SendMessage(hWnd, WM_CAP_SET_SCALE, True, 0)
SendMessage(hWnd, WM_CAP_SET_PREVIEWRATE, 30, 0)
SendMessage(hWnd, WM_CAP_SET_PREVIEW, True, 0)
SetWindowPos(hWnd, HWND_BOTTOM, 0, 0, pbCtrl.Width, pbCtrl.Height, SWP_NOMOVE Or SWP_NOZORDER)
Else
DestroyWindow(hWnd)
End If
End Sub

Answer 4

I had the same issue. Make sure you call capDriverDisconnect once you no longer need the webcam. Note that I'm using Logitech C110, but I suppose it should work in your case too.

Answer 5

Came over here searching for a solution for the "WM_CAP_DRIVER_CONNECT" and "Video Setup" dialog popup Error.
FOUND the solution:
It's a driver problem. Use the OEM's driver, because the Generic Microsoft Drivers are NOT working for your camera.
Use www.astra32.com to find out the USB camera's device info: Manufacturer or Model; then google for the correct drivers.
Good Luck!