OpenEuphoria

1. AviCap problem

• Posted by Alexander Toresson <alexander.toresson at gmail.com> Apr 20, 2005
• 489 views

I'm trying to translate a piece of C++ code that fetches an image from a web
camera. But for some reason, I can't even create the capturewindow.

Here's the original C++ code:

HWND hWnd=capCreateCaptureWindow(_T("AviCap_FrameGrabber_lite"),
        			WS_CHILD|WS_CLIPSIBLINGS, x, y, 160, 120, 
				pParentWnd?pParentWnd->GetSafeHwnd():NULL, 0xffff);

The msdn for that function can be found here:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/multimed/htm/_win32_capcreatecapturewindow.asp

Here's my code:

include win32lib.ew
include get.e
include machine.e

constant avicap_dll = open_dll("avicap32.dll")

constant xCapCreateCaptureWindow = define_c_func(avicap_dll,
"capCreateCaptureWindowA", {C_POINTER, C_INT, C_INT, C_INT, C_INT, C_INT, C_INT,
C_INT}, C_INT)

function CreateCaptureWindow(sequence title, atom flags, integer x, integer y,
integer width, integer height, atom parent, atom unknown)
atom title_mem, ret
    title_mem = allocate_string(title)
ret = c_func(xCapCreateCaptureWindow, {title_mem, flags, x, y, width,
    height, parent, unknown})
    free(title_mem)
    return ret
end function

constant MainWin = create(Window, "Test", 0, Default, Default, 320, 240, 0)

constant CapWin = CreateCaptureWindow("AviCap_Framegrabber_lite",
or_all({WS_CHILD, WS_CLIPSIBLINGS}), 0, 0, 160, 120, MainWin, 65535)

print(1, CapWin)

WinMain(MainWin, Normal)

For some reason, CreateCapttureWindow() returns NULL.

I wish those windows api errors could be a little more informative...

Regards, Alexander Toresson

3. Re: AviCap problem

• Posted by Alexander Toresson <alexander.toresson at gmail.com> Apr 20, 2005
• 459 views

Greg Haberek wrote:
> 
> > constant CapWin = CreateCaptureWindow("AviCap_Framegrabber_lite", or_al=
> l({WS_CHILD, WS_CLIPSIBLINGS}), 0, 0, 160, 120, MainWin, 65535)
> 
> You're attempting to pass a Win32Lib ID number to a Windows API
> routine. That routine is expecting a Windows handle. Use
> getHandle(MainWin) instead.
> 
> ~Greg
> 
> 

Thank you! It works now.

Regards, Alexander Toresson

5. Re: AviCap problem

• Posted by Alexander Toresson <alexander.toresson at gmail.com> Apr 21, 2005
• 448 views

Dave Probert wrote:
> 
> Alexander, 
> I hope you are successful with the Webcam capture software - are you going to
> release
> it once it's done?

This is going to be a part of a commercial program. But this part of the program
is quite standard, and there's nothing secret in it.

Sorry, all open source freaks.

I'll have to speak with the other guy working on it, but I don't think it will
pose a problem.

> I tried a while ago to write a wrapper for avicap.dll, but I couldn't do it -
> not enough
> skill on my part to work it out!!
> 

Actually, it's avicap32.dll. And I have a piece of code in C++ (yuck) which I'm
translating from. As far as I've seen, there won't be any problem writing it in
Euphoria.

Regards, Alexander Toresson