CoCreateInstance Fails using LeadTools MultiMedia Com Interface

[cdigeek]

Using LeadTools v.13 with VC++ 6.0 sp6 on XP Pro sp1, I am getting E_NOINTERFACE (0x80004002) When I try to create the multimedia capture interface as follows:

hr = CoCreateInstance(CLSID_ltmmCapture, NULL, CLSCTX_INPROC_SERVER, IID_IltmmCapture, (void**) &m_capture);

It used to work. Now it fails in both the debug and release builds. Other third-party COM objects work fine.

I downloaded the latest patches to get the most recent ltmm.h, ltmmuuid.lib and ltmm_n.dll (13.0.0.7). I unregistered the old dll (regsvr32 /u ltmm_n.dll), copied the new dll to \windows\system32 and then registered it (regsvr32 ltmm_n.dll). I searched the entire hard drive to make sure there is only one copy of ltmm.h, ltmmuuid.lib, and ltmm_n.dll. Also, ltmm.lic is in \windows\system32.

The raster imaging dll's work fine, but when it comes time to use the multimedia capture interface it fails.

Any help will be greatly appreciated.

 

[IonelBurtan]

as far as I know. you ask for IID_IUnknown first in the call to CoCreateInstance.

....
IUnknown* pUnknown = NULL;

hr = CoCreateInstance(CLSID_ltmmCapture, NULL, CLSCTX_INPROC_SERVER, IID_IUnknown, (void**) &pUnknown);

hr = pUnknown->QueryInterface(IID_xxxxxx, (void**)&m_capture);

pUnknown->Release();
....

s-)

Blessed is he who in the name of justice and goodwill, sheperds the weak through the valley of darkness...

http://www20.brinkster.com/ionelb

 

[cdigeek]

You are right. I thought so, too. But the leadtools example shows it using IID_IltmmCapture, which is defined in one of their headers, instead of IID_IUnknown. The strange thing is that it was working.

I posted the same problem in LeadTools moderated Mutlimedia forum but after a week there was no reply. I am hoping I can get a conversation going here with suggestions. Leadtools has a great imaging libaray but the support stinks.