DirectShow BindToObject returning invalid handle - c++

Question

EDIT
Just tested playcap.cpp and I'm also getting the same error so I know it's a not a fault with my code.
--
EDIT 2
Edited my code to preserve the goodMoniker pointer. Same error, however.
+if(pMoniker != goodMoniker)
+{
pMoniker->Release();
+}
--
Having a problem with getting my webcam to work with DirectShow. This line:
hr = goodMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)(&pCap));
returns the following error from MSVC++ 2010 EE:
First-chance exception at 0x777ff9d2 in WebcamControlTest.exe: 0xC0000008: An invalid handle was specified.
Full code here (ripped almost completely from MSDN):
#include <DShow.h>
#include <iostream>
int main(void)
{
IGraphBuilder* pGraph = NULL;
ICaptureGraphBuilder2* pBuild = NULL;
HRESULT hr;
//Initialize pGraph
hr = CoInitialize(NULL);
hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void**) &pBuild);
if(FAILED(hr))
{
printf("ERROR - Could not initialize COM library");
return 1;
}
//Initialize pBuild
hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void **) &pGraph);
if(FAILED(hr))
{
printf("ERROR - Could not create the Filter Graph Manager.");
return 2;
}
pBuild->SetFiltergraph(pGraph);
//Initialize pCap
ICreateDevEnum* pDevEnum = NULL;
IEnumMoniker* pEnum = NULL;
hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, reinterpret_cast<void**>(&pDevEnum));
if(SUCCEEDED(hr))
{
hr = pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pEnum, 0);
}
IMoniker* goodMoniker = NULL;
HWND hList;
IMoniker *pMoniker = NULL;
while(pEnum->Next(1, &pMoniker, NULL) == S_OK)
{
IPropertyBag* pPropBag;
hr = pMoniker->BindToStorage(0, 0, IID_IPropertyBag, (void**)(&pPropBag));
if(FAILED(hr))
{
pMoniker->Release();
continue;
}
VARIANT varName;
VariantInit(&varName);
hr = pPropBag->Read(L"Description", &varName, 0);
if(FAILED(hr))
{
hr = pPropBag->Read(L"FriendlyName", &varName, 0);
}
if(SUCCEEDED(hr))
{
for(int i=0;i<8;i++)
{
std::cout<<(char)*(varName.bstrVal + i);
}
char yn;
std::cin>>yn;
if(yn=='Y')
{
std::cout<<"SUCCESSFUL"<<std::endl;
goodMoniker = pMoniker;
VariantClear(&varName);
}
}
pPropBag->Release();
if(pMoniker != goodMoniker)
{
pMoniker->Release();
}
}
IBaseFilter* pCap;
hr = goodMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)(&pCap));
if(SUCCEEDED(hr))
{
hr = pGraph->AddFilter(pCap, L"Capture Filter");
}
hr = pBuild->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, pCap, NULL, NULL);
while(SUCCEEDED(hr));
pGraph->Release();
pBuild->Release();
pCap->Release();
}
It might be a driver problem as there is one device that works (a virtual driver for screencapping and not actual webcam input) but I've updated, uninstalled and reinstalled to no luck. Any ideas?

Answer 1

After saving a pointer in goodMoniker you release the object a couple of lines below (pMoniker->Release() ). Now goodMoniker points to a released object. You should have increased its reference count.