QueryInterface returning undocumented result

Im getting an undocumented return code from a call to IUnknown::QueryInterface.

here is the code -

Code:

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    hr = CoCreateInstance(CLSID_FilterGraph , NULL , CLSCTX_ALL , IID_IGraphBuilder , (void**)&pGraphBuilder);

    hr = pGraphBuilder->QueryInterface(IID_IMediaControl , (void**)pMediaControl);
    switch(hr){
        case S_OK:
            break;
        case E_NOINTERFACE:
        case S_FALSE:
            MessageBox(NULL , "Media Control Interface IID_IMediaControl not supported" , "DirectShow Failure" , MB_OK);
            goto cleanup;
        default:
            MessageBox(NULL , "Some Unknown HRESULT returned" , "Unknown Result" , MB_OK);
            goto cleanup;
        }

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Im getting the messagebox about unkown HRESULT returned. I checked the help file, and MSDN, these are the only values that they say can be returned.
P.S. I snipped out the error handler for the call to cocreateinstance, its returning S_OK;

Found the bug,

Code:

---

(void**)pMediaControl

---

needed to be

Code:

---

(void**)&pMediaControl

---

Are you using ATL, cause CComPtrs could help get rid of those gotos. I used to see those dangled around in some code I deal with :D

ATL is just as bloated and worthless as MFC IMO, all those context switches just eat clock cycles. I know alo of programmers find goto's distasteful, and generally I shun them as well, but as long as you remember to avoid inline variable declarations, I dont see any reason to not use them when they can turn an otherwise obfuscated piece of code into something merely kludgey.

Now it seems I cant get the pins to connect (from the log file)-

Connect: Trying to connect output pin 3887c to input pin 3c6ec
Connect: Trying direct connection from output pin 3887c to input pin 3c6ec
Connect: Could not get a media type from pin 3887c, hr=80040209
Connect: Indirect connection from Output pin 3887c to input pin 3c6ec FAILED, hr=0x80040209
Connect: FAILED to connect output pin 3887c to input pin 3c6ec, hr=0x80040209

The output pin is from a logitech USB camera, so im not sure why I cant get a media type from it. The logitech filter was added to the graph builder, so it should allow at least an indirect connection. I know it can be done because amcap manages to make the link.