title: Call to NotifyAllocator fails when connection filter to InPlaceTransformFilter
body: <p>I get a : Access violation reading location 0xFFFFFFFFFFFFFFFF. in <code>DecideAllocator</code> method of my custom mux filter when trying to connect the filter to another custom written TransInPlaceFilter.</p>
  
  <p>The filters:</p>
  
  <p><img src="https://i.stack.imgur.com/py7Fq.png" alt="filters"></p>
  
  <p>The first filter is derived from CBaseFilter. The second from CTransInPlaceFiler.</p>
  
  <p>Connecting the mux filter to a avi mux filter works fine. The error could be in the transformer filter. However I am not sure where, because CTransInPlace filters do not use custom written pins but predefined pins. </p>
  
  <p>The DecideAllocator function:</p>
  
  <pre><code>HRESULT MCMyOutputPin::DecideAllocator(IMemInputPin *pPin, IMemAllocator **ppAlloc)
  {
      ALLOCATOR_PROPERTIES *pprops = new ALLOCATOR_PROPERTIES;
      HRESULT hr = pPin-&gt;GetAllocatorRequirements(pprops);
      if (FAILED(hr))
          return hr;
  
          hr = InitAllocator(ppAlloc);
          if (FAILED(hr))
              return hr;
  
      hr = DecideBufferSize(*ppAlloc, pprops);
      if (FAILED(hr))
          return hr;
  
  -    hr = pPin-&gt;NotifyAllocator(*ppAlloc, TRUE); //error happens here
  
      if (FAILED(hr))
      {
          return hr;
      }
  
      *ppAlloc = m_pAllocator;
      //m_pAllocator = *ppAlloc;
  
      m_pAllocator-&gt;Commit();
      m_pAllocator-&gt;AddRef();
      return hr;
  
  }
  </code></pre>
  
  <p>The stack trace</p>
  
  <pre><code>qasf.dll!000007f8c5e5ec90() Unknown
  qasf.dll!000007f8c5e611c9() Unknown
  myfilter64.ax!MCMyOutputPin::DecideAllocator(IMemInputPin * pPin, IMemAllocator * * ppAlloc) Line 193   C++
  myfilter64.ax!MCMyOutputPin::CompleteConnect(IPin * pReceivePin) Line 58    C++
  myfilter64.ax!CBasePin::AttemptConnection(IPin * pReceivePin, const CMediaType * pmt) Line 1799 C++
  myfilter64.ax!CBasePin::TryMediaTypes(IPin * pReceivePin, const CMediaType * pmt, IEnumMediaTypes * pEnum) Line 1890    C++
  myfilter64.ax!CBasePin::AgreeMediaType(IPin * pReceivePin, const CMediaType * pmt) Line 1956    C++
  myfilter64.ax!CBasePin::Connect(IPin * pReceivePin, const _AMMediaType * pmt) Line 1728 C++
  [External Code] 
  GraphStudioNext64.exe!000007f63a90206e()    Unknown
  GraphStudioNext64.exe!000007f63a899ee1()    Unknown
  GraphStudioNext64.exe!000007f63a8a519d()    Unknown
  GraphStudioNext64.exe!000007f63a6543c2()    Unknown
  GraphStudioNext64.exe!000007f63a656084()    Unknown
  GraphStudioNext64.exe!000007f63a65011b()    Unknown
  GraphStudioNext64.exe!000007f63a650c04()    Unknown
  [External Code] 
  GraphStudioNext64.exe!000007f63a667ad6()    Unknown
  GraphStudioNext64.exe!000007f63a66811e()    Unknown
  GraphStudioNext64.exe!000007f63a803eed()    Unknown
  GraphStudioNext64.exe!000007f63a7e4c6c()    Unknown
  [External Code] 
  </code></pre>