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diff --git a/AVStream/avscamera/mft0/SampleHelpers.h b/AVStream/avscamera/mft0/SampleHelpers.h
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+/**************************************************************************
+
+    A/V Stream Camera Sample
+
+    Copyright (c) 2013, Microsoft Corporation.
+
+    File:
+
+        SampleHelpers.h
+
+    Abstract:
+
+        Helper classes for the MFT0.
+
+    History:
+
+        created 4/26/2013
+
+**************************************************************************/
+
+#pragma once
+
+/***************************************************************************\
+*****************************************************************************
+*
+* class CAutoLock
+*
+* Locks a critical section at construction time and unlocks it automatically
+* when the object goes out of scope
+*
+*****************************************************************************
+\***************************************************************************/
+
+class CAutoLock
+{
+private:
+    // Make copy constructor and assignment operator inaccessible
+    CAutoLock(const CAutoLock &refAutoLock);
+    CAutoLock &operator=(const CAutoLock &refAutoLock);
+
+    // CAutoLock should not be created on the heap, so declare
+    // (but do not implement) private operator new/delete.
+    static void *operator new(size_t);
+    static void  operator delete(void *);
+    static void *operator new[](size_t);
+    static void  operator delete[](void *);
+
+protected:
+    CRITICAL_SECTION *m_pLock;
+
+public:
+    _Acquires_lock_(m_pLock)
+    explicit CAutoLock(CRITICAL_SECTION *pLock):
+        m_pLock(pLock)
+    {
+        EnterCriticalSection(m_pLock);
+    }
+
+    _Releases_lock_(m_pLock)
+    ~CAutoLock()
+    {
+        LeaveCriticalSection(m_pLock);
+    }
+};
+
+class MediaBufferLock
+{
+public:
+    MediaBufferLock(_In_ IMFMediaBuffer *pBuffer):
+        m_bLocked(false)
+    {
+        m_spBuffer = pBuffer;
+    }
+
+    HRESULT LockBuffer(
+        _Outptr_result_bytebuffer_to_(*pcbMaxLength, *pcbCurrentLength)  BYTE **ppbBuffer,
+        _Out_opt_  DWORD *pcbMaxLength,
+        _Out_opt_  DWORD *pcbCurrentLength)
+    {
+        if(!m_spBuffer)
+        {
+            return E_INVALIDARG;
+        }
+
+        HRESULT hr = m_spBuffer->Lock(ppbBuffer, pcbMaxLength, pcbCurrentLength);
+        if(FAILED(hr))
+        {
+            return hr;
+        }
+        m_bLocked = true;
+        return S_OK;
+    }
+
+    ~MediaBufferLock()
+    {
+        if(m_spBuffer && m_bLocked)
+        {
+            //Unlock fails only if we did not lock it first
+            (void) m_spBuffer->Unlock();
+        }
+    }
+
+private:
+    ComPtr<IMFMediaBuffer> m_spBuffer;
+    bool m_bLocked;
+};