From 6bcf419d2e8f739b432d4790d1ba9d48ab65365b Mon Sep 17 00:00:00 2001
From: fcolin
Date: Fri, 18 Nov 2011 12:14:12 +0000
Subject: 

---
 ARMFCaptureD3D/BufferLock.h | 125 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 125 insertions(+)
 create mode 100644 ARMFCaptureD3D/BufferLock.h

(limited to 'ARMFCaptureD3D/BufferLock.h')

diff --git a/ARMFCaptureD3D/BufferLock.h b/ARMFCaptureD3D/BufferLock.h
new file mode 100644
index 0000000..d566d5b
--- /dev/null
+++ b/ARMFCaptureD3D/BufferLock.h
@@ -0,0 +1,125 @@
+//////////////////////////////////////////////////////////////////////////
+//
+// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
+// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
+// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
+// PARTICULAR PURPOSE.
+//
+// Copyright (c) Microsoft Corporation. All rights reserved.
+//
+//////////////////////////////////////////////////////////////////////////
+
+
+
+#pragma once
+
+
+//-------------------------------------------------------------------
+//  VideoBufferLock class
+//
+//  Locks a video buffer that might or might not support IMF2DBuffer.
+//
+//-------------------------------------------------------------------
+
+class VideoBufferLock
+{
+public:
+    VideoBufferLock(IMFMediaBuffer *pBuffer) : m_p2DBuffer(NULL), m_bLocked(FALSE)
+    {
+        m_pBuffer = pBuffer;
+        m_pBuffer->AddRef();
+
+        // Query for the 2-D buffer interface. OK if this fails.
+        (void)m_pBuffer->QueryInterface(IID_PPV_ARGS(&m_p2DBuffer));
+    }
+
+    ~VideoBufferLock()
+    {
+        UnlockBuffer();
+        SafeRelease(&m_pBuffer);
+        SafeRelease(&m_p2DBuffer);
+    }
+
+    //-------------------------------------------------------------------
+    // LockBuffer
+    //
+    // Locks the buffer. Returns a pointer to scan line 0 and returns the stride.
+    //
+    // The caller must provide the default stride as an input parameter, in case
+    // the buffer does not expose IMF2DBuffer. You can calculate the default stride
+    // from the media type.
+    //-------------------------------------------------------------------
+
+    HRESULT LockBuffer(
+        LONG  lDefaultStride,    // Minimum stride (with no padding).
+        DWORD dwHeightInPixels,  // Height of the image, in pixels.
+        BYTE  **ppbScanLine0,    // Receives a pointer to the start of scan line 0.
+        LONG  *plStride          // Receives the actual stride.
+        )
+    {
+        HRESULT hr = S_OK;
+		DWORD cbMaxLength;
+		DWORD cbCurrentLength;
+
+        // Use the 2-D version if available.
+        if (m_p2DBuffer)
+        {
+            hr = m_p2DBuffer->Lock2D(ppbScanLine0, plStride);
+        }
+        else
+        {
+            // Use non-2D version.
+            BYTE *pData = NULL;
+
+            hr = m_pBuffer->Lock(&pData, &cbMaxLength, &cbCurrentLength);
+			if (SUCCEEDED(hr))
+            {
+                *plStride = lDefaultStride;
+                if (lDefaultStride < 0)
+                {
+                    // Bottom-up orientation. Return a pointer to the start of the
+                    // last row *in memory* which is the top row of the image.
+                    *ppbScanLine0 = pData + abs(lDefaultStride) * (dwHeightInPixels - 1);
+                }
+                else
+                {
+                    // Top-down orientation. Return a pointer to the start of the
+                    // buffer.
+                    *ppbScanLine0 = pData;
+                }
+            }
+        }
+
+        m_bLocked = (SUCCEEDED(hr));
+
+        return hr;
+    }
+
+    //-------------------------------------------------------------------
+    // UnlockBuffer
+    //
+    // Unlocks the buffer. Called automatically by the destructor.
+    //-------------------------------------------------------------------
+
+    void UnlockBuffer()
+    {
+        if (m_bLocked)
+        {
+            if (m_p2DBuffer)
+            {
+                (void)m_p2DBuffer->Unlock2D();
+            }
+            else
+            {
+                (void)m_pBuffer->Unlock();
+            }
+            m_bLocked = FALSE;
+        }
+    }
+
+private:
+    IMFMediaBuffer  *m_pBuffer;
+    IMF2DBuffer     *m_p2DBuffer;
+
+    BOOL            m_bLocked;
+};
-- 
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