Revert "Video backend"

This reverts commit 4ffbb97abf.

apps/LoopThroughWithOpenGLCompositing/gl/OpenGLComposite.h

@@ -39,7 +39,8 @@ public:
 	OpenGLComposite(HWND hWnd, HDC hDC, HGLRC hRC);
 	~OpenGLComposite();
 
-	bool InitializeVideoIO();
+	bool InitDeckLink();
+	bool InitVideoIO();
 	bool Start();
 	bool Stop();
 	bool ReloadShader();