use correct size with media node

app/render/renderinstance.h

@@ -41,6 +41,7 @@ class RenderInstance : public QObject
 public:
   RenderInstance(const int& width,
                  const int& height,
+                 const int& divider,
                  const olive::PixelFormat& format,
                  const olive::RenderMode& mode);
 
@@ -60,6 +61,8 @@ public:
 
   const int& height() const;
 
+  const int& divider() const;
+
   const olive::PixelFormat& format() const;
 
   const olive::RenderMode& mode() const;