title: VMR9 Allocator and SwapEffect.Discard
body: <p>I'm developing an application using a VMR9 Allocator. </p>
  
  <p>The allocator allow me to draw the directshow filter graph output to a texture. 
  I noticed that if I don't use the <em>SwapEffect.Copy</em> in exclusive mode my video rate is bellow 25 (the nominal rate). </p>
  
  <p>I need to use <em>SwapEffect.Discard</em> in order to activate multisampling. </p>
  
  <p>Is there any workaround to use vmr9 allocator with <em>SwapEffect.Discard</em>?</p>