public override void RenderContextChanged(AVVideoCompositionRenderContext newRenderContext)
 {
     renderContextQueue.DispatchSync(() => {
         renderContext          = newRenderContext;
         renderContextDidChange = true;
     });
 }
		public override void RenderContextChanged (AVVideoCompositionRenderContext newRenderContext)
		{
			renderContextQueue.DispatchSync (() => {
				renderContext = newRenderContext;
				renderContextDidChange = true;
			});
		}