public EffectHost(Size outputSize, IRenderService renderService)
 {
     _outputSize = outputSize;
     renderService.Init(outputSize);
     _renderService        = renderService;
     _renderTransformBlock = new TransformBlock <OutputFrame, ArraySegment <byte> >(Render, new ExecutionDataflowBlockOptions {
         BoundedCapacity = 20, MaxDegreeOfParallelism = 16
     });
 }