title: Concatenation video streams UWP
body: <p>I'm developing UWP(C#) app for some custom device that has following functional:</p>
  <ol>
  <li>Device has 3 camera's that directed at some object in different angles.</li>
  <li>UWP can use IBasicVideoEffect interface to apply video effects by DirectX API.</li>
  <li>Streams from device must be concated in 1 image</li>
  <li>Concatenation use simple GPU operations like rotation, cropping, scaling, affine transform etc. No hard logic like OpenCV::hconcat.</li>
  </ol>
  <p>As I know, video effects by GPU can be applied by</p>
  <pre><code>var effect = await mediaCapture.AddVideoEffectAsync(
      _effectDefinition, 
      MediaStreamType.VideoPreview
  );
  effect.SetProperties(...);
  captureElement.Source = mediaCapture;
  await mediaCapture.StartPreviewAsync();
  </code></pre>
  <p>But each of 3 <code>mediaCaptures</code> will be previewed in 3 different <code>captureElement</code>'s.</p>
  <p>I have to find a way to place 3 <code>MediaCapture</code>'s on 1 <code>CaptureElement</code> or <code>CanvasControl</code> or etc.</p>
  <p>P.S. <code>MediaFrameReader</code> cant be used in my case because of bad performance. <code>IBasicVideEffect</code> works more faster.</p>
  <p>Any ideas?</p>