with imgPreview.IO.MediaFoundationSourceReader do
begin
  if VideoInputs.Count > 0 then
  begin
    SetSelectedStreams(mmf_VIDEO_STREAM, true);
    SelectMediaType(mmf_VIDEO_STREAM, cbModes.ItemIndex);

    // auto-rotation (win8 only!)
    if goIsWindows8OrHigher then
    begin
      VideoProcessor.SetMirror(mfpmNone);
      VideoProcessor.SetRotation(mfprNormal);
    end;

    //  ...

    // start capturing
    StartCapturing;

    // ....
  end;  
end;