message: samples: check for valid input in gpu/super_resolution.cpp
diff: @@ -55,7 +55,7 @@ static Ptr<cv::superres::DenseOpticalFlowExt> createOptFlow(const string& name,
  int main(int argc, const char* argv[])
  {
  CommandLineParser cmd(argc, argv,
  - "{ v video | | Input video }"
  + "{ v video | | Input video (mandatory)}"
  "{ o output | | Output video }"
  "{ s scale | 4 | Scale factor }"
  "{ i iterations | 180 | Iteration count }"
  @@ -65,14 +65,14 @@ int main(int argc, const char* argv[])
  "{ h help | false | Print help message }"
  );
  - if (cmd.get<bool>("help"))
  + const string inputVideoName = cmd.get<string>("video");
  + if (cmd.get<bool>("help") || inputVideoName.empty())
  {
  cout << "This sample demonstrates Super Resolution algorithms for video sequence" << endl;
  cmd.printMessage();
  return EXIT_SUCCESS;
  }
  - const string inputVideoName = cmd.get<string>("video");
  const string outputVideoName = cmd.get<string>("output");
  const int scale = cmd.get<int>("scale");
  const int iterations = cmd.get<int>("iterations");
  