func: void help(void)
  
  {
  
      printf("dct-test [-i] [<test-number>]\n"
  
             "test-number 0 -> test with random matrixes\n"
  
             "            1 -> test with random sparse matrixes\n"
  
             "            2 -> do 3. test from mpeg4 std\n"
  
             "-i          test IDCT implementations\n"
  
             "-4          test IDCT248 implementations\n");
  
      exit(1);
  
  }
  