func: void show_help(void)
  
  {
  
      const char *prog;
  
      const OptionDef *po;
  
      int i, expert;
  
      
  
      prog = do_play ? "ffplay" : "ffmpeg";
  
  
  
      printf("%s version " FFMPEG_VERSION ", Copyright (c) 2000, 2001, 2002 Gerard Lantau\n", 
  
             prog);
  
      
  
      if (!do_play) {
  
          printf("usage: ffmpeg [[options] -i input_file]... {[options] outfile}...\n"
  
                 "Hyper fast MPEG1/MPEG4/H263/RV and AC3/MPEG audio encoder\n");
  
      } else {
  
          printf("usage: ffplay [options] input_file...\n"
  
                 "Simple audio player\n");
  
      }
  
             
  
      printf("\n"
  
             "Main options are:\n");
  
      for(i=0;i<2;i++) {
  
          if (i == 1)
  
              printf("\nAdvanced options are:\n");
  
          for(po = options; po->name != NULL; po++) {
  
              char buf[64];
  
              expert = (po->flags & OPT_EXPERT) != 0;
  
              if (expert == i) {
  
                  strcpy(buf, po->name);
  
                  if (po->flags & HAS_ARG) {
  
                      strcat(buf, " ");
  
                      strcat(buf, po->argname);
  
                  }
  
                  printf("-%-17s  %s\n", buf, po->help);
  
              }
  
          }
  
      }
  
  
  
      exit(1);
  
  }
  