func: static int video_open(VideoState *is){
  
      int flags = SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_HWACCEL;
  
      int w,h;
  
  
  
      if(is_full_screen) flags |= SDL_FULLSCREEN;
  
      else               flags |= SDL_RESIZABLE;
  
  
  
      if (is_full_screen && fs_screen_width) {
  
          w = fs_screen_width;
  
          h = fs_screen_height;
  
      } else if(!is_full_screen && screen_width){
  
          w = screen_width;
  
          h = screen_height;
  
      }else if (is->video_st && is->video_st->codec->width){
  
          w = is->video_st->codec->width;
  
          h = is->video_st->codec->height;
  
      } else {
  
          w = 640;
  
          h = 480;
  
      }
  
  #ifndef SYS_DARWIN
  
      screen = SDL_SetVideoMode(w, h, 0, flags);
  
  #else
  
      /* setting bits_per_pixel = 0 or 32 causes blank video on OS X */
  
      screen = SDL_SetVideoMode(w, h, 24, flags);
  
  #endif
  
      if (!screen) {
  
          fprintf(stderr, "SDL: could not set video mode - exiting\n");
  
          return -1;
  
      }
  
      SDL_WM_SetCaption("FFplay", "FFplay");
  
  
  
      is->width = screen->w;
  
      is->height = screen->h;
  
  
  
      return 0;
  
  }
  