func: int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar)
  
  {
  
      int64_t scaled_dim;
  
  
  
      if (!sar.den)
  
          return AVERROR(EINVAL);
  
  
  
      if (!sar.num || sar.num == sar.den)
  
          return 0;
  
  
  
      if (sar.num < sar.den)
  
          scaled_dim = av_rescale_rnd(w, sar.num, sar.den, AV_ROUND_ZERO);
  
      else
  
          scaled_dim = av_rescale_rnd(h, sar.den, sar.num, AV_ROUND_ZERO);
  
  
  
      if (scaled_dim > 0)
  
          return 0;
  
  
  
      return AVERROR(EINVAL);
  
  }
  