func: static unsigned int find_best(struct vf_instance *vf){
  
    int is_format_okay = vf->next->query_format(vf->next, IMGFMT_YV12);
  
    if ((is_format_okay & VFCAP_CSP_SUPPORTED_BY_HW) || (is_format_okay & VFCAP_CSP_SUPPORTED))
  
      return IMGFMT_YV12;
  
    else
  
      return 0;
  
  }
  