static GFINLINE GF_Err gpp_write_modifier(GF_BitStream *bs, GF_Box *a)
{
	GF_Err e;
	if (!a) return GF_OK;
	e = gf_isom_box_size(a);
	if (!e) e = gf_isom_box_write(a, bs);
	return e;
}
static GFINLINE GF_Err gpp_write_modifier(GF_BitStream *bs, GF_Box *a)
{
	GF_Err e;
	if (!a) return GF_OK;
	e = gf_isom_box_size(a);
	if (!e) e = gf_isom_box_write(a, bs);
	return e;
}