GF_Err gf_isom_text_set_scroll_delay(GF_TextSample *samp, u32 scroll_delay)
{
	if (!samp) return GF_BAD_PARAM;
	if (!samp->scroll_delay) {
		samp->scroll_delay = (GF_TextScrollDelayBox*) gf_isom_box_new(GF_ISOM_BOX_TYPE_DLAY);
		if (!samp->scroll_delay) return GF_OUT_OF_MEM;
	}
	samp->scroll_delay->scroll_delay = scroll_delay;
	return GF_OK;
}
GF_Err gf_isom_text_set_scroll_delay(GF_TextSample *samp, u32 scroll_delay)
{
	if (!samp) return GF_BAD_PARAM;
	if (!samp->scroll_delay) {
		samp->scroll_delay = (GF_TextScrollDelayBox*) gf_isom_box_new(GF_ISOM_BOX_TYPE_DLAY);
		if (!samp->scroll_delay) return GF_OUT_OF_MEM;
	}
	samp->scroll_delay->scroll_delay = scroll_delay;
	return GF_OK;
}