s32 gf_media_vvc_parse_nalu_bs(GF_BitStream *bs, VVCState *vvc, u8 *nal_unit_type, u8 *temporal_id, u8 *layer_id)
{
	Bool is_slice = GF_FALSE;
	s32 ret = -1;
	VVCSliceInfo n_state;

	gf_bs_enable_emulation_byte_removal(bs, GF_TRUE);

	memcpy(&n_state, &vvc->s_info, sizeof(VVCSliceInfo));
	if (!vvc_parse_nal_header(bs, nal_unit_type, temporal_id, layer_id)) return -1;

	n_state.nal_unit_type = *nal_unit_type;

	switch (n_state.nal_unit_type) {
	case GF_VVC_NALU_ACCESS_UNIT:
	case GF_VVC_NALU_END_OF_SEQ:
	case GF_VVC_NALU_END_OF_STREAM:
		ret = 1;
		break;

	case GF_VVC_NALU_SLICE_TRAIL:
	case GF_VVC_NALU_SLICE_STSA:
	case GF_VVC_NALU_SLICE_RADL:
	case GF_VVC_NALU_SLICE_RASL:
	case GF_VVC_NALU_SLICE_IDR_W_RADL:
	case GF_VVC_NALU_SLICE_IDR_N_LP:
	case GF_VVC_NALU_SLICE_CRA:
	case GF_VVC_NALU_SLICE_GDR:
		/* slice - read the info and compare.*/
		ret = vvc_parse_slice(bs, vvc, &n_state);
		if (ret < 0) return ret;

		ret = 0;
		if (n_state.picture_header_in_slice_header_flag) {
			is_slice = GF_TRUE;
			vvc_compute_poc(&n_state);
			if (vvc->s_info.poc != n_state.poc) {
				ret = 1;
				break;
			}
			if (!(*layer_id) || (n_state.prev_layer_id_plus1 && ((*layer_id) <= n_state.prev_layer_id_plus1 - 1))) {
				ret = 1;
				break;
			}
		}
		break;

	case GF_VVC_NALU_PIC_HEADER:
		if (vvc_parse_picture_header(bs, vvc, &n_state)<0) {
			ret = -1;
			break;
		}
		is_slice = GF_TRUE;
		vvc_compute_poc(&n_state);
		if (!(*layer_id) || (n_state.prev_layer_id_plus1 && ((*layer_id) <= n_state.prev_layer_id_plus1 - 1))) {
			ret = 1;
		}
		break;
	case GF_VVC_NALU_SEQ_PARAM:
		vvc->last_parsed_sps_id = gf_media_vvc_read_sps_bs_internal(bs, vvc, *layer_id, NULL);
		ret = (vvc->last_parsed_sps_id>=0) ? 0 : -1;
		break;
	case GF_VVC_NALU_PIC_PARAM:
		vvc->last_parsed_pps_id = gf_media_vvc_read_pps_bs_internal(bs, vvc);
		ret = (vvc->last_parsed_pps_id>=0) ? 0 : -1;
		break;
	case GF_VVC_NALU_VID_PARAM:
		vvc->last_parsed_vps_id = gf_media_vvc_read_vps_bs_internal(bs, vvc, GF_FALSE);
		ret = (vvc->last_parsed_vps_id>=0) ? 0 : -1;
		break;
	case GF_VVC_NALU_DEC_PARAM:
		ret = 0;
		break;
	case GF_VVC_NALU_APS_PREFIX:
		//we use the mix aps type + aps id (first 8 bits) as unique identifier
		vvc->last_parsed_aps_id = gf_bs_read_int_log(bs, 8, "aps_id");
		ret = 0;
		break;
	default:
		ret = 0;
		break;
	}

	/* save _prev values */
	if ((ret>0) && vvc->s_info.sps) {
//		n_state.frame_num_offset_prev = vvc->s_info.frame_num_offset;
//		n_state.frame_num_prev = vvc->s_info.frame_num;

		n_state.poc_lsb_prev = vvc->s_info.poc_lsb;
		n_state.poc_msb_prev = vvc->s_info.poc_msb;
		if (is_slice)
			n_state.prev_layer_id_plus1 = *layer_id + 1;
	}
	if (is_slice) vvc_compute_poc(&n_state);
	memcpy(&vvc->s_info, &n_state, sizeof(VVCSliceInfo));

	return ret;
}
s32 gf_media_vvc_parse_nalu_bs(GF_BitStream *bs, VVCState *vvc, u8 *nal_unit_type, u8 *temporal_id, u8 *layer_id)
{
	Bool is_slice = GF_FALSE;
	s32 ret = -1;
	VVCSliceInfo n_state;

	gf_bs_enable_emulation_byte_removal(bs, GF_TRUE);

	memcpy(&n_state, &vvc->s_info, sizeof(VVCSliceInfo));
	if (!vvc_parse_nal_header(bs, nal_unit_type, temporal_id, layer_id)) return -1;

	n_state.nal_unit_type = *nal_unit_type;

	switch (n_state.nal_unit_type) {
	case GF_VVC_NALU_ACCESS_UNIT:
	case GF_VVC_NALU_END_OF_SEQ:
	case GF_VVC_NALU_END_OF_STREAM:
		ret = 1;
		break;

	case GF_VVC_NALU_SLICE_TRAIL:
	case GF_VVC_NALU_SLICE_STSA:
	case GF_VVC_NALU_SLICE_RADL:
	case GF_VVC_NALU_SLICE_RASL:
	case GF_VVC_NALU_SLICE_IDR_W_RADL:
	case GF_VVC_NALU_SLICE_IDR_N_LP:
	case GF_VVC_NALU_SLICE_CRA:
	case GF_VVC_NALU_SLICE_GDR:
		 
		ret = vvc_parse_slice(bs, vvc, &n_state);
		if (ret < 0) return ret;

		ret = 0;
		if (n_state.picture_header_in_slice_header_flag) {
			is_slice = GF_TRUE;
			vvc_compute_poc(&n_state);
			if (vvc->s_info.poc != n_state.poc) {
				ret = 1;
				break;
			}
			if (!(*layer_id) || (n_state.prev_layer_id_plus1 && ((*layer_id) <= n_state.prev_layer_id_plus1 - 1))) {
				ret = 1;
				break;
			}
		}
		break;

	case GF_VVC_NALU_PIC_HEADER:
		if (vvc_parse_picture_header(bs, vvc, &n_state)<0) {
			ret = -1;
			break;
		}
		is_slice = GF_TRUE;
		vvc_compute_poc(&n_state);
		if (!(*layer_id) || (n_state.prev_layer_id_plus1 && ((*layer_id) <= n_state.prev_layer_id_plus1 - 1))) {
			ret = 1;
		}
		break;
	case GF_VVC_NALU_SEQ_PARAM:
		vvc->last_parsed_sps_id = gf_media_vvc_read_sps_bs_internal(bs, vvc, *layer_id, NULL);
		ret = (vvc->last_parsed_sps_id>=0) ? 0 : -1;
		break;
	case GF_VVC_NALU_PIC_PARAM:
		vvc->last_parsed_pps_id = gf_media_vvc_read_pps_bs_internal(bs, vvc);
		ret = (vvc->last_parsed_pps_id>=0) ? 0 : -1;
		break;
	case GF_VVC_NALU_VID_PARAM:
		vvc->last_parsed_vps_id = gf_media_vvc_read_vps_bs_internal(bs, vvc, GF_FALSE);
		ret = (vvc->last_parsed_vps_id>=0) ? 0 : -1;
		break;
	case GF_VVC_NALU_DEC_PARAM:
		ret = 0;
		break;
	case GF_VVC_NALU_APS_PREFIX:
		 
		vvc->last_parsed_aps_id = gf_bs_read_int_log(bs, 8, "aps_id");
		ret = 0;
		break;
	default:
		ret = 0;
		break;
	}

	 
	if ((ret>0) && vvc->s_info.sps) {
 
 

		n_state.poc_lsb_prev = vvc->s_info.poc_lsb;
		n_state.poc_msb_prev = vvc->s_info.poc_msb;
		if (is_slice)
			n_state.prev_layer_id_plus1 = *layer_id + 1;
	}
	if (is_slice) vvc_compute_poc(&n_state);
	memcpy(&vvc->s_info, &n_state, sizeof(VVCSliceInfo));

	return ret;
}