s32 gf_media_avc_parse_nalu(GF_BitStream *bs, u32 nal_hdr, AVCState *avc)
{
	u8 idr_flag;
	s32 slice, ret;
	AVCSliceInfo n_state;

	slice = 0;
	memcpy(&n_state, &avc->s_info, sizeof(AVCSliceInfo));
	n_state.nal_unit_type = nal_hdr & 0x1F;
	n_state.nal_ref_idc = (nal_hdr>>5) & 0x3;

	idr_flag = 0;

	switch (n_state.nal_unit_type) {
	case GF_AVC_NALU_ACCESS_UNIT:
	case GF_AVC_NALU_END_OF_SEQ:
	case GF_AVC_NALU_END_OF_STREAM:
		ret = 1;
		break;

	case GF_AVC_NALU_SVC_SLICE:
		SVC_ReadNal_header_extension(bs, &n_state.NalHeader);
		slice = 1;
		// slice buffer - read the info and compare.
		/*ret = */svc_parse_slice(bs, avc, &n_state);
		if (avc->s_info.nal_ref_idc) {
			n_state.poc_lsb_prev = avc->s_info.poc_lsb;
			n_state.poc_msb_prev = avc->s_info.poc_msb;
		}
		if (slice)
			avc_compute_poc(&n_state);

		if (avc->s_info.poc != n_state.poc) {
			memcpy(&avc -> s_info, &n_state, sizeof(AVCSliceInfo));
			return 1;
		}
		memcpy(&avc -> s_info, &n_state, sizeof(AVCSliceInfo));
		return 0;

	case GF_AVC_NALU_SVC_PREFIX_NALU:
		SVC_ReadNal_header_extension(bs, &n_state.NalHeader);
		return 0;

	case GF_AVC_NALU_NON_IDR_SLICE:
	case GF_AVC_NALU_DP_A_SLICE:
	case GF_AVC_NALU_DP_B_SLICE:
	case GF_AVC_NALU_DP_C_SLICE:
	case GF_AVC_NALU_IDR_SLICE:
		slice = 1;
		/* slice buffer - read the info and compare.*/
		ret = avc_parse_slice(bs, avc, idr_flag, &n_state);
		if (ret<0) return ret;
		ret = 0;
		if (
		    ((avc->s_info.nal_unit_type > GF_AVC_NALU_IDR_SLICE) || (avc->s_info.nal_unit_type < GF_AVC_NALU_NON_IDR_SLICE))
		    && (avc->s_info.nal_unit_type != GF_AVC_NALU_SVC_SLICE)
		) {
			break;
		}
		if (avc->s_info.frame_num != n_state.frame_num) {
			ret = 1;
			break;
		}

		if (avc->s_info.field_pic_flag != n_state.field_pic_flag) {
			ret = 1;
			break;
		}
		if ((avc->s_info.nal_ref_idc != n_state.nal_ref_idc) &&
		        (!avc->s_info.nal_ref_idc || !n_state.nal_ref_idc)) {
			ret = 1;
			break;
		}
		assert(avc->s_info.sps);

		if (avc->s_info.sps->poc_type == n_state.sps->poc_type) {
			if (!avc->s_info.sps->poc_type) {
				if (!n_state.bottom_field_flag && (avc->s_info.poc_lsb != n_state.poc_lsb)) {
					ret = 1;
					break;
				}
				if (avc->s_info.delta_poc_bottom != n_state.delta_poc_bottom) {
					ret = 1;
					break;
				}
			} else if (avc->s_info.sps->poc_type==1) {
				if (avc->s_info.delta_poc[0] != n_state.delta_poc[0]) {
					ret =1;
					break;
				}
				if (avc->s_info.delta_poc[1] != n_state.delta_poc[1]) {
					ret = 1;
					break;
				}
			}
		}

		if (n_state.nal_unit_type == GF_AVC_NALU_IDR_SLICE)  {
			if (avc->s_info.nal_unit_type != GF_AVC_NALU_IDR_SLICE) { /*IdrPicFlag differs in value*/
				ret = 1;
				break;
			}
			else if (avc->s_info.idr_pic_id != n_state.idr_pic_id) { /*both IDR and idr_pic_id differs*/
				ret = 1;
				break;
			}
		}
		break;
	case GF_AVC_NALU_SEQ_PARAM:
	case GF_AVC_NALU_PIC_PARAM:
	case GF_AVC_NALU_SVC_SUBSEQ_PARAM:
	case GF_AVC_NALU_FILLER_DATA:
		return 0;
	default:
		if (avc->s_info.nal_unit_type <= GF_AVC_NALU_IDR_SLICE) ret = 1;
		//To detect change of AU when multiple sps and pps in stream
		else if ((nal_hdr & 0x1F) == GF_AVC_NALU_SEI && avc -> s_info .nal_unit_type == GF_AVC_NALU_SVC_SLICE)
			ret = 1;
		else if ((nal_hdr & 0x1F) == GF_AVC_NALU_SEQ_PARAM && avc -> s_info .nal_unit_type == GF_AVC_NALU_SVC_SLICE)
			ret = 1;
		else
			ret = 0;
		break;
	}

	/* save _prev values */
	if (ret && avc->s_info.sps) {
		n_state.frame_num_offset_prev = avc->s_info.frame_num_offset;
		if ((avc->s_info.sps->poc_type != 2) || (avc->s_info.nal_ref_idc != 0))
			n_state.frame_num_prev = avc->s_info.frame_num;
		if (avc->s_info.nal_ref_idc) {
			n_state.poc_lsb_prev = avc->s_info.poc_lsb;
			n_state.poc_msb_prev = avc->s_info.poc_msb;
		}
	}
	if (slice) avc_compute_poc(&n_state);
	memcpy(&avc->s_info, &n_state, sizeof(AVCSliceInfo));
	return ret;
}
s32 gf_media_avc_parse_nalu(GF_BitStream *bs, u32 nal_hdr, AVCState *avc)
{
	u8 idr_flag;
	s32 slice, ret;
	AVCSliceInfo n_state;

	slice = 0;
	memcpy(&n_state, &avc->s_info, sizeof(AVCSliceInfo));
	n_state.nal_unit_type = nal_hdr & 0x1F;
	n_state.nal_ref_idc = (nal_hdr>>5) & 0x3;

	idr_flag = 0;

	switch (n_state.nal_unit_type) {
	case GF_AVC_NALU_ACCESS_UNIT:
	case GF_AVC_NALU_END_OF_SEQ:
	case GF_AVC_NALU_END_OF_STREAM:
		ret = 1;
		break;

	case GF_AVC_NALU_SVC_SLICE:
		SVC_ReadNal_header_extension(bs, &n_state.NalHeader);
		slice = 1;
		 
		 svc_parse_slice(bs, avc, &n_state);
		if (avc->s_info.nal_ref_idc) {
			n_state.poc_lsb_prev = avc->s_info.poc_lsb;
			n_state.poc_msb_prev = avc->s_info.poc_msb;
		}
		if (slice)
			avc_compute_poc(&n_state);

		if (avc->s_info.poc != n_state.poc) {
			memcpy(&avc -> s_info, &n_state, sizeof(AVCSliceInfo));
			return 1;
		}
		memcpy(&avc -> s_info, &n_state, sizeof(AVCSliceInfo));
		return 0;

	case GF_AVC_NALU_SVC_PREFIX_NALU:
		SVC_ReadNal_header_extension(bs, &n_state.NalHeader);
		return 0;

	case GF_AVC_NALU_NON_IDR_SLICE:
	case GF_AVC_NALU_DP_A_SLICE:
	case GF_AVC_NALU_DP_B_SLICE:
	case GF_AVC_NALU_DP_C_SLICE:
	case GF_AVC_NALU_IDR_SLICE:
		slice = 1;
		 
		ret = avc_parse_slice(bs, avc, idr_flag, &n_state);
		if (ret<0) return ret;
		ret = 0;
		if (
		    ((avc->s_info.nal_unit_type > GF_AVC_NALU_IDR_SLICE) || (avc->s_info.nal_unit_type < GF_AVC_NALU_NON_IDR_SLICE))
		    && (avc->s_info.nal_unit_type != GF_AVC_NALU_SVC_SLICE)
		) {
			break;
		}
		if (avc->s_info.frame_num != n_state.frame_num) {
			ret = 1;
			break;
		}

		if (avc->s_info.field_pic_flag != n_state.field_pic_flag) {
			ret = 1;
			break;
		}
		if ((avc->s_info.nal_ref_idc != n_state.nal_ref_idc) &&
		        (!avc->s_info.nal_ref_idc || !n_state.nal_ref_idc)) {
			ret = 1;
			break;
		}
		assert(avc->s_info.sps);

		if (avc->s_info.sps->poc_type == n_state.sps->poc_type) {
			if (!avc->s_info.sps->poc_type) {
				if (!n_state.bottom_field_flag && (avc->s_info.poc_lsb != n_state.poc_lsb)) {
					ret = 1;
					break;
				}
				if (avc->s_info.delta_poc_bottom != n_state.delta_poc_bottom) {
					ret = 1;
					break;
				}
			} else if (avc->s_info.sps->poc_type==1) {
				if (avc->s_info.delta_poc[0] != n_state.delta_poc[0]) {
					ret =1;
					break;
				}
				if (avc->s_info.delta_poc[1] != n_state.delta_poc[1]) {
					ret = 1;
					break;
				}
			}
		}

		if (n_state.nal_unit_type == GF_AVC_NALU_IDR_SLICE)  {
			if (avc->s_info.nal_unit_type != GF_AVC_NALU_IDR_SLICE) {  
				ret = 1;
				break;
			}
			else if (avc->s_info.idr_pic_id != n_state.idr_pic_id) {  
				ret = 1;
				break;
			}
		}
		break;
	case GF_AVC_NALU_SEQ_PARAM:
	case GF_AVC_NALU_PIC_PARAM:
	case GF_AVC_NALU_SVC_SUBSEQ_PARAM:
	case GF_AVC_NALU_FILLER_DATA:
		return 0;
	default:
		if (avc->s_info.nal_unit_type <= GF_AVC_NALU_IDR_SLICE) ret = 1;
		 
		else if ((nal_hdr & 0x1F) == GF_AVC_NALU_SEI && avc -> s_info .nal_unit_type == GF_AVC_NALU_SVC_SLICE)
			ret = 1;
		else if ((nal_hdr & 0x1F) == GF_AVC_NALU_SEQ_PARAM && avc -> s_info .nal_unit_type == GF_AVC_NALU_SVC_SLICE)
			ret = 1;
		else
			ret = 0;
		break;
	}

	 
	if (ret && avc->s_info.sps) {
		n_state.frame_num_offset_prev = avc->s_info.frame_num_offset;
		if ((avc->s_info.sps->poc_type != 2) || (avc->s_info.nal_ref_idc != 0))
			n_state.frame_num_prev = avc->s_info.frame_num;
		if (avc->s_info.nal_ref_idc) {
			n_state.poc_lsb_prev = avc->s_info.poc_lsb;
			n_state.poc_msb_prev = avc->s_info.poc_msb;
		}
	}
	if (slice) avc_compute_poc(&n_state);
	memcpy(&avc->s_info, &n_state, sizeof(AVCSliceInfo));
	return ret;
}