id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
775	Unintended parsing dependency in subpicture level information SEI	ksuehring		"In the subpicture level information SEI the syntax element sps_num_subpics_minus1 is used as limit for a loop

{{{
			for( j = 0; j  <=  sps_num_subpics_minus1; j++ )
}}}

This seems to make it the only SEI that depends on the SPS for parsing. We believe that this was a unintentional mistake while creating document JVET-P0984 from a number of contributions during the meeting.

The dependency can easily be avoided by num_subpics_minus1 to the SEI:

{{{
subpic_level_info( payloadSize ) {	
	sli_seq_parameter_set_id					u(4)
	num_ref_levels_minus1						u(3)
	explicit_fraction_present_flag					u(1)
	sli_num_subpics_minus1						u(8)
	for( i = 0; i  <=  num_ref_levels_minus1; i++ ) {	
		ref_level_idc[ i ]					u(8)
		if( explicit_fraction_present_flag )	
			for( j = 0; j  <=  sli_num_subpics_minus1; j++ )	
				ref_level_fraction_minus1[ i ][ j ]	u(8)
	}		
}		
}}}

Note: sps_num_subpics_minus1 is coded u(8), which perfectly works with the intended byte alingment in the SEI."	defect	closed	minor		spec	VVC D7 vE	fixed		ksuehring bbross XiangLi fbossen jvet@…