id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
890	Inconsistency in weighted pred flags values in case wp_info_in_ph_flag = 1	audrey.turquin		"In the specification, in case wp_info_in_ph_flag = 1 and weighted pred is actually not enabled, there is no mechanism to 'reset' the values for the weighted pred flags (luma_weight_l0_flag, luma_weight_l1_flag, chroma_weight_l0_flag, chroma_weight_l1_flag).
And this is an issue because these flags take part of the conditions to send the syntax element 'bcw_idx'.

For example, in case :
- wp_info_in_ph_flag = 1
- pps_weighted_pred_flag = 1
- pps_weighted_bi_pred_flag = 0
- slice_type = 0 (slice B)

The weighted pred table is sent in the PH, but as the slice_type is B and pps_weighted_bi_pred_flag = 0, the weighted pred is not enabled on this slice.
So, luma_weight_l1_flag[i] is supposed to be equal to which value ?
According to the spec, luma_weight_l1_flag[i] should be equal to the value sent in the PH (as there is no mechanism to change these values), which can be 1. But it is not consistent with the fact that WP is not enabled on this slice.

I think a mechanism is missing in the spec to reset the weight flags to 0 in case the weighted pred is not enabled on a slice.
This mechanism is present in the VTM, so there is a mismatch between spec and VTM."	defect	closed	minor		spec	VVC D8 vB	fixed		ksuehring bbross XiangLi fbossen jvet@…