id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
1338	Adaptive QP Selection and multiple slices / slice segments	karlsharman		"Adaptive QP selection appears to be incorrect when multiple slices / slice segments are used.

The statistics are reset at the start of compressSlice, and the delta calculated previously is added to the QpBase (a rate-controlled version of the slice's QP, used only for Adaptive Qp Selection) if the slice is not an I_SLICE.

The statistics are used to update the delta at the end of encodeSlice.

However, all slices are compressed. Once all slices are compressed, they are then encoded. So the statistics will only ever represent values gathered from the last slice of the previously coded picture.

Is the intension to gather statistics on a picture and use that for the next picture, or to gather statistics on a slice (including all slice segments) and use that for the next slice?

In addition, the 52 element array TComTrQuant::m_qpDelta will underflow if negative QPs are used as an index (valid for bit depths > 8)."	defect	new	minor		HM	HM-16.1			ksuehring davidf karlsharman jct-vc@…