id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
920	Redundancy processing on qPY_PREV derivation	abe.kiyo		"In 8.7.1 Derivation process for quantization parameters, there is the following processing.

1. The variable qPY_PREV is derived as follows:
 - If one or more of the following conditions are true, qPY_PREV is set equal to SliceQpY:
   - The current quantization group is the first quantization group in a slice.
   - The current quantization group is the first quantization group in a tile.
   - [[span(style=color: #FF0000, The current quantization group is the first quantization group in a CTB row of a tile and sps_entropy_coding_sync_enabled_flag is equal to 1.)]]
 - Otherwise, qPY_PREV is set equal to the luma quantization parameter QpY of the last luma coding unit in the previous quantization group in decoding order.

 ....

4. The predicted luma quantization parameter qPY_PRED is derived as follows:
 - [[span(style=color: #0000FF,If all the following conditions are true, then qPY_PRED is set equal to the luma quantization parameter QpY of the coding unit containing the luma coding block covering ( xQg, yQg − 1 ):)]]
  - [[span(style=color: #0000FF,availableB is equal to TRUE.)]]
  - [[span(style=color: #0000FF,The current quantization group is the first quantization group in a CTB row within a tile.)]]
 - Otherwise, qPY_PRED is derived as follows:
   qPY_PRED = ( qPY_A + qPY_B + 1 )  >>  1  (1140)

qPY_PREV is set equal to SliceQpY by the condition of [[span(style=color: #FF0000, red text)]] for WPP. However, according to the  [[span(style=color: #0000FF, blue text)]], qPY_PRED is set equal to QpY of above CU without using qPY_PREV for both WPP and non-WPP. To avoid the confusion in WPP specification, I think the processing of  [[span(style=color: #FF0000, red text)]] should be removed."	defect	closed	minor		spec		fixed		ksuehring bbross XiangLi fbossen jvet@…