id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
299	Deblocking filter has been always disabled on independent tile boundary	shilin.xu		"As a result of the integration of QP averaging for deblocking (from JCTVC-G1031), HM5.x deblocking filter is no longer applied across independent tile boundaries leaving very visible block artifacts on tile boundaries in some cases. Taking HM5.1-rc2 for example, the bug exists in two places of TComLoopFilter.cpp file:

1) From line 905 to 908, the following code will disable luma sample DLF if the neighbor CU is in another independent tile.

     if (!pcCUP)
     {
       return;
     }

2) From line 1220 to 1223, the following code will disable chroma sample DLF if the neighbor CU is in another independent tile.

     if (!pcCUP)
     {
       return;
     }

From the code, it is clear that the implementer has chosen not to filter (i.e., return) when the neighboring QP is not available.  We believe that the spirit of JCTVC-G1031 and WD 5 is to use both QP values and availability is not an issue since both QP values are available at the time the deblocking filter is applied.


"	defect	closed	minor	HM-6.1	HM	HM-5.1	fixed		fbossen ksuehring davidf jct-vc@…