id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
300	Encoder may produce uncompliant AlfCoeff for Chroma	fbarbier	jennylai	"Accordingly to specification, AlfCoeffC shall be in the range of −127 to 127, inclusive.

Please find a related merge request that checks AlfCoeff values for Luma and Chroma:

https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/570

The following command lines show that the current VTM encoder may produce invalid bitstreams :

git fetch https://vcgit.hhi.fraunhofer.de/fbarbier/VVCSoftware_VTM.git alf_compliance_check
git checkout -b fbarbier/VVCSoftware_VTM-alf_compliance_check1 FETCH_HEAD

cd build
cmake ..
make -j 8
cd ..

$ ./bin/EncoderAppStaticd --SourceWidth=144 --SourceHeight=192 --InputChromaFormat=420 --InputBitDepth=8 --Profile=next --FrameRate=60 --FramesToBeEncoded=1 --GOPSize=4 '--Frame1=B 1 5 -6.5 0.2590 0 0 1.0 0 0 0 4 4 -1 -5 -9 -13 0' '--Frame2=B 2 4 -6.5 0.2590 0 0 1.0 0 0 0 4 4 -1 -2 -6 -10 1 -1 5 1 1 1 0 1' '--Frame3=B 3 5 -6.5 0.2590 0 0 1.0 0 0 0 4 4 -1 -3 -7 -11 1 -1 5 0 1 1 1 1' '--Frame4=B 4 1  0.0 0.0    0 0 1.0 0 0 0 4 4 -1 -4 -8 -12 1 -1 5 0 1 1 1 1' --FastSearch=1 --MaxCUWidth=12 --MaxCUHeight=16 --CTUSize=128 --MaxPartitionDepth=5 --PCMEnabledFlag=0 --SAO=0 --LoopFilterDisable=1 --ALF=1 --DisableIntraInInter=0 --DepQuant=0 --SignHideFlag=0 --DualITree=1 --LMChroma=1 --TransformSkip=0 --MaxDeltaQP=0 --MTS=2 --Triangle=1 --RDPCM=1 -i alf_source.yuv -b alf_compliance_issue.vvc

$ ./bin/DecoderAppStaticd -b alf_compliance_issue.vvc -o decoded.yuv

ERROR: In function ""alfFilter"" in source/Lib/DecoderLib/VLCReader.cpp:3084: AlfCoeffC shall be in the range of −127 to 127, inclusive



"	defect	closed	minor		VTM		fixed		ksuehring XiangLi fbossen jvet@…