APS payload data description is spread over different places. This may need harmonization.

• scaling_list_data is under "7.3.2 RBSP, trailing bits and byte alignment"
• alf_data [empty!] is under "7.3.6 Slice header syntax" (with a note from YK saying it should not be there)
• lmcs_data is also under "7.3.6 Slice header syntax"

Note: in HEVC, scaling_list_data was in a separate section between "Profile, tier and level" and "SEI message"

The slice header sematics have the following constraints:

When multiple ALF APSs with the same value of adaptation_parameter_set_id are referred to by two or more slices of the same picture, the multiple ALF APSs with the same value of adaptation_parameter_set_id shall have the same content.

and

When multiple LMCS APSs with the same value of adaptation_parameter_set_id are referred to by two or more slices of the same picture, the multiple LMCS APSs with the same value of adaptation_parameter_set_id shall have the same content.

On the other hand, the semantics of adaptation_parameter_set_id contains a note:

adaptation_parameter_set_id provides an identifier for the APS for reference by other syntax elements. NOTE – APSs can be shared across pictures and can be different in different slices within a picture.

I think the first two (normative) references contain the design intent. The note should be corrected accordingly.

When running the encoder in valgrind, I get the following error during encoding of the first frame:

==96718== Conditional jump or move depends on uninitialised value(s)
==96718==    at 0x1002CE4FB: CABACWriter::codeAlfCtuEnableFlag(CodingStructure&, unsigned int, int, AlfSliceParam*) (CABACWriter.cpp:3456)
==96718==    by 0x1002CDDB4: CABACWriter::coding_tree_unit(CodingStructure&, UnitArea const&, int (&) [2], unsigned int, bool) (CABACWriter.cpp:172)
==96718==    by 0x1003B84A6: EncSlice::encodeCtus(Picture*, bool, bool, unsigned int, unsigned int, EncLib*) (EncSlice.cpp:1773)
==96718==    by 0x1003B5EFF: EncSlice::compressSlice(Picture*, bool, bool) (EncSlice.cpp:1480)
==96718==    by 0x100337355: EncGOP::compressGOP(int, int, std::__1::list<Picture*, std::__1::allocator<Picture*> >&, std::__1::list<UnitBuf<short>*, std::__1::allocator<UnitBuf<short>*> >&, bool, bool, InputColourSpaceConversion, bool, bool) (EncGOP.cpp:2331)
==96718==    by 0x10036A75D: EncLib::encode(bool, PelStorage*, PelStorage*, InputColourSpaceConversion, std::__1::list<UnitBuf<short>*, std::__1::allocator<UnitBuf<short>*> >&, int&) (EncLib.cpp:657)
==96718==    by 0x10000A02A: EncApp::encode() (EncApp.cpp:767)
==96718==    by 0x1000577DA: main (encmain.cpp:153)
==96718== 
==96718== Conditional jump or move depends on uninitialised value(s)
==96718==    at 0x1002CE899: CABACWriter::codeAlfCtuFilterIndex(CodingStructure&, unsigned int, bool) (CABACWriter.cpp:3591)
==96718==    by 0x1002CDE2B: CABACWriter::coding_tree_unit(CodingStructure&, UnitArea const&, int (&) [2], unsigned int, bool) (CABACWriter.cpp:176)
==96718==    by 0x1003B84A6: EncSlice::encodeCtus(Picture*, bool, bool, unsigned int, unsigned int, EncLib*) (EncSlice.cpp:1773)
==96718==    by 0x1003B5EFF: EncSlice::compressSlice(Picture*, bool, bool) (EncSlice.cpp:1480)
==96718==    by 0x100337355: EncGOP::compressGOP(int, int, std::__1::list<Picture*, std::__1::allocator<Picture*> >&, std::__1::list<UnitBuf<short>*, std::__1::allocator<UnitBuf<short>*> >&, bool, bool, InputColourSpaceConversion, bool, bool) (EncGOP.cpp:2331)
==96718==    by 0x10036A75D: EncLib::encode(bool, PelStorage*, PelStorage*, InputColourSpaceConversion, std::__1::list<UnitBuf<short>*, std::__1::allocator<UnitBuf<short>*> >&, int&) (EncLib.cpp:657)
==96718==    by 0x10000A02A: EncApp::encode() (EncApp.cpp:767)
==96718==    by 0x1000577DA: main (encmain.cpp:153)
==96718== 

Steps to reproduce:

git clone https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM.git
git checkout f84a8bc5059bb27dce70120727fbe317bc65121b
make debug
valgrind <path_to>/EncoderApp -c cfg/per-sequence/RaceHorses.cfg -c cfg/encoder_randomaccess_vtm.cfg -q 37 -ipp <source path> -f 16

May be related to #281