The number of candModeLists in PU::getIntraMPMs of UnitTools.cpp is different from the number in JVET_R2001_V10.docx

[annci]

The number of candModeLists in PU::getIntraMPMs of UnitTools.cpp is six, but the number is five in JVET_R2001_V10.docx.

[biaowang]

It is another way of implementation for the special intra_luma_not_planar_flag and five MPM.
The codeword of 6 MPM index and the combination of intra_luma_not_planar_flag and 5 MPM are the same. You can refer to the following table.

intra_luma_not_planar_flag	5 MPM idx	5 MPM idx codeword	combination (6 MPM idx codeword)	mode
0			0	Planar
1	0	0	10
1	1	10	110
1	2	110	1110
1	3	1110	11110
1	4	1111	11111

Planar mode is always put in the first entry in a 6 MPM in original proposal (JVET-N0185).
Because of this, it can be considered as a special intra_luma_not_planar_flag.
When the current mode is planar mode, intra_luma_not_planar_flag is zero.
It can also be considered idx 0 (the first entry) of a 6 MPM is used to derive the intra mode.

The decision of such a conversion can be found in meeting note of JVET-N_Notes_dF.docx:

"Different from the proposal, it is suggested to remove the planar mode from the MPM list and code it as a separate context-coded flag before the MPM list (with the 5 remaining entries, all
bypass coded). This is purely editorial, no change in the bitstream."