JVET-AC0191 Non-EE2: Modification to MPM list derivation [H. Wang, Y.-J. Chang, V. Seregin, M. Karczewicz (Qualcomm)]

This contribution investigates a unified method to derive MPM lists for the regular intra and template-based multiple reference line intra (TMRL) modes coding. In method 1, an MPM derivation process is developed using the existing logic in the MPM generation of regular intra modes and TMRL intra modes. In method 2, on top of method 1, an intra mode is derived for the MIP/intraTMP coded CUs for future MPM list generation, and a re-ordering process is further applied to the MPM list.

The experimental results on top of ECM-7.0 are as follows:

Method 1

AI(Y/U/V): -0.03%/0.00%/-0.04%, EncT 100%, DecT 100%

RA(Y/U/V): -0.01%/-0.07%/-0.15%, EncT 100%, DecT 100%

Method 2

AI(Y/U/V): -0.06%/-0.06%/-0.11%, EncT 102%, DecT 100%

It was suggested to also investigate other options of mode derivation in method 2.

It was pointed out that a similar approach of mode derivation had been used in an EE2-4.1b, but no gain was found.

Several experts supported this proposal to be investigated in an EE (along with other proposals targeting MPM modifications).