Fix #278: Adjust HashME fast algorithm to avoid PSNR drop.

CUrrently when HashME is enabled, for some TGM sequences, e.g. Desktop, there is several dB's drop for some pictures. This MR is to adjust the early termination to avoid such situations.

It addresses the issue described in https://jvet.hhi.fraunhofer.de/trac/vvc/ticket/278. With the fix, compared with VTM5.0, it shows some coding efficiency improvement as follows RA classF{-0.01, 0.00, 0.00} TGM{-1.95,-1.15,-1.16} LDB classF{0.04, -0.06, 0.50} TGM{-1.24, -1.25, -1.17} Per-picture PSNR improvement over VTM5.0 for Desktop@QP22_LDB is showed in the attached figure.

The encoder log file of Desktop with QP 22 under LDB configuration.

LDB_classTGM_02Desktop_22_seg_0_enc.log

added 1 commit

• 39a2015d - Remove bug fix macro

Compare with previous version

resolved all discussions

changed title from Adjust HashME fast algorithm to avoid PSNR drop. to Fix #278: Adjust HashME fast algorithm to avoid PSNR drop.

mentioned in commit d0c270c5

merged