Enc/Dec mismatch for Inter MTS in class F

[chollmann]

Encoder/decoder mismatch for class F random access if MTS is enabled for inter when using parallel encoding.

Example: SlideEdit, QP22
When encoding part 7 (33 frames starting at #224) the resulting values for the I-frame #224 are:

653360 bits [Y 50.7612 dB U 48.0983 dB V 48.3139 dB]

When running a single thread encoding the resulting values for the same I-frame #224 are:

654320 bits [Y 50.7300 dB U 48.1538 dB V 48.3735 dB]

Following frames are affected and differ until the next I-frame (#256) is reached. This frame is identical for both encodings (as well as an encode of only part 8 starting at frame #256) and subsequent frames are identical.
Doing a partial encode for parts 6 and 7 (65 frames starting at #192) yields identical results to the corresponding frames of the complete encoding.

Similar mismatches can be found in other class F sequences (ArenaOfValor, BasketballDrillText).

Binaries are based on VTM-4.0 (commit 20671d8e).

Commands:
Only part 7:
bin/EncoderAppStatic_VTM-4.0 -c cfg/encoder_randomaccess_vtm.cfg -c cfg/per-class/classF.cfg -c cfg/per-sequence/SlideEditing.cfg -i SlideEditing_1280x720_30.yuv -b SlideEdit7.bin -o SlideEdit7_rec.yuv -q 22 --MTS=3 -fs 224 -f 33

Entire sequence:
bin/EncoderAppStatic_VTM-4.0 -c cfg/encoder_randomaccess_vtm.cfg -c cfg/per-class/classF.cfg -c cfg/per-sequence/SlideEditing.cfg -i SlideEditing_1280x720_30.yuv -b SlideEdit.bin -o SlideEdit_rec.yuv -q 22 --MTS=3

Attached files:
logs for part 7 of SlideEdit and full sequence

[chollmann]

Log for part 7

[chollmann]

Full encoder log

[fbossen]

Issue still present in commit eb547a55f9a002db28780f392009a5a75807a331

[fbossen]

Suggested fix:
​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/324