JVET-E0023 AHG5: Improved fast encoding setting [Y. Yamamoto, T. Ikai, Y. Yasugi (Sharp)]
This contribution proposes a fast encoding setting, which changes the threshold for stopping further splitting. The threshold is determined by the distance between current and reference pictures. Simulation results reportedly show around 12% encoding speed up with 0.23% BD-rate loss.
The criterion is the minimum distance in the RPL, computed once per slice. In RA, this means that smaller value of skip depth (2) is used for higher hierarchy layers. For LDB, always a skip depth 2 would be used. This is a pure encoder change for early termination of checking QTBT splitting options.
Two configurations were investigated:
- A – use skip depth 2 when minimum distance is <=2, otherwise use skip depth 3; this reduces encoder runtime by 12% for RA, 0.23% loss, for LDB, it saves 17% encoder time, loses 0.25%.
- B - use skip depth 2 when minimum distance is <=1, otherwise use skip depth 3; this reduces encoder runtime by 8% for RA, 0.12% loss, for LDB, no results are presented, but likely same as configuration A.
Another result is given in the contribution where skip depth 2 is always used for RA; this reduces the encoder time by approx. 17% and gives a loss of 0.33%.
No results on LDP were provided.