JVET-AN0118 AHG6: ECM software extension for RDO count information [Y. Tokumo, S. Hong, T. Ikai (Sharp)]

This contribution proposes ECM software extension for RDO count information. The proposed software outputs three types of RDO count, i.e. rdoCountRdCost, rdoCountBestMode, and rdoCountModeCost for all the RD cost, tracing best mode and tracing mode cost calculation, respectively. Experimental results show that encoding runtime and RDO count are correlated and RDO count seems to be useful for developing as this is a reliable complexity metric; that is, exactly same values are obtained irrespective of environments. It is recommended to adopt the proposal to the next version of ECM software.

The proponents suggest that they do not intend to require RDO count report for all proposals. It is instead meant for experts to utilize this evaluation method for their tool development.

The source code based on ECM-18.0is available at JVET ECM fork repository, https://vcgit.hhi.fraunhofer.de/tokumo/ECM/-/tree/ECM-18.0-rdoCount.

It was commented that if someone writes a separate RDO branch of code within the ECM, the code in this contribution might not be able to catch that RDO. RDO count is currently not normalized by CU size.

Cross checker commented that the proposed software change seems straightforward, and would not put burden on future tool/software development.

Several experts commented that more careful study should be conducted on this proposed software, and the activity should be moved to AHG7 for further inspection of the code, as well as RDO complexity in terms of block sizes.

Further study in the conext of AHG7, e.g. RDO complexity impact in relation to block size, etc..