JVET-AD0101 Additional conformance tests of scaling window functionality for multilayer coding [S. Iwamura, S. Nemoto, A. Ichigaya (NHK)]
This contribution proposes additional conformance test of scaling window functionality for multilayer coding. In 28th JVET meeting, it was decided to issue additional conformance bitstreams for VVC multilayer configurations. Content layering is one of the practical multilayer coding use cases reported in JVET-AB0087, where main content is coded as base layer and main content with overlaying sub-content is coded as enhancement layer. When the main content is scaled down and the L-shaped content is placed in the margin as the input for the enhancement layer, scaling window functionality might work quite efficiently. The proposed conformance bitstreams are attached in the contribution and the merge request for the software package for supporting scaling window will be submitted during meeting.
It is reported that the scaling window functionality is not supported by current VTM encoder. The software implementation is basically ready, however a problem still exists when combining scaling window in multi-layer coding with RPR in the base layer (which could be either an encoder or decoder problem). Therefore, no merge request was issued yet. The conformance streams proposed in this contribution are not affected by this.
It is noted that also a plain combination of RPR and multi-layer is currently not tested in the conformance test set (but is supported by the VTM encoder and decoder).
Decision: Adopt JVET-AD0101 into JVET-AD2028.
AHG7: ECM tool assessment (4)
Contributions in this area were discussed at 1445–1545 on Tuesday 25 April 2023 (chaired by JRO).