JVET-AO0208 AHG18: GDR functionality with LowDelay-B configuration [A. Dzugaev, M. Sychev, K. Malyshev, S. Ikonin, E. Alshina (Huawei)] [late]

This contribution provides an extension of GDR functionality to support multi-reference configuration like LDB. Proposed solution is described and accompanied with simulation results obtained according ULL CTC (JVET-AN2039) and GDR configuration from (JVET-AN0195).

Current implementation of GDR in VTM enforce GOP=1 once GDR enabled which leads to IPPI configuration. There are two SW fixes proposed for fixing issues with GDR in combination with LDB configuration. The removal of this configuration restriction and further fixing functionality demonstrate BD-PSNR-Y 5.5 dB improvement on average under ULL CTC in broadcast scenario. The freezing ratio reduced from 68% down to 44% versus classic VTM anchor.

IDR pictures were replaced by GDR pictures with same intra refresh period, and GDR period of 8 pictures. GDR increases the bit rate by 7.8% in the lossless case.

Results are reported for a (non-scalable) broadcast scenario, where APS NAL units are transmitted with priority. It was noted that the results are almost identical for priority and no-priority cases, which may be due to the fact that APS packets often lost, or available ones are still appropriate to be used.

It was reported that for the unicast (with feedback) scenario, no benefit was observed.

V. Zakharchenko had conducted a cross-check. He reported verbally on Thursday that so far, results were matching, and implementation was found to be appropriate. It was requested to register an input document on the cross-check.

Decision (SW): Adopt JVET-AO0208 into AHG18 software.