JVET-F0049 AHG8: Adaptive QP for ERP 360º video [Hendry, M. Coban, G. Van der Auwera, M. Karczewicz (Qualcomm)]

This contribution proposes a method for encoding 360º video with the ERP projection by using adaptive QP at the CTU level based on the location of the CTU in the picture. The QP offset is calculated based on the WS-PSNR weight. The proposed method is an encoder change only. Simulation results reportedly show that the proposed method provides average gain of −4.3% RA coding impact (E2E WS-PSNR).

A revision of the contribution updates the viewport quality for AerialCity sequence with ISP projection.

This presented the same idea as F0038, but the QP at the equator is decreased by 2 (and thus clipping to 51 may occur less often in the CTC).

Comparison was also performed against ISP for viewports in the poles, and gain was shown. It was however pointed out that in most sequences the amount of detail in the poles is low, and this might change when there was more detail. Experiments with rotating high-detailed content to the poles could show the effect better.