JVET-Q0299 Residual coding simplification [J. Choi, S. Yoo, J. Heo, J. Lim, S. Kim (LGE)]
In the current VVC draft, Rice parameter for transform skip is derived from a predetermined equation. However, a look-up table of 32 entries is still used to derive the Rice parameter in regular residual coding. This contribution proposes a few candidate equations to derive the Rice parameter without the look-up table. The proposed equations require shift and additions, and generate exactly the same or almost the same Rice parameters as the look-up table. The coding performance of each proposed method is shown below:
Method 1:
Exactly the same with the VTM-7.0 anchor
Method 2:
CTC QPs: 0.00% (AI), 0.00% (RA), -0.03% (LD)
Low QPs: -0.02% (AI), 0.08% (RA), 0.06% (LD)
Method 3:
CTC QPs: 0.00% (AI), 0.01% (RA), 0.02% (LD)
Low QPs: 0.00% (AI), 0.00% (RA), -0.01% (LD)
There was no need for consideration of this after the CE3 decision.