How to decide the weight of Luma and Chroma distortion in the RDO process?

Question

In the HEVC reference software HM, in the RDO process, the distortion contains the luma and chroma, and they have different weights. Through debugging the codes, I find the chroma weight is higher than 1. So does anyone know how to decide the the weights? Are there any papers talking about this problem?

Answer 1

I will answer my own question. This topic is discussed in the proposal JCT-VC F386. It is about the RDO of Chroma.