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After all, I set aq-mode 0 and it almost solves the problem. But i don't know how it affects to encode quality in general.

Originally Posted by benwaggoner

Level 5.1 has maxrate/bufsize limits of 40000, not 160000.

Level 5.1 High has 160000, --high-tier is a default value

Originally Posted by benwaggoner

It appears you've not set CRF OR bitrate, which means it's being encoded at the default CRF, which is quite high. If you're aiming for excellent quality, I'd start with 18 and iterate from there.

I use CRF 20 (21-23mbps) for UHD and CRF 12-14 (17-18mbps) for FHD.

Originally Posted by benwaggoner

--hdr-opt will tweak the chroma QPs better than just setting the offsets. And if you didn't set HDR, you didn't get HDR metadata, and the video is likely playing back as if it had SDR values, which would look terrible!

--hdr-opt is definitely necessary, but --cbqpoffs -3 --crqpoffs -3 fixes color issues a little. I don't know why it needed with HDR.

Originally Posted by benwaggoner

And don't set --chromaloc unless you've actually changed the chroma location. If you DID change that, let me know what tool you used to do it!

I didn't change chromaloc, but UHD requires Chroma subsampling : 4:2:0 (Type 2), so i add flag --chromaloc 2

Originally Posted by benwaggoner

Also, where did you get your MaxCLL and MaxFALL values? A MaxFALL of 900 suggest at least one blindingly bright frame, and no consumer TV available can actually display a MaxCLL of 3200 nits. Not that content doesn't get made that way sometimes, but I'd definitely investigate the content to make sure something didn't go horribly wrong.

There is mediainfo of my sample below (it is a general movie, nothing special):

Color range : Limited
Color primaries : BT.2020
Transfer characteristics : PQ
Matrix coefficients : BT.2020 non-constant
Mastering display color primaries : Display P3
Mastering display luminance : min: 0.0050 cd/m2, max: 4000 cd/m2
Maximum Content Light Level : 3241 cd/m2
Maximum Frame-Average Light Level : 902 cd/m2