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Old 16th October 2018, 17:11   #6435  |  Link
benwaggoner
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Join Date: Jan 2006
Location: Portland, OR
Posts: 4,750
Quote:
Originally Posted by Boulder View Post
Source was 4K, downsampled to 1080p. These are the basic parameters that I've set...

I've then also tested ctu 32 with max-tu-size 32 or 16.

In the 1080p encode, the bitrate is as follows:

CTU 64 / TU 32 - 15078 kbps
CTU 32 / TU 32 - 14608 kbps
CTU 32 / TU 16 - 14472 kbps

Of these, CTU 32 / TU 32 resembles the original the most. It's interesting that setting TU 16 also causes distortion in the same areas as CTU 64 / TU 32. I checked areas like eyes, hair etc. which have easily some sort of distortion because there are many fine lines and things that can be compared quite easily.

I've just started testing what CRF value is visually enough for 1080p so the final bitrate will probably be lower than what I got from my tests. I'd estimate CRF 20-21 would be the final value.
Target CRF will also depend on other parameters, if you are still adjusting those.

Overall, that is a very idiosyncratic set of options. Nothing looks wrong (and I'd love to hear who you picked some of those!, but it's definitely outside of any combination of settings that MCW would be doing psychovisual optimization for.


I'm curious about why you chose these particular settings:
  • --merange 44
  • --splitrd-skip
  • --max-merge 2
  • --deblock -2:-2
  • --rdpenalty 1
  • --qg-size 16
  • --bframes 10
Is this for encoding anime or some other kind of synthetic or mixed synthetic/natural image encoding?
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