x265 CRF value equivalent to x264

[Wakaku]

Hello, I would like to ask those whore are quite experienced to both x264 and x265 CRF encoding. What I am looking for is the exact or "closest to exact" value of x264 CRF 17 to x265's. The value I use for x264 CRF is 17 and I may go to 18 if I find the file size too big for my taste. I don't go to x264 CRF 16 or 19, as 16 is just the same to me but bigger file size thus waste of space, and 19 is just not quality enough for me. Again, I am kindly asking for those who have both the x264 and x265 CRF encoding experience. Thank you in advance, friends.

Let's say same profile, same tune, same preset, same source file:
1. x264 CRF 17 = x265 CRF ??
2. x264 CRF 18 = x265 CRF ??

[gdx]

There is no clear answer, basically each preset and each revision of the codec can have a different equivalences, but normally is assumed that x264 CRF = x265 CRF -2 (x264 CRF 17 = x265 CRF 19) but this is not always true and can vary from video to video, it also possible that it varies depending of the CRF value (the equivalence is not exactly linear).

[Bernix]

There is lot of articles about this. It is of not of course some firm rule. It is not presise, but I believe in FFMPEG that they know what saying.
Higher resolution is in favor to x265 (I hope someone will understand this made up english)
Good to read.
https://trac.ffmpeg.org/wiki/Encode/H.265


Bernix

[Marsia Mariner]

F.W.I.W........

https://forum.doom9.org/showthread.php?t=174079