x264 CRF22 equals old CRF20?

[valnar]

I've been happily encoding for awhile with an older x264 and I see now that the new one increased the size of my constant quality CRF20 encodes dramatically. In the AutoMKV thread, it mentions that CRF22 is now equivalent to CRF20 from x264 builds several months ago. My testing shows that is roughly true - and about the same file size.

Of course, searching for x264 and CRF on Doom9 is like looking for a needle in a haystack. Can somebody point me to the thread or posts that define all these new changes within the last month? And why CRF22 is now approx the same quality as CRF20 from before?

Thanks.

[LoRd_MuldeR]

Yes, recent changes in x264 also changed the meaning of CRF values. But there is no formula to calculate the "new" CRF value from an "old" one.

It's like it has always been: Find the highest CRF value that still satisfies your eyes and use that one for all future encodes ;)

[Dark Shikari]

It depends on the source; some sources rose in bitrate, others dropped. I tried to keep it centered, but obviously things like anime reacted very differently as compared to live-action, for example.

[valnar]

It depends on the source; some sources rose in bitrate, others dropped. I tried to keep it centered, but obviously things like anime reacted very differently as compared to live-action, for example.

Is there a thread about that?

I did a Buffy TV show episode - 43 minutes. Old encode was 496MB at CRF20. New x264 encode at CRF20 is 770MB. I assume the encoder didn't get worse, so setting it to CRF22 makes it 503MB. In most cases the new CRF22 encode should be as good if not better than the old CRF20, strictly due to the enhancements in the encoder?

ie. I assume it should be rare that a 500MB encode from an older version would be better than a 500MB encode on the new version? If I were to do a two-pass and set the size to 500MB, would that be the case?

I am using CRF, but if I re-do all these episodes again, I want to keep it around the same file size, and not go up to 700MB+

[Dark Shikari]

ie. I assume it should be rare that a 500MB encode from an older version would be better than a 500MB encode on the new version? If I were to do a two-pass and set the size to 500MB, would that be the case?The new version will certainly be better than the old version at the same bitrate; the change that affected the bitrate for a given CRF also improved ratecontrol considerably (nevermind all other changes since then).