x265's CRF versus low contrast HDR sources..

[Boulder]

Originally Posted by benwaggoner

Going to a fixed file size at a reasonably challenging bitrate (so you're going to see some artifacts) is what I've found as the most efficient way to do these comparisons.

Then again, if bitrate is a property that I don't need to control (because I cannot tell a static average bitrate for all material), I shouldn't worry about it. As CRF is as close to constant quality that we can ever get, I have been able to set a satisfying CRF level which means it should be fixed to that.

For example, I just ran two test encodes; aq-mode 1, strength 1.0 gave me 6013 kbps and strength 1.8 needed 11610 kbps for the same clip with all the other settings kept the same. Running a 2-pass encode comparison at 6000 kbps, it's quite easy to predict that strength 1.0 will have less artifacts or is sharper and more detailed. It still doesn't mean it's any better at my desired base quality level