[FFmpeg-user] FFmpeg and libx264 presets and Constant Rate Factor (CRF)

[Bill Crockett]

First of all, I am not doing 2 pass encoding.  I am using the CRF option.

They say for constant quality encoding, you will save bitrate by choosing a 
slower preset.   A slower preset will provide better compression.

ultrafast
superfast
veryfast
faster
fast
medium – default preset
slow
slower
veryslow
placebo

I do not care about compression or files size.  But I do care about quality.

If I choose a CRF of 20, and I use the "veryslow" preset, the quality will 
still be the same if I choose a CRF of 20 and use the "superfast" preset?

The same with this.  If I choose a CRF of 10, and I use the "veryslow" 
preset, the quality will still be the same if I choose a CRF of 10 and use 
the "superfast" preset?

Is this correct about the quality please?