[FFmpeg-user] CRF and Preset in H265, am I loosing it?

Bouke / VideoToolShed bouke at videotoolshed.com
Sat May 2 15:30:26 EEST 2020

I’ve always thought that setting -crf [x] determines the output quality, while (in the same line) -preset [x] affected the output file size.
(Where faster speeds result in bigger output files at the same quality.

But now this:
https://trac.ffmpeg.org/wiki/Encode/H.265 <https://trac.ffmpeg.org/wiki/Encode/H.265>

Under the Constant Rate Factor (CRF):

-Put differently, if you choose ultrafast, the encoding process is going to run fast, and the file size will be smaller when compared to medium.

WTF? I would think the output file size will be bigger? (I take it this is just a stupid mistake…)

Then, the line continues:
-The visual quality will not be as good. 
Now it gets confusing. This sorta kinda suggests that -crf and -preset are not to be used together?

What am I missing here?



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