quality based H.264 encoding

[screenshaper]

Is there a way to encode H.264 with "custom ffmpeg" using CRF (Constant Rate Factor) quality parameter instead of bitrate?
As recommended on ffmpeg H.264 encoding guide:
https://trac.ffmpeg.org/wiki/Encode/H.264

The bitrate field in FFAStrans' custom ffmpeg pane controls witch parameter(s) of ffmpeg command line? Maybe "-maxrate"?

[admin]

The built in bitrate sliders/inputs sets the "-b:v" and "-b:a" parameters. If you manually insert bitrate and codecs in the command options the built inn will be omitted. Generally, you can use the "Custom FFmpeg"-encoder just like any ffmpeg.exe command except for the first input file and the last output.file.

In future versions the bitrate and codec options might be removed.

-steipal

[screenshaper]

How can I disable b:v parameter in the current version?
What happens if I put it to zero?

[admin]

You don't need to disable them. If you use -b:v, -b:a, -c:v or -c:a in you command line the built in will be omitted. Simple as that

-steipal

[screenshaper]

Ok!
Many thanks.
You're so kind, quick and useful.
As usual.