[FFmpeg-user] request for review: feature request of "disallow unallowed bitrates"

[Carl Eugen Hoyos]

Roger Pack <rogerdpack2 <at> gmail.com> writes:

> $ ffmpeg -i in.mp3 -b:a 40000k out.mp3
> 
> (it ends up writing it as a 320 Kb/s audio bitrate--not the specified
> "impossible" number).
> 
> Similarly.
> $ ffmpeg -i in.mp3 -b:a 310k out.mp3
> 
> seemingly "magically" produces a file with 320 Kb/s bitrate--not 310)
> 
> So I was thinking of filing a trac with a request to at least "warn"
> when it ends up picking some bitrate other than that specified.
> Any feedback before I do so?

How should FFmpeg know that (the installed version of) lame 
will not encode the requested bit-rate?

Carl Eugen