[FFmpeg-user] cutoff argument not passed to libmp3lame

Bernhard Döbler programmer at bardware.de
Mon Dec 19 00:58:46 EET 2016


i recently looked into an mp3 file.

It contained the string with arguments is was encoded with. It looked 
like: -m j -V 0 -q 0 -lowpass 22.1 --vbr-mt -b 32

I looked into ffmpeg documentation and saw there's an argument "-cutoff" 
that should do, what "-lowpass" does in LAME.

I encoded some files with ffmpeg playing with the cutoff argument and 
saw no change in the resulting file.

When I used "-c:a aac" instead of "-c:a libmp3lame" cutoff had an 
impact. I looked at the mp3/m4a file with a tool "Spek" that draws a 
graph of the frequencies used in the file.

I now wonder why the argument is not passed to the LAME library?


Bernhard Döbler

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