what is the option for a veriable bit rate, instead of a fixed one for mp3?

[sommers]

ffmpeg.exe −i 1% −ab 384k xxx.mp3


what is the command option for a veriable bit rate, instead of a fixed one, to make a mp3?

something like this
ffmpeg.exe −i 1% −abvar 190k xxx.mp3 causes it to fuctuate around 190k

[sneaker]

-q:a 2
https://trac.ffmpeg.org/wiki/Encode/MP3

[gregalan]

ffmpeg.exe −i 1% -vn -c:a libmp3lame -abr 1 -b:a 192k xxx.mp3

for average bit rate.

ffmpeg.exe −i 1% -vn -c:a libmp3lame -q 2 xxx.mp3

for full vbr mode, q is from 0-9, 0 being best quality, and 9 worst.

[sommers]

ffmpeg.exe −i 1% -vn -c:a libmp3lame -q 2 xxx.mp3 worked as i wanted, thanks and https://trac.ffmpeg.org/wiki/Encode/MP3 thanks for this too.

i need to ask few things to remove some loose ends.

1. -qscale was found in video option in the document, but i suppose it would work for audio as well.
2. -qscale:a, can i interpret this as a quality control for audio ? since it came with :a

3. -codec option is not found in document, documemt only has -vcodec or -acodec

i found the option in https://ffmpeg.org/ffmpeg.html#Main-options
-c[tream_specifier] codec
-codec[tream_specifier] codec

4. why is -q:a 2 the same as -q 2?
5. -vn disable video, would this option encode it faster?

[sneaker]

Stop saying "in the document". We have no idea what document you are talking about.

2. Yes. http://ffmpeg.org/ffmpeg.html#Stream-specifiers
3. Already told you: -vcodec and -acodec are deprecated. They mean(t) the same as -c:v/-codec:v and -coded:a
4. see 2.
5. No. If you specifiy "xxx.mp3" output file ffmpeg already knows you don't want video because mp3 is implicitly audio-only. If you specify an output format that can hold video (e.g. "xxx.mkv") then it will make a difference.

[sommers]

ffmpeg.exe came with these documents

faq.html
ffmpeg.html
ffmpeg-doc.html
general.html