[FFmpeg-user] -b:a doesn't give me desired output bitrate

Moritz Barsnick barsnick at gmx.net
Wed Jul 5 11:05:54 EEST 2017

On Wed, Jul 05, 2017 at 09:52:21 +0200, Moritz Barsnick wrote:
> It is being set, but according to lame/libmp3lame's documentation, the
> lowest constant bitrate it can encode at 48 kHz sample rate is 32
> kbits/s.

Actually, that's a limitation of the MP3 codec, not of the libmp3lame

> I believe MP3 just isn't suitable. Opus is basically quite efficient.
> MP3 can't match that. If you need those recordings in MP3, they'll be
> larger. If it's an option, you may want to try the codec HE-AAC v2
> instead. (You'll need libfdk_aac to encode to that variant, I believe.)
> I understand that codec is also great with low bitrates (and I have
> heard quite "good" sounding music in 48 kbits/s stereo.)

So this remains the recommendation: Live with it or choose a suitable
codec. How about Opus? ;-)


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