[libav-tools] AAC encoded files show "0 kbps" average bitrate.

Oliver Hookins oliver at soundcloud.com
Tue Oct 9 14:43:29 CEST 2012

> From: Luca Barbato <lu_zero at gentoo.org>
> > Well, I'm encoding these with "-b:a 96000" and I would expect constant
> > bitrate to be used, so this makes no sense on two levels. Given what I
> > discovered above with the keyframe fragment option, the average
> > bitrate metadata seems to be a red herring, but even obeying the
> > standard, avconv should be setting a constant bitrate and expressing
> > that bitrate in the metadata.
> Apparently it isn't constant for the muxer check, looks like something
> is going on there...
> Which is your exact command line ?

avconv -i input-resampled.wav -b:a 96000 -acodec libfdk_aac -movflags
frag_keyframe output-libfdk_aac.mp4

But you can substitute -acodec for libfaac, libvo_aacenc, etc as we
tried all the different AAC codecs avconv supports.

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