[FFmpeg-devel] [PATCH] VBR header for "libmp3lame"

[Michael Niedermayer]

On Sat, Apr 16, 2011 at 03:35:35PM +0200, Reimar Döffinger wrote:
> On Fri, Apr 15, 2011 at 08:07:27PM +0200, Peter Belkner wrote:
> > Hi,
> > 
> > in case the switch "-aq" is provided to the "libmp3lame" codec a VBR
> > MP3 is generated as e.g. in
> > 
> >    ffmpeg -i a.wav -aq 2 b.mp3
> > 
> > This corresponds to
> > 
> >    lame -V2 a.wav b.m3
> > 
> > Unfortunately no VBR header is written often leading to a completely
> > wrong estimate of the duration during playback (cf. e.g. http://lists.mplayerhq.hu/pipermail/ffmpeg-user/2007-October/011573.html).
> > 
> > The patch allows for writing the VBR header as generated by "libmp3lame.a".
> 
> Unfortunately I don't know what exactly the header contains, but I think

google says:
http://www.codeproject.com/KB/audio-video/mpegaudioinfo.aspx

and i think it should be generated in the mp3 muxer independant of
the encoder doing anything special

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
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