[FFmpeg-devel] [PATCH] Lost VBR header
michaelni at gmx.at
Sat Apr 16 16:39:09 CEST 2011
On Sat, Apr 16, 2011 at 04:36:54PM +0200, Michael Niedermayer wrote:
> On Fri, Apr 15, 2011 at 12:19:32PM +0200, Peter Belkner wrote:
> > Hi,
> > FFmpeg is known for eating up the VBR header of MP3 files in case of
> > stream copy as e.g.
> > ffmpeg -i a.mp3 -acodec copy -y b.mp3
> > The patch fixes this provided the "-acodec" switch is given in front of
> > the "-i" switch:
> > ffmpeg -acode copy -i a.mp3 -y b.mp3
> > Apart from this subtility the patch should improve "libavformat.a" in
> > order that third party client code may copy MP3s without losing the VBR
> > header (as. e.g. my R128GAIN, see below).
> > I really would apreciate if you could apply the patch or provide an
> > equivalent solution.
> If the muxer simply generates a vbr header which should be quite
> trivial for it to do (just counting packets and their sizes for
> duration and buikding a simple index too)
also note that the muxer gets exactly 1 mp3 frame at a time so you
dont need to parse the bytestream or anything
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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