[FFmpeg-devel] [PATCH] mpeg4videodec: silence "Invalid and inefficient vfw-avi packed B frames detected" warning

[Reimar Döffinger]

On Thu, Aug 29, 2013 at 04:44:21PM +0200, Michael Niedermayer wrote:
> On Thu, Aug 29, 2013 at 04:38:30AM +0200, Reimar Döffinger wrote:
> > 
> > 
> > On 29.08.2013, at 00:29, wm4 <nfxjfg at googlemail.com> wrote:
> > 
> > > ---
> > > I mentioned it on IRC, and it wasn't really clear why this message is
> > > needed. On the other hand, this is printed with virtually every AVI
> > > file, and raises more questions than it answers, so I guess this is up
> > > to discussion.
> > 
> > The reason the warning is that files with this feature were written by broken software, the files are incorrect and waste space.
> 
> they arent valid mpeg4 in avi
> they could be considered valid divx in avi though if "you" simply
> define that to be valid for divx
> 
> 
> > IIRC programs like virtualdub can fix these broken files, at least losslessly, possibly even in-place.
> 
> can someone confirm that ?
> 
> (iam asking as this seems almost the only use the warning would have
>  to an end user)

I just tested with avidemux. It asks "Packed Bitstream detected. Do you
want me to unpack it?". If you answer yes and just save the file you get
a fixed one.
Tested with
http://samples.mplayerhq.hu/V-codecs/MPEG4/pegasus-1958-chiptune.avi
I am quite certain virtualdub has the same feature, and in a similarly
easy to use way.