[Ffmpeg-devel] overall license review - adding proper license headers

Michael Niedermayer michaelni
Fri Sep 1 20:02:56 CEST 2006


On Fri, Sep 01, 2006 at 07:22:25PM +0200, Diego Biurrun wrote:
> On Fri, Sep 01, 2006 at 07:06:35PM +0200, Michael Niedermayer wrote:
> > 
> > On Fri, Sep 01, 2006 at 04:13:47PM +0200, Diego Biurrun wrote:
> > > I took the time to look through all of the files in FFmpeg and review
> > > the licensing conditions.  Not the most exciting thing in the world to
> > > do, but I figured it would be worth the while.  I've stumbled across
> > > some things that demand attention and/or clarification.  I'm willing to
> > > commit the fixes, but I'll need your opinions, comments and permission.
> > > 
> > > 
> > > libavcodec/fdctref.c claims all rights reserved.  This is non-free.
> > > Houston, we have a problem.  Where does this file come from?
> > 
> > some reference code, mpeg1 or 2 probably, and as already known its not
> > part of libavcodec just dct-test so dont compile dct-test if you dont
> > have an explicit written and with blood signed license from the author
> The problem is that we are redistributing a file that does not come with
> a license that allows redistribution ...

its only a tiny part of the reference code and its only used for testing and
comparing our (i)dcts against it furthermore it is as said not part of compiled
ffmpeg libavcodec or libavformat IMO thats fair use, but iam not against it
if someone wants to rewrite it, its very little work, just a schoolbook (i)dct

> > > libavcodec/i386/idct_mmx.c is marked as GPL but with the exception that
> > > it can be used as LGPL in libavcodec.  IMO this is equivalent to
> > > releasing it under the LGPL in libavcodec.  The licensing note should be
> > > updated.
> > 
> > disagree, the code can either
> > A. be LGPL
> > B. be GPL with an exception that linking with LGPL lavc is ok
> > 
> > its not completely clear which it is
> Let's look at the actual wording, at the top of the file there is a
> note saying
>   Note: For libavcodec, this code can also be used under the LGPL license
> This does not really fit B. IMO, there is no mention of linking.  I read
> it to mean that we are allowed to use it under the LGPL license, i.e.
> redistribute it as LGPL.  Changing the license header to LGPL should be
> OK then.

why dont you simply ask the author? i too think he wants the IDCT to be
useable under LGPL but its really nicer to ask instead of guessing what a
comment which maybe has been written by fabrice means ...
btw, try the mpeg2dec-devel ML if the email address in the header doesnt

> > > libavutil/adler32.c says
> > > 
> > >  * For conditions of distribution and use, see copyright notice in zlib.h
> > > 
> > > we don't include zlib.h so the conditions should be pasted there IMO.
> > 
> > agree
> Which zlib.h was it?  The standard one included with zlib and found on
> most systems?

i dont know, IIRC i didnt commit that stuff to cvs

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is

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