Bug#694657: closed by Reinhard Tartler <siretart at tauware.de> (Bug#694657: fixed in libav 6:9.1-1)

Wed Jan 9 22:27:44 UTC 2013

Quoting Francesco Poli (2013-01-09 22:07:30)
> On Wed, 09 Jan 2013 21:10:06 +0100 Jonas Smedegaard wrote:
> > Quoting Francesco Poli (2013-01-09 19:18:02)
> > > At the beginning of the new debian/copyright file, I read the following
> > > comment:
> > > 
> > > | Comment:
> > > |  Because the libavcodec-extra-* package (since libavcodec-extra-54)
> > > |  links against libraries licensed under Apache-2.0 (not compatible with
> > > |  LGPL), effective license of that package and libav-dbg is GPL-3+.
> > > 
> > > This does not look too clear to me.
> > > 
> > > Which license is the libavcodec-extra-* package released under?
> > > LGPL-2.1+ or GPL-2+ ?
> > 
> > GPL-2+.  I fail to understand how that can be misunderstood from that 
> > comment.
> 
> Well, I think it _can_ be misunderstood because... it's not what it is
> written there!   :-/

You did not ask what was written, but how some package was licensed.

What I answered (and what the comment attempts to communicate) is which 
licensing could reasonably apply to said binary - i.e. which (new or 
exisisting, not necessarily one in use anywhere in the World already) 
license might be compatible with the licenses issued by all copyright 
holders involved in the final binary package.

A comment is not a licensing statement.  The comment does not indicate 
what licensing Debian issues for that package. Nor do the comment 
indicate what licensing _anyone_ have issued for the binary package.

> Moreover, the comment states that Apache-2.0 is incompatible with 
> LGPL: I think this is incorrect and misleading.

Ah, yes - I agree there is a typo in the comment:  s/LGPL/GPL-2/

> > So even if you cannot find a single GPL-3+ licensed piece anywhere 
> > in this project, the very purpose of libavcodec-extra-* (as compared 
> > to libavcodec-*) is to link against GPL-licensed parts.
> 
> This is the part that's not clear.
> Where is this stated?

As I wrote earlier as well: In the long description of that binary 
package.

> The comment does clarifies this subtlety.

Apparently that comment confuses more than it helps.  I suspect that is 
because that comment relates to licensing of _binary_ package which is 
not really the purpose of debian/copyright file.

> And I cannot see it documented in the binary package description,
> either: http://packages.debian.org/experimental/libavcodec-extra-54

Uhm, look for the keywords Apache and GPL on that page.

> Unless I start digging into the debian/copyright files of all the
> dependencies, and find out that
> 
>   * libx264-123 is under GPL-2+
>   * libxvidcore4 is also under GPL-2+
>   * a small part of libmp3lame0 is under GPL-1+
> 
> Is this (together with the linking with Apache-2.0 libraries) the
> reason why the _binary_ package libavcodec-extra-* is effectively under
> GPL-3+, rather than "GPL-3+ or LGPL-2.1+ (excluding GPL-2)" ?

Yes.

> If this is the case, then I think the comment should be clarified (and
> also the binary package description).

Instead of trying to improve it, I suggest we *remove* that comment!

> > > If this is really the case, then, although it's true that 
> > > Apache-2.0 is not compatible with GPL-2, I don't think it's 
> > > accurate to say that Apache-2.0 is not compatible with LGPL...
> > 
> > Correct.  One need to check the long description and 
> > build-dependencies of libavcodec-extra-* to get an epiphany here.
> 
> If one has to dig into all the dependencies anyway, then the comment 
> does not seem to be too useful...

What is wrong with "check the long description"?

> > > This seems to imply that I cannot distribute a program under a 
> > > GPL-3-incompatible license (for instance, BSD-4-clause) linked 
> > > with libavcodec-extra-*: I don't see any reason why such a program 
> > > should be considered as legally undistributable...
> > 
> > Not sure what you are trying to say here.
> > 
> > It is legal to distribute libavcodec-extra-* and it is legal to 
> > distribute GPL-3-incompatible code.
> 
> Not if one wants to distribute the two together, linked with each 
> other, though.
> At least, this is what is said by the FSF legal theory of linking...

...and I looked out the window this morning.

Let me repeat: Not sure what you are trying to say.

> Anyway, let's see whether you think that the following re-formulation
> is accurate:
> 
> | Comment:
> |  Because the libavcodec-extra-* package links against libraries
> |  licensed under GPL-2+ and (since libavcodec-extra-54) against libraries
> |  under Apache-2.0 (compatible with GPL-3, but not with GPL-2), effective
> |  license of that package and libav-dbg is GPL-3+ (rather than LGPL-2.1+).

Your rewrite introduce new confusions.  I would prefer we drop the 
comment instead.

> A similar clarification may be applied to the description of the
> libavcodec-extra-* binary package.

I fail to see what is wrong with current wording in long description of 
libavcodec-extra-* binary package.

 - Jonas

-- 
 * Jonas Smedegaard - idealist & Internet-arkitekt
 * Tlf.: +45 40843136  Website: http://dr.jones.dk/

 [x] quote me freely  [ ] ask before reusing  [ ] keep private
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