License impact of opencore-amr and vo-aacenc/amrwbenc

[Fabian Greffrath]

[Posting this again to debian-legal, as suggested by Jonas. Keeping 
pkg-multimedia and pkg-gstreamer in CC for this initial mail, but 
please keep replying to -legal. Sorry for the inconvenience!]

Hi all,

I'd like to discuss an issue with you that I have not yet fully 
understood. It is about the opencore-amr and vo-aacenc/amrwbenc 
packages, which are licensed under the Apache-2.0 license and which 
apparently has an impact on the licenses of the software linking 
against them.

AFAIUI the GPL-2 is not compatible with the Apache-2.0 license, but 
the GPL-3 is. This means, for all software which is released under the 
terms of GPL-2+ the GPL-3 has to apply once it is linked against a 
library licensed under Apache-2.0, such as the ones mentioned before.

Well, in Debian gstreamer0.10-plugins-bad is linked against vo-aacenc 
and vo-amrwbenc and gstreamer0.10-plugins-ugly is linked against 
opencore-amr, but according to their respective debian/copyright 
files, the packages are still released under the terms of the GPL-2+. 
Is this simply an oversight and should get changed to GPL-3?

For the same reason we have a libav-extra package in Debian which 
provides a libavcodec library linked against the aforementioned 
libraries. According to its debian/copyright file, the GPL-3 applies 
to the resulting binary packages. What does this mean for packages 
linking against this variant of libavcodec? What are the exact license 
incompatibilities that we want to avoid by providing this variant? 
Does this mean that a package which is licensed under GPL-2 (not 2+) 
cannot get linked against the GPL-3'ed libavcodec?

Please enlighten me!

Best regards,
Fabian