[FFmpeg-devel] GP License question

[Aaron Boxer]

Hi Ismail,


On Tue, Mar 22, 2016 at 8:48 AM, Ismail Donmez <ismail at i10z.com> wrote:

> On Tue, Mar 22, 2016 at 2:44 PM, Aaron Boxer <boxerab at gmail.com> wrote:
> > Hi Carl,
> >
> >
> > On Tue, Mar 22, 2016 at 8:32 AM, Carl Eugen Hoyos <cehoyos at ag.or.at>
> wrote:
> >
> >> Aaron Boxer <boxerab <at> gmail.com> writes:
> >>
> >> > I am developing a jpeg 2000 codec licensed under Affero GPL.
> >>
> >> Why don't you work on fixing the remaining issues with
> >> FFmpeg's implementation instead?
> >>
> >
> > That would be OpenJPEG.  I have made quite a few contributions to
> OpenJPEG.
> > For a number of reason which I don't want to bore you with, I decided to
> > fork the project.
> >
> > Now, since parts of FFMpeg are licensed under GPL 2, and usage of them
> > flips the license to GPL 2,
> > it seems to me that adding an Affero component should not be a big deal.
> >
> > Or am I wrong?  Someone mentioned EVIL :)
>
> AGPL is incompatible with GPLv2:
>
> "Please note that the GNU AGPL is not compatible with GPLv2. It is
> also technically not compatible with GPLv3 in a strict sense: you
> cannot take code released under the GNU AGPL and convey or modify it
> however you like under the terms of GPLv3, or vice versa. However, you
> are allowed to combine separate modules or source files released under
> both of those licenses in a single project, which will provide many
> programmers with all the permission they need to make the programs
> they want. See section 13 of both licenses for details."
>
> See https://www.gnu.org/licenses/license-list.en.html#AGPLv3.0


Thanks. I don't mean to start a nasty license argument here, just trying to
understand things better.

Yes, AGPL is not compatible with GPL v2, but LGPL v2 is compatible with
AGPL,  i.e. FFMPeg using AGPL component
can simply be released under AGPL.  Not to create an AGPL fork of FFMPeg,
just to offer this option for people
who want to use the AGPL component.  This is the same situation as FFMpeg
being released under GPL v2 when
using GPL v2 components.


Kind Regards,
Aaron