[FFmpeg-devel] Support master branch of OpenJPEG and Grok J2K codecs

Ronald S. Bultje rsbultje at gmail.com
Mon Apr 4 14:56:17 CEST 2016


Hi,

On Mon, Apr 4, 2016 at 8:43 AM, Aaron Boxer <boxerab at gmail.com> wrote:

> Hi Ronald,
>
>
> On Mon, Apr 4, 2016 at 8:34 AM, Ronald S. Bultje <rsbultje at gmail.com>
> wrote:
>
> > Hi,
> >
> > On Mon, Apr 4, 2016 at 7:59 AM, Aaron Boxer <boxerab at gmail.com> wrote:
> >
> > > On Mon, Apr 4, 2016 at 7:13 AM, wm4 <nfxjfg at googlemail.com> wrote:
> > >
> > > > On Sun, 3 Apr 2016 17:31:25 -0400
> > > > Aaron Boxer <boxerab at gmail.com> wrote:
> > > >
> > > > > Hi Folks,
> > > > >
> > > > > Here is a small patch to get FFmpeg working with both OpenJPEG
> master
> > > and
> > > > > Grok master, for J2K support.  The comment on the commit has all of
> > the
> > > > > details; the main change is to remove the OPJ_STATIC flag from
> > > configure,
> > > > > so that FFmpeg can be configured with a dynamic build of both
> codecs.
> > > > >
> > > > > I also want to reiterate that because FFmpeg can be distributed
> under
> > > GPL
> > > > > v3, and Grok is licensed under the AGPL, there are no licensing
> > issues
> > > > > regarding distributing FFmpeg together with Grok.
> > > > >
> > > > > Quoting from Wikipedia:
> > > > >
> > > > > "By contrast, GPLv3 and AGPLv3 each include clauses (in section 13
> of
> > > > each
> > > > > license) that together achieve a form of mutual compatibility for
> the
> > > two
> > > > > licenses. These clauses explicitly allow the "conveying
> > > > > <https://en.wiktionary.org/wiki/convey#Verb>" of a work formed by
> > > > linking
> > > > > code licensed under the one license against code licensed under the
> > > other
> > > > > license,[3]
> > > > > <
> > >
> https://en.wikipedia.org/wiki/Affero_General_Public_License#cite_note-3
> > > > >
> > > > > despite the licenses otherwise not allowing relicensing under the
> > terms
> > > > of
> > > > > each other.[4]
> > > > > <
> > > >
> > >
> >
> https://en.wikipedia.org/wiki/Affero_General_Public_License#cite_note-fsf2-4
> > > > >
> > > > > In this way, the copyleft of each license is relaxed to allow
> > > > distributing
> > > > > such combinations.[4] "
> > > > > <
> > > >
> > >
> >
> https://en.wikipedia.org/wiki/Affero_General_Public_License#cite_note-fsf2-4
> > > > >
> > > > >
> > > > > So, this patch will expand the choice of J2K codecs for all users
> who
> > > use
> > > > > FFmpeg under the GPLv3 license.
> > > >
> > > > AGPL is evil. That alone warrants creating a better, actually free
> > > > version of the decoder.
> > > >
> > >
> > > The only difference between AGPL and GPL is the proviso that users
> > > connecting to a program using AGPL code
> > > must be provided with the full source code for the program. This is to
> > > close the loophole in the GPL where
> > > someone can take free software, put it in the "cloud", and then treat
> it
> > as
> > > closed, non-free software, because they
> > > do not have to distribute modifications.
> > >
> > > Please explain why you think this is a Bad Thing (TM)  ?
> >
> >
> > Because it's a fork, not in the codebase sense but in the licensing
> sense,
> > but the effect is the same. We will not be able to combine multiple
> > branches of the fork because each of them is only compatible in its own
> > direction - "LGPL code can be merged into AGPL code to create AGPL code"
> > but not the other way around.
> >
> > That is fundamentally unfair for those of us that actually _want_ a
> > LGPLv2.1-or-later codebase. Why would you get all our spoils but not the
> > other way around?
> >
>
> Sorry, I was wrong in my original statements. I've learned a bit more about
> how these
> licenses work.
>
> This is not a fork. FSF allows GPL 3 and AGPL 3 code to be combined.
> If FFmpeg can be distributed according to GPL 3, then it can included AGPL
> 3 code.
>
> Very simple.


Oh, no, no, no. Very simple for _you_, with your _simple_ goal of using
ffmpeg and profiting from it by AGPL'ing your component.

But for me, as a maintainer, can I combine GPLv2 with AGPLv3? For example,
can I link a GPLv2 application with a AGPLv3 build of ffmpeg and distribute
the result? Can I link an AGPLv3 build of ffmpeg with a closed-source
application and distribute the result? Can "big" users of ffmpeg, companies
that fund out project (through e.g. GSoC), like, say, Google, use AGPLv3
builds of ffmpeg without a change in their respective requirements for
complying with the license terms?

Or, to say it differently: who profits from AGPLv3 components? FFmpeg? Or
just you? I think it's just you, and that's extremely selfish. It's not in
the best interest of our project to accept AGPLv3 components, it's only in
your self-interest that it be accepted. And _that_'s a fundamental problem.

Ronald


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