Select provider of libav* libraries

[Bálint Réczey]

Hi Andreas,

2015-06-06 19:15 GMT+02:00 Andreas Cadhalpun <andreas.cadhalpun at googlemail.com>:
> Hi,
>
> On 06.06.2015 02:01, Bálint Réczey wrote:
>> GPL imposes no restrictions on _using_ software, but on distributing
>> it without properly licensed source, i.e. distributing a binary
>> compiled from GPLv3 source without also providing the source under
>> GPLv3 is prohibited.
>> Compiling hedgewars without libavcodec-extra creates a GPLv2 binary
>> which is distributable.
>> The user can install libavcodec-extra which would also work with
>> hedgewars, but no one violated GPLv3 up to this point AFAIK.
>
> On 06.06.2015 02:07, Reinhard Tartler wrote:
>> The keyword in this sentence is "using". I do NOT think we need to
>> prevent users from doing stupid things, but we must ensure that Debian
>> as a (re-)distributor does not violate any licenses. The dependencies
>> are set up in a way that ensures that all packages build against the
>> GPLv2+ variants, and nowhere on the buildds or on any other Debian
>> machine we distribute a piece of software that would be in violation
>> here. And that was the point of this exercise.
>
> The problem is that Debian users must be allowed to redistribute it,
> but as far as I understand it, it is not allowed to distribute e.g.
> a live DVD with hedgewars and libavcodec-extra installed.
> I also pointed this out in the previous discussion [1].
I'm not absolutely sure, but IMO yes, such Live DVD-s would not be
allowed, but it is a problem of live DVD makers to care about. Package
maintainers can't and should not prevent this usage.

>
>> Since the hassle makes more work for active ffmpeg maintainers and
>> while I sponsored a few uploads I don't consider myself one I should
>> not make the call, but it would be really nice to provide the AMR
>> encoder as well in Debian and also keeping hedgewars in the archive.
>>
>> Maybe there is a way of providing libavcodec-extra and having modern
>> packaging scripts. Maybe patching the build could help, but I have not
>> checked this idea.
>
> The AMR encoder is anyway just a wrapper around libopencore/libvo.
> Gstreamer also has similar wrappers and since they are plugins, the
> license is less of a problem.
> Thus anyone really wanting to encode AMR can use gstreamer.
I'm OK with disabling AMR encoder in ffmpeg and stay GPLv2 compatible
with the packages since I have no packages requiring it nor use-cases
as a user requiring it, but I prefer the choice provided by by current
libav packaging.

Would it be hard to patch the build system?

Cheers,
Balint