[pulseaudio-discuss] License problem: LDAC codec & pulseaudio

[Tanu Kaskinen]

On Fri, 2019-04-19 at 00:17 +0200, Pali Rohár wrote:
> On Saturday 23 February 2019 17:59:57 Tanu Kaskinen wrote:
> > On Sat, 2019-02-23 at 16:06 +0100, Pali Rohár wrote:
> > > Hello,
> > > 
> > > I would like to discuss about licence problems with usage of LDAC
> > > encoder libldac in pulseaudio. LDAC is a codec used by some Sony
> > > bluetooth headsets and it would be nice to have support for it after my
> > > patch series for Modular API for A2DP codecs is merged.
> > > 
> > > There is only one released LDAC encoder. It is libldac which can be
> > > found at: https://android.googlesource.com/platform/external/libldac/
> > > It is licensed under Apache License Version 2.0.
> > > 
> > > If I understood correctly pulseaudio is licensed under LGPL v2.1 or
> > > later with some exceptions when some optional GPL dependences are
> > > enabled then server part is licensed under GPL v2 or later. So it can be
> > > distributed under GPL v3, right? Please correct me if I'm wrong.
> > > 
> > > According to FSF https://www.gnu.org/licenses/license-list.html#apache2
> > > Apache License Version 2.0 is compatible with GPL v3, but is
> > > incompatible with GPL v2.
> > > 
> > > So, would it be feasible to write LDAC specific code for pulseaudio
> > > under GPL v3 license (in separate files) and make compile time option to
> > > enable/disable GPL v3 LDAC support? When enabled it would mean that
> > > compiled binary of puleaudio server and server modules are forced to be
> > > distributed under GPL v3 and thanks to compatibility with Apache License
> > > Version 2.0, it would be possible to use libdac library. When disabled
> > > then it would be like before (without LDAC and with license like
> > > before). Am I correct?
> > 
> > Yes, I believe you're correct, and at least I am fine with adding LDAC
> > support via libldac.
> 
> I asked people in SUSE and I got answer that it should be ok if there is
> no GPLv2-only code. So has pulseaudio some GPLv2-only code or is all code
> compatible with GPLv3 (i.e. GPLv2-or-later)?

PulseAudio doesn't have any GPL code, but it has optional GPL
dependencies, all of which seem to be either GPLv2-or-later or GPLv3-
or-later (gdbm is the one that is nowadays licensed under GPLv3). The
LICENSE file could be more clear on these details...

You suggested writing LDAC specific code under GPLv3, but since
LGPLv2.1-or-later is convertible to GPLv3, I think the LDAC code should
be under LGPLv2.1-or-later like the rest of the code base.

-- 
Tanu

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