[Libav-user] Complying with L-GPL license

Carl Eugen Hoyos cehoyos at ag.or.at
Tue Feb 12 16:07:45 CET 2013

Kalileo <kalileo at ...> writes:

> From a practical point of view, I understand that the 
> sources (even if unmodified) should be either - added 
> to the software package (which gets distributed, and 
> contains the .dll files) or 

Iirc, the license uses the word "accompany", I believe 
no court has so far decided what this is means in this 
context, but making the source a part of the distribution 
certainly fulfills the requirement.
If you read http://ffmpeg.org/legal.html you can see 
that the FFmpeg developers believe that providing the 
source code on the same server as the binary 
distribution and pointing to the source code in the 
same way as to the binary distribution also fulfills 
the requirement.

> - there should be an offer included in the software 
> package with a download link to the sources pointing to
> server(s) of the creator or distributor of that 
> software package (and not the servers of ffmpeg or Zerranoe).

Your sentence is not entirely clear:
If you talk about an "offer" for the source, it usually means 
that you offer in a legally binding way that you "ship" 
the source code to your customer on request.
This certainly cannot be fulfilled with sources on a 
webserver which is outside of your control, but it 
imo does not make much sense today anyway because it 
is highly "unpractical".

(Note that this "offer" that made a lot of sense 
at the time the license was written when disk 
space was expensive.)

If you talk about links that point to the sources 
next to links that point to the binary distribution
(to "accompany" your distribution with the sources), 
then it is of course your responsibility that the 
links actually work: An easy way to make sure they 
do is to host the source package on the same server 
as the binary distribution.

A definite way - imo - to make clear that the 
distributor is not interested in fulfilling the 
license by offering source code is to link to an 
external server that is supposed to contain the 
source code (like for example "ffmpeg.org" - 
this for example happens very often).

Carl Eugen

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