License and copyright of GStreamer examples

[Tim-Philipp Müller]

On Mon, 2014-01-13 at 02:34 +0400, Fedor Lyakhov wrote:

Hi,

> I want to use GStreamer examples (e.g.
> <src>/tests/examples/helloworld/) as test applications of my own
> project (called Melange), which is licensed and distributed under GNU
> LGPL. I want to modify and re-distribute the examples - but I cannot
> find copyright notice there, nor the license. (I want to distribute
> both slightly modified and substantially modified files eventually...)
>
> There is a list of authors for GStreamer manual
> (http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/index.html),
> and indication that it is distributed under Open Publication License,
> v1.0 or later (the latest version is presently available at
> http://www.opencontent.org/opl.shtml). Still this information lacks
> copyright notice (at least the years are missing). Also AFAIK examples
> aren't fully published inside the manual - rather excerpts from them
> (at least the helloworld example - as compared to the one inside
> /tests/examples/helloworld). Moreover, these examples seem to be tests
> of GStreamer at the same time - that's why I hope they're
> LGPL-licensed as well.
> 
> So my questions are
> 1. Under what license are the examples published? (LGPL or OPL?)

I think you can assume that code examples without license headers are
licensed at least under LGPL v2 or later. We generally aim to license
example code more liberally even, so people can copy'n'paste it into
their own possibly proprietary code as well. There may be no header, but
there's a COPYING file in the top-level directory.

> 2. What are the copyright notes there? (authors and years are needed)

IANAL, but I don't think the copyright notices are actually mandatory.
'git blame' suggests that Stefan Kost rewrote the hello world example
almost entirely in 2011, in case you do feel like you want the name of
the original author in there.


> 3. Can I modify and re-distribute them as part of LGPL-licensed
> project under LGPL?

Yes.


> 4. How should I write new copyright notice in my modified files?Will
> following be acceptable:
> 
> Copyright <XXXX-YYYY> <GStreamer author1>
> Copyright <XXXX-YYYY> <GStreamer author2>
> Copyright 2014 Fedor Lyakhov
> 
> This file is part of Melange.
> 
> Melange is free software: you can redistribute it and/or modify
> it under the terms of the GNU Lesser General Public License as published by
> the Free Software Foundation, either version 3 of the License, or
> (at your option) any later version.
> 
> Melange is distributed in the hope that it will be useful,
> but WITHOUT ANY WARRANTY; without even the implied warranty of
> MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> GNU Lesser General Public License for more details.
> 
> You should have received a copy of the GNU Lesser General Public License
> along with Melange. If not, see <http://www.gnu.org/licenses/>
> .
> This file was derived from helloworld.c test/example of GStreamer framework.

That looks fine to me. I don't think it is required that you say what
you based it on, esp. in the case of example code made for
copy'n'pasting purposes.

 Cheers
  -Tim