--- /dev/null
+<sect1 id="chapter-legal">
+ <title id="title-legal">GStreamer Legal Issues</title>
+ <para>
+This part of the FAQ is based on a series of questions we asked the FSF
+to understand how the GPL works and how patents affects the GPL. These
+questions were answered by the <ulink url="http://www.fsf.org/">
+FSF lawyers</ulink>, so we view them as the
+final interpretation on how the GPL and LGPL interact with patents in our
+opinion. This consultancy was paid for by
+<ulink url="http://www.fluendo.com/">Fluendo</ulink>
+in order to obtain clear and quotable answers. These answers were certified
+by the FSF lawyer team and verified by FSF lawyer and law professor Eben Moglen.
+ </para>
+
+ <qandaset>
+
+ <qandaentry>
+ <question id="legal-distribute-three">
+ <para>
+Can someone distribute the combination of
+<itemizedlist>
+ <listitem><para>GStreamer, the LGPL library</para></listitem>
+ <listitem><para>Totem, a GPL playback application</para></listitem>
+ <listitem><para>The binary-only Sorenson decoder</para></listitem>
+</itemizedlist>
+together in one distribution/operating system ? If not, what
+needs to be changed to make this possible ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+This would be a problem, because the GStreamer and Totem licenses would
+forbid it. In order to link GStreamer to Totem, you need to use section
+3 of the LGPL to convert GStreamer to GPL. The GPL version of GStreamer
+forbids linking to the Sorenson decoder. Anyway, the Totem GPL
+license forbids this.
+ </para>
+
+ <para>
+If the authors of Totem want to permit this, we have an
+exception for them: the controlled interface exception from the FAQ.
+The idea of this is that you can't get around the GPL just by including
+a LGPL bit in the middle.
+ </para>
+
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-binary-plugin">
+ <para>
+Suppose Apple wants to write a binary-only proprietary
+plugin for GStreamer to decode Sorenson video, which will be shipped
+stand-alone, not part of a package like in the question above.
+Can Apple distribute this binary-only plugin ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+Yes, modulo certain reverse engineering requirements in section 6 of
+the LGPL.
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-gpl-program">
+ <para>
+If a program released under the GPL uses a library that
+is LGPL, and this library can dlopen plug-ins at runtime, what are the
+requirements for the license of the plug-in ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+You may not distribute the plug-in with the GPL application.
+Distributing the plug-in alone, with the knowledge that it will be used
+primarily by GPL software is a bit of an edge case. We will not advise you
+that it would be safe to do so, but we also will not advise you that it
+would be absolutely forbidden.
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-safe-countries">
+ <para>
+Can someone in a country that does not have software patents distribute
+code covered by US patents under the GPL to people in, for example, Norway ?
+If he/she visits the US, can he/she be arrested ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+Yes, he can.
+No, there are no criminal penalties for patent infringement in the US.
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-unsafe-countries">
+ <para>
+Can someone from the US distribute software covered by
+US patents under the GPL to people in Norway ? To people in the US ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+This might infringe some patents, but the GPL would not forbid it
+absent some actual restriction, such as a court judgement or agreement.
+The US government is empowered to refuse importation of patent
+infringing devices, including software.
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-gpl-library-patents">
+ <para>
+There are a lot of GPL- or LGPL-licensed libraries that
+handle media codecs which have patents. Take mad, an mp3 decoding library,
+as an example. It is licensed under the GPL. In countries where patents
+are valid, does this invalidate the GPL license for this project ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+The mere existence of a patent which might read on the program does not
+change anything. However, if a court judgement or other agreement
+prevents you from distributing libmad under GPL terms, you can not
+distribute it at all.
+ </para>
+
+ <para>
+The GPL and LGPL say (sections 7 and 11):
+<quote>If you cannot distribute so as to satisfy simultaneously your
+obligations under this License and any other pertinent obligations, then
+as a consequence you may not distribute the Library at all.</quote>
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-gpl-court-judgment">
+ <para>
+So let's say there is a court judgement. Does this mean that the GPL license is
+invalid for the project everywhere, or only in the countries where it conflicts
+with the applicable patents ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+The GPL operates on a per-action, not per-program basis. That is, if
+you are in a country which has software patents, and a court tells you
+that you cannot distribute (say) libmad in source code form, then you
+cannot distribute libmad at all. This doesn't affect anyone else.
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-gpl-and-binary">
+ <para>
+Patented decoding can be implemented in GStreamer either by
+having a binary-only plugin do the decoding, or by writing a plugin
+(with any applicable license) that links to a binary-only library.
+Does this affect the licensing issues involved in regards to GPL/LGPL?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+No.
+ </para>
+ </answer>
+ </qandaentry>
+
+ <qandaentry>
+ <question id="legal-gpl-patent-distribution">
+ <para>
+Is it correct that you cannot distribute the GPL mad library to
+decode mp3's, *even* in the case where you have obtained a valid license
+for decoding mp3 ?
+ </para>
+ </question>
+
+ <answer>
+ <para>
+The only GPL-compatible patent licenses are those which are open to
+all parties posessing copies of GPL software which practices the
+teachings of the patent.
+ </para>
+
+ <para>
+If you take a license which doesn't allow others to distribute
+original or modified versions of libmad practicing the same patent
+claims as the version you distribute, then you may not distribute at
+all.
+ </para>
+ </answer>
+ </qandaentry>
+ </qandaset>
+</sect1>
projects / platform / upstream / gstreamer.git / commitdiff