[FFmpeg-devel] [PATCH] enforce --enable-nonfree for lame Re: Linking against lame considered non-free?

[Reinhard Tartler]

On Fri, Aug 13, 2010 at 16:24:39 (CEST), Reinhard Tartler wrote:

> For full context, please see
> http://thread.gmane.org/gmane.comp.audio.mp3.lame/5092
>
> Short summary, the Lame licsense places additional restrictions on its
> LGPL license, as seen in
> http://lame.cvs.sourceforge.net/viewvc/lame/lame/README?view=markup:
>
> 09      This code is distributed under the GNU LESSER PUBLIC LICENSE
> 10	(LGPL, see www.gnu.org) with the following modification:
> 11
> 12	1. If you determine that distribution of LAME requires a patent license,
> 13         and you obtain a patent license, you may distribute LAME even though
> 14         redistribution of LAME may also require a patent license.
> 15
> 16	2. You agree not to enforce any patent claims for any aspect of
> 17         MPEG audio compression, or any other techniques contained in
> 18         the LAME source code.
>
>
> AFAIUI, these limitations also apply to conveyings like libraries and
> executables of ffmpeg that are linked against a copy of libmp3lame,
> which render them unredistributable.
>
> Please explain me why I'm wrong here; otherwise I guess we'd need to
> adjust configure to make an appropriate statement, just like we
> currently do for libfaac, etc..

This would implemented by the following patch:

Index: configure
===================================================================
--- configure	(revision 24796)
+++ configure	(working copy)
@@ -2403,6 +2403,7 @@
 die_license_disabled gpl x11grab
 
 die_license_disabled nonfree libfaac
+die_license_disabled nonfree libmp3lame
 
 die_license_disabled version3 libopencore_amrnb
 die_license_disabled version3 libopencore_amrwb


I am really sad that something like this is necessary. Perhaps anyone
here knows some lame developers and can talk again to them to do
something about that license exception?

Or what ffmpeg could do is to grant a special exception that linking
against lame is OK, even if it violates the GPLv2?

Speaking of GPL, I've just read GPLv3 paragraph 11 here. AFAIUI, the
additional terms as expressed by the lame license are fully covered
there. For this reason, distributing a conveying of libavcodec and
libmp3lame under the GPLv3 should be OK. In that case, this patch to
configure should do it:


Index: configure
===================================================================
--- configure	(revision 24796)
+++ configure	(working copy)
@@ -2406,6 +2406,7 @@
 
 die_license_disabled version3 libopencore_amrnb
 die_license_disabled version3 libopencore_amrwb
+die_license_disabled version3 libmp3lame
 
 enabled version3 && { enabled gpl && enable gplv3 || enable lgplv3; }
 


-- 
Gruesse/greetings,
Reinhard Tartler, KeyID 945348A4