Two good reasons why the license of mplayer must be GPL without restrictions (Re: [MPlayer-users] Re: License)

Michael Hunold M.Hunold at t-online.de
Wed Oct 10 17:41:44 CEST 2001


Hello Andrém,

> I didn't get your response to this, but I would be interested to hear
> your opinion:

It's good to hear that you are interested in an *opinion*
not in a flamewar. 8-)

But most of the time in this discussion, my opinion
does not count. It's the GPL and the consequences that
count. So most of the stuff can be answer by the
GPL and the faq itself -- my opinion is not involved.

> > > Mplayer simply *includes* libraries like libmpeg2, libac3, ...
> > > which are GPL. The faq clearly says to this fact:
> >
> > And that code is still GPL. The only code that isn't GPL is the code
> > that Arpi & co has written from scratch and that doesn't use any other
> > code. If that code needs the other GPL code to function I would agree
> > with you, but does it?

The point is not, whether mplayer *needs* or *does not need*
the GPL libraries to function. 

The point is, whether Arpi (and the others developers) have 
decided to use the GPL libraries or not.

And as we know they decided to use them, so the consequences are
there.

Look at this interesting part in the GPL faq: 

> Can I use the GPL for a plug-in for a non-free program?

Let's assume that Mplayer is a non-free program
and that the libaries are free plug ins.

> If the program uses fork and exec to invoke plug-ins,
> then the plug-ins are separate > programs, so the
> license for the main program makes no
> requirements for them. So you can use the GPL for
> a plug-in, and there are no special requirements. 

This is clearly not the case.

> If the program dynamically links plug-ins, and they
> make function calls to each other and share data
> structures, we believe they form a single
> program, so plug-ins must be treated as extensions
> to the main program.

This is true with no doubt in my eyes for mplayer.

> This means that linking the GPL-covered plug-in with the main program
> would violate the GPL. 

This is the point. 

> However, you can resolve that legal problem by adding an 
> exception to your program's license which gives permission to
> link it with the non-free main program. 

Ok, but because of the fact that most libraries (= plug ins)
are GPL, the situation is clear.

Or is it?

> André Dahlqvist <andre.dahlqvist at telia.com>

CU
Michael.



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