[MPlayer-dev-eng] Small talk on the GPL by laymen (was: Re: help on libmpdemux usage)

[D Richard Felker III]

On Thu, Jan 15, 2004 at 08:03:04PM +0100, Romain Dolbeau wrote:
> D Richard Felker III wrote:
> 
> >That's not the question. The question is whether a binary _containing_
> >libmpdemux is a derived work of MPlayer, and the answer is of course
> >YES!
> 
> Obviously.
> 
> > Distributing that derived work is not legal if it doesn't meet
> >the conditions of the GPL.
> 
> Obviously. Well, 'til the GPL has been tried in
> court, anyway.

No. The GPL does not have to be tried in court. If you do not meet its
terms, then you have no license to copy, and thus you're infringing
copyright. It's very simple.

> > And if that derived work is linked, even
> >dynamically, to QuickTime, then it's not meeting the conditions of the
> >GPL.
> 
> I disagree. But then, I'm not a lawyer (one in the family
> is more than enough :-
> 
> PMlayer *is* linked to QuickTime, yet the mplayer authors
> can't re-licence QuickTime under the GPL, so dynamic
> linking better be OK....

WTF is PMlayer? We certainly don't distribute it.

> >You can't breach the GPL on code to which you hold copyright, since
> >you don't need to accept it yourself. Obviously for all code written
> >by MPlayer developers, they're implicitly giving their permission to
> >make binaries that use QuickTime codecs by putting that functionality
> >in the source to begin with. This does NOT imply that they're giving
> >their permission for parts of MPlayer source to be used in the (highly
> >proprietary) QuickTime framework.
> 
> MPlayer uses QuickTime for audio and video (through the SDL)
> output, not for codecs (well maybe for codecs too)
> And there's only one QuickTime framework.
> 
> What makes mplayer calling QuickTime legal, but QuickTime
> calling mplayer illegal ?

The former does not involve infringing any copyrights, since MPlayer
developers hold the copyright to MPlayer. The latter does involve
infringing copyrights. Maybe you want to argue that distributing the
qt binary dll's infringes a copyright, but that's entirely separate
from the MPlayer codebase.

> >If one really wanted, one could built 2 MPlayer binaries: one with
> >QuickTime but not libmpeg2, and the other with libmpeg2 but not
> >QuickTime. So for all practical purposes, the two aren't linked.
> >There's certainly no dependence between them, unlike the example we're
> >dealing with of incorporating libmpdemux into QuickTime.
> 
> W/o quicktime, mplayer has no sound and almost no video
> (X11 would still work). So on MacOSX, no, you can't
> build mplayer w/o QuickTime (<rant> w/o Troll Tech

Huh? This is utter nonsense.

> >It's not possible to be more restrictive than the GPL in this area.
> >It's the maximum allowed under the law (in most countries at least).
> 
> Well, I'd say that the average software company
> uses licenses that are a lot more restrictive than
> the GPL :-)

And they have no legal basis. You are not forced to accept them to use
the software, according to the law.

Rich