[MPlayer-dev-eng] Re: help on libmpdemux usage (Modifié par Jérôme Cornet)

[D Richard Felker III]

On Wed, Jan 14, 2004 at 01:25:51PM +0000, Adam Rice wrote:
> Quoting D Richard Felker III (dalias at aerifal.cx):
> > This is NOT a restriction on use. It's a restriction on what you can
> > do when preparing derived works.
> 
> Here is what the GPL says about derived works:
> 
>   2. You may modify your copy or copies of the Program or any portion
> of it, thus forming a work based on the Program, and copy and
> distribute such modifications or work under the terms of Section 1
> above, provided that you also meet all of these conditions:
> 
>     a) You must cause the modified files to carry prominent notices
>     stating that you changed the files and the date of any change.
> 
>     b) You must cause any work that you distribute or publish, that in
>     whole or in part contains or is derived from the Program or any
>     part thereof, to be licensed as a whole at no charge to all third
>     parties under the terms of this License.
> 
>     c) If the modified program normally reads commands interactively
>     when run, you must cause it, when started running for such
>     interactive use in the most ordinary way, to print or display an
>     announcement including an appropriate copyright notice and a
>     notice that there is no warranty (or else, saying that you provide
>     a warranty) and that users may redistribute the program under
>     these conditions, and telling the user how to view a copy of this
>     License.  (Exception: if the Program itself is interactive but
>     does not normally print such an announcement, your work based on
>     the Program is not required to print an announcement.)
> 
> >                                  If you make a derived work that hooks
> > the code into the QuickTime API, and distribute a binary of that which
> > is dynamically linked to and intended to be used with QuickTime, that
> > is definitely not permitted by the GPL, and thus distributing that
> > binary is copyright infringement.
> 
> I must be going blind, because I can't find the bit of the GPL that says
> this. Which of the above three conditions limits what APIs a GPL-derived
> program may use?

Yes it does say this. You need to understand that the "derived work"
is the entire program -- everything linked, including dynamically. If
your derived work contains QuickTime (even if you are distributing
that separately or telling users to get it from Apple) then you cannot
cause the whole work to be licensed under the GPL, and thus you cannot
distribute your derived work.

Rich