[Ffmpeg-devel] Patch for dynamic liba52.so loading

Måns Rullgård mru
Sat Jun 11 20:20:59 CEST 2005

Diego Biurrun <diego at biurrun.de> writes:

> OK, now you are starting to make a lot more sense.  You began this
> discussion with a rather incomplete argument..
> On Sat, Jun 11, 2005 at 07:25:45PM +0200, M?ns Rullg?rd wrote:
>> Diego Biurrun <diego at biurrun.de> writes:
>> > On Sat, Jun 11, 2005 at 06:06:25PM +0200, M?ns Rullg?rd wrote:
>> >> 
>> >> That's a good example.  Now consider this: an application (A) uses a
>> >> GPL library (B), and, according to the FSF, is covered by the GPL.
>> >> Suppose that there exists a compatible library (C), under a
>> >> GPL-incompatible license.  By the same logic that made A a derivative
>> >> of B, it will now also be a derivative of C.
>> >
>> > False.  The logic that makes A a derivative of B is the fact that A
>> > _uses_ B, nothing else.
>> It will use whichever of B or C is found first by the dynamic linker.
>> The decision is made each time A is executed.
> But this has nothing to do with distribution.  The GPL does not restrict
> usage in any form.

Exactly.  Ergo, the GPL does not restrict linking to a library.

>> > A need not comply with the license requirements of C, unless it uses C.
>> > If it uses C it need not comply with the license requirements of B.
>> It can use B or C.  It's all up the dynamic linker on the machine
>> where A is run.  Hence, distributing A does not bind the distributor
>> to either of the licenses of B or C.
> You are basing your musings on the OpenSSL thread on debian-legal,
> right?

The topic appears regularly on debian-legal, and OpenSSL is usually
mentioned at some point.

> I skipped that one due to lack of time.  I haven't given the issue
> too much thought yet, so I haven't completely made up my mind.

When you do think about it, I hope you will see past the FSF's
political agenda, and apply the proper combination of law and logic
according to the letter, rather than mistaking the wishful thinking
of the FSF for the truth.  Be they right or wrong, they are definitely
biased in their opinions.

M?ns Rullg?rd
mru at inprovide.com

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