[Libav-user] Getting to grips with ffmpeg

[Phil Turmel]

John,

On 02/05/2012 10:29 PM, John Dexter wrote:
> 
> If you're going to make such assertions please back them up. My
> research into dynamic linking of (L)GPL libraries finds multiple
> explicit claims that distribution of the library source code is _not_
> required if I haven't modified the original, according to LGPL section
> 6, specifically 6b.
> (http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html linked from
> ffmpeg legal page).

Section 6b applies only when the LGPL object is "already present on the
user's computer system", that is, when installed by the user from other
sources and your code just dynamically links to it.  Whomever they got
the binary from must comply with one of the other methods in section 6.

If your installer supplies the LGPL DLLs, 6b doesn't apply to you.  You
will need to be prepared to offer the source code if you don't ship it
with your installer.  If you are getting the DLLs you use from a compliant
third party, and they cease operating, you are still required to offer
the source code for the versions you shipped.  Maybe as long as three
years later.

Of course, I Am Not A Lawyer, and you are free to disagree.  You should
consult a real lawyer for a more definitive opinion.

HTH,

Phil