[FFmpeg-devel] [PATCH] VP8 de/encode via libvpx

[Diego Biurrun]

On Thu, May 20, 2010 at 12:26:48PM +0300, Uoti Urpala wrote:
> On Thu, 2010-05-20 at 10:12 +0200, Diego Biurrun wrote:
> > On Wed, May 19, 2010 at 02:28:10PM -0400, James Zern wrote:
> > > 
> > > --- /dev/null	2010-02-26 16:50:52.000000000 -0500
> > > +++ libavcodec/libvpxdec.c	2010-05-17 23:46:16.000000000 -0400
> > > @@ -0,0 +1,168 @@
> > > + * 
> > > + *  Subject to the terms and conditions of the above License, Google
> > > + *  hereby grants to You a perpetual, worldwide, non-exclusive,
> > > + *  no-charge, royalty-free, irrevocable (except as stated in this
> > > + *  section) patent license to make, have made, use, offer to sell, sell,
> > > + *  import, and otherwise transfer this implementation of VP8, where such
> > > + *  license applies only to those patent claims, both currently owned by
> > > + *  Google and acquired in the future, licensable by Google that are
> > > + *  necessarily infringed by this implementation of VP8. If You or your
> > > + *  agent or exclusive licensee institute or order or agree to the
> > > + *  institution of patent litigation against any entity (including a
> > > + *  cross-claim or counterclaim in a lawsuit) alleging that this
> > > + *  implementation of VP8 or any code incorporated within this
> > > + *  implementation of VP8 constitutes direct or contributory patent
> > > + *  infringement, or inducement of patent infringement, then any rights
> > > + *  granted to You under this License for this implementation of VP8
> > > + *  shall terminate as of the date such litigation is filed.
> > 
> > Ah, so the patent grant only covers this implementation!  Once we come
> > up with our native and faster decoder, we will be liable again.  Good
> > job Google!
> > 
> > Also note the language about "necessarily infringed" - if Google comes
> > up with some clever tricks to speed up this implementation tenfold and
> > then go on to patent it, you are *not* granted a license.  You can,
> > after all, implement VP8 the slow way...
> 
> Well what else would you expect such a patent license to say? It could
> hardly specify that it'd cover any patent in any code whatsoever as long
> as that code managed to decode VP8 as one of its functions.

I would expect such a patent license to cover any VP8 implementation, not
just a particular implementation of VP8 made by Google.  I wouldn't mind
language that excluded code not related to handling VP8, but covering
just a single implementation is not good enough.

> However having that license text in FFmpeg code could be a problem. It
> talks about Google granting a patent license for "this implementation of
> VP8". The code is glue code and it's questionable whether it can be said
> to really "implement VP8". And more importantly it could be changed and
> distributed by parties other than Google. "This implementation" becomes
> a questionable term after modifications by people not associated with
> Google - after all Google probably doesn't intend their patent grant to
> cover all code that could possibly be placed in the same file by anyone
> else.

Yes, that's why I suggested to go with the standard FFmpeg license
boilerplate.

Diego