[FFmpeg-devel] [RFC v4] libbavcodec: add a native decoder for the Daala video codec

Andreas Cadhalpun andreas.cadhalpun at googlemail.com
Sat Jan 2 13:51:59 CET 2016

On 02.01.2016 01:52, Rostislav Pehlivanov wrote:
>> To the very best of my knowledge you are allowed
>> to relicense code that was published under a two-
>> (or three-) clause BSD license under the GPL (and
>> the LGPL) as long as you keep the copyright
>> notice.

The BSD license is a very liberal license. Thus one can use BSD licensed
code together with code covered by most licenses and even distribute
the code with a different license.
This is what is typically called e.g. 'relicensing BSD code under GPL'.

However, this is not quite correct as only the copyright holder can
relicense. Thus the original BSD license has to be followed, as well.

> Yes, that's what I've concluded as well.
> Basically, the license says:
>> Redistributions of source code must retain the above copyright notice,
> this list of conditions and the following disclaimer.
> Which means as long as I keep all the copyright notice of previous
> contributors (e.g. Copyright 2001-2015 Xiph.org) I am allowed to change the
> license. I was under the impression I was unable to remove the BSD license

Indeed, the license explicitly requires to list it's conditions, so you
can't just remove it.
If you add the LGPL then the code will be licensed under both licenses.
But since the LGPL is stricter than the BSD license, the effect is mostly
the same as if you just use the LGPL, except that the BSD license text has
to be kept by anyone using the code.

> So for the next RFC I'll just use the project's LGPL license, which is what
> I prefer.

Since the intent of the BSD is only to keep attribution you could just
ask if the authors of it are OK with you only using the LGPL, but keeping
their copyright information.

Also you said that you wrote this decoder from scratch/rewrote the parts
from libdaala, and thus it is not clear whether or not their license applies
at all.

Happy new year,

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