Re: No policy? Re: Is EME usable regardless of the software/hardware I use ?

On Thursday 2013-06-06 21:27 -0400, Jeff Jaffe wrote:
> On 6/6/2013 9:14 PM, Duncan Bayne wrote:
> >Do you disagree with any of my premises, or the conclusion that a DRM
> >recommendation by the W3C is in practice incompatible with any FOSS
> >license?
> 
> I'm not an attorney, but I agree that the EME draft document may be
> incompatible with GPLv3.
> 
> I don't agree that W3C has a DRM recommendation.
> 
> I'm not familiar with the universe of FOSS licenses so I can't
> answer your general question.  I'm not aware of any reason that EME
> would be incompatible with Apache, Mozilla, or GPLv2 licenses.

I think the use of the term "compatible with" in licensing
discussions is somewhat unfortunate, since license compatibility is
not a symmetric relation.  When people talk about license
compatibility, they're generally talking about answers to the
question "if I have code under license A, do I have the rights to
use and distribute it under the terms of license B".  There are
common cases where it's obvious which direction they're talking
about:  for example, the GPL imposes (relative to other common
software licenses) a lot of restrictions on the licensee, so when
people talk about GPL-compatibility they're nearly always talking
about the above question with B == the GPL.

Though I'm (also) not a lawyer, it seems to me that the above
question roughly reduces to whether the restrictions on the licensee
in license A are a subset of those in B, and the grants by the
licensor in B are a subset of those in A.


I think the interesting question about license compatibility for
implementations of a standard involves A being the minimal set of
restrictions possible for a complete and usable implementation of
the standard plus the grants associated with that standard.

A usable (in practice) implementation of EME requires a DRM system
containing secrets that cannot be published.  Such a system cannot
be licensed under open-source licenses that require that the source
code [1] be available to recipients of the executable software, such
as the MPL or GPL [2].  Worse, a usable (in practice) implementation
of EME requires an implementation of one of the DRM systems accepted
by major content producers.  The workings of these systems are
confidential far beyond just the secret key, and whether (given
knowledge of the necessary secrets) they can be implemented without
infringing patents is unknown.

This means EME would be a highly unusual W3C specification.  It is
exceptional for a W3C specification not to be implementable in
practice in open-source software.  (I say "in practice" because EME
as a specification doesn't require support for particular CDMs, but
in practice it requires them in order to be usable for its intended
uses.)  EME avoids triggering the rules of the W3C patent policy by
not actually requiring what is, in practice, actually required.

So I agree with Duncan's claim of incompatibility, though I would
prefer to express it as EME not being compatible with a usable
open-source-licensed implementation.

-David

[1] preferred form for making modifications, see e.g. [MPL2] §1.13,
    [GPL2] §3, or [GPLv3] §1
[2] [MPL2] §3.2, [GPL2] §3, [GPLv3] §6
[MPL2] http://www.mozilla.org/MPL/2.0/
[GPL2] http://www.gnu.org/licenses/gpl-2.0.html
[GPLv3] http://www.gnu.org/licenses/gpl-3.0.html

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                           http://www.mozilla.org/   𝄂

Received on Friday, 7 June 2013 11:01:36 UTC