[Theora] Theora, great stuff!

Ralph Giles giles at xiph.org
Sun Aug 21 16:24:51 PDT 2005

On Sun, Aug 21, 2005 at 11:27:00PM +0100, Nick Hill wrote:

> I manage the audio-video section of the GNU web site 
> http://audio-video.gnu.org/. I have tried the Theora codec and am very 
> impressed by the level of integration with free desktops and the bit 
> rate/quality combinations.

Thanks for your kind comments and support of free multimedia formats!

> [embrace and extend]
> A solution to pre-emptively defend the theora project from such games 
> would be for further changes to be placed under a license which requires 
> public disclosure of derivative source code. Given incompatible versions 
> based on the Theora code base would no longer be secret, business plans 
> based around releasing incompatible versions will be substantially less 
> attractive to those so inclined. The GNU GPL would provide protection.

Doing so would also raise the barrier to entry for people wanting to use 
our formats in proprietary applications, both software- and hardware-
based. Network effects are extremely important in file format success, 
and we have generally felt that licensing our reference implementations
under a BSD license to encourage the broadest possible adoption of free
formats is a more important goal.

Also, the format specification is itself freely available and freely 
implementable by everyone (that being what makes Theora a free format), 
and we explicitly encourage outside implementations. Thus, while a GPL 
reference implementation would raise the barrier for a significant 
classes of casual adopters, it is not a significant impediment to a 
resourceful group intent on embrace-and-extend.

We do generally use the GPL for our application software, however. A 
new multimedia format lives and dies by the quality of its tool support, 
and this is a place where it is most effective to out-code proprietary 
offerings. The protections of the GPL are useful at the application
level for all the reasons you cite. (Not that we as Xiph have done a 
great job with tools, but others are starting to, as you've noticed.)

Finally, we do claim Theora and our other names as trademarks, and 
will defend them against non-conforming implementations. This does a
lot to prevent the sort of confusion that could lead users to adopting
a poised fork of the standard, while still providing for the right to 
fork under a different name in support of the goals of Software Freedom.

People are welcome to develop their own Theora-related code under 
whatever license they wish, including the GPL, but I hope this explains 
our (Xiph.org's) reasoning on the licensing of our reference 


P.S. You brought up DRM. Such methods are orthogonal to codec 
design/choice and usually implemented at the container level,
so I don't think this is a particular concern. (Though I do
understand that cultural issues have kept certain formats 
traditionally associated with open exchange taboo among 
those who insist on DRM-encumbering their content.)
DRM can as easily be applied to any Ogg file, for example
by running it through gpg. However, we generally recommend
those interested in DRM with Ogg Vorbis or Theora add a comment
"COPYPROTECTED=yes" to the native metadata. Such a scheme is 
simple, easily extendable, and exactly as effective at the
more cumbersome DRM schemes in use with other formats.

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