Dirac video codec (Re: Opportunity to hack)

[Rob Sharp]

Slashdot had an article on this recently - I've tried to answer your
question with "useful" comments on the story.

http://slashdot.org/article.pl?sid=04/04/30/1650234

HTH.

Rob.


On Thu, 2004-10-07 at 03:47, Matt Zimmerman wrote:
> On Thu, Oct 07, 2004 at 05:12:05AM +0800, John wrote:
> 
> > The Beeb wants help developing open source video codec, and I'm sure 
> > most of us would like to encourage that.
> > 
> > There's an article about it at 
> > http://www.theregister.co.uk/2004/10/06/bbc_open_source_video_codec/
> 
> The key questions would be:
> 
> - How does it stand with regard to patents on video encoding?

http://slashdot.org/comments.pl?sid=105976&threshold=1&commentsort=0&tid=188&tid=141&tid=8&mode=thread&cid=9021472

"I spoke to one of the BBC team demonstrating the codec at the London
Linuxexpo. They said that the BBC had patented their codec although I
was told that they have no real interest in patents. It was said to be a
defensive patent whch they implied to me that they would not enforce,
however the person I spoke to didnt know the details of the patent or
its licencing scheme so it's a little unclear to me how this is going to
work.

They also said that while they had no objection to paying licensing
fee's per se, and that they did pay MS and Real, these were so
inflexible in their licencing that scaling up operations was
problematic. Their expressed hope was that with such a codec widely
adopted they could massively scale up operations such as streaming
without being crippled with licencing costs, or having the
administrative burden of unwieldy licensing schemes. "


> - How does it compare to Theora?
No direct answer, but this indicates why they started from the ground up...

http://slashdot.org/comments.pl?sid=105976&threshold=1&commentsort=0&tid=188&mode=thread&cid=9021589

"A matter of disclaimer: I've done some work on Dirac, for BBC, over the
last several months. Here's a bit of background on Dirac:

By nature, Dirac has many similarities to existing algorithms such and
MPEG-2 and H.264/AVC -- however, Dirac is an original invention that
uses wavelet transforms, arithmetic encoding, rate-distortion
optimization, variable block-size motion compensation, and hierarchical
motion estimation in some new and unique ways. Again, this is a research
project, so there's much experimentation to be done!

As a research project, Dirac continues to be analyzed, optimized, and
documented. What you're seeing now is very preliminary code; I suspect
it will improve and evolve dramatically in the coming months, both in
terms of clarity and functionality. The goal is to produce a universal
codec, which is one reason behind the open source move.

The codec source code is licensed under dual MPL/GPL licenses.

Dirac is modular, and thus well-suited to implementation with an
object-oriented programming language. The reference engine is written in
ISO Standard C++, and has been tested under various forms of 32- and
64-bit Linux, as well as under Windows 2000/XP.

I'll try to answer questions here, to the best of my ability. "

"It's a very tricky world out there right now. Arithmetic coding can be
implemented without hitting patents, I believe -- and the modular design
of Dirac should allow a different coding scheme -- say, Huffman -- to be
implemented if patents become an issue."


> 
> The article says "the BBC had taken care to make sure the technology could
> be taken up by the community without entangling developers in patent
> disputes.", which is a bit vague regarding the first point, but oddly
> doesn't mention Theora at all.
> 
> -- 
>  - mdz