The Dirac video codec is nearly fixed and part of it is set to become an SMPTE standard. The BBC has tried hard to ensure it is as unencumbered as possible.
http://dirac.sourceforge.net/specification.html
Apart from the coder and decoder both being somewhat inefficient at present, I understand there isn't much that plays it back as yet (VLC in experimental builds).
What would we need before allowing Dirac-encoded video on Wikimedia?
- d.
On Jan 28, 2008 9:46 AM, David Gerard dgerard@gmail.com wrote:
The Dirac video codec is nearly fixed and part of it is set to become an SMPTE standard. The BBC has tried hard to ensure it is as unencumbered as possible.
As an aside, what is up for SMPTE is "Dirac pro", an simplified i-frame only version of Dirac. It is the dirac-equivalent of MJPEG. As such it's not suitable for streaming but is a really good high bandwidth archival format.
http://dirac.sourceforge.net/specification.htmlApart from the coder and decoder both being somewhat inefficient at present, I understand there isn't much that plays it back as yet (VLC in experimental builds).
What would we need before allowing Dirac-encoded video on Wikimedia?
Allowing? Well since there Dirac-in-Ogg is well defined and audio is needed for many uses, arguably we allow it already! \0/ (http://wiki.xiph.org/index.php/OggDirac)
More seriously, before dirac pro would useful as anything other than a "source/archival format" we'd need infrastructure for transcoding.
For real use of Dirac (not Pro) on the sites getting real-time decoding in Java would be needed to get anywhere parity with Theora. This may well be really hard, but there has been some work done on this (http://dirac.cvs.sourceforge.net/dirac/soc_javadec_luis/). (In fact, it is quite possibly not possible on current hardware :( )
In general Dirac is about two years behind on tools but it should catch up quickly now that the specifications are done.
None of these are reasons that it couldn't be allowed for upload, but they are reasons why no one may care yet. :)
On 28/01/2008, Gregory Maxwell gmaxwell@gmail.com wrote:
As an aside, what is up for SMPTE is "Dirac pro", an simplified i-frame only version of Dirac. It is the dirac-equivalent of MJPEG. As such it's not suitable for streaming but is a really good high bandwidth archival format.
Apparently it's not awful even in that state, at least in terms of quality per size (if not rapid decodability).
What would we need before allowing Dirac-encoded video on Wikimedia?
Allowing? Well since there Dirac-in-Ogg is well defined and audio is needed for many uses, arguably we allow it already! \0/ (http://wiki.xiph.org/index.php/OggDirac)
:-)
In general Dirac is about two years behind on tools but it should catch up quickly now that the specifications are done. None of these are reasons that it couldn't be allowed for upload, but they are reasons why no one may care yet. :)
Yeah, it feels a bit like Ogg Vorbis in 2000/2001 really. Not actually problematic as a format except the minor detail of a lack of code and a lack of machines capable of running the code if it existed.
- d.