[annodex-dev] update of CMML Internet-Draft

[Silvia.Pfeiffer at csiro.au]

Dear all,

I was slightly shocked last night to discover that the version of CMML that is currently active at IETF is Version 2.0 ( http://www.ietf.org/internet-drafts/draft-pfeiffer-cmml-02.txt, with an expiry date of 20th Sep 2005, gosh!).


Im March 2005, we defined an updated version of CMML, CMML 2.1, which extends version 2.0. This version has been sitting in svn ready to go ever since:

http://svn.annodex.net/standards/draft-pfeiffer-cmml-03.xml
http://svn.annodex.net/standards/cmml_3_0.dtd

libcmml supports CMML 2.1 since version 0.9.9 (April 2005) and
libannodex suppports it since version 0.7.0 (July 2005).


Here are the changes that were made in comparison to version 2.0:

* added the link tag to the head, which has recognized link types of html
  plus "edit".
  -> this is necessary to specify types of relationships a linked document
     may have to the current one.
  -> we added "editing" to allow an "edit" button to appear on an Annodex
     file that may

* added title tags for each element.
  -> this is a short description for each clip which is much nicer to
     display in interfaces than the full description as in the desc tag
  -> it is also a tag that is being available in xhtml for all elements
     and therefore makes CMML more compatible

* added granulerate to the cmml root tag and changed the muxing
  description for CMML tracks.
  -> this is preparing CMML for an independent use from the skeleton track
     such that CMML can be used by itself as a logical bitstream in Ogg

* replaced timebase with basetime as a better name.
  -> long discussions about the name of this tag have resulted in actually
     renaming it to "basetime".
  -> we keep the old "timebase" element around in CMML 2.1 for compatibility
     reasons, but it is deprecated.
  -> we may take it out of future versions of CMML with a major number larger
     than 2.
  -> we also kept the basetime attribute of the stream tag for
     compatibility reasons.


Now, I could just simply submit the document to IETF.

However, I'd actually like to probe you all for any further changes that are necessary to the current version of the CMML I-D (see http://svn.annodex.net/standards/cmml-ids/draft-pfeiffer-cmml-03.txt).

One particular fix that I've been shying away from is to actually make the DTD valid so that xml parsers will validate the CMML files against the DTD. I think there are some problems, but I haven't had time to fix them. If anybody feels a kick, please do. In future we should move to schema instead of DTD for a more flexible specification.


Cheers,
Silvia.