All,

I must admit to a feeling of deja-vu reviewing the discussion taking
place here. Some while back I pointed out that the requirements for
the container have ben previously well addressed in the MPEG-21
Digital Item.

Digital Items are 'virtual containers' and may consist of just a
Declaration file in XML - this allows the author to create the
structure of the content. The content can be anything - metadata,
resources (any MIME type) and music albums are a classic example.

Digital Items provide the ability to reference resources anywhere on
the Internet (the download or streaming model) or in the local
pacakage. Digital Item packages are provided using the ISO File
Format (which is basically the Quicktime file format). This is used
(as opposed to zip) to allow for e.g. direct random access into media
files which is not possible in zip.

It is very easy to create a Digital Item that references multiple
versions of a resource (different formats and bit rates). It is even
possible to allow negotiation of formats using MPEG-21 metadata but
this is probably beyond the current requirements.

So in summary:

1. A international, standardised XML schema exists
2. A international, standardised container format exists

What does not exist (quite rightly) is a mandated presentation
mechanism for the DI container. It would seem that for XIPF, such a
presentation format should be required - but I would recommend
keeping it separate to the container itself (Imagine creating 1000s
of container files with embedded presentations which then get
superseded by a new user presentation approach!).

Hence, a presentation format is required - Flash? AJAX? SVG? LASeR? -
all are quite feasible and can easily be referenced from the DI
container or could 'import' the container.

Just my thoughts ....................

Ian