MPEG-7 and Xerces

[Claude <cs...@acland.fr>]

Dear all,

A standard about multimedia content description is 
in development within the MPEG community (Motion 
Picture Expert Group). This standard, known as 
MPEG-7, should be released in one year. 

The language we used for describing multimedia 
content is XML and the schema language (known as 
the DDL - Description Definition Language) mostly 
relies on XMl Schema.

As the chairman of the DDL Group, I'm in charge of 
the development of the language itself and associated
tools. Of course, one of the tool we need is a DDL 
parser.

We are currently evaluating the use of Xerces as 
the basis of our parser. I have few questions which 
I hope won't take too much of your time :

1- Do you have a time schedule for the development 
   of the Xerces Parsers (J and C) version 2 ?

2- Will you drastically change the architecture of 
   Xerces version 1? 

3- Would it be possible to add an MPEG-7 personality 
   to Xerces (in such case we will provide developers) ?

4- Can we rely on the "internal" API for the MPEG-7 
   extensions ?

Thank you for your help.

Regards,
Claude.

_________________________________________________________
Claude Seyrat
Chair of the MPEG-7 DDL AHG 
University of Paris 6
claude.seyrat@lip6.fr

Re: MPEG-7 and Xerces

[Dean Roddey <dr...@charmedquark.com>]

No, Schema (like DTD) is a generic structural (and for Schema type)
description language. Your schema for DDL would describe a valid DDL
document, the parser will parse it and check for basic XML well formedness
issues, and pass that data on to the schema validator which will validate it
according to your particular schema.

If DDL cannot be described fully with Schema, then the rest of the
validation must be done at an application level. So you'd end up writing a
program that sits on top of the parser, uses the parser for everything that
it and schema can do for you, then provides any other validation semantics
itself.

If you depend on a custom version of a parser, you are asking for trouble.
You'll never get your markup language widely accepted.

--------------------------
Dean Roddey
The CIDLib C++ Frameworks
Charmed Quark Software
droddey@charmedquark.com
http://www.charmedquark.com

"You young, and you gotcha health. Whatchoo wanna job fer?"


----- Original Message -----
From: "Claude Seyrat" <cs...@acland.fr>
To: <xe...@xml.apache.org>
Sent: Thursday, August 10, 2000 1:45 AM
Subject: Re: MPEG-7 and Xerces


>
> Dear Andy,
>
> thank you very much for your response.
>
> > > 3- Would it be possible to add an MPEG-7 personality
> > >    to Xerces (in such case we will provide developers) ?
> >
> > I don't quite understand what this means.  If MPEG-7 is xml with
> > a specific schema grammar, why would it need a specialized version
> > of the parser?
>
> We need a specialized version of at least the schema parser
> which will deal validate XML wrt to a scheme written in
> DDL ? Am I wrong ?
>
> Claude.
>
> ---------------------------------------------------------
> Claude Seyrat
> University of Paris 6
> Claude.Seyrat@lip6.fr
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: xerces-c-dev-unsubscribe@xml.apache.org
> For additional commands, e-mail: xerces-c-dev-help@xml.apache.org
>

Re: MPEG-7 and Xerces

[Claude Seyrat <cs...@acland.fr>]

Dear Andy,

thank you very much for your response.

> > 3- Would it be possible to add an MPEG-7 personality
> >    to Xerces (in such case we will provide developers) ?
> 
> I don't quite understand what this means.  If MPEG-7 is xml with
> a specific schema grammar, why would it need a specialized version
> of the parser?

We need a specialized version of at least the schema parser 
which will deal validate XML wrt to a scheme written in 
DDL ? Am I wrong ?
 
Claude.

---------------------------------------------------------
Claude Seyrat
University of Paris 6
Claude.Seyrat@lip6.fr

Re: MPEG-7 and Xerces

[Andy Heninger <an...@jtcsv.com>]

From: "Claude" <cs...@acland.fr>
> We are currently evaluating the use of Xerces as 
> the basis of our parser. I have few questions which 
> I hope won't take too much of your time :
> 
> 1- Do you have a time schedule for the development 
>    of the Xerces Parsers (J and C) version 2 ?

There are no existing plans in place for a rearchitected version 2
of xerces-c.  There is an effort underway to rearchitect
xerces-j, with discussions taking place on the xerces-j-dev list.

The C++ and Java parsers do not currently share a common
internal architecture.  The C++ code is somewhat more
approachable than the existing Java code.

The C++ and Java DOM implementations are largely the same.
It was implemented first in Java and then ported to C++.

Xerces-c does not support xml-schema.  One possible route
for getting schema would be to port it from xerces-J, which
would probably also involve taking some or all of Java's
still-under-design new architecture.


> 
> 2- Will you drastically change the architecture of 
>    Xerces version 1? 


> 
> 3- Would it be possible to add an MPEG-7 personality 
>    to Xerces (in such case we will provide developers) ?

I don't quite understand what this means.  If MPEG-7 is xml with
a specific schema grammar, why would it need a specialized version
of the parser?

> 
> 4- Can we rely on the "internal" API for the MPEG-7 
>    extensions ?
> 
In the C++ parser the "framework" interfaces have been reasonably
stable.  For the other internal interfaces, anything can change
at any time.   The introduction of schemas has the potential
of causing fairly widespread changes.  

Schema implementation design for Xerces-C has not yet really
begun.

I hope this helps,

Andy Heninger
IBM XML Technology Group, Cupertino, CA
heninger@us.ibm.com