updated proposal for multimedia support in DocBook 5.x

["Grosso, Paul" <pgrosso@ptc.com>]

Here is my response to:

> ACTION: Paul to submit a revised multimedia proposal that
> is backwards compatible.

[There were more details discussed during the telcon than
just compatibility that this latest proposal also addresses.]

Summary
-------
To improve support for specifying multimedia objects in DocBook,
this proposal adds several (optional) attributes to audiodata
and videodata and adds an (optional) set of parameter-specifying
children to audioobject and videoobject.

Details
-------
The classid and autostart attributes are added to audiodata
and videodata.  While these attributes could just be specified 
using the generic multimedia parameter markup discussed below, 
I've found that these values require special handling to get 
things to work across the majority of browsers, so it's best 
to provide a better handle on them.  Then the generics can 
generally just be passed through without special processing.

(Note:  The format attribute on audiodata and videodata is
used to specify values analogous to the type attribute on
HTML's object element.)

Also, because an audio object still needs to put a "player" 
into the output, it needs all the sizing attributes that are
included on videodata, so this proposal adds them to audiodata.

Finally we allow zero or more multimedia parameter elements as 
children of audioobject and videoobject.  These are to specify 
all the many param elements that may be needed as children of 
the HTML object element in the resulting HTML.

Below I show the additions to the existing 5.x content models:

 <xsd:element name="audioobject">
    <xsd:complexType>
      <xsd:sequence>
        ...
        <xsd:element minOccurs="0" maxOccurs="unbounded"
                                       ref="multimediaparam"/>
      </xsd:sequence>
    </xsd:complexType>
 </xsd:element>

 <xsd:element name="audiodata">
    <xsd:complexType>
      ...
      <xsd:attribute name="align" type="..."/>
      <xsd:attribute name="contentdepth" type="xsd:string"/>
      <xsd:attribute name="contentwidth" type="xsd:string"/>
      <xsd:attribute name="depth" type="xsd:string"/>
      <xsd:attribute name="scale" type="xsd:string"/>
      <xsd:attribute name="scalefit" type="xsd:string"/>
      <xsd:attribute name="valign" type="..."/>
      <xsd:attribute name="width" type="xsd:string"/>
      <xsd:attribute name="classid" type="xsd:string"/>
      <xsd:attribute name="autostart" type="xsd:string"/>
    </xsd:complexType>
  </xsd:element>

 <xsd:element name="videoobject">
    <xsd:complexType>
      <xsd:sequence>
        ...
        <xsd:element minOccurs="0" maxOccurs="unbounded"
                                       ref="multimediaparam"/>
      </xsd:sequence>
    </xsd:complexType>
 </xsd:element>

 <xsd:element name="videodata">
    <xsd:complexType>
      ...
      <xsd:attribute name="classid" type="xsd:string"/>
      <xsd:attribute name="autostart" type="xsd:string"/>
    </xsd:complexType>
  </xsd:element>

  <xsd:element name="multimediaparam">
    <xsd:complexType>
      <xsd:attribute name="name" use="required" type="xsd:NMTOKEN"/>
      <xsd:attribute name="value" use="required" type="xsd:string"/>
      <xsd:attribute name="valuetype" type="xsd:string"/>
    </xsd:complexType>
  </xsd:element>

paul