19. SMIL 3.0 DAISY Profile

This section is normative.

DAISY [DAISY] digital talking books are fully accessible for persons with print disabilities, such as those with blindness, low vision, hearing impairments, deaf-blindness, motor disabilities, dyslexia, and a wide range of cognitive/intellectual disabilities. DAISY is the recognized international standard for digital talking books and has been adopted worldwide by organizations serving these groups.

With the release of SMIL 3.0, the pre-existing DAISY standard has gotten the opportunity to move into the mainstream of multimedia development. Several accessibility features have been added to the SMIL language, and a fully-conforming language profile has been defined for DAISY books.

This section is normative.

In the text in this profile specification, the term DAISY profile will be considered to refer exclusively to the SMIL 3.0 DAISY profile as defined in this document.

19.4.1 SMIL 3.0 DAISY Profile Conformance

The definition of conformance for a SMIL 3.0 profile is given in the Definitions section of the SMIL 3.0 Scalability Framework. Based on these definitions, the DAISY profile is a Strict Host-Language Conformant SMIL 3.0 Profile.

Within the referenced sections of the Scalability Framework, the following definitions should be used:

1. The profile identification string for the DAISY profile is: http://www.w3.org/2008/SMIL30/Daisy.
2. Documents written for the DAISY profile must declare the default SMIL namespace with the xmlns attribute on the smil root element. For SMIL 3.0, this is:

   xmlns="http://www.w3.org/ns/SMIL"

3. The SMIL 3.0 DAISY profile DOCTYPE is:

   <!DOCTYPE smil PUBLIC "-//W3C//DTD SMIL 3.0 Daisy//EN"
   "http://www.w3.org/2008/SMIL30/SMIL30Daisy.dtd">

   If a document contains this declaration, it must be a valid XML document. Note that this implies that extensions to the syntax defined in the DTD (or in the corresponding XML or RelaxNG schemas) are not allowed. If the document is invalid, the user agent should issue an error.
4. The identification string for the non-normative DTD used for integration of errata is:

   http://www.w3.org/2008/SMIL30/informative-DTD/SMIL30Daisy.dtd

5. Documents written for the DAISY profile must declare (explicitly or implicitly via the DTD) the following values for the version and baseProfile attributes:

   version="3.0" baseProfile="Daisy"

   As a consequence of the two requirements above, the effective root element declaration for a DAISY profile document must be:

   <smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Daisy">
        ...
   </smil> 

   The root element may be extended as required with additional atttributes.

This version of SMIL provides a definition of strict host-language conformant SMIL 3.0 documents, which are restricted to tags and attributes from the SMIL 3.0 namespace. The Section "Extending/Restricting a SMIL 3.0 Profile" provides information on using the SMIL 3.0 DAISY profile with other namespaces, for instance, on including new tags within SMIL 3.0 documents.

Language designers and implementors wishing to extend the DAISY profile must consider the implications of the use of namespace extension syntax. Please consult the section on Scalable Profiles for restrictions and recommendations for best practice when extending SMIL.

19.4.2 SMIL 3.0 DAISY Profile User Agent Conformance

The definition of user agent conformance for SMIL 3.0 DAISY profile documents is given in the Conforming SMIL 3.0 User Agents section of the SMIL 3.0 Scalability Framework. Conforming DAISY profile user agents must adhere completely to this section.

19.4.3 The DAISY Profile

The DAISY profile includes the following SMIL modules:

• Structure functionality
  • Structure Module
  • Identity Module
• Metainformation functionality
  • Metainformation Module
• Timing functionality
  • BasicInlineTiming Module
  • EventTiming Module
  • MultiArcTiming Module
  • BasicTimeContainers Module
  • BasicExclTimeContainers Module
• Content Control functionality
  • BasicContentControl Module
  • RequiredContentControl Module
  • SkipContentControl Module
• State functionality
  • StateTest Module
  • UserState Module
  • StateSubmission Module
  • StateInterpolation Module
• Layout functionality
  • BasicLayout Module
  • StructureLayout Module
  • SubRegionLayout Module
• Linking functionality
  • BasicLinking Module
• Media functionality
  • BasicMedia Module
  • MediaClipping Module
  • MediaParam Module
  • MediaAccessibility Module
  • MediaDescription Module

The collection names contained in the following table define the DAISY profile vocabulary.

In the following sections, we define the set of elements and attributes used in each of the modules included in the DAISY profile. The content model for each element is described. The content model of an element is a description of elements which may appear as its direct children. The special content model "EMPTY" means that a given element may not have children.

All attributes in the collection Core are defined for all the elements of the DAISY profile. The xml:id attribute is used in the DAISY profile to assign a unique XML identifier to every element in a SMIL document.

XHTML Role Attribute Module

The DAISY profile includes the separate XHTML Role Attribute Module [XHTMLrole]. This provides a mechanism for allowing a semantic classification of elements via the xhtml:role attribute. The DAISY profile adds the xhtml:role attribute to the switch, region, a, area, text, img, audio, video, ref, textstream, par, seq, and excl elements.

<smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Daisy" xmlns:xhtml="http://www.w3.org/1999/xhtml" >
    ...
    <par xhtml:role="...">
        ...
    </par>
    ...
</smil>

19.4.4 Content Control Modules

In the DAISY profile, Content Control elements may have the following attributes and content model :

This profile adds the switch element to the content model of the par, seq and excl elements of the Timing and Synchronization Modules, of the body and the head elements of the Structure Module, of the content model of the a element of the Linking Modules.

The switch element has the restriction that the content of the switch may only be from the same set of elements.

The Content Control functionality is used to define the Attribute set "Test":

19.4.5 Layout Modules

In the DAISY profile, Layout elements may have the following attributes and content model :

The attribute collection SubregionAttributes is defined as follows:

This profile adds the layout element to the content model of the head element of the Structure Module. It also adds this element to the content model of the switch element of the Content Control Modules, when the switch element is a child of the head element.

19.4.6 Linking Modules

This profile includes both timing and linking modules; however, the profile authors have decided to explicitly exclude timing attributes on linking elements because it introduces too much complexity.

Both the a and area elements have an href attribute, whose value must be a valid URI or XPointer [XPTR] fragment identifier.

In the DAISY profile, linking elements may have the following attributes and content model :

This profile adds the a element to the content model of the par, seq, and excl elements of the Timing and Synchronization Modules. It also adds these elements to the content model of the body element of the Structure Module.

19.4.7 Media Object Modules

In the DAISY profile, media elements may have the following attributes and content model:

The attribute collection MediaDescriptionAttributes is defined as follows:

This profile adds the ref, animation, audio, img, video, text, and textstream elements to the content model of the par, seq, and excl elements of the Timing and Synchronization Modules. It also adds these elements to the content model of the body element of the Structure Module. It also adds these elements to the content model of the a element of the Linking Modules.

Examples

<par>
    <text src="text.xml#id"/>
    <audio src="audio.mp3"/>
</par>

<par>
    <text src="text.xml#xpointer(/body/p[2])"/>
    <audio src="audio.mp3"/>
</par>

Using param

The param element conveys rendering instructions about a media type.

The DAISY profile defines the following name values as rendering instructions for text media:

It is expected that media objects using <param name="daisy:use-renderer" value="..." /> exist alongside a default rendering of the media.

In the case where the whole document is being shown at once (<param name="daisy:display-in-context" value="true"/>), an intelligent renderer will ensure that the portion of the parent document containing the specified fragment will be put in view so the fragment may be seen. It is left to the renderer to decide how much of the surrounding document context to include (lines above and below the target fragment).

Examples:

<smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Daisy" >
    ...
  <body>
      ...
      <par>
          <text src="example.html#p2" region="centerTextRegion" >
              <param name="daisy:display-in-context" value="true" />
              <param name="daisy:css-highlight-style" value="background-color: yellow; color: black; border: solid thin green"/>
          </text>
      </par>
      ...
  </body>
</smil>

<smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Daisy" >
    <head>
        <paramGroup xml:id="textParams">
              <param name="daisy:display-in-context" value="true" />
            <param name="daisy:css-highlight-style" value="background-color: yellow; color: black; border: solid thin green"/>
        </paramGroup>
        <region xml:id="textWindow" width="100%" height="100%" paramGroup="textParams"/>
        ...
    </head>
    <body>
        ...
        <par>
            <text src="my_text.txt" region="textWindow"/>
            <audio src="audio.mp3" clipBegin="0.00s" clipEnd="3.00s"/>
        </par>
        ...
    </body>
</smil>

MIME Types

This profile does not require support of any particular formats. However, it is strongly recommended to support the formats listed in the SMIL 3.0 Language profile's Required MIME Types section.

19.4.8 Metainformation Modules

In the DAISY profile, Metainformation elements may have the following attributes and content model :

This profile adds the meta element to the content model of the head element of the Structure Module.

The content model of metadata is EMPTY. Profiles that extend the DAISY profile may define the RDF (Resource Description Framework) schema to be used in extending the content model of the metadata element. The Resource Description Framework is defined in the W3C RDF Recommendation [RDFsyntax].

Note that because the metadata element may appear on its own, it may be used to wrap a meta element and placed anywhere in the document.

The following name attribute values may be used to specify the relationship between documents:

An example using this to define the static default playback order in a multi-document SMIL presentation:

<-- chapter2.smil -->
<smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Daisy" >
    <head>
        <meta name="next" content="chapter3.smil"/>
        <meta name="prev" content="chapter1.smil"/>
        ...
    </head>
    <body>
        ...
    </body>
</smil>

19.4.9 State Modules

The State Modules provide a framework for declaratively manipulating various bits of state in a SMIL presentation. The State Modules define semantics for the submission, send, state, setvalue, newvalue, and delvalue elements and the expr, submission, action, method, replace, target, language, ref, where, name, value attributes. The DAISY profile includes the State functionality of the StateTest, UserState, StateSubmission, and StateInterpolation modules.

In the DAISY profile, the State elements may have the following attributes and content model:

This profile adds the state and submission elements to the content model of the head element of the Structure Module, and the setvalue, newvalue, delvalue, and send elements to the content model of the body, switch, a, par, seq, excl elements. It also adds the expr attribute to all elements within the content model of the body element (i.e. excluding the body element itself).

The content model of the state element is declared as EMPTY. The state element defines the data model of the SMIL State engine using the XForms 1.0 syntax. The elements are not imported into SMIL 3.0 and must be fully qualified.

The submission attribute value is an IDREF that refers to a submission element.

The method attribute must at least support the values get, put and post. Serialization and submission must follow the description of these methods in [XFORMS10], section 11.2. Support for other methods described in that document is optional.

Interpolation of values using the mechanism from the StateInterpolation module is supported on the href, src, clipBegin, clipEnd and value attributes.

Expression Language and Data Model

Support for using XPath 1.0 [XPATH10] as the expression language is required. The default value for the language attribute is http://www.w3.org/TR/1999/REC-xpath-19991116, which denotes the use of XPath 1.0 as the expression language.

The content of the state element must be a single XML document. If this document is empty at initialization time a single empty <data/> root element is added.

The following constraints are in force:

• The expr attribute value is an XPath 1.0 expression that must evaluate to a boolean.
• The ref attribute value is an XPath 1.0 expression that must evaluate to a nodeset containing exactly one node.
• The target attribute value is an XPath 1.0 expression that must evaluate to a nodeset containing exactly one node.
• The value attribute value is an XPath 1.0 expression that must evaluate to a string.
• The name attribute value must be a valid XML element name.

Interpretation of XPath expressions depends on an expression context. That context is defined thus:

• The context node is the root of the document defined in the state element.
• The context position and context size refer to that same root node.
• The variable bindings are empty.
• The function library consists of the functions defined in the StateTest module and the XPath Core Function Library [XPATH-CoreFunctionLibrary].
• The set of namespace declarations is defined by the xmlns attribute on the context node.

<smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Daisy" >
  <head>
  <--This state data model could live in a separate file and be accessed by other user agent components -->
  <state xmlns:f="http://www.w3.org/2002/xforms">
    <f:model>
      <data xmlns="">
        <brailleAvailable>true</brailleAvailable>
      </data>
    </f:model>
    <f:bind nodeset="brailleAvailable" type="xsd:boolean"/>
</state>
    ...
  </head>
  <body>
      <seq>
          <par>
            <-- This is the Braille rendering equivalent of the text contents.  A Braille display is required to show it. -->
            <text src="special-notation-for-braille.xml#p4" dur="indefinite" expr="brailleAvailable">
                <param name="daisy:use-renderer" value="braille"/>
            </text>
            <-- This is the default visual rendering of the text contents.-->
            <text src="my_text.xml#p4"/>
            <audio src="audio.mp3" clipBegin="0.00s" clipEnd="3.00s"/>
          </par>
          ...
      </seq>
  </body>
</smil>

19.4.10 Structure Modules

In the DAISY profile, Structure elements may have the following attributes and content model:

19.4.11 Timing Modules

In the DAISY profile, Timing elements may have the following attributes and content model:

The Attribute collection Timing is defined as follows:

Special values for the end attribute

This profile defines the following values for the end attribute, in addition to what is given by SMIL.

This section is normative.

The DAISY profile Document Type Definition is defined as a set of SMIL 3.0 modules, with the addition of the XHTML Role Attribute Module [XHTMLrole]. All SMIL 3.0 modules are integrated according to the guidelines in the W3C Note "Synchronized Multimedia Modules based upon SMIL 1.0" [SMIL-MOD], and defined within their respective module sections. The XHTML Role Attribute Module's DTD Implementation [XHTMLrole-DTDImpl] is used for integrating role into the DAISY profile DTD.