This section is informative.
There are three sets of changes to this module. First, the SMIL 3.0specification now allows metainformation to be placed on elements within thebody instead of being restricted to the head element. This may make it easierto provide information on semantic intent within a SMIL presentation bymaking the binding of that information with the relevant nodes more local.Second, the text in this section makes it clear that several different typesof metainformation encodings may be used within a single presentation. Third,thelabel attribute has been added totheMetainformation module so thatextended content information can be provided for document components.
This section is normative.
This section defines the SMIL 3.0 Metainformation Module. The SMILmetainformation facilities are composed of a module containing elements andattributes that allow description of metadata annotation of presentationcreation information and presentation semantic intent to be added to SMILdocuments. Since these elements and attributes are defined in a module,designers of other markup languages may choose whether or not to include thisfunctionality in their languages.
This section is informative.
The SMIL 1.0 specification allowed authors to describe documents with avery basic vocabulary using themetaelement. This was extended in the SMIL 2.0 specification with theintroduction of themetadataelement. Themetadata elementintroduced the capability for describing metadata using the ResourceDescription Framework Model and Syntax
Both themeta and
SMIL 3.0 also extends the capabilities presented for describing the natureof a content fragment within a document by introducing the label attribute.This attribute specifies a URI to a SMIL document that provides additionalinformation in an accessible manner on the related element.
Unless specified otherwise by a profile, a SMIL user agent is not requiredto process or otherwise interpret specific metainformation strings. In allcases, metainformation may be considered to be optional information in apresentation.
This section is normative.
This section defines the elements and attributes that make up thefunctionality in the SMIL Metainformation module.
The SMIL 3.0Metainformationmodule defines two elements and one attribute that provide basic support formetainformation markup within a SMIL presentation.
The elements defined in this module are:
The attribute defined in this module is:
Themeta element specifies a singleproperty/value pair in its name and content attributes, respectively.Multiple property/value pairs must be described in multiple instances of themeta element.
The meta element defines the following attributes:
This section is informative.
Note: the base property has been deprecated in favor of the more general XML base URL mechanism described in[XMLBase]. The language profile including the SMIL 3.0 metainformation module will determine if the base property will be supported by that profile.Themeta element is an emptyelement.
Themetadata element containsinformation that is also related to metainformation of the document ordocument components. Themetadataelement allows metainformation to be defined using a wide range ofmetainformation structuring languages. In many cases, it will act as the rootelement of an RDF tree, but it may also act as the root of otherapplication-domain-specific metainformation structuring languages. Thecontents of themetadata elementare not processed within the context of a SMIL presentation, althoughdifferent user agents may use the information within the element to supportfunctionality such as searching or content labelling.
The metadata element does not define any new attributes.
When used with RDF, themetadataelement is expected to contain anRDF element andits sub-elements[RDFsyntax].
When used with other metainformation structuring languages, the
Thelabel attribute specifies thename of a SMIL presentation that may be referenced by the user agent toprovide additional information on the element to which this attribute isattached. A SMIL file is used as the target because this can provide a richerdescription of an element than a single text string or audio fragment. Inthis way, a richer mechanism is providing information on the intent of therelevant element than is available with other metadata facilities.
This section is informative.
To insure backward compatibility with SMIL 1.0, the
SMIL 2.1 extended SMIL 1.0 metainformation functionalities with the newmetadata element to host RDFstatements. RDF is a declarative language and provides a W3C-recommended wayfor using XML to represent metadata in the form of statements aboutproperties and relationships of items on the Web. Such items, known asresources, can be almost anything, provided they have a Web address. This meansthat you may associate metadata information with a SMIL document, but also agraphic, an audio file, a movie clip, or a structural sub-portion of a SMILdocument. The specifications for RDF can be found at:
SMIL 3.0 maintains the use of both themeta andmetadata elements. Newto SMIL 3.0 is the explicit possibility to allow the
This section is informative.
This section contains five examples of the use of metainformation in aSMIL presentation.
The first example uses the Dublin Core version 1.0 RDF schema
<?xml version="1.1" ?><smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Language" xml:base="http://example.org/metaInf/assets/" > <head> <meta xml:id="meta-smil1.0-a" name="Publisher" content="W3C" /> <meta xml:id="meta-smil1.0-b" name="Date" content="2007-01-03" /> <meta xml:id="meta-smil1.0-c" name="Rights" content="Copyright 2007 John Smith" /> <meta xml:id="meta-smil1.0-d" http-equiv="Expires" content="16 Apr 2051 12:00:00 UTC"/> <metadata xml:id="meta-rdf"> <rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#" xmlns:dc = "http://purl.org/dc/elements/1.1/" xmlns:smilmetadata = "http://www.example.org/AudioVideo/.../smil-ns#" ><!-- Metadata about the SMIL presentation --> <rdf:Description rdf:about="http://www.example.com/meta.smil"> ... </rdf:Description><!-- Metadata about the video --> <rdf:Description rdf:about="http://www.example.com/videos/meta-1999.mpg"> ... </rdf:Description><!-- Metadata about a scene of the video --> <rdf:Description rdf:about="#scene1" > ... </rdf:Description> </rdf:RDF> </metadata> <layout> <region xml:id="a" top="5" /> </layout> </head> <body> <video region="a" src="/videos/meta-1999.mpg" > <area xml:id="scene1" begin="0s" end ="30s"/> <area xml:id="scene2" begin="30s" end ="60s"/> </video> <video region="a" src="/videos/meta2-1999.mpg"/> </body></smil>
The second example is similar to the first, except that references onindividual media elements are placed within the document definition insteadof the head element.
<?xml version="1.1" ?><smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Language" xml:base="http://example.org/metaInf/assets/" > <head> <meta xml:id="meta-smil1.0-a" name="Publisher" content="W3C" /> <meta xml:id="meta-smil1.0-b" name="Date" content="2007-01-03" /> <meta xml:id="meta-smil1.0-c" name="Rights" content="Copyright 2007 John Smith" /> <meta xml:id="meta-smil1.0-d" http-equiv="Expires" content="16 Apr 2051 12:00:00 UTC"/> <metadata xml:id="meta-rdf"> <rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#" xmlns:dc = "http://purl.org/dc/elements/1.1/" xmlns:smilmetadata = "http://www.example.org/AudioVideo/.../smil-ns#" ><!-- Metadata about the SMIL presentation --> <rdf:Description rdf:about="http://www.example.com/meta.smil"> ... </rdf:Description> </rdf:RDF> </metadata> <layout> <region xml:id="a" top="5" /> </layout> </head> <body> <video xml:id="v1" region="a" src="/videos/meta-2006.mpg" > <metadata xml:id="meta-rdf"> <rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#" xmlns:dc = "http://purl.org/dc/elements/1.1/" xmlns:smilmetadata = "http://www.example.org/AudioVideo/.../smil-ns#" > <!-- Metadata about the video --> <rdf:Description rdf:about="http://www.example.com/videos/meta-1999.mpg" > ... </rdf:Description> </rdf:RDF> </metadata> <area xml:id="scene1" begin="0s" end ="30s"> <metadata xml:id="meta-rdf"> <rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:rdfs = "http://www.w3.org/2000/01/rdf-schema#" xmlns:dc = "http://purl.org/dc/elements/1.1/" xmlns:smilmetadata = "http://www.example.org/AudioVideo/.../smil-ns#" > <!-- Metadata about a scene of the video --> <rdf:Description rdf:about="#scene1" > ... </rdf:Description> </rdf:RDF> </metadata> </area> <area xml:id="scene2" begin="30s" end ="60s"/> </video> <video region="a" src="/videos/meta2-2007.mpg"/> </body></smil>
In this example, separate metainformation blocks have been defined for thepresentation, the video element 'v1' and each of the scenes of the video.Although RDF has been used for all of these objects, other formalisms (suchas MPEG-7 or TV-Anytime) may also be used.
The third example shows the use of the label attribute as a pointer to aseparate SMIL presentation. It can therefore be referred using a simple URIwith no XPointer or ID fragment.
<?xml version="1.1" ?><smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Language" xml:base="http://example.org/metaInf/assets/" > ... <body> <!–– This part of the presentation is a chapter ––> <seq label="chapterlabel.smil"> <par> <text src="example.html#fragment_one"/> <audio src="audio_document.mp3" clipBegin="0.00s" clipEnd="5.00s"/> </par> ... </seq> </body></smil>
The label is in a separate file (chapterlabel.smil):
<?xml version="1.1" ?><smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Language" xml:base="http://example.org/metaInf/assets/" > ... <body> <!––the label itself, as text and audio––> <par> <text>Chapter</text> <audio src="chapter.mp3"/> </par> </body></smil>The fourth example shows a presentation with two content control options, tobe set by the user. Both labels used here are found in the same external SMILfile, wrapped in an excl container (so that only one is played at a time).The referencing URI specifies which label is required.
... <head> <customAttributes> <!–– the option to play page numbers ––> <customTest xml:id="pagenumbersOn" defaultState="false" override="visible" label="labels.smil#pagenumbers"/> <!–– the option to play footnotes ––> <customTest xml:id="footnotesOn" defaultState="true" override="visible" label="labels.smil#footnotes"/> </customAttributes> </head> ...
The following SMIL file (labels.smil) contains both labels used in examplefour:
<?xml version="1.1" ?><smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Language" xml:base="http://example.org/metaInf/assets/" > ... <body> <excl> <par xml:id="footnotes"> <text>Footnotes</text> <audio src="footnotes.mp3" clipBegin="0.00s" clipEnd="1.54s"/> </par> <par xml:id="pagenumbers"> <!–– the label's textual content may reference inline or external text ––> <text src="labeltext.xml#pagenum"/> <audio src="pagenumbers.mp3"/> </par> </excl> </body></smil>
The fifth example illustrates how SMIL meta content can be included withinthe body of a presentation by including it as content of the metadataelement.
<?xml version="1.1" ?><smil xmlns="http://www.w3.org/ns/SMIL" version="3.0" baseProfile="Language" xml:base="http://example.org/metaInf/assets/" > <head> <meta xml:id="meta-smil1.0-a" name="Publisher" content="W3C" /> <meta xml:id="meta-smil1.0-b" name="Date" content="2007-01-03" /> <meta xml:id="meta-smil1.0-c" name="Rights" content="Copyright 2007 John Smith" /> <meta xml:id="meta-smil1.0-d" http-equiv="Expires" content="16 Apr 2051 12:00:00 UTC"/> <layout> <region xml:id="a" top="5" /> </layout> </head> <body> <video xml:id="v1" region="a" src="/videos/meta-2007.mpg" > <metadata xml:id="meta-rdf"> <meta name="Studio" content="AmstelProductions" /> <meta name="Director" content="Willem.van.Oranje" /> <meta name="Rights" content="OpenSourceVideo-v1a" /> </metadata> </video> </body></smil>
The collection of elements that allow the