In order to link a media object to a region in the head element,
one of the following types of elements is used:
The "img" element, which is enclosed in <img> tags
The "ref" element, enclosed in <ref> tags
The "animation" element, enclosed in <animation> tags
The "audio" element, in <audio> tags
The "video" element, enclosed in <video> tags
The "text" element, enclosed in <text> tags
The "textstream" element, enclosed in <textstream> ags
and the group that a media object falls into should be reflected in the element name.
If there is any
uncertainty about which group to use, the media object
should use the "ref" element, which is a generic element.
The "region" attribute of a media object element is a pointer to the corresponding
region defined for this object in the "head" element.
The "src" attribute specifies the URI of the media object.
The "alt" attribute specifies alternative text for user agents that cannot display
the particular media object.
The "author" attribute gives the name of the author of the content contained in the element.
The "copyright" attribute provides the copyright notice of the content contained in the
element.
The "id" attribute gives a unique id to the media object.
The "type" attribute specifies the MIME type of media object.
The "begin" attribute specifies the time for the explicit begin of the element. Two types
of values can be assigned to "begin": a delay-value or an event-value. A delay-value
is a clock value, and the media object will begin play at the specified time after
its parent begins. If the value is an event-value, a specified id and time is
associated with the "begin" attribute. The media object would then start at the
time given relative to the media object of the specified id.
The "dur" attribute specifies the explicit duration of the element. The value is either
a clock value or the string "indefinite."
The "end" attribute specifies the explicit end of the element. As with "begin," a
delay-value or an event-value can be assigned to "end."
The media object elements can contain an "anchor" element.
example
<smil>
<head>
<region id = "reg1", left = "10", top = "20", width = "30", height = "50" />
</head>
<body>
<img src = "mypic.gif", region = "reg1", author = "regina", alt = "my picture" />
</body>
</smil>
