endSync attribute

The endSync attribute enables you to base the end of an excl element on the end of one of its child elements.

The endSync attribute is used in situations in which child elements in an excl element can be activated randomly, such as through a program created using the Windows Media Services Software Development Kit (SDK). In these cases, the elements' begin attribute values or durations may be undetermined when the playlist is created, and the endSync attribute provides a way to control playback within the excl container after the playlist is online. The endSync attribute is particularly useful for an excl element that contains child elements of unknown durations or whose end is based on a particular event.

The endSync attribute can have the following values.

Value	Description
`first`	Specifies that the excl element ends after the first active child element ends.
`all`	Specifies that the excl element ends after all child elements that have a resolved begin attribute value end. Elements with an unresolved begin attribute value will prevent the excl element from ending because the duration cannot be determined.
`id-value`	Specifies that the excl element ends when the child element with the specifed id attribute value ends.
`last`	Specifies that the excl element ends when the last active child element with a resolved and definite begin attribute value ends. If there are no children with a resolved begin attribute value, the excl element ends immediately.

When you specify an endSync attribute value for an excl element, you define the duration of the excl element based on the duration of its child elements. The following rules dictate how the playlist evaluates the endSync attribute value:

If both the endSync and dur attributes are specified for an excl element, the endSync attribute is ignored because the dur attribute defines the duration of the excl element.
If both the endSync and end attributes are specified for an excl element, but not the dur, repeatDur or repeatCount attributes, the endSync attribute is ignored. In this case, the element's duration is indefinite and is defined by the end attribute value.
If an element is paused, it has not ended its active duration. The playlist must consider paused elements when evaluating the endSync attribute. For example, if a excl element has an endSync attribute that is equal to last and child elements that are paused, the excl element cannot end until the paused children resume or otherwise end.

In the following example, the endSync attribute value is first. The second and third media elements are never played because the excl element ends after the first media element, Clip_1.wmv, ends.

<?wsx version="1.0"?>
<smil>
  <excl endSync="first">
	<media src="C:\Wmpub\Wmroot\Clip_1.wmv" begin="0s" clipEnd="10s" />
	<media src="C:\Wmpub\Wmroot\Clip_2.wmv" begin="15s" dur="15s" />
	<media src="http://encoder_name:80" begin="Event1" />
  </excl>
</smil>

However, if the endSync attribute value in this example was equal to last, the first and second media elements would play, but the third media element would not, because it has an indeterminate start time. If the endSync attribute value in this example was equal to all, all three media elements would play, but the element that sources from an encoder would not start playing until the event specified by the begin attribute occurs.

The endSync attribute can be specified for the following playlist element:

excl element

Note Image Notes

If an endSync attribute value is not specified for an excl element, the excl element acts as if the endSync attribute was defined as last, by default.
For more information about defining playlist attributes, see the Windows Media Services SDK at the Microsoft Web site.
If you are creating or editing server-side playlists by using either a text editor or an automated script, ensure that the endSync attribute tags are in the correct case. XML is a case-sensitive language, and Windows Media Services will not recognize playlist attributes that are not listed properly.

endSync attribute

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