About announcements

An announcement is a Windows Media metafile with an .asx extension that provides a player with the information needed to connect to a Windows Media server to receive content. You can place a link to an announcement on a Web page, make the announcement available in a shared file, or send an announcement in an e-mail message. Users can access your content either by clicking the link to the announcement on a Web page or by opening the announcement directly. The announcement wizards on the Announce tab of the Windows Media Services snap-in help you create announcement files (.asx files) and multicast information files (.nsc files) that players can use connect to your content. The wizards can also help you create a Web page with an embedded Windows Media Player control or provide you with the syntax to embed a Player in your own Web page.

When delivering content as a unicast stream, either through an on-demand publishing point or a broadcast publishing point, use the Unicast Announcement Wizard to create the announcement file. The announcement file contains the following information:

• The URL of the content
• Announcement metafile elements, such as the author, title, and copyright

When a user opens the announcement in his or her player, the player extracts the URL of the content and the metafile elements from the announcement and then begins playing the content.

If you are delivering content as a multicast stream through a broadcast publishing point, you must use the Multicast Announcement Wizard. When you use this wizard, the announcement that is created contains the following information:

• The URL of the multicast information file
• Announcement metafile elements, such as author, title, and copyright

When a user opens the announcement in his or her player, the player extracts the URL of a multicast information file. This file contains information the player needs to access and decode the stream, such as the IP address, port, and stream format. The player downloads the multicast information file and then begins playing the content.

This section contains the following topics:

• Sample announcement file
• Customizing announcement files
• Embedding the Player in a Web page
• Understanding MIME types

Note

• Multicast streaming and the WMS Multicast Data Writer plug-in are available only if Windows Media Services 9 Series is running on the following editions of the operating system: Windows Server 2003, Enterprise Edition and Windows Server 2003, Datacenter Edition. If you are running Windows Server 2003, Standard Edition, these features are not supported.

Related topics

• Working with the announcement wizards
• Announcing content