Microsoft Windows Media Resource Kit (Pro-Resource Kit)

Contoso planners want to build traffic to the site and keep people engaged once they arrive. They feel the info channel is one way to do that. The end user who wants a particular movie will locate the title and go right to the rental page. However, the planners feel that the info channels will appeal to users who want to browse. Each channel will repeat continuously, so a user can tune in at any point during the 20-minute broadcast.

In addition to trailers and insider movie fan information, the info channels will include MoreInfo banners and URLs. If an end user sees a movie she likes while viewing the channel, she can click the link and the details page for that movie will open. Figure 11.3 shows a banner as it appears in Windows Media Player.

Figure 11.3: An example of a MoreInfo banner on the Contoso Web site.

There will be 10 info channels, one for each movie genre. Each channel is a broadcast publishing point that sources from two server-side playlists: the main playlist and a wrapper. The playlists will source primarily from digital media content on the local Windows Media server. However, they can source from content on other servers.

The Contoso Movies Online staff will create a mockup of a movie info channel from the following components:

• Broadcast publishing point. The address that Players use to access a movie channel. Publishing points are the basic components for configuring a Windows Media server. They connect the client to digital media content, such as a file, a directory of files, a live stream from an encoder, or a server-side playlist.

  A publishing point is created from two basic pieces of information: a publishing point name and a source. A client accesses the name to receive the source content. For example, when a client accesses a movie info channel using the name of the channel (such as rtsp://WMServer/Channel01), the server streams the source content defined in the playlist. After you create either a broadcast or on-demand publishing point, you can configure properties and plug-ins that modify the operation of the publishing point.

• Main server-side playlist. The main source of the publishing point; the content that the end user has requested. The playlist is a metafile with a .wsx extension. It is located on a local hard drive or on a computer accessible over a network using a UNC path, such as \\RemoteComputer\Folder\File.wsx.

• Wrapper playlist. The playlist file that is added to the publishing point as a wrapper. End users play the wrapper playlist, if one is assigned, when they come to a publishing point. Therefore, in order for the main playlist to stream to end users, it must be an element of the wrapper. In the Contoso scenario, the wrapper playlist begins with an intro image file that plays for 10 seconds, and then cuts to the main broadcast playlist.

• ASP pages. Elements in the playlist that enable you to assign digital media sources dynamically. One ASP page simply returns the location of a playlist containing one digital media file; another returns a playlist with a random ad. In practice, ASP pages can be used to return URLs of dynamic playlists from an ad server, for example.

• Image files. These are used in the info channel publishing point in two ways. One is used as an introductory image in the wrapper playlist; the other is used as a MoreInfo banner.

• Digital media content. All movie channels will pull content from the same pool of Windows Media video files. Figure 11.4 shows how the digital media feeds into the info channel playlists.

  Figure 11.4: How files are added to the info channel playlists.

In the WMRoot directory, for example, folders can be added to separate the types of digital media, such as movies, trailers, publicity material, bumpers, commercials, and playlists. When creating a playlist, the Contoso Movies Online producer views all the material available, and then lays the playlists out with content appropriate for each genre and for the best flow. The following table shows an example of part of the lineup of two channels.

Several of the media elements can be included in two or more channels. For example, the bumper files can be used on all channels, and there is a comedy trailer that fits in both the comedy and action/adventure genres. The Ad01.asp entry is accessed by switching to the wrapper playlist from the main playlist. Immediately after the ad returned by the ASP page ends, playback returns to the main playlist.

It may seem complicated and resource-intensive, but creating and implementing server-side playlists can be simplified by using ASP pages. For example, an entire playlist can be created dynamically and automatically by configuring an ASP page as the source of a broadcast publishing point. In the next part of this chapter, we will see how Contoso creates a mockup info channel that includes all of the components discussed here. We will see how they write the scripts, create the metafiles, configure the server, and then check playback of the publishing point.