Alternating between live and prerecorded content in your broadcast
Applies To: Windows Server 2008, Windows Server 2008 R2
This section demonstrates how to use Windows Media Services to stream both live and prerecorded (stored) content. Despite the inclusion of stored content, users do not have the ability to pause, fast-forward, or rewind the broadcast. The user has the option of starting, stopping, and resuming the broadcast stream, creating a user experience similar to tuning into a radio or television broadcast.
This section shows how versatile server-side playlists can be and how they are used to manipulate the playback at the client computer. For this task, you must be streaming live content from a computer running an encoder and you must have prerecorded content, such as an advertisement, in a Windows Media file. In the following procedure, the client receives five minutes of live content, which is then is interrupted for an advertisement. When the advertisement ends, the live content resumes for another five minutes.
To alternate between live and prerecorded content
In Windows Media Services, in the console tree, click Publishing Points. In the details pane, click the View playlist editor button. The Windows Media Playlist Editor opens.
Add container elements to the playlist to control how different playlist elements are played back with respect to each other. In this procedure, the publishing point will pause the content when one element interrupts another. To specify this behavior do the following:
In the Windows Media Playlist Editor, click the Add element arrow on the toolbar and then click Exclusive. An excl element appears in the playlist tree.
Click the excl element that you just created. Click the Add element arrow on the toolbar and then click PriorityClass. A priorityClass element appears in the below the excl element.
Click the priorityClass element that you just created. In the properties area, click the peers attribute and then type Pause in the text box. Press ENTER. This setting instructs the publishing point to pause this content whenever it switches to another media element.
Add live content to the playlist by doing the following:
In the Windows Media Playlist Editor, click the Add element button on the toolbar. The Add Media Elements dialog box appears.
Type the URL of the encoder stream by using the following syntax: https://encoder:port. Select the Add as a child element check box and then click OK. The media element appears in the playlist tree beneath the priorityClass element and displays the URL of the encoder.
In the Windows Media Playlist Editor, set the following values to define how the live content should be played back. In this example, the content will start immediately and stream for 10 minutes:
In the playlist tree, click the media element that you added in the previous step.
Click the begin attribute in the properties area and then type 0 in the text box. Press ENTER. This setting instructs the publishing point to begin streaming the live content when the publishing point starts.
Click the dur attribute in the properties area and then type 10min in the text box. Press ENTER. This setting instructs the publishing point to stream the live content for a total of 10 minutes.
To provide a unique identifier for the live content, click the id attribute in the properties area and then type a name for the media element, such as M1, in the text box. Press ENTER. This setting provides this media element with a name that can be referenced by other elements in the playlist.
Add prerecorded content to the playlist by performing the following steps. In this example, the prerecorded content is an advertisement:
In Windows Media Playlist Editor, click the priorityClass element in the playlist tree.
Click the Add element button on the toolbar. The Add Media Elements dialog box appears.
Type the name and location of the advertisement that you want to add. Select the Add as a child element check box and then click OK.
Define how the advertisement should be played back by doing the following. In this example, the advertisement starts five minutes after the content starts:
In the playlist tree, click the advertisement media element that you just added.
Click the begin attribute in the properties area and then type M1.begin + 5min, for example, in the text box. Press ENTER. This instructs the publishing point to wait until the live content has played for five minutes and then play the advertisement.
Provide a unique identifier for the advertisement by clicking the id attribute in the properties area. Type a name for the advertisement, such as M2, in the text box. Press ENTER. This provides this media element with a name that can be referenced by other elements in the playlist.
Save the playlist and then close the Windows Media Playlist Editor.
Use the Add Publishing Point Wizard to create a new broadcast publishing point by doing the following:
On the Action menu, click Add Publishing Point (Wizard). The Add Publishing Point Wizard appears.
On the welcome page, click Next.
On the Publishing Point Name page, type a name for the new publishing point.
On the Content Type page, click Playlist.
On the Publishing Point Type page, click Broadcast Publishing Point.
On the Delivery Options for Broadcast Publishing Points page, click Unicast.
Use the wizard to reference the playlist that you created in steps 1 through 9 by using the following settings:
On the File Location page, click Existing playlist. In File name, type the name and location of the new playlist.
On the Unicast Logging page, select the check box if you want to log data about your clients.
On the Publishing Point Summary page, verify that the settings for the new publishing point are correct.
On the Completing the Add Publishing Point Wizard page, clear all of the check boxes, and then click Finish.
Configure the following publishing point settings to have the publishing point start when the first client connects:
In the console tree, click the publishing point you just created. In the details pane, click the Properties tab. In Category, click General.
Click the Start publishing point when first client connects property and then click the Enable button.
Users can now receive the content in the playlist by typing the URL of your publishing point in their player. The URL to a publishing point uses the following syntax: protocol://server/publishing_point (for example, mms://server1/my publishing point).