How To Create A Playlist Using An External Captions File
Starting in Blend, with a Silverlight application that already has the SMFPlayer embedded, select the SMFPlayer and find the Playlist property under Common Properties.
Click Playlist and “Add another item”. Configure this PlaylistItem to for some media by setting DeliveryMethod and MediaSource.
On the Playlist item, find and click the “New” button next to the MarkerResource property. Then set the Source property to the location of the external, DFXP formatted, caption file.
Click the “Ok” buttons to exit the dialog boxes and save changes. Open the XAML view and notice that the XAML for our Marker Resource, which will be used for parsing our captions, has been added to the Playlist Item.
Run the application and turn on captions, then verify that the captions from the file are visible.