Abstract: A playlist having an entry that points to a media file in a first format is processed to be played at a client that has a player suitable for rendering files of a second format. A primary description file of the media file is generated at a server. The description file can be used by a second format player to render the first format media file. When a request for the playlist is received at the server from the client, a secondary description file is generated that points to the location of the media file. The server replaces the playlist entry pointing to the media file with an entry pointing to the location of the secondary file. When the client plays the entry from playlist, the client requests and receives the secondary description file, which the client uses to find and render the media file using the second format player.