https://developer.apple.com/library/ios/technotes/tn2288/_index.html
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/Introduction/Introduction.html
Live Playlist (Sliding Window)
For live sessions, the index file is updated by removing media URIs from the file as new media files are created and made available.
Important: The EXT-X-ENDLIST tag is not present in the Live playlist, indicating that new media files will be added to the index file as they become available.
The EXT-X-ENDLIST tag indicates that no more media files will be added to the playlist file.
