Stream Requirements for Low-Latency Streaming

While the DASH-IF IOP guidelines and Apple HLS specification extensively outline stream requirements and recommendations for the low latency use case the following is a boiled-down list of the key aspects for compatibility with the Bitmovin Web player.

LL-DASH

• Manifest signals partial availability of live edge segment through availabilityTimeOffset and availabilityTimeComplete attributes
• Content is encoded in chunked CMAF (recommending chunk duration of max. 1 second)
• Content is delivered using HTTP Chunked Transfer Encoding (CTE)
• Recommended: Content carries Producer Reference Time boxes (prft) for precise latency estimation on the client
• Recommended: Manifest includes UTCTiming element to allow compensating client-clock drift

LL-HLS

• Stream requirements as per HLS spec for Low-Latency Mode:
  • Partial Segments
  • Blocking Playlist Reloads
  • Preload Hints
  • Recommended: Playlist Delta Updates (for streams with long live window)
• EXT-X-PROGRAM-DATE-TIME tags in media playlists