Low Latency Streaming

  • Low latency streaming (different approaches)
    • CMF
    • Default user interface
    • Contribution / formats
    • MSE
      • Edge - need 3 seconds of buffer. There should be an explicit flag to indicate low latency.
      • If you write a web platform test, it's more likely to get accepted.
      • We rely on keyframes - sometimes content providers don't map keyframes properly.
      • Tell the browser you won't have b-frames (it will also disable seeking)
      • Players would like to have live streaming features to be defined one-by-one, instead of being bundled into a single “live” setting.
      • A lot of live content have b-frames - browsers cannot trust it and therefore hard to give too much flexibility
      • Player can back-seek to keyframe to learn how to decode b-frames
      • A lot of choices for the players are publisher-driven
      • MSE tracks keyframes
      • Common problems: video doesn't start, or it stalls
      • Why not have MSE report issues back to the player?
      • For chrome, live mode means waiting for 1 frame instead of 4 frames
      • What about getting a javascript API to the decoder?
        • It's hard to do right in a reliable manner
    • lHLS
      • Big issue - plugging into existing HLS (bandwidth estimation is off)
      • Current ABR algorithms (throughput estimation) aren't taking it into account
      • Search for “abortable fetch”
      • Streaming body response API needs to be standardized
    • Talking about let browser handle hls/dash or player handle it
      • Chrome doesn't want to carry a hls/dash player
    • People seem to use Safari's native player
    • Browser stream testing tools
      • chrome://media-internals
      • media devtools for firefox
    • Ingest container validation

Topics for tomorrow

  • Adaptive bitrate
  • Webrtc / UDP based streaming
  • SVC
  • Codec / protocol
  • Open source tools
  • Low-level protocols
  • HEVC, VP9? into live streaming ingest
  • Automated Testing
  • WebRTC? to offload
  • Live caption