streamlab

Overview ¶

Package streamlab is StreamLab, a video service that delivers HLS: a catalogue, playback sessions with signed tokens, multivariant and media playlists, MPEG-TS segments in four renditions for 30 on-demand videos, two live channels whose playlists slide forward every two seconds, and playback heartbeats. It is the reference app for the streaming pack.

Planted bottlenecks (see README.md), each switched off by a fix flag:

• package: every segment request packages the segment again (muxing MPEG-TS packets), so a live event's viewers, who all want the same newest segment, repeat the same work thousands of times (fix "package" keeps packaged segments in a bounded cache).
• playlist: every live playlist request lists every segment since the event started to find the newest six, so playlists slow down as the event goes on (fix "playlist" renders each playlist once per segment and serves that).
• startup: starting playback checks entitlement, fetches a DRM license and picks a CDN one after another (fix "startup" does the three at once).