Live edge
The live edge is the newest point of a live stream that a player can show, the moment closest to real time. In HLS or DASH it is the latest segment the server has published. A viewer watching at the live edge has the smallest possible delay, while a viewer who has paused or rewound is behind it.
Why it matters
The distance from the live edge is the delay viewers feel. A player that drifts behind shows spoilers late and puts chat, bets and offers out of step with the video. Managing the live edge well keeps live products feeling live after pauses or network hiccups.
How it works
- The server keeps adding new segments to the end of the live playlist.
- The newest segment the player can fetch marks the live edge.
- The player starts a set distance behind the edge to keep a safety buffer.
- If playback falls behind, the player can speed up slightly or jump forward to catch up.
Why is my player behind the live edge?
Your player is behind the live edge because it keeps a safety buffer, or because a pause, stall or rewind pushed it back. Players usually start a few segments behind to avoid freezing. Each buffering event can add delay unless the player catches up by playing slightly faster or jumping forward.
What does "go to live" do in a video player?
"Go to live" moves playback from an earlier point in the stream back to the live edge, the newest available moment. It appears after a viewer pauses or rewinds a live stream with DVR. Pressing it skips the missed portion so the viewer sees what is happening now.
Where it's used
Player teams at live sports and live shopping apps keep viewers near the live edge so plays and offers arrive close to real time. They add a go-to-live button after rewinding.
By the numbers
- Apple's Low-Latency HLS guidance says the server removes partial segments from the playlist once they are older than three target durations from the live edge. (Enabling Low-Latency HTTP Live Streaming (Apple Developer))
