In this guide
Reconstruct one sequence explicitlyDo not join separate renditions by counter aloneInterpret an apparent gap with current evidenceA jump from segment 800 to segment 805 is a change of five sequence positions. It is not automatically five seconds, thirty seconds or a sign that five files were lost. The meaning depends on which playlist snapshots you compared and on the durations and resources they advertise.
This matters when a player resumes after a pause, when a log shows a sequence gap, or when a filename looks like a counter. Start with the actual media playlist rather than guessing from a resource name.
Reconstruct one sequence explicitly
In an original hypothetical example, a saved playlist begins with EXT-X-MEDIA-SEQUENCE:800 and lists four segments lasting 4, 6, 5 and 5 seconds. Their sequence numbers are 800, 801, 802 and 803. The listed media span is twenty seconds, even though the difference between first and last sequence values is only three.
A second snapshot starts at 802 and lists four segments. The first two items have left the window. In this example they covered ten seconds, found by adding four and six. Replacing that calculation with “two sequence numbers equals two seconds” would be wrong.
Do not join separate renditions by counter alone
Video and audio playlists may have different segment boundaries. Even if both contain a sequence value 802, that numerical match is not sufficient proof that their first samples correspond to the same instant. Their media timestamps and the stream’s alignment rules determine synchronization.
The same caution applies when comparing channels. Sequence 802 in one channel has no necessary relationship to sequence 802 in another. A continuous channel can also continue its numbering across programme changes, so a counter does not identify the beginning of a film or a live event.
Interpret an apparent gap with current evidence
If a request fails for an old segment, retrieve or inspect the player’s current playlist snapshot. Was the resource still advertised when requested, or did the client retain a stale window after a long pause? If the current playlist itself references the failed resource, save that association and the request status for support.
A compact report should identify the first sequence of the snapshot, the failed resource’s assigned position, the listed duration and the observation time. This makes it possible to discuss a concrete publication or delivery failure. It avoids claims about packet loss or encoder resets that a segment-number jump alone cannot support.
| Question | Evidence needed |
|---|---|
| How much media left the window? | Durations of the removed segments |
| Are audio and video synchronized? | Track timing and alignment, not matching counters |
| Was a requested segment current? | Playlist snapshot at request time |
| How far behind live is playback? | Playback position and a valid time reference |