Transport-stream subtitle work often begins with a broadcast capture or joined streaming segments. Packet loss and timestamp resets are expected risks, so cue alignment needs a map of program boundaries rather than a single start-time check.
Where this workflow fits
- Broadcast capture subtitles
- Streaming segment captions
- Live event archive access
Build a discontinuity map
Anchor cues immediately before and after each boundary. If timestamps reset, retime only the affected range against continuous playback rather than shifting captions that were already correct in another segment.
Verify the joined program linearly
After local repairs, watch the entire program with the SRT enabled. Verify no caption bridges a missing interval, the selected language remains consistent, and the final cue ends within the captured program.
Before cue editing
- Identify the intended program and audio language in the multiplexed transport stream.
- List segment joins, ad breaks, reception faults, and timestamp discontinuities as cue checkpoints.
Limits worth knowing
- Missing packets can remove speech or timing references without making the whole file unreadable.
- Concatenated segments may repeat or reset timestamps while appearing continuous in a tolerant player.
Questions from the workflow
Why can TS subtitle timing jump?
A transport stream can reset timestamps at joins or carry missing packets. Cue timing must be checked on both sides of each discontinuity instead of trusting one offset.
Reviewed sources
- IANA Media Types registry · checked 2026-07-20
- RFC 3555: MPEG transport stream media type · checked 2026-07-20