Bilingual Caption Doctor

Understand overlapping subtitle cues

An overlap occurs when a cue starts before an earlier cue has ended. The overlap fixture has one cue from 1 to 4 seconds and another from 3 to 5 seconds. Both are active between 3 and 4 seconds.

An overlap can be intentional

Two speakers, a translation and its source, or dialogue alongside an on-screen label may intentionally share time. Caption Doctor reports the cue involved and explains the overlap; it does not decide which speech is expendable.

The nested-overlap fixture is a useful edge case. A long first cue runs from 1 to 10 seconds, while shorter cues occur inside it. Comparing only adjacent end times would miss some overlaps. The diagnostic retains the furthest active end time so the later short cue is still reported.

Inspect before editing

  1. Move the preview time into the reported overlap.
  2. Read every active cue and decide whether the timing matches the intended speech.
  3. Check the result in the target editor, where positioning may differ.
  4. If one cue needs a different duration, edit the original deliberately and inspect again.

An end at or before the cue's start is a separate duration error, demonstrated by reverse and zero-duration. A fixed offset preserves that error because both ends move equally. Sequence renumbering also does not fix timing. These distinctions keep a mechanical repair from hiding a content decision.

Tested examples: overlap,nested-overlap,out-of-order,reverse,zero-duration. Original synthetic fixtures maintained with the tool.