What it checks
A subtitle displayed for less than the profile's minimum duration produces one issue.
How it is measured
- Duration = end time − start time, computed exactly.
- The minimum can be declared in milliseconds (
1000ms), seconds (1s) or frames (15f). Frames are converted with the frame rate declared by the profile's writer configuration: at 25 fps,15fis 0.600 s. - Subtitles with a zero or negative duration are skipped here; the structural duration check reports them.
- When CueNorm validates a file it has just written, the minimum is first projected onto the output's time grid, rounded down:
20fat 24 fps (0.833 33 s) becomes 0.833 s for a millisecond format such as TTML, so a subtitle of exactly 20 frames passes after quantization.
Parameters
| Parameter | Type | Meaning |
|---|---|---|
duration |
duration (ms, s or f) |
Minimum display duration |
Example
With duration: 15f at 25 fps, a subtitle displayed for 14 frames is reported as 0.560 s (minimum 0.600 s).
How to fix
- Extend the out time, provided the next subtitle still respects MINIMUM_GAP.
- Merge a very short subtitle with the previous or next one.
- Start the subtitle slightly earlier, when the dialogue allows it.