What it checks
Every subtitle must stay on screen for some time: its end time must be later than its start time. A subtitle that ends when it starts, or before, is never displayed and usually comes from a typing or conversion error.
How it is measured
CueNorm compares the start and end times of each subtitle, exactly (no rounding). When a file is converted, the check runs on the generated file, after its times were rounded to the destination's frame grid.
When it applies
Always, for every delivery profile: it is built in and cannot be removed or relaxed by a profile. It is an error. Mezzanine profiles, which judge a source file by its own format, do not apply it.
Example
00:00:05,000 --> 00:00:02,000 in an SRT file is reported as End time is not after start time.
How to fix
- Correct the times of the subtitle in the authoring tool.
- If the subtitle is not needed, delete it.