What it checks
For each subtitle, CueNorm computes the reading speed in characters per second (CPS). A subtitle is reported when it is above the recommended value.
When the profile also defines MAX_READING_SPEED, a subtitle above that maximum is not reported again here. It is already reported by the stricter rule, so each subtitle gets a single reading-speed issue.
Profiles usually give this rule the warning severity: it is advice, not a delivery blocker.
How it is measured
CPS = visible characters of the whole subtitle ÷ display duration in seconds
Counting and duration work exactly as for MAX_READING_SPEED: grapheme clusters over all lines, exact rational duration. Subtitles with a zero or negative duration are skipped.
Parameters
| Parameter | Type | Meaning |
|---|---|---|
cps |
positive integer | Recommended maximum characters per second |
Example
With cps: 16 and a maximum of 20, a subtitle at 18.4 CPS is reported as 18.4 CPS (recommended maximum 16). A subtitle at 22 CPS is reported by MAX_READING_SPEED instead.
How to fix
The same remedies as for a hard reading-speed violation apply: condense the text, extend the display time within the gap and duration limits, or merge with an adjacent subtitle.