gabrielmoreira Subtitle & Caption Skill
Subtitles fail when they're too long to read before they vanish, badly segmented, or a literal
translation that overruns the timing. Good subtitling obeys real constraints: reading speed (≈17
chars/sec / 160–180 wpm), line length (42 chars), max 2 lines, and sentence-aware segmentation.
This skill writes or translates captions to those rules — readable, well-timed, and condensed to fit.
Required Inputs
Ask for these only if they aren't already provided:
- The content — a transcript, script, or existing subtitles (with timecodes if you have them).
- Task — caption (same language), translate-subtitle (to another language), or SDH (deaf/HOH captions with sound cues).
- Format — SRT, WebVTT, or plain; and any platform limits (YouTube, broadcast, Netflix-style specs).
- Constraints — reading-speed/line-length target if non-standard.
Output Format
Subtitles: [content] — [task]
The subtitles in the requested format (SRT/VTT), each cue:
- ≤2 lines, each ~42 chars, broken at natural phrase boundaries (don't split an article from its noun).
- Timed to reading speed — long sentences are condensed (not every word — paraphrase to the gist) so they're readable in the time available. Where you have timecodes, respect them; where not, note suggested durations.
- For translation: render meaning compactly — the target must fit the same time slot, so condense more aggressively than prose translation, keeping the essential meaning.
- For SDH: include speaker IDs and
[sound cues](e.g.[door slams],[tense music]).
Notes — where you condensed/cut and why, any cue that's tight on reading speed (a 🔴 flag to adjust timing), and segmentation choices.
Quality Checks
- Each cue is ≤2 lines and within the line-length limit (~42 chars)
- Cues are readable at standard reading speed — long lines are condensed, not crammed
- Line breaks fall at natural phrase boundaries (no orphaned articles/prepositions)
- Translations are condensed to fit the original timing, keeping the meaning
- SDH captions include speaker IDs and sound cues where requested
- Output is in the requested format (valid SRT/VTT structure)
Anti-Patterns
- Do not exceed reading speed — a perfectly accurate caption no one can read in time has failed
- Do not translate verbatim for subtitles — the target overruns the slot; condense to the gist
- Do not break lines mid-phrase — split at clause/phrase boundaries for readability
- Do not exceed 2 lines per cue — split into multiple cues instead
- Do not omit sound cues in SDH — they're the point of accessible captions
Based On
Subtitling standards — reading-speed (CPS) limits, ~42-char lines, 2-line max, phrase-boundary segmentation, SDH conventions.