Subtitles: how many words per line with design.phrasing

With Sume video captions, design.phrasing sets how much text shows at once: max_words, max_chars and pause_seconds. The API schema bounds them at 1 to 12 words, 4 to 60 characters and 0.05 to 3 seconds of silence. There is no single right number; pick by style and frame width.

Fields are from the Video captions docs and the API schema, read 2026-10-01. Blackmagic's Resolve 21.1 release added subtitle support to Cloud Presentations; here the captions are burned into the video.

What do the three phrasing fields do?

The OpenAPI descriptions are short: words per on-screen phrase, characters per on-screen phrase, and silence that breaks one phrase into the next.

Which styles accept it?

design is not supported on punch or tiktok-green, which still render on a path that reads none of these tokens. Use slam or one of the Hangul styles. Numbers outside their range are a 400, so a bad look fails at request time instead of billing a wrong render.

How do I set shorter phrases?

Each field merges over the style's own value, so one key changes one thing. This sample keeps everything else and shortens phrases to three words.

The korean-ad style already shows one short phrase at a time; see design overrides on punch and tiktok-green for the unsupported styles.

curl -X POST https://api.sume.com/v1/video-captions \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: captions-phrasing-001" \
  -d '{
    "video_url": "https://example.com/clean.mp4",
    "style": "slam",
    "design": { "phrasing": { "max_words": 3, "max_chars": 24 } }
  }'