Korean sale captions: slam and punch reject Hangul, use black-outline

If you send Korean text to a Latin caption style on Sume, the API returns 400 caption_hangul_text_latin_style and burns nothing. The slam, punch and tiktok-green styles use Latin display faces with no Hangul glyphs, and the video captions docs say the alternative would be a video full of tofu boxes at the same price as a good video. For Korean speech or Korean overlay cards, use black-outline, another Hangul identity or korean-ad. A job is $0.20 for a clip up to 60 seconds.

If you omit style, Korean text resolves to black-outline, not the Latin default.

Which style for which job

The docs list six Hangul identities, and korean-ad as the ad karaoke look for Korean speech, used with language: "ko". The language field only tells speech-to-text what to expect; it never selects the style or the font.

The font rule

The font field takes a Hangul face and works only with Hangul styles. Send one of those faces on a Latin style and the API returns 400 caption_font_requires_hangul_style. Both rules are request-time checks, so a wrong pairing fails before you pay for a render.

curl -X POST https://api.sume.com/v1/video-captions \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: kr-bf26-sku9-v1" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/example/clean.mp4",
    "style": "korean-ad",
    "language": "ko"
  }'

A bilingual sale clip

If one clip carries Korean speech and you also want an English cue for a price, split the work. Burn the Korean speech with a Hangul style first. The authored cues path does not run speech-to-text and burns text exactly as written, which suits a short price or a legal line. Remember that you send only one of script_text, words, cues and segments per job.

Check the output on a phone. Phrase cards sit in the lower third for korean-ad, so a platform interface may overlap them; the placement design tokens move the line if needed, and a restyle is still a render at the same price.

• Korean on slam, punch or tiktok-green is a 400.
• Omit style and Korean falls to black-outline.
• language is a speech hint, not a style.

Test a style on one clip first

Before you caption a whole Korean catalog, run one clip in two styles and compare on a phone. Each job is $0.20, so a two-style test is $0.40. Look for line breaks that split a word badly, a card that sits where the platform's own buttons will be, and a speech clip where the highlighted word drifts from the voice.

If the look is close but not right, do not switch styles at random. Use a design override on the same style: it changes colors, typography, placement, phrasing and motion for that one request, and each field you omit keeps the style's value. A number outside its documented range is a 400, so you find the mistake at submit time. Note that punch and tiktok-green do not support design.

Keep your sale clips consistent across the campaign. Choose one style and one set of overrides, write them down, and use the same body shape for each SKU. A Black Friday feed looks sharper when every clip shares one caption identity, and it makes the batch easier to review.