Seedance 2.5 adds subtitles or music I did not ask for: fixes

If a Seedance 2.5 clip has background music you did not want, send generate_audio: false to drop the generated audio track; if it has burned-in subtitles, Sume has no setting for that, so you have to steer it in the prompt. ByteDance says the model minimises "uncontrolled occurrences in subtitles and background music", which concedes that both can still appear.

The quote is from ByteDance Seed's Seedance 2.5 launch post (read 2026-10-02). The parameter is documented in Sume's Video generation: generate_audio is a boolean that "defaults to the model's audio capability", and seedance-2.5 reports audio support.

Which lever fixes which problem?

Audio is a separate track in the output; subtitles are drawn into the picture. Sume's request has one field for the first and none for the second.

How do I turn the audio off?

Set generate_audio to false in the request. It is optional, so leaving it out gives the model's default. Whether it changes the price is a separate question, answered in Do reference images or audio change the price?.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: silent-clip-001" \
  -d '{"model":"seedance-2.5","prompt":"A ceramic mug rotating on a plain grey table, no on-screen text","duration":6,"generate_audio":false}'

Can the prompt stop subtitles?

It can help; nothing here guarantees it. A plain instruction such as "no on-screen text, no subtitles, no captions" costs nothing to add. Seed's wording means the model has been tuned to produce fewer stray subtitles, not that the behaviour is removed.

If a clip still has text, regenerate with a changed prompt and a new Idempotency-Key. Reusing the key with a changed body returns a conflict, and reusing it with the same body returns the original job rather than a new clip.

What if I want subtitles, on my terms?

Generate clean video, then add captions as a separate step so the text, font and timing are yours. How to add subtitles to a video from a transcript covers that with Sume's tools, and Add background music to a video covers the audio side.