Disclosure first: I work on Seedance TV, an independent AI video site (not affiliated with ByteDance). Our Seedance 2.5 page covers the model this post is about.
Seedance 2.5 can now generate a single clip up to 30 seconds long with native audio, and it accepts a lot of references (up to 50: images, video and audio). Longer clips and more inputs sound like less work, but in practice they move the work to before you press generate. This is the checklist I’d go through for a 30-second clip:
- Write the beats with timestamps. 30 seconds is about 4-6 beats. Write each one as “0-5s: …”, “5-12s: …” so the model gets an order of events, not a list of nice-to-haves.
- Decide what the audio is doing. Dialogue, ambient sound, music or nothing. If there is a spoken line, keep it short and put it in quotes in the prompt; long lines tend to drift out of sync with the picture.
- Pick references with a job. Each reference should answer one question: who the character is, what the product looks like, what the lighting or style is. Twenty loosely related images usually make the result less consistent, not more.
- Lock one camera idea per beat. “Slow push-in”, “handheld follow”, “static wide”. Changing camera style inside a beat is a common reason a long clip looks like several clips glued together.
- Keep the first 3 seconds strong on their own. Most people decide in the first seconds whether to keep watching, so the opening beat should work even if nobody sees the rest.
- Check the result like an editor. Watch once with sound off for continuity (hands, logos, text), once with sound on for sync. If one beat is wrong, regenerate that beat as a short clip rather than rerolling the whole 30 seconds.
If you need something faster or cheaper for drafts, lighter models such as Seedance 2.0 Fast are fine for testing the beat order before the final pass.
What do you plan first when you make longer AI clips: the script, the audio, or the references?