Seedance 2.5 green screen editing: what Sume can do

Sume's docs do not describe a green screen edit mode for seedance-2.5. What they do document is a video edit mode for gemini-omni-flash-1.1 through video_url, and video references that the Seedance 2.x models honor. Seed's own post is where the green screen claim comes from.

Seed's statements are from its July 31, 2026 Seedance 2.5 post; Sume's from Video generation and Video Router, read 2026-10-01.

What does Seed say green screen editing does?

The post says Seedance 2.5 enhances editing features such as green screen, camera perspective and reference-based editing, with timestamp-level control for targeted editing of audio and video. In its green screen example the model can replace backgrounds and tell different stories while keeping the main subject intact, and render how clothes, hair and lighting respond to the new environment. Its example prompt references a video as @Video 1 and assigns scenes to time ranges such as 0–4s.

Which Sume path matches an edit?

Two paths, with different guarantees.

How does an edit request look on Sume?

For Omni, the prompt describes the edit and video_url is the source. The docs state that video_url is the edit source, not a reference: it cannot be combined with image_url, end_image_url or reference_*_urls. A background swap is therefore a prompt-level request to Omni, with no separate green screen parameter in the docs.

For Seedance, you would pass your footage as a video reference and describe the new scene in the prompt. Whether the result matches Seed's green screen behavior is not something Sume's docs promise, so test on your own footage before building on it.

What should I do for a background replacement job?

Try an Omni edit when you want an edit-in-place request; the docs list Omni clips at 3–10 seconds. Use seedance-2.5 with a video reference when you need up to 30 seconds. In both cases send an Idempotency-Key, and compare against Seedance 2.5 clay render and camera references for how reference inputs behave.