Seedance 2.5 aspect ratios on Sume: eight values incl. adaptive

seedance-2.5 on Sume accepts eight aspect ratio values: auto, adaptive, 21:9, 16:9, 4:3, 1:1, 3:4 and 9:16. The Seedance 2 family lists the same eight, and no other Sume video model lists more. It also runs 4 to 30 seconds at 480p, 720p or 1080p and accepts every reference type the catalog lists. There is no 4:5 value, so a 4:5 feed ad needs 3:4 plus a crop, or a different tool.

That matters because ad placements ask for different shapes, and a model that cannot produce the shape forces a crop that can cut text.

What do auto and adaptive mean?

The catalog lists both as values, but the Sume docs do not give a rule beyond naming them. Treat them as follows: test auto and adaptive on your own input before you rely on either, and read the ratio of the returned file. If you need a known frame, pass one of the six fixed ratios.

How do I check what came back?

Read the dimensions of the completed file and compare with the ratio you asked for. Log both with the job id, so a mismatch is easy to find later. If you are producing a batch across placements, create one job per ratio instead of cropping one master, because a crop can cut a headline.

What does it cost?

seedance-2.5 is priced per 1,000 video tokens, not per second: $0.0214 list at most resolutions and $0.0234 at 1080p, with Sume billing list times 1.25. Because the unit is tokens, estimate with a trial job and read the billed amount on the job record before you scale a batch.