Generative Extend any aspect ratio: Sume video ratios

Adobe says Premiere 26.5 Generative Extend accepts 360p to 4K UHD, any aspect ratio, and interlaced or non-square-pixel footage. Sume's video models are narrower: gemini-omni-flash-1.1 makes 3 to 10 second clips at 16:9 or 9:16, and its video_to_video edit takes no aspect_ratio. For an odd-shaped source, conform it to a standard frame with Timeline's fit option.

Sume facts are from Video Router and Timeline 1.0, read 2026-09-30.

Which ratios do Sume video models take?

The Video Router page says auto create controls default to 720p and 8s, with 3 to 10 second clips at 16:9 or 9:16. gemini-omni-flash-1.1 is listed at 360p, 720p, 1080p or 4K in 16:9 or 9:16. Other catalog models have their own envelopes, so read capabilities from GET /v1/video-router/models rather than assuming one.

Does Sume extend a clip the way Generative Extend does?

Not as one tool. Sume has no extend-this-clip endpoint. The workable pattern is to generate a new clip starting from the last frame of the old one and join them; see extend an AI video past 30 seconds. The new clip has the ratio you request (16:9 or 9:16 on Omni), so a source in another shape needs conforming first or after.

How do I fit an odd-ratio source into 16:9 or 9:16?

Timeline 1.0 takes a Sume-hosted clip per slot and an output.width / height (even integers, 256 to 2160). Each slot's fit decides what happens when the source ratio differs: cover (default), contain, stretch or blur. cover fills the frame and crops, contain keeps the whole picture, and blur fills the gap with a blurred version. Pick by what you can afford to lose. More in Timeline fit.

What does Sume not do?

The docs make no claim about interlaced or non-square-pixel sources, so deinterlace and set pixel aspect in your editor before importing. And the model's ratio limit is its own: if you need a 1:1 or 4:5 generated clip, check the catalog for a model that lists it.