Luma Ray 3.2 video edit ignores aspect_ratio: Sume video_url edit

On Luma's Ray 3.2, a video_edit request derives its aspect ratio from the source video, and an aspect_ratio you send is silently ignored; to change shape you use video_reframe, where the target ratio is required. On Sume, an edit is a Video Router call with the source in video_url, and the ratios the model accepts are listed in supported_aspect_ratios.

What does Luma do with aspect ratio on edits?

Luma's model guide, read 2026-10-01, lists video editing as "aspect ratio is derived from the source video and is silently ignored on the request", and video reframing as "aspect ratio is required and names the target shape". Because the field is ignored rather than rejected, a wrong value will not raise an error.

How does an edit work on Sume?

The video docs say Gemini Omni Flash 1.1 exposes its edit mode "through the Video Router video_url field". The Video Router example sends model, prompt, video_url, resolution and mode, with an Idempotency-Key.

curl -X POST https://api.sume.com/v1/video-router/generate \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: video-router-edit-001" \
  -d '{
    "model": "gemini-omni-flash-1.1",
    "prompt": "Replace the bottle with an apple. Keep everything else the same.",
    "video_url": "https://example.com/clip.mp4",
    "resolution": "720p",
    "mode": "async"
  }'

Does Sume say what happens to aspect_ratio on an edit?

Yes, for Gemini Omni Flash 1.1: the Video Router table says an edit (video_to_video) takes video_url, with an optional resolution (default 720p) and no aspect_ratio or duration, so the shape comes from the source clip. The docs also say video_url is the edit source, not a reference, and cannot be combined with image_url, end_image_url or reference_*_urls. Compare the output to the source before relying on a ratio.

What should I do to change a clip's shape?

On Luma, send video_reframe with a target ratio. For Sume, the docs describe no separate reframe request in these pages; see Ray 3.2 modify video to video for the Luma edit side.