Digital signage loop with Omni: 9:16 at 4K, cost and limits

A vertical lobby-screen loop from Omni is a 10-second 9:16 clip: $3.75 at 4K on Sume ($0.375 per second), $1.875 at 1080p and $1.25 at 720p. Google's Omni page, read 2026-10-08, lists 4K as an option and labels its 1080p and 4K outputs as upscaled. Check a 4K frame on the real screen before you pay for the batch.

For a loop, use the same image as the first and last frame so the end meets the start.

Make it loop

On Sume the image-to-video mode takes image_url and end_image_url. Send the same image for both and describe a motion that returns to rest, such as steam rising and settling or a slow light sweep. Google's page lists first-and-last-frame interpolation as supported.

curl https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gemini-omni-flash-1.1","prompt":"Slow light sweep across the lobby, then return to the opening position. No people, no dialogue.","image_url":"https://example.com/lobby.jpg","end_image_url":"https://example.com/lobby.jpg","aspect_ratio":"9:16","duration":10,"resolution":"4k"}'

Cost by resolution

Most signage players are 1080p panels. A 4K file only helps if the player and screen are 4K.

Sound and playback

Omni always generates an audio track, and Sume rejects generate_audio: false. A lobby player is usually muted, but if yours is not, ask for silence in the prompt and mute the file in your player settings. Run the clip for an hour in the player before you ship, since a visible seam at the loop point shows up quickly on a large screen. Veo 3.1 can make 4K at $0.60 per second on Google's price page, but Sume lists no Veo model.

Before you order the batch

Order one 4K clip first and play it on the real screen at viewing distance. A lobby display is usually seen from a few meters, where 1080p and 4K often look alike, and the 4K file costs twice as much per second. If the two are indistinguishable on your panel, use 1080p and save $1.875 per 10-second clip.

Submit with an Idempotency-Key header so a retry after a dropped connection returns the original job instead of a second charge; the same key with a different payload returns 409. Then poll GET /v1/jobs/:id/status and fetch GET /v1/jobs/:id/result when it finishes.

Sume also rejects a request whose prompt passes 20,000 characters, which a signage prompt never needs. Keep it to the motion and the light, and reuse the same prompt text across venues so the loops match.