Netflix Ads: 10-75 s at 16:9 1920x1080, render 16:9 native

A third-party spec listing for Netflix Ads pre-roll and mid-roll video says creative should be 16:9 at 1920x1080, 10 to 75 seconds long, and H.264 with AAC audio. To avoid black bars, request 16:9 from the model directly instead of cropping or padding a vertical clip. Confirm against Netflix's current spec before you deliver.

Ask for 16:9 at the source

Black bars come from fitting a 9:16 or 1:1 render into a 16:9 frame. The Sume video request takes an aspect_ratio field with 16:9 among the documented values, so ask for it at generation time. The model then composes the scene for the wide frame, which also changes framing and subject placement.

Duration is the real constraint

The listing calls for 1920x1080. seedance-2.5 offers 480p, 720p and 1080p, so request 1080p.

Getting past 30 seconds

No single Sume clip reaches 75 seconds, since the longest catalog limits are 30 seconds. For a 45 or 60 second spot, generate separate clips and join them. The docs list Timeline 1.0 as the tool that sequences several clips, so use it instead of a manual edit when you want the join to stay in the API.

A 30-second spot in one request keeps continuity best, so write the prompt as one continuous scene and test a shorter version first.

curl -X POST https://api.sume.com/v1/videos \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: wide-spot-001" \
  -d '{"model":"seedance-2.5","prompt":"A wide cinematic shot of a car on a coastal road at dusk","duration":30,"resolution":"1080p","aspect_ratio":"16:9"}'