Price plate over a product clip: Timeline compose overlay, $0.02

To put a price plate over a product clip on Sume, use Timeline compose with operation: "overlay": the image is the plate and the video plays beneath it. One job costs $0.02, so 40 product clips cost 40 x $0.02 = $0.80. Size and position come from position, width_ratio, and margin_ratio.

Overlay layout keys

Overlay shares the request shape of stack, but only these layout keys are allowed, per the docs.

A request

The plate and clip must be files of your workspace on media.sume.com; import them first with POST /v1/media-imports. Send an Idempotency-Key. A price plate at the bottom, 60 percent of the width, looks like this.

{
  "operation": "overlay",
  "image": { "url": "https://media.sume.com/artifacts/artf_p1/price-plate.png" },
  "video": { "url": "https://media.sume.com/artifacts/artf_v1/product.mp4", "duration": 8 },
  "layout": { "position": "bottom", "width_ratio": 0.6, "margin_ratio": 0.08 }
}

Errors

Mixing keys from the two operations is a 400. split, image_region, and ratio are stack keys, and position, width_ratio, and margin_ratio are overlay keys. The codes are compose_stack_takes_no_overlay_layout and compose_overlay_takes_no_stack_layout. The image must probe as a still or you get compose_image_not_still.

The output length comes from the video layer. A plate cannot make the clip longer, and a video.duration past the end of the file is clamped with a warning, compose_duration_clamped_to_source, while the job still succeeds.

Plate or stack

Use overlay when the clip should fill the frame and the plate sits on top of it, as with a price or a logo. Use stack when you want a banner in its own region that never covers the footage. With a transparent PNG the plate sits on the footage cleanly; a solid plate covers whatever is beneath it, so keep it small.

For a promotion, make one plate per price tier and one compose job per clip and tier. Ten clips with three tiers are 30 jobs, which is $0.60. Join the results with Timeline when you want a single reel, at $0.10 per output minute.

Cost and receipts

Compose is worker ffmpeg only, with no model inference, at a flat $0.02 per job. Each result is a new artf_ video with its duration_seconds, which you can feed to Timeline video[], to Video captions at $0.20, or to a publish step. Log the plate, the clip, and the layout beside each result so a price change later means one rerun of only the affected clips.

Check before the batch

Run one clip first and look at the safe areas of your target platform, since app interface sits over the bottom of a vertical frame. A larger margin_ratio of 0.15 lifts the plate; the range allows up to 0.45. When one result looks right, reuse the same layout for all the rest, so every clip in the set has the plate in the same place.