Wix video poster 1944x2880: stills from a clip with video frames

Sume can pull a still from your clip for a Wix poster, but it will not produce a 1944 x 2880 image on its own. POST /v1/video-frames returns stills at the source frame size, or clamped by max_edge, whose range is 16 to 2160. A 2880 long edge is outside that, so size the poster in your image editor or pick a source that already has the pixels.

Wix figures are from its supported-files page; Sume figures from Video frames, read 2026-10-01.

What does Wix require for a poster?

The page lists JPG, GIF and PNG as file types and 1944 x 2880px for a video poster. The cover image is listed separately at 1920 x 1080px.

How do I extract a still?

Pass a media.sume.com clip and exactly one of at[] (1 to 24 times in seconds) or fps. format is jpeg (default) or png. Omit max_edge to keep the source size. Submit returns 202; read the result at GET /v1/video-frames/:id. The route is unbilled, so extra attempts cost nothing. See also extract video frames.

curl -X POST https://api.sume.com/v1/video-frames \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: poster-frames-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/film.mp4",
    "at": [1, 4.5, 9],
    "format": "png"
  }'

Where does max_edge stop?

What can I do about the 2880 edge?

Treat the Sume still as a source frame and resize or crop it to 1944 x 2880 in your own tool, or cut the poster from a taller or higher-resolution master. The docs describe the clamp as a long-edge limit, not an upscaler, and a still from a 1080p clip has only that many pixels to begin with. A portrait crop of a landscape frame also changes what the poster shows, so check the framing.

What errors should I expect?

Every at value must satisfy 0 <= t < duration, or the worker fails with frame_time_out_of_range. One instant that fails to extract comes back with url null and does not fail the job. See frame_time_out_of_range.