Freeze the last 1.5 seconds of a Short for an end card

To freeze the end of a Short, extract the frame at your clip's duration minus 1.5 seconds with Sume video frames, then build a Timeline 1.0 render whose last slot is that still. The video slot plays up to the freeze point, the still holds for the last 1.5 seconds, and the audio spine keeps its full length. A Short up to a minute costs $0.10 to render.

Why hold the last frame

A held last frame leaves room for a closing line or a prompt to watch the next episode. YouTube's help page says Shorts are portrait or square and can run up to 3 minutes (YouTube Help), so a freeze does not change eligibility as long as the total stays inside that limit.

Step 1: pull the frame

Say the clip is 20 seconds long. The freeze frame sits at 18.5. Ask for it as a PNG so the still is lossless.

curl -X POST https://api.sume.com/v1/video-frames \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: freeze-18-5" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/short.mp4",
    "at": [18.5],
    "format": "png"
  }'

Step 2: the timeline body

The first slot plays the clip from 0 for 18.5 seconds. The second slot starts at 18.5 and uses the still for 1.5 seconds. Stills are static holds, so any motion field is ignored. The spine stays the original audio at 20 seconds, so the voice or music plays under the hold.

{
  "audio": { "url": "https://media.sume.com/artifacts/artf_demo/short.wav",
             "duration_seconds": 20 },
  "video": [
    { "source_url": "https://media.sume.com/artifacts/artf_demo/short.mp4",
      "start": 0, "duration": 18.5 },
    { "source_url": "https://media.sume.com/artifacts/artf_frames/18-5.png",
      "start": 18.5, "duration": 1.5 }
  ]
}

The recipe uses one extraction job, one audio detach if your source has no separate audio file, and one render.

Check and tune

Check the plan first with the free POST /v1/timeline-1.0/plan. Keep the hold short, since a freeze looks like a stall when it runs long. If the last second of the source has a fade or blur, choose a frame a little earlier.