Check a Short before you upload: duration, size and audio in one probe

Run one free probe on the file before you upload it: Sume's video inspect returns the probe and still frames, with no charge for either, and you can compare the duration with the 3 minute Shorts limit on YouTube Help. The probe takes seconds, and it catches the wrong frame size, a missing audio track or a clip that ran long.

What the call does

The call is POST /v1/video-inspect. The video inspect docs say probe and stills are free, that the default mode is sync and waits up to 30 seconds, and that a result that does not finish in time returns 202 with a job to poll. The clip must be a media.sume.com artifact, so import an outside file first with POST /v1/media-imports.

What to compare it with

The YouTube Help page for Shorts (read 2026-10-05) is the source for the 3 minute limit in the table. The other rows are from the Sume docs.

Choose how many stills

With no frames field you get 8 mid-bin stills, or one a second if the clip is shorter than 8 seconds. Send frames: false for the probe only. For a quick look, seek: "fast" returns the keyframe at or before each instant, which can be earlier by up to about one GOP (roughly 0 to 5 seconds on typical sources). Use precise, the default, when the timestamp matters.

A concrete call

A probe that also grabs the first and last second of a 20 second file:

curl -X POST https://api.sume.com/v1/video-inspect \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: pre-upload-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/short.mp4",
    "frames": { "at": [0.5, 19.5], "format": "jpeg", "max_edge": 1080 }
  }'

Read the stills

Read the first still to see the opening frame, because that is what a viewer sees first. Read the last to see whether a hard cut or a half-finished word is at the end. If either is wrong, a video trim call with precision: exact makes a corrected file for $0.02.

Transcript only when needed

A transcript is optional and billed: transcribe: true costs $0.01 per audio minute plus the compute hold. If the clip has no audio, a transcript request fails with inspect_source_has_no_audio, so check probe.has_audio first.

Use it as a gate

The probe is most useful as a gate in a script. Fetch the result, parse the duration, and refuse to continue if it is longer than your limit. A Short has a 3 minute ceiling on YouTube Help, but your own limit can be much lower: if the plan was a 30 second ad, anything over 35 seconds is probably a mistake, such as a clip that kept an unwanted tail. A gate that fails loudly saves a bad upload and the time it takes to find out why a video looks wrong.

Look at the stills

The stills are the part people skip, and they are the part that finds real problems. A model clip can have a perfect duration and frame size and still open on a black frame, or end mid-motion. Eight evenly spaced stills show the pacing of the whole file at a glance, and the first still is what a viewer sees before the clip plays. If you want the exact first frame, ask for at: [0] or a very small time like 0.1.

Keep the record

Treat a result as a record, too. The inspect resource is stored, and GET /v1/video-inspect/$REQUEST_ID reads it again later, so you can link a probe to each file you shipped. If a platform later questions a file, you have the numbers from the day you uploaded it, instead of trying to measure a file you no longer have.

What this does not check

Do not use this to check platform rules you did not read. The only platform number in this post is the 3 minute Shorts limit from YouTube Help. For a TikTok or Reels ad, read the ad spec page for that placement and add its numbers to your own gate.

The takeaway

Make the probe a habit before every upload, and let it fail the build when duration, size or audio is not what you planned.