Gemini SynthID video check: 100 MB, under 90 seconds, trim first

What are the Gemini app's limits for checking a video for SynthID?

Google's Gemini Apps Help page lists a maximum of 100 MB per file, videos under 90 seconds, and single-file uploads only. If your Sume video is longer, cut a section with video trim and upload that.

The same page says a hit means all or part of the content was created or edited by Google's AI models, and that a miss does not rule out AI from other systems.

The numbers on Google's page

These are the figures I read on the help page today. Google may change them.

Check the file before you upload it

Run video inspect with frames: false. The probe returns duration_seconds and size_bytes, so you can see whether the clip is under 90 seconds and under 100 MB before you open the app. The probe only reads container facts and the docs say it never re-encodes the source.

Gemini Omni Flash 1.1 on the Sume Video Router makes clips of 3 to 10 seconds, so those fit the length limit by themselves. A finished edit of several clips usually does not.

Cut a section that fits

Video trim takes one clip, a start in seconds and exactly one of end or duration, and returns a new MP4 without touching the source. The default precision: exact re-encodes frame-accurately. precision: keyframe copies the stream, but the cut can start up to one GOP early, so read actual_start_seconds in the result. A trim job is $0.02 per job per the docs, and the live price is in the catalog.

Neither Google's page nor the Sume docs say what a trim does to a watermark. Do not assume. Take a clip you know came from a Google model, trim a copy both ways, and run each copy through the app yourself. Keep the untrimmed original for the record.

curl -X POST https://api.sume.com/v1/video-trim \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: synthid-trim-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/edit.mp4",
    "start": 0,
    "duration": 60
  }'

Record what you checked

A check only helps if you can show what it covered. The trim result returns a new video_url (a new artifact, never the source) with duration_seconds and actual_start_seconds. Save those with the job id, plus the date, the file you uploaded to the app and the words the app answered with.

Say only what the page lets you say. A hit means all or part of the file was created or edited by Google's AI models. A miss means Google's tools did not leave a mark it can read, and nothing more.