Threads video audio: AAC, 128 kbps, 48 kHz max, and what trim keeps

Threads video uses AAC audio, mono or stereo, at up to 48 kHz and a maximum of 128 kbps. Sume video-trim with exact precision remuxes kept audio as AAC, but the docs expose only audio: keep or drop and no bitrate field, so confirm the bitrate on the output file before you upload.

What does each side control?

Compare the Threads limits with what the Sume trim contract says. Where the docs are silent, test the file.

How do I know if a clip has audio?

A silent clip behaves differently from a clip with a track. Send a probe-only inspect and read probe.has_audio, as the video-inspect docs recommend.

curl -X POST https://api.sume.com/v1/video-inspect \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: threads-audio-001" \
  -d '{"video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4", "frames": false}'

What happens if I send codec fields?

Trim refuses codec, crf and similar fields with ffmpeg_fields_rejected, because the server compiles ffmpeg itself. Use audio: drop for a silent post, and run a local probe to measure the bitrate of a kept track.