Uploading while recording (advanced)

For live recordings, upload while the recording is still being made, so the result is ready moments after it stops:

1. Create with "streaming": true (no sizeBytes). Add "prestart": true to have processing ready and waiting. It waits up to 5 minutes; for longer recordings it stands down and starts normally when you complete (about 30–60 seconds later).
2. Request each part's URL with its exact size: {"parts": [{"partNumber": 4, "sizeBytes": 8388608}]}. Every part except the last must be at least 5 MiB.
3. With prestart, send POST /videos/{id}/heartbeat every ~10 seconds while recording. If heartbeats stop for 2 minutes, the waiting job gives up.
4. When recording ends, call complete with the totals: {"source": {"sizeBytes": …, "partCount": …}}. To cancel instead, call abort.