Timeline render pricing: why 61 seconds costs twice what 60 does

A 60-second timeline render costs $0.10 and a 61-second one costs $0.20, because Sume bills $0.10 per ceil(output minute) and reserves ceil(audio.duration_seconds / 60) minutes up front (Timeline 1.0). No provider inference is involved, only worker ffmpeg.

Price ladder

Trim to the minute

The cheapest fix for a 61-second edit is to make it 60. audio.duration_seconds sets the output length, from 1 to 1800 s, so shaving one second from the spine moves you down a bracket.

Plan before you render

POST /v1/timeline-1.0/plan is unbilled. It returns duration_seconds, segment_count, billable_minutes and estimated_cost_usd_micros, and creates no job.

curl -X POST https://api.sume.com/v1/timeline-1.0/plan \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "audio": {"mode": "silence", "duration_seconds": 61},
    "video": [{"source_url": "https://media.sume.com/artifacts/artf_demo/a.mp4", "start": 0, "duration": 61}]
  }'