Musician teaser video from cover art and a 20-second cut

A musician can make a 20-second teaser for a single from cover art, one phone clip and the best 20 seconds of the track using Sume's Timeline render. The song is the audio spine, the pictures are slots with start times, and the whole render costs $0.10 because Timeline bills $0.10 per rounded-up output minute and uses no model inference. It is assembly, not generation, so the result is exactly your art and your audio.

Use only audio you own or have cleared. A Timeline render does not clear rights for you, and platforms match uploaded audio against catalogues.

How do I pick the 20 seconds?

Timeline's audio.source_in is an in-point into a single audio file, and audio.duration_seconds is the output length. Set source_in to the start of your chorus or hook, set the duration to 20, and the render plays that section only. Add fade_out_seconds under output so the cut does not end abruptly. Avoid audio.parts here: it cannot be combined with source_in.

What does the render request look like?

Import the audio, the cover and the phone clip into your workspace first, because every URL has to be Sume-hosted. Then send something like this, with your own artifact URLs:

curl -X POST https://api.sume.com/v1/timeline-1.0/render \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: single-teaser-001" \
  -d '{
    "audio": {
      "url": "https://media.sume.com/artifacts/artf_demo/track.wav",
      "source_in": 62,
      "duration_seconds": 20
    },
    "video": [
      { "source_url": "https://media.sume.com/artifacts/artf_demo/cover.jpg", "start": 0, "duration": 6 },
      { "source_url": "https://media.sume.com/artifacts/artf_demo/studio.mp4", "start": 6, "duration": 10,
        "transition": { "type": "fade", "duration": 0.5 } },
      { "source_url": "https://media.sume.com/artifacts/artf_demo/cover.jpg", "start": 16, "duration": 4,
        "transition": { "type": "dissolve", "duration": 0.5 } }
    ],
    "output": { "fade_out_seconds": 1 }
  }'

What can go wrong and what does it cost?

Run the unbilled plan endpoint first. It checks the schema and the Sume-host URLs and returns the duration and the estimated cost. Output defaults to 1080 by 1920, which suits Reels, TikTok and Shorts. Video slots must start at 0 and increase, and coverage can stop at most half a second before the end of the audio.

Can Sume write a bed if I have no finished track?

Music 1.0 runs on Google Lyria 3.5 and can make a track from a text prompt, with section markers such as an intro from 0:00 to 0:30. That is useful for a lyric-video backing, but a teaser for your own single should use your own master. Try two or three different 20-second cuts with different source_in values: at $0.10 a render, testing hooks is almost free.