Can a YouTube Shorts episode run 4 minutes? Split with source_in

What is the longest Shorts series episode?

180 seconds. YouTube's shows page says a Shorts series playlist must contain only Shorts that are portrait or square and have a maximum duration of 180 seconds. A four-minute video does not qualify as a Shorts episode.

The API will happily make one, though. Timeline 1.0 accepts an audio length from 1 to 1800 seconds, so the limit you need to enforce is YouTube's, not Sume's.

Splitting a long cut into two parts

If you already have a finished voice track and a matching picture source, make two renders from the same files. Audio source_in is the in-point into a single audio file, while duration_seconds is the output length. Video slots take their own source_in into the clip, and the first slot must start at 0.

For a 320-second cut, part 1 is 0 to 170 seconds, and part 2 is 170 to 320. The cut point should fall at a natural pause, not a fixed number, so choose it from the transcript.

{
  "audio": {
    "url": "https://media.sume.com/artifacts/artf_demo/talk.wav",
    "source_in": 170,
    "duration_seconds": 150
  },
  "video": [{
    "source_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
    "source_in": 170,
    "start": 0,
    "duration": 150
  }]
}

Handling the seam

Send each part as its own render with its own Idempotency-Key, for example talk-part-1 and talk-part-2, and POST them to the render endpoint, or plan them first at no charge. Each part bills in output minutes rounded up, so 170 and 150 seconds are three minutes and three minutes, $0.30 in total at $0.10 per minute.

Close part 1 on a beat that makes the viewer want part 2, and open part 2 with a one-line recap, since a viewer may reach either from the feed.

Check the episode order in YouTube Studio after you add both parts, and set it by hand if part 2 lands before part 1. Both parts are ordinary Shorts, so each can carry its own custom thumbnail if you choose to make them.

• Both parts must be 180 seconds or less.
• Pick the cut at a pause, not at 170 exactly.
• Check each result's duration_seconds before you add it to the show.