Discord soundboard clip from Sume music: 5.2 s, 512 kb, mp3 or ogg

A Discord soundboard sound must be an mp3 or ogg, at most 512 kb and 5.2 seconds, sent as a data URI. A Sume Music Router track is much longer, so cut a clip with POST /v1/timeline-1.0/audio using operation: "split" and output.format: "mp3". Do not use the wav default: 5.2 seconds of 44.1 kHz 16-bit stereo wav is about 917 kB, which is over the limit.

Discord's limits

From Discord's soundboard reference:

The arithmetic for wav

CD-quality stereo is 44,100 samples per second, 2 channels and 2 bytes each, which is 176,400 bytes per second. For 5.2 seconds that is about 917,000 bytes. This is a calculation from standard PCM, not a Sume figure; it shows why the wav default cannot meet the limit while a compressed mp3 can.

Split, then check

Timeline audio takes Sume-hosted media.sume.com audio, up to 20 ranges per job, at a flat $0.01 per job. The optional output.format is wav by default or mp3. Ask for a range of at most 5.2 seconds. Sume documents that mp3 adds priming padding at each edge, so leave a small margin under the Discord length.

curl -X POST https://api.sume.com/v1/timeline-1.0/audio \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: soundboard-airhorn-001" \
  -d '{
    "operation": "split",
    "url": "https://media.sume.com/artifacts/artf_demo/track.mp3",
    "ranges": [{ "start": 0, "end": 5.0 }],
    "output": { "format": "mp3" }
  }'
# then: curl -sI "$SEGMENT_AUDIO_URL" | grep -i content-length   (must be under 512 kb)

Getting a short, hard-hitting sound

The Music Router has no duration field, so the model decides how long the track runs. A prompt for a sting, such as a 3-second stinger, steers it, and the split range removes the rest. The result is a take you listen to and keep or redo; Discord needs the clip to be short enough, not perfect.

Before you ship

Soundboard sounds also have their own server and permission rules on Discord's side, which this post does not cover; read the page linked in the sources before you build the upload.

• Put the length in the prompt, then trim with split ranges.
• Request mp3 output; do not send the wav default.
• Check the byte size of the file before you encode it.
• Encode the data URI from the downloaded bytes, never from the URL.