FFmpeg Loudnorm

Endpoint

POST https://api.roasos.com/v1/assembly/loudnorm

Send your API key as a bearer token. The key needs the scope api:write. Every paid request also needs an Idempotency-Key header.

The envelope fields quote_only, quote_id, webhook_url and wait_timeout_seconds behave the same on each model endpoint. Refer to Jobs and Quotes and credits.

Good at

Make a music bed or a voice-over the correct level before you put it under a clip. For a music bed under speech, set integrated_loudness to -30. Then use Merge Audio and Video or Compose to put the track onto the clip.

The price is one credit, flat.

Pricing

The unit is one operation. Pricing key: loudnorm.

The credits come from the roasOS pricing table. No other field changes the price. To get the exact price of your request, send it with quote_only: true first.

Modes

• loudnorm

Provider endpoints: fal-ai/ffmpeg-api/loudnorm.

Request fields

The schema is strict. A field that is not in this table gets 400 unsupported_option. The field names are the roasOS role names. One role has one name in every family.

Media

This endpoint accepts these media roles:

• audio_url — the driving audio track

Every other role is refused: avatar_id, elements, product_id, product_images, references, reference_images, image_url, end_image_url, scene_id, scene_image, video_urls, video_url, audio_urls, voice_id. A refused role gets 400 unsupported_option.

Prompt

None. This operation takes no prompt.

audio_url is required. It must be an audio file that your workspace owns on cdn.roasos.com. The three targets are optional. If you do not send a target, the provider default applies:

• integrated_loudness is the target loudness in LUFS, from -70 to -5. The default is -18.
• true_peak is the maximum true peak in dBTP, from -9 to 0. The default is -0.1.
• loudness_range is the target loudness range in LU, from 1 to 20. The default is 7.

The result is a WAV file.

Not exposed

These catalog entries describe omitted inputs, pinned values and source constraints. They do not imply that the provider accepts every listed field.

• offset — not accepted by this public endpoint.
• linear — not accepted by this public endpoint.
• dual_mono — not accepted by this public endpoint.
• print_summary — not accepted by this public endpoint.
• measured_i — not accepted by this public endpoint.
• measured_lra — not accepted by this public endpoint.
• measured_tp — not accepted by this public endpoint.
• measured_thresh — not accepted by this public endpoint.

Result

The result kind is audio. Always present: url. Present when the run makes it: timestamps.

{
  "data": {
    "id": "gen_…",
    "kind": "video",
    "model": "loudnorm",
    "status": "completed",
    "result": {
      "timestamps": [
        {}
      ],
      "url": "https://cdn.roasos.com/workspaces/ws_01/result"
    }
  }
}

The files are immutable objects on https://cdn.roasos.com. A result URL is a valid media input for your next request.

Example

The three steps are always the same: quote, run, poll.

# 1. Quote. Nothing is spent.
curl -X POST https://api.roasos.com/v1/assembly/loudnorm \
  -H "Authorization: Bearer roasos_sk_live_..." \
  -H "Idempotency-Key: 0f1c9e2a-loudnorm-0001" \
  -H "Content-Type: application/json" \
  -d '{"quote_only":true,"audio_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/audio_url.mp3"}'
# 200 { "data": { "kind": "quote", "quote_id": "q_7Hk...", "credits": 1, "expires_at": "...",
#        "confirmation": { "model": "loudnorm", "example": "per_operation" } } }

# 2. Run. Same body, same Idempotency-Key, quote_id in place of quote_only.
curl -X POST https://api.roasos.com/v1/assembly/loudnorm \
  -H "Authorization: Bearer roasos_sk_live_..." \
  -H "Idempotency-Key: 0f1c9e2a-loudnorm-0001" \
  -H "Content-Type: application/json" \
  -d '{"quote_id":"q_7Hk...","audio_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/audio_url.mp3"}'
# 201 { "data": { "id": "gen_...", "status": "queued", "credits_reserved": 1 } }

# 3. Poll, then read the result.
curl https://api.roasos.com/v1/jobs/gen_.../status -H "Authorization: Bearer roasos_sk_live_..."
curl https://api.roasos.com/v1/jobs/gen_.../result -H "Authorization: Bearer roasos_sk_live_..."

Today

The endpoint is POST /v1/assembly/loudnorm.

It is live.

See also

• llms.txt for this model — the same facts as one plain-text file for an agent.
• GET https://api.roasos.com/v1/catalog/loudnorm — the machine-readable form: enums, defaults, limits and prices. Refer to the API reference.
• Jobs — how to poll a job and read its result.
• Provider endpoints: fal-ai/ffmpeg-api/loudnorm.