Loudness Unit (LUFS) Reference / Target Checker implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-083

Effect

Computation or source lookup only

Input and validation requirements

The specification has no division or domain trap, but an extreme finite LUFS input causes the target offset to disappear through floating-point precision, and the instrument does not state finite-range or plausibility validation. The sign of the reported gain adjustment is also convention-dependent unless delta and corrective gain are kept distinct.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "measured_integrated_lufs": -12,
    "target_platform_preset": "Spotify"
  },
  "expected_outputs": {
    "target_lufs": -14,
    "delta_measured_minus_target_lufs": 2,
    "gain_adjustment_suggestion_db": -2,
    "pass": false
  },
  "reference_data": {
    "Spotify_target_lufs": -14,
    "source_convention": "widely tabulated platform guidance value; verify current Spotify documentation"
  },
  "working": "1. Target = -14.0 LUFS from the Spotify table row. 2. Delta = measured - target = (-12.0) - (-14.0) = 2.0 LUFS. 3. Gain adjustment to reach target = target - measured = (-14.0) - (-12.0) = -2.0 dB, so reduce gain by 2.0 dB. 4. Pass test: -12.0 == -14.0 is false."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json