LoudnessEBUR128¶

streaming mode | Loudness/dynamics category

Inputs¶

signal (stereosample) - the input stereo audio signal

Outputs¶

momentaryLoudness (real) - momentary loudness (over 400ms) (LUFS)

shortTermLoudness (real) - short-term loudness (over 3 seconds) (LUFS)

integratedLoudness (real) - integrated loudness (overall) (LUFS)

loudnessRange (real) - loudness range over an arbitrary long time interval [3] (dB, LU)

Parameters¶

hopSize (real ∈ (0, 0.1], default = 0.1) :
the hop size with which the loudness is computed [s]

sampleRate (real ∈ (0, ∞), default = 44100) :
the sampling rate of the audio signal [Hz]

startAtZero (bool ∈ {true, false}, default = false) :
start momentary/short-term loudness estimation at time 0 (zero-centered loudness estimation windows) if true; otherwise start both windows at time 0 (time positions for momentary and short-term values will not be syncronized)

Description¶

This algorithm computes the EBU R128 loudness descriptors of an audio signal.

The input stereo signal is preprocessed with a K-weighting filter [2] (see LoudnessEBUR128Filter algorithm), composed of two stages: a shelving filter and a high-pass filter (RLB-weighting curve).
Momentary loudness is computed by integrating the sum of powers over a sliding rectangular window of 400 ms. The measurement is not gated.
Short-term loudness is computed by integrating the sum of powers over a sliding rectangular window of 3 seconds. The measurement is not gated.
Integrated loudness is a loudness value averaged over an arbitrary long time interval with gating of 400 ms blocks with two thresholds [2].
- Absolute ‘silence’ gating threshold at -70 LUFS for the computation of the absolute-gated loudness level.
- Relative gating threshold, 10 LU below the absolute-gated loudness level.
Loudness range is computed from short-term loudness values. It is defined as the difference between the estimates of the 10th and 95th percentiles of the distribution of the loudness values with applied gating [3].
- Absolute ‘silence’ gating threshold at -70 LUFS for the computation of the absolute-gated loudness level.
- Relative gating threshold, -20 LU below the absolute-gated loudness level.