Audio Normalizing

Audio normalization adjusts audio levels for consistent loudness — useful when combining sources at different volumes, or meeting a platform's loudness target.

Auto-Editor supports two kinds: peak scales by the highest amplitude (simple, fast, preserves dynamic range); ebu (EBU R128) analyzes perceived loudness over time to meet broadcast standards.

Peak

Example:

auto-editor --audio-normalize peak:-3  # set max peak to -3dB

EBU

Example:

auto-editor --audio-normalize ebu  # use default values
auto-editor --audio-normalize ebu:i=-16  # set integrated loudness target
auto-editor --audio-normalize "ebu:i=-5,lra=20,gain=5,tp=-1"  # customize all parameters

Parameters

• i (integrated loudness): Target integrated loudness in LUFS (Loudness Units Full Scale)

  • Default: -24.0
  • Range: -70.0 to 5.0
  • Common values: -23 (EBU R128), -16 (streaming), -14 (podcasts)

• lra (loudness range): Target loudness range in LU

  • Default: 7.0
  • Range: 1.0 to 50.0
  • Describes the variation between soft and loud passages

• tp (true peak): Maximum true peak level in dBTP

  • Default: -2.0
  • Range: -9.0 to 0.0
  • Prevents clipping during digital-to-analog conversion

• gain: Additional gain offset in dB

  • Default: 0.0
  • Range: -99.0 to 99.0
  • Applied on top of the loudness normalization

How It Works

EBU normalization uses a two-pass process:

1. Analysis Pass: Measures the integrated loudness, loudness range, and true peak of the entire audio
2. Normalization Pass: Applies the FFmpeg loudnorm filter with the measured values to normalize the audio to your target levels