Fact · Transcription
The loudnorm filter in ffmpeg performs EBU R128 loudness normalization, with both dynamic and linear normalization modes.
Checked against its source on October 17, 2026
In the source's own words
“EBU R128 loudness normalization. Includes both dynamic and linear normalization modes.”
FFmpeg Filters Documentation, FFmpeg project, 2026, loudnorm filter section.
Open the original- What it measures
- The filter raises or lowers the loudness of a file toward a target. It is one of the filters in the FFmpeg command-line tool, which Whisper's loader also uses to decode audio.
- What it does not show
- The manual describes what the filter does, not whether a recording becomes easier to transcribe after it. Test the output against the original before you rely on it.